10th International Symposium on Technetium and

2018 10th International Symposium on Technetium and Rhenium – Science and Utilization

Eds.: K. German, X. Gaona, M. Ozawa, Ya. Obruchnikova, E. Johnstone, A.Maruk, M. Chotkowski, I. Troshkina, A. Safonov IPCE RAS - GRANICA

International Symposium Dedicated to 100th Anniversary of Anna Kuzina

October 3-6, 2018 - Moscow - Russia

Eds.: K. German, X. Gaona, M. Ozawa, Ya. Obruchnikova, E. Johnstone, A. Maruk, M. Chotkowski, I. Troshkina, A. Safonov

Moscow - 2018

10th International Symposium on Technetium and Rhenium – Science and Utilization, Moscow, 2018

Proceedings and selected lectures of the 10th International Symposium on Technetium and Rhenium – Science and Utilization, October 3-6, 2018 - Moscow – Russia, Eds: K. German, X. Gaona, M. Ozawa, Ya. Obruchnikova, E. Johnstone, A. Maruk, M. Chotkowski, I. Troshkina, A. Safonov. Moscow: Publishing House Granica, 2018, 518 p.

ISBN 978-5-9933-0132-7

Russian Academy of Sciences, State Corporation on atomic energy (ROSATOM), Interdisciplinary scientific council on radiochemistry, Japanese Nuclear Society, Japanese Radiochemical society, Dmitry Mendeleev University of Chemical Technology of Russia, SENA (CEA&CNRS-France), UNLV (USA), IAEA, IPCE RAS, Burnasyan Federal SRC-FMBC hold on October 3-6, 2018 in Moscow the 10th International Symposium on Technetium and Rhenium – Science and Utilization

Sections: 1.

Fundamental Physics and Chemistry of Tc and Re

2.

Analytical Chemistry of Tc and Re

3.

Tc in Nuclear Fuel Cycle and in the Biosphere

4.

Re Hydrometallurgy

5.

Tc and Re in Nuclear Medicine

ISTR2018 is dedicated to the 100th birthday anniversary of Prof. Anna Kuzina, the famous Russian chemist in the field of technetium chemistry. The Symposium was prefaced with a separate School-seminar on Fundamental basis for Advanced treatment of Radioactive waste on Sept 28-Oct 02, 2018 Chairman - K.E. German, IPCE RAS [email protected] ; Secretary: A.V. Safonov e-mail [email protected] Org. committee A. Maruk [email protected] The organizational and technical support was provided by MKC LLC professional congress organizer company. Phone: +7 (495)-726-5135 E-mail: [email protected] Website: www.mkcongress.ru

4

Panorama of Moscow with the view at the hosting President hotel and Gorky Park (Photo by K. German) CONTENT 1. Fundamental Physics and Chemistry of Tc and Re. Chairs : K.E. German and Masaki Ozawa Roald Hoffmann. MESSAGE TO INTERNATIONAL SYMPOSIUM ON TECHNETIUM AND RHENIUM SCIENCE AND UTILIZATION, 2018 Aleksey Buryak. WELCOME ADDRESS FROM IPCE - RUSSIAN ACADEMY OF SCIENCES Andrey Romanov. WELCOME ADDRESS FROM THE MINISTRY OF SCIENCE AND HIGHER EDUCATION OF RUSSIAN FEDERATION Mikhail Igorevich Panasyuk. ANNA KUZINA: BIOGRAPHY. K.E. German. PROF. ANNA FEDOROVNA KUZINA – 100TH ANNIVERSARY OF BIRTHDAY T. Yoshimura, M. Seike, H. Ikeda, K. Nagata, A. Ito, E. Sakuda, N. Kitamura, A. Shinohara PHOTOLUMINESCENCE SWITCHING OF NITRIDORHENIUM(V) COMPLEXES B. Grambow, X. Gaona, W. Runde, R. Konings, A.V. Plyasunov, L. Rao, A.L. Smith, E. Moore, M.-E. Ragoussi, J. Martinez-Gonzalez, I. Grenthe. CHEMICAL THERMODYNAMICS OF TECHNETIUM IN THE OECD/NEA UPDATE VOLUME E.S. Kulikova, Zh.K. Majed, D.V. Drobot, E.I. Efremova. HIGHLY SELECTIVE CATALYSTS BASED ON BIMETALLIC RHENIUM-RUTHENIUM COMPLEXES OBTAINED BY ALKOXYTECHNOLOGY E.S. Kulikova, D.V. Drobot, E.I. Efremova. THE FIRST EXAMPLE OF BI AND THREEMETALLIC ALKOXIDES CONTAINING RHENIUM AND RUTHENIUM T. Matsuzaki, H. Sakurai. A NEW PRODUCTION METHOD OF 99Mo BY MUON NUCLEAR TRANSMUTATION N. Budantseva, G. Andreev, A. Fedoseev THE U(VI), NP(VI) AND PU(VI) COMPLEXES WITH TcO4-, ReO4-. THE DIFFICULTIES IN ASSIGNING OF AnO22+ GROUPS VIBRATIONAL FREQUENCIES. J.S. McCloy, C. Soderquist, J. Weaver, Jason Lonergan. SPECTROSCOPIC STUDIES OF ALKALI PERTECHNETATES AND PERTECHNIC ACID E. Il’in, V. Ivanov, A. Buryak, A. Kopytin, A.S. Parshakov, K.E. German. COMPLEXES OF D- AND F-TRANSITION METALS - PRECURSORS FOR NANOSCALE REFRACTORY OXIDES 5

16 17 17 18 25 34

35

51 61 62

81 82

83

A.A. Revina, M.A. Kuznetsov, A.M. Chekmarev. THE SELF-ASSEMBLY OF RHENIUM NANOPARTICLES IN REVERSE MICELLAR SOLUTIONS М. S. Grigoriev, A. M. Fedoseev. SYNTHESIS AND CRYSTAL STRUCTURE OF NEW COMPLEX [Pu(DMSO)8](TcO4)3∙0.5H2O K.E. German, Ya.A. Obruchnikova, A.A. Levtsova, M.S. Grigoriev, A.V. Afanasyev, S.N. Ryagin PRECIPITATION OF POORLY SOLUBLE TECHNETIUM COMPOUNDS FROM MODEL RADIOACTIVE WASTE AND THEIR CONVERSION INTO SOLID MATRICES FOR TRANSMUTATION K.E. German, N.S. Legkodimova, M.S. Grigoriev, Ya.A. Obruchnikova, G.V. Kolesnikov, Yu.A. Ustynyuk, F. Poineau, E.V. Belova, O.S. Kryzhovets. SUPRAMOLECULAR INTERACTIONS OF CAFFEINE MOLECULES WITH EACH OTHER, WATER MOLECULES AND OXYGEN ATOMS OF TETRAOXIDOANIONS IN THE THREE NEW DIFFERENT COMPOUNDS Me(H2O)6[ReO4]2. CAFFEINE (Me= Co, Cd, Mg) A.G. Matveeva, I.Yu. Kudryavtsev, M.P. Pasechnik, R.R. Aysin, T.V. Baulina, S.V. Matveev, A.N. Turanov, V.K. Karandashev. TRIPODAL ORGANOPHOSPHORUS LIGANDS FOR THE LIQUID EXTRACTION OF PERRHENIC ACID (ReVII): IR, NMR and DFT INVESTIGATION OF PROTON LOCATION A.N. Turanov, V.K. Karandashev, A.V. Kharlamov, N.A. Bondarenko EXTRACTIVE AND SORPTION PRECONCENTRATION OF REO4- IONS WITH AZAPODANDS CONTAINING DIPHENYL- AND DIBUTYLPHOSPHORYL TERMINAL GROUPS A.M. Fedosseev, M.S. Grigoriev, K.E. German, F. Poineau, G.A. Kirakosyan, K. Czerwinski, A. Sattelberger. SINGLE CRYSTAL STRUCTURE OF TETRA-HYDROXONIUMDIAQUA TETRATECHNETYL(V)HEXADECATECHNETYL(VII) TETRAHYDRATE [H7O3]4[TcV TcVII О68]·4H2O CALLED EARLIER “RED SOLID HTcO4” T.I.A. Gerber, J. Mukiz, E. Hosten. DIMERIC RHENIUM(IV) COMPOUNDS OF HYDROXY-PICOLINIC ACID 2. Analytical Chemistry of Tc and Re - Chairs : Xavier Gaona and Alesya Maruk D.S. Ostapenko, N.V. Zarubuna, V.V. Ivanov. DETERMINATION OF RHENIUM IN CARBON-TERIGENOUS, ORGANO-MINERAL AND ORGANOGENIC GEOLOGICAL SAMPLES BY ICP-MS METHOD M. Chotkowski. ELECTROCHEMICAL AND SPECTROELECTROCHEMICAL INVESTIGATIONS OF TcO4- REDUCTION IN ALKALINE SOLUTIONS A.P. Mel'nikov, L.Yu.Martynov, N.K. Zaitsev. MOBILE METHODS FOR CONTROL OF THE UNDERGROUND LEACHING SOLUTION COMPOSITION G.А. Kirakosyan, K.E. German, A.V. Afanasiev, S.N. Ryagin, A.V. Safonov, E.A. Kataev, F. Poineau, K.R. Czerwinski, E.V. Johnstone, A.P. Sattelberger APPLICATIONS OF 99TcNMR IN CHEMISTRY AND NUCLEAR MEDICINE Wangsuo Wu, Xuejie Sun, Keliang Shi. RAPID DETERMINATION OF LONG-LIVED FISSION PRODUCT TECHNETIUM-99 IN UO2 SAMPLES K.E. German, T. Reich, G.A. Kirakosyan, E.V. Johnstone, K.R. Czerwinski, F. Poineau, A.P. Sattelberger TECHNETIUM METAL, TECHNETIUM CHLORIDES AND CHLORINE SPECIES IN PYROMETALLURGICALLY FORMED SEDIMENTS AND MELTS SPECIATION BY Tc-99 AND Cl-35,36,37-NMR AND EXAFS / XANES Keliang Shi, Xuejie Sun, Wangsuo Wu, Xiaolin Hou. ANALYSIS OF TECHNETIUM SPECIES AND FRACTIONS IN NATURAL SEAWEED USING BIOCHEMICAL SEPARATION AND ICP-MS MEASUREMENT A. V. Kopytin, A.V. Afanasiev, K. E. German, T.V. Zhukova, V. F. Peretrukhin. A NEW PERTECHNETATE-SELECTIVE ELECTRODE BASED ON SUPRAMOLECULAR POLYMER COMPOSITION

6

86 88

90

92

94

96

97 100 110

111 113 114

115 117

118

125

126

2. Tc in Nuclear Fuel Cycle and in the Biosphere – Chairs: John McCloy and Mikhail Grigoriev L. Bondareva. RHENIUM (AS ANALOG TECHNETIUM) - ACCUMULATION AND DISTRIBUTION IN MACROALGAE, FONTINALIS ANTIPIRETICA K. Dardenne, J. Rothe, T. Vitova, X. Gaona, M. Herm, E. González-Robles, V. Metz, M. Altmaier, H. Geckeis. USE OF ADVANCED SPECTROSCOPIC TECHNIQUES FOR THE CHARACTERIZATION OF Tc AQUEOUS SPECIES AND SOLID COMPOUNDS: ACT BEAMLINE AT KIT SYNCHROTRON SOURCE X. Gaona, M. Altmaier, H. Geckeis. SOLUTION CHEMISTRY OF Tc UNDER CONDITIONS RELEVANT FOR NUCLEAR WASTE DISPOSAL S. Duckworth, A. Baumann, X. Gaona, M. Altmaier, H. Geckeis. IMPACT OF SULFATE ON THE SOLUBILITY OF TC(IV) UNDER REDUCING CONDITIONS M. Altmaier, A. Baumann, X. Gaona, E. Yalcintas, R. Polly, K. Dardenne, H. Geckeis. SOLUBILITY AND COMPLEXATION OF Tc(IV) IN THE PRESENCE OF CARBONATE E. Yalcintas, A. Baumann, X. Gaona, M. Altmaier, H. Geckeis. SOLUBILITY AND HYDROLYSIS OF Tc(IV) IN DILUTE TO CONCENTRATED SALT SYSTEMS: APPLICATION TO COMPLEX MIXTURES A. Baumann, S. Duckworth, E. Yalcintas, X. Gaona, K. Dardenne, M. Altmaier, H. Geckeis. IMPACT OF NITRATE ON THE REDOX CHEMISTRY OF Tc A.B. Melentev, A.N. Mashkin, S.A. Lukin, N.S. Samarina, V.S. Ermolin. THE TECHNETIUM BEHAVIOR IN THE NEW SNF REPROCESSING FLOWSHEETS OF THE RT-1 PLANT S.S. Danilov, S.A. Kulikova, S.E. Vinokurov. IMMOBILIZATION OF TECHNETIUM-99 IN SODIUM-ALUMINUM- IRON-PHOSPHATE GLASS M.A. Volkov, K.E. German, V.V. Kuznetsov. ELECTROCHEMICAL RECOVERY OF Tc FROM SOLUTIONS ISSUING FROM SNF REPROCESSING A.V. Voit, L.A. Zemskova. SIMULATION OF THE INTERACTION OF ReO4- and MoO2ANIONS WITH CHITOSAN. QUANTUM CHEMISTRY APPROACH W. Um. 99Tc IMMOBILIZATION IN VARIOUS WASTE FORMS M. Khan, S. Hong, W. Um. INCORPORATION OF RHENIUM IN TIN DIOXIDE FOR 99Tc IMMOBILIZATION A. Laplace, E. Régnier, M. Neyret, I. Giboire, N. El Jeaidi, J.C. Laugier, M. Chartier, V. Ansault, C. Vallat, O. Pinet . RHENIUM BEHAVIOR IN A MOLTEN BOROSILICATE GLASS K. Uruga, T. Usami, T. Tsukada . IMMISCIBILITY AND VOLATILITY OF RHENIUM IN VITRIFICATION PROCESS OF SIMULATED PUREX RAFFINATE K. Schmeide, A. Rossberg, S. Weiss, A.C. Scheinost. SPECTROSCOPIC AND BATCH STUDIES OF TECHNETIUM UPTAKE BY SIDERITE D.M. Rodríguez, N. Mayordomo, T. Stumpf, K. Müller. 99Tc RETENTION ON PYRITE AND ALUMINA: THE EFFECT OF Fe2+ A. Ledoux, Jf. Hollebecque, C. Michel, S. Schuller, E. Sauvage, M. Delaunay, V-Labe, S. Lemonnier, L. Meslin. VOLATILITY MECHANISM STUDY IN THE WASTE VITRIFICATION PROCESS K. E. German, V. F. Peretrukhin, Ya.A. Obruchnikova, A.V. Afanasiev, S.N. Ryagin. VOLATILITY OF PERTECHNETATES J. Lin, L. Zhu, J.-Q. Wang, S. Wang. IMMOBILIZATION OF ReO4– BY A FAMILY OF RARE-EARTH PLUMBITE PERCHLORATES BASED ON SINGLE CRYSTAL-TOSINGLE CRYSTAL TRANSFORMATION S.V. Stefanovsky, B.S. Nikonov, A.L. Trigub. RHENIUM SPECIATION IN SODIUM ALUMINO(IRON) PHOSPHATE GLASSES E.V. Johnstone, K.R. Czerwinski, T. Hartmann, F. Poineau, D.J. Bailey, N.C. Hyatt, N. Mayordomo, A. Nuñez, F.Y. Tsang, A.P. Sattelberger, K.E. German, E. J. Mausolf. 7

130

131

132 134 162 164

165 167

168 181 182 184 185 208

209 216 226

237

253 254

257 270

CALCIUM MOLYBDATE, CaMoO4: A PROMISING TARGET MATERIAL FOR 99mTc AND ITS POTENTIAL APPLICATIONS IN NUCLEAR MEDICINE AND NUCLEAR WASTE DISPOSITION I. Zinicovscaia, A. Safonov, I. Troshkina, I. Shirokova, K. German. SORPTION OF Re(VII) BY CYANOBACTERIA SPIRULINA PLATENSIS A.Safonov, R. Aldabaev, N. Andryshchenko, K. Boldyrev, T. Babich, E. Zakharova, K. German. BIOGEOCHEMICAL IMPACT OF TECHNETIUM MIGRATION IN SUBSURFACE WATER NEAR TO RW REPOSITORY D.A. Kamorny, A.V. Safonov, I.M. Proshin, E.A. Tyupina, K.E. German, O.A. Gorbunova STABILIZATION OF TECHNETIUM BY ORGANIC MODIFIERS FOR LONG-TERM STORAGE IN A CEMENT COMPOUND A. Makarov, N. Andryushchenko, A. Safonov, E. Zakharova, K. German. SORPTION OF 99Tc ON THE SHUNGITE A.Makarov, N. Andryushchenko, A. Safonov, E. Zakharova, K. German. 99Tc SORPTION ON THE CARBONE MATERIALS (LIDITE AND SHALE) A. Makarov, N. Andryushchenko, A. Safonov, E. Zakharova, K. German. SORPTION OF 99Tc ON ACTIVATED CHARCOAL A. Makarov, N. Andryshchenko, A. Safonov, E. Zakharova, E.V. Belova, K. German. SORPTION OF 99Tc ON NANODIAMONDS A. Makarov, N. Andryushchenko, A. Safonov, E. Zakharova, K. German. SORPTION OF 99Tc ON TAUNITE 4.

Re Hydrometallurgy - Chairs : I.D. Troshkina and Ya. Obruchnikova

V.N. Rychkov, A.O. Taukin, E.V. Kirillov, S.V. Kirillov, G.M. Bunkov, V.S. Semenishchev. THE STUDY OF SORPTION CONCENTRATION OF RHENIUM FROM ACIDIC SOLUTIONS I.A. Lebedev, T.D. Batueva, N.B. Kondrashova, M.G. Scherban. SORPTION RHENIUM ON MESOPOROUS SILICAS MODIFIED WITH DIMETHYLHYDRAZIDE GROUPS Yu.V. Sokolova, V.I. Shishkevich. EXTRACTION OF RHENIUM FROM RECYCLE SULFURIC ACID SOLUTION OF UNDERGROUND URANIUM LEACHING I.P. Sandalov, V.I. Bogdanov. EXTRACTION OF PLATINUM AND RHENIUM FROM IRON COLLECTOR OBTAINED BY PLASMA FUSION METHOD S.N. Rasulova, V.P. Guro, R.D. Allabergenov. METHOD FOR RE RECOVERY FROM THE TAILING DUMP OF RESEARCH-AND-PRODUCTION ASSOCIATION OF ALMALYK GMK JSC (FORMER UZKTZHM) S.N. Rasulova, V.P. Guro, R.D. Allabergenov. METHOD FOR RECOVERY RHENIUM FROM THE TAILING DUMP OF RESEARCH-AND- PRODUCTION ASSOCIATION OF ALMALYK GMK JSC (FORMER UZKTZHM) K.Ya. Agapova, S.K. Kilibayeva, A.N. Zagorodnyaya, A.S. Sharipova, Z.S. Abisheva, Zh.E. Yakhiyayeva. RECOVERY OF RHENIUM FROM THE WASTES OF HEAT-RESISTANT NICKEL ALLOYS S.K. Kilibayeva, L.Ya. Agapova, Z.S. Abisheva, Zh.E. Yakhiyayev, G.S. Ruzakhunova, A.V. Panichkin . ELECTROLYTIC DEPOSITION OF RHENIUM-CONTAINING ALLOYS FROM AQUEOUS SOLUTIONS OF ELECTROLYTES S.A. Temerov, S.I. Plechkina, M.P. Loseva. ON THE PRODUCTION OF RHENIUM ACID V. Korovin, Yu. Pogorelov, A. Zontov, L. Zontova. EQUILIBRIUM AND KINETICS OF RHENIUM SORPTION FROM SULPHURIC SOLUTIONS WITH AMR ANIONITE N.A. Bektenov, E.E. Ergozhin, L.K. Ybraimzhanova, B.K. Masalimova. STUDY OF THE SORPTION CAPACITY OF RHENIUM IONS BY NEW MODIFIED ION EXCHANGERS S.V. Zakharyan, E.I. Gedgagov, A.B. Yun. NEW POSSIBILITIES OF SORPTION PROCESSES WITH THE USE OF FINELY DISPERSED FORMS OF ION EXCHANGE RESINS (ON THE EXAMPLE OF RHENIUM RECOVERY) 8

277 287

288

297 312 314 315 316 317 318

319 320 321 322

323

331

333

334 335 336 337

343

L.M. Gapoyan, A.A. Blokhin, M.A. Mikhaylenko, Yu V. Murashkin. EVALUATION OF USING ZWITTERIONIC ION EXCHANGE RESINS FOR RECOVERY OF RHENIUM I.D. Troshkina, N.V. Balanovskyi, Ya.A. Obruchnikova, F.Ya. Vatsura, I.A. Vanin, O.A. Zhukova, K.A. Ratchina. RECOVERY OF RHENIUM BY AMINE-CONTAINED SORBENTS I.D. Troshkina, N.B. Balanovskiy, Ya.A. Obruchnikova, V.A. Vanin, F.Ya. Vatsura. SORPTION OF RHENIUM FROM SULFURIC ACID SOLUTIONS OF POLYMETALLIC ORES LEACHING I.D. Troshkina, W.M. Aung, M.V. Marchenko, O.A. Zhukova, Pyae Phyo Aung, V.M. Muchin RHENIUM ADSORPTION FROM SULFURIC ACID SOLUTIONS BY ACTIVE COALS Kasikov A.G., Dvornikova A.M., Areshina N.S. RHENIUM AND RUTHENIUM RECOVERY FROM SUBSTANDARD WASTE OF NICKEL-BASED LAST GENERATION SUPERALLOYS Kasikov A.G., Shchelokova E.A., Dvornikova A.M. NEW SOLVENT IMPREGNATED SORBENTS FOR RHENIUM RECOVERY FROM ACID MEDIA, BASED ON MESAPOROUS SILICA OBTAINED BY COPPER-NICKEL WASTE PROCESSING 5.

Tc and Re in Nuclear Medicine - Chairs : G.E. Kodina and T. Gerber

A.O. Malysheva, G.E. Kodina, O.Е. Klementyeva, N.A. Taratonenkova, E.A. Lyamtseva, N.A. Konstantinov, M.V. Zhukova. BEHAVIOR OF THE THERAPEUTIC RADIOPHARMACEUTICALS WITH RHENIUM-188 ELUATES OF HIGH VOLUME ACTIVITY A. Avetisyan, R. Dallakyan, I. Kerobyan CYCLOTRON BASED TECHNETIUM-99M AND RHENIUM-186 PRODUCTION TECHNOLOGY DEVELOPMENT AT YEREVAN PHYSICS INSTITUTE Tsugio Yokoyama, Masaki Ozawa. PRODUCTION OF LOW SPECIFIC RADIOACTIVITY RHENIUM IN FAST REACTORS S.A. Dorovatovskiy, A.V. Zverev, V.M. Petriev, V.G. Skvortsov. RESEARCH AND DEVELOPMENT OF INNOVATIVE RADIOPHARMACEUTICALS BASED ON THERAPEUTIC RADIONUCLIDE 188Re T. Ohtsuki, S. Sekimoto, T. Tadokoro, Y. Kani, Y. Ueno. Mo-99/Tc-99m PRODUCTION USING AN ELECTRON LINEAR ACCELERATOR Yu.А. Naumova, А.Е. Miroslavov, А.А. Lumpov, G.V. Sidorenko. OXIDATIVE DECRABONYLATION OF TECHNETIUM PENTACARBONYL IODIDE IN THE PRESENCE OF IRON(III) А.А. Кuznetsov, N.A. Nerozin, A.A. Semenova, D.V. Stepchenkov, E.V. Sulim “GREN-1” 188W/188Re GENERATOR. CURRENT STATUS R.R. Kumar, D.K. Dhawan, V.D. Chadha. 99mTc LABELED N-ACETYL NEURAMINIC ACID AS A NEW RADIOTRACER FOR RENAL IMAGING, PREPARATION AND PRECLINICAL STUDY Yu.A. Mitrofanov, A.Ya. Maruk, M. Behe. LABELING OF EXENDIN DERIVATE WITH 99mTc G.E. Kodina, A.O. Malysheva. HISTORY AND PERSPECTIVES OF RHENIUM-188 APPLICATION IN NUCLEAR MEDICINE Toktosinov Mansur Yangivaevich. PROSPECTS FOR THE USE OF Re-188. O.E. Klementieva, A.B. Bruskin, V.B. Bubenshchikov, M.G. Rakhimov, A.Ya. Maruk, A.S. Lunev, D.N. Tumanova, K.A. Luneva, M.G. Gezina, G.E. Kodina. NEW RADIOPHARMACEUTICAL BASED ON α-MSH FRAGMENT FOR DIAGNOSIS OF MELANOMA B.L. Garashchenko, R.Y. Yakovlev, K.E. German, B.F. Myasoedov SURFACE-MODIFIED NANODIAMONDS AS CARRIERS FOR 99mTc M.A. Klenner, G. Pascali, M. Massi, G. Ciancaleoni, B.H. Fraser RHENIUM ENHANCED 9

355

356

357

381

382

384 386

387

388 424

428 429

430 442

450 451 452 465

471 472

RADIOPHARMACEUTICAL PRODUCTION OF FLUORINE-18 LABELLED BIDENTATE LIGANDS A. Avetisyan, R. Dallakyan, G. Elbakyan, N. Dobrovolski, A. Manoukyan, A. Melkonyan CYCLOTRON BASED TECHNETIUM-99M PRODUCTION TECHNOLOGY DEVELOPMENT AT YEREVAN PHYSICS INSTITUTE K. Nagata, N. Otsuji, S. Akagi, S. Fujii, N. Kitamura, T. Yoshimura. SYNTHESIS AND PHOTOPHYSICAL PROPERTIES OF TRICYANIDONITRIDORHENIUM(V) COMPLEXES WITH BIPYRIDINE DERIVATIVES A.T. Filyanin, M.P. Zykov, G.E. Kodina, A.Yu.Tsivadze, O.A. Filyanin. ON THE INDUSTRIAL PRODUCTION OF PHARMACEUTICAL GRADE 99MTc AND 188Re RADIONUCLIDES ON THE CENTRIFUGAL SEMICOUNTERCURRENT SPINNING GENERATOR M.Yu. Petrov, K.E. German, A.V. Afanasiev, O. I. Slyusar, V. G. Taktarov, V.M. Petriev, V.G. Skvortsov, A.Ya. Maruk, Ya.A. Obruchnikova, O.Vlasova, S.N. Ryagin. REVIEW OF PROSPECTIVE RADIOPHARMACEUTICALS BASED ON PROSTATE-SPECIFIC INHIBITORS OF MEMBRANE ANTIGEN FOR DIAGNOSTICS AND THERAPY OF METASTATIC PROSTATE CANCER J.S. McCloy, C. Soderquist, J. Weaver, Jason Lonergan. SPECTROSCOPIC STUDIES OF ALKALI PERTECHNETATES AND PERTECHNIC ACID. Supplimentary data

10

486

488

490

491

494

496

International Advisory Committee Chairman – K.E. German Chairman – I.D. Troshkina U. Abram X. Gaona R. Alberto M. Chotkowski K. Czerwinski F. Poineau M. Fattahi Ph. Moisy T.I.A. Gerber M.S. Grigoriev G.E. Kodina M. Ozawa T. Suzuki T. Ohtsuki H. Sakurai T. Yoshimura A. Sattelberger Ya. Obruchnikova G. Thorogood A.Yu. Tsivadze S. Wang Y. Wei W. Wu Y. Taihong

Germany Germany Switzerland Poland USA France/USA France France South Africa Russia Russia Japan Japan Japan Japan Japan USA Russia Australia Russia China China China China

11

LOCAL SCIENTIFIC COMMITTEE Honorary Chair - B.F. Myasoedov A.K. Buryak А.А. Blokhin A.V. Afanasiev G.S. Burhanov B.G. Ershov V.I. Volk E.I. Gedgagov M.S. Grigoriev D.V. Drobot E.N. Kablov S.N. Kalmykov A.G. Kasikov D.N. Kolupaev V.A. Lebedev A.E. Miroslavov A.I. Nikolaev S.A. Kulyukhin I.G. Tananaev A.M. Chekmarev A.Ya. Maruk A.V. Safonov N.E. Shingarev M.I. Panasyuk

IPCE RAS SPbSTU IPCE RAS IMET RAS IPCE RAS JSC VNIINM JSC GINTSVETMET IPCE RAS MITHT VIAM Lomonosov MSU ICTREMRM KSC RAS PO Mayak ROSATOM IPCE RAS NPO RI ICTREMRM KSC RAS IPCE RAS IPCE RAS Mendeleev MUCTR Burnasyan Federal SRC-FMBC IPCE RAS Atomexpo, ROSATOM Skobeltsyn INP MSU

12

Preface The International Symposium on Technetium and Rhenium - Science and Utilisation was initiated in 1993 and is being conducted by joint efforts of International Advisory Committee with the place moving each time (from Senday (Japan) to Moscow (Russia) and than to Shizuoka (Japan), Dubna (Russia), O-Arai (Japan), Port-Elisabeth (South Africa), Moscow (Russia), Pornichet (France), Sydney (Australia) and this year back to Moscow (Russia). The two title elements are among the ones with the most complicated chemistry in accord with their position in the Periodic Table of Elements binding these elements to the VII-th Group and among the most prospective elements with respect to their applications in different industries - from catalyst applications to modern metallurgy and from nuclear industry to nuclear medicine. The participation of both highly ranked scientists and engineers and the young generation from the international scientific community bring this symposium to the level that support each meeting with new ideas in chemistry and applications. And gives us the hope that we will be able to solve the most complicated problems of technetium and rhenium.

Irina Troshkina and Konstantin German Chairs

13

14 ISTR2018 DELEGATES

1.

Fundamental Physics and Chemistry of Tc and Re Chairs : K.E. German and Masaki Ozawa

A. MIROSLAVOV, G.KODINA. T. GERBER, X. GAONA and B. GRAMBOW

J. Lin

S. STEFANOVSKY

15


Message to International Symposium on Technetium and Rhenium Science and Utilization, 2018 The chemistry of rhenium and technetium is remarkably diverse and wideranging, given that one of the elements is among the rarest in the crust of the earth, and the other is almost entirely synthetic, the result of nuclear fission (I hope you like as much as I do, the image of nuclear physicists as synthetic chemists!) When these elements were first described nearly a hundred years ago, at much the same time, one could not have imagined that they would be used as superalloys and catalysts, tracers in medicine, or – in the Tc halide clusters – as examples of most unusual chemical bonding. But they are so used, of value to our economy and well-being, a stimulus to our thinking. I wish the explorers of the Tc and Re worlds good science and great fun! Roald Hoffmann, chemist and writer, who has worked, even if not much, with both Tc and Re chemistry , 08.08.2018

Roald Hoffmann, a theoretical chemist who won the 1981 Nobel Prize in Chemistry and was the first to support the existence of hexa- and octonuclear Tc clusters in 1983 :) Photo by M. Grigoriev: Moscow, IPC(E) RAS, 1991, Left to right: Vladimir Peretrukhin, Roald Hoffmann, Sergey Kryuchkov, Edith Chan 16

Openning ceremony Director of IPCE RAS Aleksey Buryak , Andrey Romanov on behalf of Ministry of Science and Higher Education and Konstantin German as a Chairman of ISTR2018

17

ANNA KUZINA biographic notes 1918 - 1992 By Mikhail Igorevich Panasyuk SKOBELTSYN INSTITUTE OF NUCLEAR PHYSICS LOMONOSOV MOSCOW STATE UNIVERSITY

Анна Федоровна Кузина Родилась 6 августа 1918 г. в деревне Северская Пудожского района Карело- финской АССР

В 20-х годах переехали в Петроград

Лина и Федор Кузины

18

Кузина Анна Федоровна Ленинградский химико-технологический институт Ленсовета 1936 – 1941 г.г.

Выпуск инженеров – технологов - резинщиков

Комсорг Аня Кузина

Анна Федоровна Кузина

1941 г. - защита диплома

19

Игорь Семенович Панасюк - IGOR PANASYUK

И.В. Курчатов

Ленинградский политехнический институт (1937—1941). В 1938—1939 слушал лекции и занимался в лаборатории ЛФТИ. Дипломник и аспирант И. В. Курчатова.

Игорь Семенович Панасюк - IGOR PANASYUK

В 1939—1940 : участник Советско-Финской рентгенотехник в полевых госпиталях.

20

Война 1941 – 1945 г.г.

И.С. Панасюк 1941 -1943 г.г. – служба в РККА в районе блокадного Ленинграда

Лейтенант А.Ф. Кузина – служба военпредом (г. Казань)

1943 г. Лаборатория №2

Участник создания уран-графитового (водо-графитового) реактора, физического реактора Ф-1 (с 1943 г. ) Construction of F-1 U-water-graphite reactor

21

1944 г.

ЛИПАН

Ул . Песчаная, Сокол, с 1947 г.

1945 г.

22

Командировка на базу-10 (поселок Госхимзавода им. Менделеева, и Челябинск-40). Mission to Base-10 and Chelyabinsk-40, as the Head of A-reactor construction

Оз. Иртяш

И.В. Курчатов назначил И.С. Панасюка – руководителем создания первого промышленного реактора «А» в Озерске

Впоследствие - физики I.Panasyuk, A.Kuzina and their children - later became phisicists

23

ИФХ АН СССР - in IPC AS USSR

Спасибо маме за все и Вам за внимание !

24

The 10th International Symposium on Technetium and Rhenium

DOI: 10.13140/RG.2.2.10589.05602 Prof. Anna Fedorovna KUZINA 100th Anniversary of birthday K. E. G E R M A N RUSSIAN ACAD EMY OF S CIEN CES A.N . FRUMK IN INST IT UT E OF PHYSICA L CH EMIST RY AN D ELECTROCHEMISTRY

100th Anniversary of birthday 1918 - 2018

25

In IPC AN USSR, 1956 – 1992 (after coming back from Ozersk) Some fundamental chemistry of Tc Initial studies of technetium irradiation of Mo in reactors for Tc (Krasnoyarsk) synthesis of new Tc compounds electrochemistry of technetium analytical chemistry of technetium Separation of Tc at PA Mayak Conversion to Tc metal Cluster compounds of technetium

First micro-grams of Tc-99 Mo-98 (n, g)Mo99 --- (b-decay)Tc-99 in the nuclear reactor Missions of Anna Kuzina to Krasnoyarsk Work with Anatoly Tsarenko

Laboratory of radiochemistry. Sitting: Albina Oblova, Anna Kuzina, academician Viktor Spisyn, Lyubov Barsova, Vitaly Kabanov, L. Troitsky, sdanding 1st line : Sergey Kryutchkov, Konstantin German, Valeria Pershina, A. Kisileva, Nina Budantseva, < Tamara Yurik, 2d line Sergey Kabakchi, 3rd line V. Mironov , Alexander Maslennikov, Al Vikhalin A. Kudryavtsev, R. Alimov, 1982, Moscow IPCAN USSR (now IPCE RAS)

26

First motivation for exploring Tc chemistry for the Closed Fuel Cycle Tc-99 is a key dose contributor at HLW repositories if TRU elements are greatly reduced by recycling ◦ long half-life of Tc (t1/2 = 2.14 x 105 years), ◦ high mobility, and solubility under oxidizing conditions Methods for managing the long-term threat of Tc to the environment ◦ Stable waste form/repository system providing with strict limits for Tc release over a long period of time (~1 million years?). ◦ Transmutation of radioactive Tc to stable Ru im nuclear rectors.

Main problems of Tc Tc is important item in Nuclear Industry Tc redistribution in PUREX produces flows with long-lived high radioactive wastes Tc interferes at U/Pu separation stage in PUREX process Tc accumulation in High burn-up fuel together with Mo, Ru, Rh Tc in nuclear waste vitrification: Tc-Mo-Ru metal phases, Tc(VII) volatility

27

Russian reprocessing plant RT1 , PUREX part

Technetium interfering role in the PUREX Pu/U separation stage Reducing agent + complexing agent

Extract U,Pu, Np (Tc(STc1st extcyc =80 -90%))

Back extract Pu, Np (Tc(IV))

Reductive separation of U, Pu, Np (Tc) Extract U (Tc(VII))

1. Variable red-ox states 2. Variable species

Difficulties in stability of U/Pu separation at UK, Russian and French facilities Catalytic Tc effects in many chem. reactions Variable Tc redox states Tc - Waste problems Tc-DTPA complex precipitation

28

Tc + N2H5+ = ?= Authors

Order in [N2H5]0

Order in [H+]

Krinitsyn, Tsarenko, 1982 Kuzina et all., 1981 Koltunov ey all. Ramazanov et all. Kemp et all.

0 1 0.85 1 -

0 0 1.4 2 -

Zilberman, Mashkin

Order in [TcO4-]

1 2 1 1.2 кинет. циклы HN3, catalytic cycles Конечные хим. формы в реакции Тс(VII) c N2H5+ согласно разным авторам варьируют от Tc(2+) до Tc(VII) = необходимы структ. и спектроскоп. данные

Best research award of 1980-1986 at PO MAYAK Main approach Ion-exchange separation VP-1AP -- IEX 100 kg of KTcO4 separated during the 10 sessions Purification : problems and solutions(Tc/DPu)

29

Development of ion-exchange technology for Tc separation in IPCE RAS (1971-1976) Prof. A.F. Kuzina (Tc Group leader till 1987 ) presenting her Tc samples prepared in the Institute from the concentrate separated from radioactive wastes generated at Krasnoyarsk Reprocessing Plant to Glean SEABORG (1978)

Separation of macro amounts of Tc-99g in USSR 1 kg of Tc was converted to metal in hot cell of IPCE RAS and distributed among different Russian institutes In 1971-1976 IPC RAS in collaboration with Krasnoyarsk Mining Enterprise has separated from HAW some kilograms of K99TcO4 In 1983 -1986 collaboration of PO “Mayak”, IPCE RAS and Radium Institute resulted in elaboration of anion-exchange technology for Tc separation and 40 kg of K99TcO4. This work was awarded with the special Diploma of the Russian Prof. Anna KUZINA and acad. Victor SPITSYN authorities

analyzing the sample of Tc metal

30

Searching technetium applications Anti-corrosion protection Anti-fouling protection Light-matter defectoscopy Catalysts Ophtamo Reference electro-current sources Batteries …

A few examples of new Tc compound structures made in IPCE RAS (A. Kuzina, K.German, M.Grigoriev)

[Bu4N]TcO4

[Pr4N]TcO4

[Me4N]3[Tc6Cl14]

31

The last work, ESCA, 1990, Italy, Tc&Re symp. (one of the most cited world publications on Tc )

100th Anniversary of birthday 1918 - 2018 

 



32

Anna Kuzina greatly supported international collaboration of IPC AN With Czechoslivakia, France, Poland, USA etc. A message from Roald Hoffman, 2018 :

Message to International Symposium on Technetium and Rhenium - Science and Utilization, 2018 The chemistry of rhenium and technetium is remarkably diverse and wide-ranging, given that one of the elements is among the rarest in the crust of the earth, and the other is almost entirely synthetic, the result of nuclear fission (I hope you like as much as I do, the image of nuclear physicists as synthetic chemists!) When these elements were first described nearly a hundred years ago, at much the same time, one could not have imagined that they would be used as superalloys and catalysts, tracers in medicine, or – in the Tc halide clusters – as examples of most unusual chemical bonding.

But they are so used, of value to our economy and well-being, a stimulus to our thinking. I wish the explorers of the Tc and Re worlds good science and great fun!

Roald Hoffmann, chemist and writer, who has worked, even if not much, with both Tc and Re chemistry, 08.08.2018 .

Walter Noddack, 125th Anniversary of birthday, 1893-2018 Discovery of RHENIUM + Walter Noddack + Ida Tacke + Otto Berg

 "The work was carried out with partial funding by the Ministry of Science and Higher Education of the Russian Federation (subject No. AAAA-A16-116110910010-3) "

33

PHOTOLUMINESCENCE SWITCHING OF NITRIDORHENIUM(V) COMPLEXES T. Yoshimura,1 M. Seike,2 H. Ikeda,2 K. Nagata,1 A. Ito,3 E. Sakuda,4 N. Kitamura,5 A. Shinohara2 1

Radioisotope Research Center, Institute for Radiation Sciences, Osaka University, Suita, Japan, 2 Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Japan, 3 School of Environmental Science and Engineering, Kochi University of Technology, Kochi, Japan, 4 Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, Nagasaki, Japan, 5 Department of Chemical Sciences and Engineering, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan e-mail: [email protected]

It is known that nitridorhenium(V) complexes exist either as six- or five-coordinate structures and these complexes show photoluminescence. In the six-coordinate complexes, the bond between the rhenium ion and the axial ligand at the trans site of the nitrido ligand is very weak; the axial site is labile because of the trans influence and trans effect of the nitrido ligand. In the present study, significant luminescence intensity switching by solvent-free reactions and exposure of water was conducted using five- and six-coordinate tetracyanidonitridorhenium(V) complexes. The new complexes, (PPh4)2[ReN(CN)4L] (L = imidazole (Him) (1) and 1methylimidazole (Mim) (2)) and (PPh4)2[ReN(CN)4L]•L (L = Him (3) and Mim (4)) were synthesized. 1, 2, and 4 showed intense luminescence (Φem = 0.65 – 0.75) in the solid state at 296 K. Luminescence of 3 was very weak (Φem < 0.01) in the solid state at 296 K. The mechanochemical reaction of 1 with 1 equiv. of Him in the solid state produced 3. The complex 3 was also obtained by the reaction of (PPh4)2[ReN(CN)4] (5) with 2 equiv. of Him in the solid state. The compound 1 could be reproduced by placing solid 3 in water. The compound 5 was produced under vacuum at 185°C from 1 and 3 for several days, respectively. Both 2 and 4 showed intense luminescence with similar intensities. The weak photoemission of 3 may be due to quenching by the vibronic relaxation of the N-H∙∙∙N hydrogen bond between the coordinate and free Him molecules.

34

CHEMICAL THERMODYNAMICS OF TECHNETIUM IN THE OECD/NEA UPDATE VOLUME B. Grambow1, X. Gaona2, W. Runde3, R. Konings4, A.V. Plyasunov5, L. Rao6, A.L. Smith7, E. Moore8, M.-E. Ragoussi9, J. Martinez-Gonzalez9, I.Grenthe10 1

Subatech (CNRS-IN2P2, University of Nantes, IMT Atlantique, Nantes, France) 2 Institute for Nuclear Waste Disposal, KIT, Karlsruhe, Germany 3 Los Alamos National Laboratory, New Mexico, USA 4 Joint Research Center, Karlsruhe, Germany 5 Institut of Experimental Mineralogy, Russian Academy des Sciences, Russia 6 Lawrence Berkeley National Laboratory, Berkeley, USA 7 TU Delft, Netherlands 8 University of South Carolina, USA 9 OECD-NEA, Paris, France 10 Royal Institute of Technology, Stockholm, Sweden

Since publishing “Chemical Thermodynamics of Technetium” [1999RAR/RAN] about 20 years ago many new solubility studies with hydrous oxide of Tc(IV) have been undertaken and evidence for polymerization of Tc(IV) in solutions has strongly increased, leading to the need to reassess the chemical thermodynamics of Technetium in the frame of an update volume by OECD/NEA on the chemical thermodynamics of the actinides and technetium. In particular, hydrolysis schemes and chloride complexation are affected. Slow aging/dehydration of the hydrous oxide has been taken into account. No evidence for the existence of TcO+2 has been found, leading to the rejection of thermodynamic data involving this species.

35

Chemical Thermodynamics of Technetium in the OECD/NEA Update volume B. Grambow, X. Gaona, W. Runde, R. Konings, A.V. Plyasunov, L. Rao, A.L. Smith, E. Moore, M.-E. Ragoussi, J. MartinezGonzalez, I.Grenthe Subatech (CNRS-IN2P2, University of Nantes, IMT Atlantique, Nantes, France), Institute for Nuclear Waste Disposal, KIT, Karlsruhe, Germany, Los Alamos National Laboratory, New Mexico, USA, Joint Research Center, Karlsruhe, Germany, Institut of Experimental Mineralogy, Russian Academy des Sciences, Russia, Lawrence Berkeley National Laboratory, Berkeley, USA, TU Delft, Netherlands, University of South Carolina, USA, OECD-NEA, Paris, France, Royal Institute of Technology, Stockholm, Sweden

Thermochemical Database (TDB) Project • The purpose of the TDB Project is to make available a comprehensive, internally consistent, quality-assured and internationally recognized chemical thermodynamic database of selected chemical elements in order to meet the specialized modelling requirements for safety assessments of radioactive waste disposal systems. • The TDB project aims to produce a database that: – contains data for all the elements of interest in radioactive waste disposal systems; – documents why and how the data were selected; – gives recommendations based on original experimental data, rather than compilations and estimates; – documents the sources of experimental data used; – is internally consistent; – treats all solids and aqueous species of the elements of interest for nuclear waste storage performance assessment calculations.

36

Detailed guidelines on • • • • •

Review procedures Extrapolation to zero ionic strength Assignment of uncertainties Temperature corrections Standards and conventions

Specific ion interaction theory (SIT) for ionic strenght corrections

37

• “Chemical Thermodynamics of Technetium” Joseph A. Rard et al. published in 1999 • Update to be published in 2019 – A new review excercise on the « thermodynamics of actinides and Tc » – Work since 2014 under the leadership of Prof. I. Grenthe and X. Gaona – Strong help from OECD/NEA – Tc chapter: • responsable B. Grambow • Work revieved by previous key author of the 1999 book: Joseph A. Rard

The current state of the art: Tc(V) and Tc(VI) observed as intermediate species but without being able to attribute thermodynamic data

Geochemical Factors Affecting the Behavior of Antimony, Cobalt, Europium, Technetium, and Uranium in Vadose Sediments, Krupka, Serne 2002

38

An update of the Tc volume was needed, to include new experimental insights • Since publishing about 20 years ago

• Many new solubility studies with hydrous oxide of Tc(IV) have been undertaken including long term (1yr) studies • New spectroscopic data are available • Evidence for polymerization of Tc(IV) in solutions has strongly increased • In particular, hydrolysis schemes and chloride complexation of Tc(IV) are affected. • Slow aging/dehydration of the hydrous oxide of Tc(IV) has been taken into account. • No clear evidence for the existence of TcO+2 has been found, leading to the rejection of thermodynamic data involving this species. • Spectroscopic confirmation of Tc(VII)/Tc(IV) redox couple and Tc(IV)/Tc(III)

Few changes for TcVII

Solubility data to obtain ion interaction data

log K° = – (2.239 ± 0.013) The interaction parameters for K+-TcO4 are ε1 = (1.597 ± 0.081) and ε2 = (-0.161 ± 0.142)

39

Many changes in the thermodynamics of Tc(IV) • A cornerstone in Tc(IV) chemistry are solubility data • Tc(IV) has rather low solubility at neutral pH, in natural water systems often controlled by TcO2(am, hyd) • However – This phase is often ill defined – Its properties vary with time – Solubility data for crystalline TcO2 do not exist • Another problem: aqueous species polymerize under certain conditions – This is also time dependent • Large effort on managing impact of kinetic effects

Many changes for TcIV

Reinterpretation of original solubility and spectroscopic data data in overall solution speciation model exemple: solubility data of [1991MEY/ARN]

Original interpretation by authors from semi-logarthmic plot: « solubility equilibrium has been reached »

New interpretation, plotting the same data linearly: No equilibrium has been achieved, solution concentrations continue to rise

40

What is the hydration number of TcO2.nH2O? 4.5

« fresh »

4.0

hydration number

3.5 3.0 2.5

Data used by [1999RAR/RAN]

2.0 1.5

« aged »

1.0 0.5 0.0 -1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

log time (d)

Hydration number changes with time of equilibration in solubility experiments

How taking the water content of hydrous TcO2(am) into acount? 2 options :

a) H2O is an integral part of the structure of the solid The work of [99RAR/RAN] identified n=1.6 but this is temporally variant TcO2·nH2O  TcO(OH)2 (aq) + (n-1) H20

a) Hydration water has little structural impact Data show that water is only little bounded, so we use this stoichiometry TcO2(am,hyd) + H2O  TcO(OH)2 (aq)

To account for aging of the solid we distinguish between TcO2(am,hyd,fresh) and TcO2(am,hyd,aged)

41

Activity product Q= mTcO(OH)2(aq) as a function of time -7.0 [1999MEY/ARN] [2007LIU/YAO] [2004HES/XIA] [2016YAL/GAO]

-7.5 short term

log Qs

o

-8.0

-8.5 long term

-9.0

-9.5 0

20

40

60

80

100

120

140

160

180

200

time of equilibrium (d)

Long term experiments are needed to obtain thermodynamically meaningfull solubility data

Effect of ionic strength -7.0 DI-Water MgCl2 sln

-8.0

NaCl sln

2

log [TcO(OH)2(aq)] - log aH O

CaCl2 sln -7.5

-8.5

long term data

-9.0 -9.5 -10.0 -10.5

 TcO(OH) 2 (aq) TcO2 (am)  H 2 O 0

2

4

6

8

10

Ionic strength (m)

42

12

14

16

Hydrolysis model of Tc(IV) describing solubility of TcO2(am, hyd) -2

electrodeposition [1991MEY/ARN] dillute NaCl [1991MEY/ARN] [1992ER/NDA] anaerobic, centrifuged [2007LIU/YAO] anaerobic, filtered [2007LIU/YAO] reduced by SnCl2 [2007WAR/ALD] new hydrolysis model and 95% confidence band 0.1 M NaCl data [2016YAL/GAO] hydrolysis model of [1999RAR/RAN]

-3

log Conc Tc(IV)

-4 -5 -6 -7 -8 -9 -10

-2

0

2

4

6

8

10

12

14

16

pH

Fit of solubility data of TcO2(am, hyd, aged) not improved, but new model is coherent with spectroscopically observed dominance of polymeric species in the low pH range

Time dependency of apparent solubility data: -2 -3

15YAL, 5M NaCl 04HES/XIA, 11 d

log Conc. Tc [M]

-4 -5 -6 -7 -8 -9 -10

5 M NaCl -2

0

2

4

6

8

10

12

14

16

pH

slope changes: effect of time dependent polymerisation in aqueous phase The slope of 2 was previously interpreted by presence of TcO2+ , now by Tc2O2(OH)2+2 Evidence by EAFS studies

43

Time dependency of apparent solubility values

Slow polymerisation kinetics

Slow precipitation kinetics

Yes, but TcO2+ was « spectroscopically confirmed » by 2004 Hess, Xia, Rai and Conradson…. 1,0

TcO2+ HESXIA Poinau long polymer data

TcO2+ HESXIA

0,8

Hoever, Poineau assigned the same peak to a polymer

0,6

0,4

0,2

0,0 200 250 300 350 400 450 500 550 600 650 700 750

J Wave length (nm)

Hence, this review rejected the « spectroscopic confirmation » Additional data on TcO2+ : Tumanova et al 2008 interpreted a shoulder at 400 nm as indicative of Tc(IV) in 16 M H2SO4, interpreted as momomeric TcO2+. No data have been provided to confirm the speciation of Tc(IV) but the concentration range is outside the present scope.

44

Stability constant of Tc2O2(OH)2+2 17 16

2

log  log aH O + 2DH

15 14 13 12 [2004HES/XIA] [2007LIU/XIA] [2016YAL/GAO] [1991MEY/ARN]

11 10

Log K=-12.99 ±0.41

2TcO(OH) 2 (aq)  2H +  Tc 2 O 2 (OH)22   2H 2 O

9 0

2

4

6

8

Ionic strength (molality)

Relatively large uncertainties, since principally based on slow solubility equilibria

UV-Vis spectroscopic determination of evolution of speciation with pH, including chloride complexation Comparison of experimental data (Poineau 2004) with calculated values from speciation model fo Tc(IV)

45

Redox potential of the couple TcO4-/TcO2(am, hyd) In [1999RAR/RAN]

E° = 0.746±0.012 V 2 problems: 1) the water content is fixed at x=1.6, which is arbitrary 2) the electrochemical potential has been determined using electrodes at solid /liquid equilibrium TcO2·1.6H2O/H2O established only over less than 1 d, while corresponding apparent solubility equilibria are time dependent and 1 d is not sufficient for equilibrium. We interpret this redox equilibrium as belonging to TcO2(am, hyd, fresh). No long-term measurements for aged electrodes for E° are available. A value of E° = 0.757±0.006 V for TcO 2(am, hyd,aged) is calculated from its solubility data in this review

Redox titration/spectroscopy by N. VONGSOUTHI (2009)

E  E0 

2 10 γ TcO  γ H+ [TcO 4 ]2 [H + ]10 2.3026 RT 4 ·(log10 )  log10 6F [Tc 2 O 2 (OH) 22  ]a w4 γ Tc O (OH)2 2

2

2

Slow polymerisation

E  E0 

γ Tc O (OH)2 γ 6H+ [Tc 2 O 2 (OH) 22  ][H + ]6 2.3026RT ·(log10  log10 2 2 2 2 ) 3 2 4 2F [Tc ] a w γ Tc3

46

Comparison E° (TcO4-/Tc2O2(OH)2+2) = (0.735 ± 0.088) V from redox titration = (0.731 ± 0.011) V from thermodynamic data from the ΔG°f values of the species in the reaction 10H +  2TcO4  6e    Tc2 O2 (OH)22   4H 2 O

with the value for Tc2O2(OH)22+ derived from solubility studies Coherent discription!

Tc(III) Slope analyses of Tc(IV) polymer/Tc(III) redox potential data of [2009VON] indicates, that Tc3+ is the dominant species of Tc(III) at pH values below 3 and for Tc concentrations 99%). Tc(IV) incorporated in goethite lattice.

Tc-goethite (2-5)

Tc-goethite

Noramlized Count

Initial Goethite

21030

21080

21130

Photon Energy (eV) XANES for 99Tc-doped goethite 10

From Um et al., 2011 (ES&T, 45, 4904-4913)

30

50

2 Theta

15

첨단원자력공학부

Tc Oxidation State in Goethite and XRD Results (a)

TcO4

-

2-3*

Sample 2 Sample 2-2

Sample 2-3*

2-5

Noramlized Count

Normalized Absorption

TcO2•2H2O

2-4 2-3 2-2 2-1

Sample 2-5

2

15

20

25

30

35

40

45

50

55

60

65

Initial Goethite

2 Theta 21030

21080

21130

Photon Energy (eV)

Dominant oxidation state is Tc (IV) by X-ray absorption near edge spectroscopy 16 첨단원자력공학부 (XANES) based on final solids spectra matching the TcO2 standard and not TcO4-

193

8

pH 4 pH 10 GL

7 6

pH 7 IDF

Fe (ug/g of Tc-Goethite)

Tc (ug/g of Tc-Goethite)

Leach Test Results using Tc-Goethite Powder (a)

5 4 3 2 1

30000

20000 pH 4 pH 10 GL

15000 10000

pH 7 IDF

5000 0

0 0

20 40 60 80 100 120 140 160 180 200

0

Time (days)

4

Tc (ug/g of goethite)

12

(c)

10 8

pH

(b)

25000

6 4 pH 4 pH 10 GL

2

pH 7 IDF

20 40 60 80 100 120 140 160 180 200

Time (days)

(d)

3 2 1 2

0

2-2

2-5

0 0

20 40 60 80 100 120 140 160 180 200

0

Time (days)

20 40 60 80 100 120 140 160 180 200

Time (days)

Batch leaching results for Tc-goethite powder samples as a function of reaction time with different pH buffer solutions (4, 7, and 10), IDF pore water, and glass leachate (GL). (a) Tc leaching for Sample 2; (b)17 dissolved Fe(tot) for Sample 2; (c) measured pHs for Sample 2; (d) Tc 첨단원자력공학부 leaching for Tc-goethite Samples 2, 2-2, and 2-5 in IDF pore water. 17 From W. Um, et al. J. Nucl. Mater. 429 (2012) 201-209.

Leaching Results using Tc-Goethite Monolithic Pellet 15

(a)

(b)

13

2

1.0E-09

Tc release [mg/m ]

2

Tc diffusivity (cm /s)

1.0E-08

1.0E-10 1.0E-11 1.0E-12 1.0E-13 0.01

Tc-goethite 2 Tc-goethite 2-2 Tc-goethite 2-5

11 9 y = 0.495x + 8.0083

7

R2 = 0.9044

5 3

0.1

1

10

100

1000

Cumulative leaching time [days]

0

1

2

3

4

5

6

7

8

9 10 11 12 1/2

Cumulative leaching time [days]

Calculated Tc effective diffusivities for Samples 2, 2-2, and 2-5 as a function of cumulative leaching time (a) and a linear dependence between cumulative Tc release and cumulative leaching time, t1/2 for Sample 2-5 (b). 18 18


From W. Um, et al. J. Nucl. Mater. 429 (2012) 201-209.

194

XANES and XRD Results for Reacted Samples TcO4

-

(a)

TcO2 •2H2 O


Sample 2-2 Sample 2-5

(b)

Normalized Counts

Sample 2

(c) (d) (e)

Reacted Sample 2

(f)

Reacted Sample 2-2

15 20 25 30 35 40 45 50 55 60 65 Reacted Sample 2-5

Reacted Sample 2 with air

21030

21080

Photon Energy (eV)

21130

2-Theta

(a) reacted Tc-goethite sample 2 with pH=4 solution after 180 days; (b) reacted Tc-goethite Sample 2 with pH=7 solution after 180 days; (c) reacted Tc-goethite Sample 2 with pH=10 solution after 180 days; (d) reacted Tcgoethite Sample 2 with IDF pore water after 180 days; (e) reacted Tc-goethite Sample 2 with glass leachate after 180 days; (f) non-reacted initial Tc-goethite Sample 2 19 before 19 leaching tests. The Reacted Sample 2 in air was 첨단원자력공학부 contacted for 180 days with atmospheric air.

Re(IV)-Doped Sn-Oxide  Similar approach to previos Tc-goethite for preventing Tc reoxidation and limit Tc leachability Ammonium Perrhenate 7.46mM

Tin(II) Chloride 7.46mM

+

+

0.04M HCl 30mL

0.04M HCl 30mL

ORP : 506mV DO : 3.91mg/L

ORP : 56mV 1.60mg/L

DO :

Additional 0.04M HCl 154mL All pH : ~1.4

Solution changed its color from translucent light yellow to the opaque dark brown. ORP value 20 첨단원자력공학부 was changed to -111mV which confirmed the reducing conditionssel even in open to air.

195

Re(IV)-Doped Sn-Oxide (Cont.) A

-

B

XRD & SEM results shows that the main form of the precipitate is Cassiterite (SnO2). EDX analysis also proved the presence of Re and Sn in the precipitate.

-

Re-doped SnO2 resists re-oxidation of Re and produces a chemically stable phase, so this method of incorporating 99Tc into SnO2 is also possible, inexpensive, and easily applicable at room temperature.

-

More information can be available from Poster Presentation (based on M. Kahn, W. Um, et al. J. Nucl. Mater. 505 (2018) 134-142.

-

But, do we need always reductant to reduce Tc(VII) before making Tc(IV)incorporated metal oxides ?

21


New Approach to make Tc-Incorporated Fe minerals To evaluate the transformation process of Fe(OH)2(s) to the more crystalline Fe mineral for Tc removal. Tc(IV)-incorporation within Fe mineral structure was proposed as a novel method to remove Tc from waste solution and increase Tc retention in varios waste forms. A single source of Fe(OH)2(s) can serve as both reductant and immobilizing agent (substrate) for Tc(VII) removal. Shikorr reaction: 3Fe(OH)2 → Fe3O4 + H2 + 2H2O Tc incorporation and removal by Fe mineral transformation using Fe(OH)2(s) can be used to immobilize Tc longer and stabilize Tc more even under different conditions. F.N. Smith, W. Um, et al., ES&T. 49 (22) (2015), 13699−13707. F.N. Smith, W. Um, et al., ES&T. 50 (2016), 5216−5224. S. Saslow, W. Um, et a;., ES&T, 51(15) (2017), 8635-8642. 22

196


22

Materials and Methods Tc-magnetite/maghemite synthesis About 0.05 g of the synthesized Fe(OH)2(s) was reacted with Tc-spiked DI solution. Fe(OH)2(s) was prepared using 0.07 M of FeCl 2•4H2O with pH adjustment to near 7.5 using NaOH solution (1 M) inside an anoxic chamber.

The solution with a Tc spike was prepared independently with DI water in which the solution pH was adjusted to pH ~12 using 1 M NaOH. The reaction tubes were immediately sealed and the reaction lasted for 7 days at 75-80oC temperature. After the reaction, final solid was collected and filtered using a 0.02-µm syringe filter before use.

M = magnetite, FHO = Fe(OH)2(s), F = Fougerite [Fe(OH,Cl)]

99Tc


23

removal by Fe(OH)2 transformation

More than 95% of the initial Tc (10-5 M) was removed from solution containing Fe(OH)2, even without aqueous Fe(II) or other reductants added. More Tc removal was found at elevated (75oC) temperature than room (21oC) temperature after 3-7 days reaction. Initial Tc concentrations of 10-5, 10-4, and 10-3 M in Fe(OH)2(s) slurry showed 97%, 77-86%, and 64-65% of Tc removal from solution, respectively. Tc removal by transformation product Initial Tc (M) Final Tc(μg/g) (pH:12 and high T)

10-5

10-4

1,014

8,755

Final Tc(μg/g) 1,042 7,879 (pH:12 and low T) Fe(OH)2=0.05 gram with 50 mL solution 24 첨단원자력공학부

197

10-3 66,600

62,350

XAFS study for Tc-maghemite/magnetite transformed from Fe(OH)2(s) XANES for Tc with high pH at room T and high pH at high T conditions Room temperature condition: Tc(+4) =78% and Tc(+7) = 22% High temperature condition : Tc(+4) = 98% and Tc(+7) = 2%

75 oC temperature 첨단원자력공학부

25

XAFS Results for Tc in Fe mineral (maghemite/ magnetite mixture) EXAFS analysis Tc coordination environment on a mixture of maghemite/magnetite prepared at high pH and high T. High temperature condition : Tc(+4) = 98% and Tc(+7) = 2% from XANES EXAFS fitting parameters for Tc-RT (S 02=0.9 (fixed); ΔE=-0; Oh=octahedral site; Td=tetrahedral site) Neighbor

# of Neighbors

Distance (Å)

s2 (Å2)

p

Structure of Fe3O4

Structure of Tc

O O

0.6(2) 5.2(2)

1.74(3) 1.997(7)

0.0040(6) 0.0040(6)

0.011 0.02 g/mL) even for higher Cr (1560 ppm) concentration than Tc (1 ppm).

20 0 8

-4

10

2

4

6 8

-3

2

4

6 8

-2

2

4

10 10 Fe(OH)2:Solution Ratio (g/mL)

● 99Tc (1 ppm, no Cr) ● 99Tc (1 ppm, with Cr) ▲ Cr (no 99Tc) ▲ Cr (1 ppm 99Tc, with Cr) Error bars represent the standard deviation of the average30determined from 2-3 replicate experiments

200


30

XAFS analysis for Tc oxidation state changes Decreasing Tc(VII)

Has Tc(VII) been reduced to Tc(IV)?

TcO4-

Bulk 99Tc oxidation state determined by

1000 ppm Tc(VII), 0 Cr(VI) 1000 ppm Tc(VII), Cr(VI)


110 ppm Tc(VII), Cr(VI) 110 ppm Tc(VII), Cr(VI)* 11 ppm Tc(VII), Cr(VI)

TcO2·2H2O

X-ray Absorption Near Edge Spectroscopy (XANES) Oxidation State determined from Linear Combination Analysis using TcO2·2H2O and TcO4_ references

[Tc(VII)]

[Cr]

Fe(OH)2:Solution Ratio g/mL

TcO4-

TcO2•2H2O

ppm

ppm

1000

0

0.05

0.30(2)

0.70(2)

1000

1560

0.05

0.15(3)

0.85(2)

110

1560

0.05

0.00(3)

1.00(2)

*110

1560

0.02

0.01(3)

0.99(2)

11

1560

0.05

0.00(3)

1.00(2)

Tc(VII) completely reduced to Tc(IV) if starting [Tc(VII)]≤110 ppm Data Fit

21040

21070 21100 Photon Energy (eV)

21130

Cr(VI) does not inhibit reduction of Tc(VII) 31 W. Um, et a;., ES&T, 51(15) 첨단원자력공학부 From S. Saslow, (2017), 8635-8642.

31

Tc Retention in Magnetite at High T. by Different Dopants

Figure 3| Atomic density profiles with different dopants at 900K. Red lines represent Tc, blue lines for three different doping atoms (Ni, Zn, and Co), gray lines for Fe, and green lines for O.

Tc concentration (μg/g) Dopant

Retention (%)

initial final Figure 2| Atomic density profile, geometry, and XANES spectra in Tcincorporated magnetite. a, b, Atomic density profile showing atomic Ni 18,228 726 4 arrangement along z-direction at 298 and 900 K obtained from AIMD Zn 15,548 1,930 12 simulations where dotted vertical line denotes the magnetite surface. c, Snapshot of the structure at 900 K from AIMD trajectories where a blue circle Co 14,565 4,280 2929 October 2018 represents Tc, red for oxygen, and cyan for Fe. d, Normalized XANES 32 첨단원자력공학부 spectra at RT and 600 °C. From M-S. Lee, W. Um et al., Nat. Commun. 7 (2016), 12067.

201

32

Immobilization of 99Tc in Glass Waste Form Recent studies have shown that iron minerals are stable hosts phases capable of immobilizing reduced Tc(IV) even at vitrification temperatures Spinels (e.g. Magnetite, Fe3O4) Physically and chemically stable Can form during vitrification and remain in the final borosilicate glass

Goethite (α-FeOOH) Most common and stable iron oxyhydroxide in nature Common steel corrosion product

Objective: Determine the dependence of Tc retention in borosilicate glass melt tests on the Tc(IV)-incorporated host phase prepared before vitrification

33

29 October 2018 첨단원자력공학부

33

Background 99Tc

volatility issue in vitrification process

Tc2O7 (boiling point: 311oC; melting point: 119.5 oC) Tc-O bond distance of 1.72 Å in tetrahedral coordination

TcO2 (s) sublimes at 900 oC Tc-O bond distance of 2.00 Å in octahedral coordination

Tc(VII) is more volatile than Tc(IV) More reducing condition increases Tc retention in glass. However, too much reduction condition can be also bad for glass formation.

Tc(IV)-incorporation within Fe mineral structures such as spinel is proposed as a novel method to increase Tc retention even at high temperature process conditions used for making glass waste forms. Because of its physical and chemical stability, spinel can be present in a final borosilicate glass prepared with glass feed containing Fe2O3, and is considered an effective sink for Tc in glass. 34

202


Tc-Incorporated Magnetite and Goethite Characterization: XRD XRD analysis confirms synthesis of Tc-incorporated goethite and magnetite

35


Tc-Incorporated Magnetite and Goethite Characterization: XANES

Tc(VII): Tetrahedral symmetry, 1s to 4d transition produces strong pre-edge feature TcO2∙xH2O: Double-peak structure characteristic of Tc(IV) coordinated by six oxygen atoms in a distorted octahedral geometry

Tc XANES data and fits for synthesized Tc-goethite and Tc-magnetite show complete reduction of Tc(VII) to Tc(IV)

36

203


Materials and Methods Glass melter test

Target glass compositions (mass%) AN-102 waste Additives * AN-102 glass

Three different samples (Tc-goethite, Tcmagnetite/maghemite, and KTcO4 salt) were prepared and tested using a furnace. About 5 g of Tc-iron mineral was mixed with other basic glass feeds in a Pt crucible and heated up to 1,000 °C at 5°C per min. The baseline glass for Tc-retention testing was AN-102 glass (see Table). After air-quenching, the final glass was pulverized and the activity of Tc in glass was analyzed using LSC to compare with initial Tc activity measured in glass feeds.

Loadin g Al2O3 B2O3 CaO Cr2O3 Fe2O3 K2O Li2O MgO Na2O NiO PbO SiO2 TiO2 ZnO ZrO2 Cl F P2 O 5 SO3 Sum

16.22

83.78

100.00

6.29 0.06 0.18 0.49

5.97 11.77 7.50

6.02 9.87 6.31 0.08 5.43 0.54 3.17 1.49 13.53 0.01 0.01 44.75 1.38 3.46 2.96 0.20 0.08 0.12 0.59 100.00

6.48 3.33 3.78 1.78 83.42 0.06 0.06 0.06

53.41 1.65 4.13 3.53

1.23 0.49 0.74 3.64 100.00

100.00

* Additives contain both glass formers and glass mo difiers necessary for making the glass waste form.


37 Glass feed preparation (Left) and final glass before grinding (Right).

Tc retention in glass melts

Tc1 Retention at 800oC by LSC Magnetite

0,9

1,2

Goethite

0,8

KTcO4

0,7

KTcO4 duplicate

0,6 0,5 0,4 0,3 0,2

Relative Tc retention

Tc-Retention after 1000°C treatment

Tc-incorporated Fe minerals can limit Tc(IV) oxidation and volatilization at high temperature glass process. Tc-incorporated Fe minerals enhance Tc retention much higher than Tc salt. Tc retentions in glass melts

1

Magnetite Goethite

0,8

KTcO4

0,6 0,4 0,2 0 600

0,1

800

1000

Temperature (oC)

0 Test 1

Test 1 rerun

Test 2

38

204

October 29, 2018 첨단원자력공학부

38

Tc-Incorporated Glass Characterization: XANES XANES Spectra Tc oxidation state as a function of melting temperature consistent with decreased Tc retention upon increasing temperature. Tc(IV) incorporated into Fe minerals protected from Tc re-oxidation up to ~600°C. Tc-goethite best at preventing oxidation of Tc(IV) in glass melt. 600 oC, Tc still present as Tc(IV)

Glass precursors melt between 600°C and 800°C Above these temperatures, reduced Tc(IV) species oxidize to Tc(VII) when the iron oxides dissolve leaving the Tc(IV) unprotected from oxidation 39


39

XRD results of glass melts XRD results of Tc-magnetite as glass feed (blue), 600oC (orange), and 800oC (duplicates in black and red) showed that some magnetite could survive at 600 oC condition. However, at 800 oC, everything should be melted in glass.

40

From W. Um, et al. J. Nucl. Mater. 495 (2017), 455-462

205


40

Summary Cementitious waste form showed slow re-oxidation of Tc(IV) to Tc(VII) from before-leaching sample to after-90 days-leaching with increasing oxygen contact, which results in increasing Tc leachability in shallow-depth radioactive waste repository. Need to develop more efficient getter (or reductant) to maintain reducing condition for a long period of storage.

Tc retention during vitrification can be improved using Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite) Due to Tc(IV) incorporated into the Fe mineral structure, Tc volatilization can be delayed or limited during vitrification process. Addition of redox sensitive dopant can limit the Tc volatilization and increase final Tc retention in glass waste form.

Increased Tc retention in glass (or cementitious waste form) can reduce the cost of treatment of radioactive wastes. Mineral transformation process of Fe(OH)2(s) can be used to remove 41 99Tc(VII) even from an alkaline solution. 41 첨단원자력공학부

Summary (cont.) More works are still going on for development of waste forms. Various waste forms such as cement, geopolymer, ceramics, glass are being tested for immobilization of radionuclides, especially for mobile radioactive wastes (Tc, I, and U). Management for wastes from nuclear power plants decommissioning and decontamination are more needed.

42

206


42

감사합니다 Thank You Create your future with DANE/DESE http://danenel.postech.ac.kr/ http://dane.postech.ac.kr and http://dese.postech.ac.kr

207

INCORPORATION OF RHENIUM IN TIN DIOXIDE FOR 99Tc IMMOBILIZATION M. Khan, S. Hong, W. Um

Division of Advanced Nuclear Engineering (DANE), Pohang University of Science and Technology (POSTECH), South Korea e-mail: [email protected]

Rhenium (Re) can be incorporated into tin dioxide (SnO2) lattice using reductive coprecipitation method, which is further applicable process for 99Tc waste immobilization because of similar chemical property between 99Tc and Re. The final product, called Re(SnO2) was consisted of both Sn & Re, and characterization of Re(SnO2) using SEM-EDX and XANES spectroscopy showed that Re mainly existed as reduced species, Re(4+). Re was well incorporated into SnO2 lattice after reduction from perrhenate (ReO4-) and the Re(Sn)O2 precipitates showed higher stability than α-ReO2. The precipitate resisted re-oxidation, and the dissolved Re species were re-precipitated after ~ 1 day. A major portion of Re dissolved during the solubility and re-oxidation tests was assigned to the species of Re+ (12.0%), Re2+ (47.4%), Re4+ (28.5%), and Re7+ (12.2%) on the surface of Re(Sn)O2 precipitate, while Re+ (1.05%), Re2+ (15.4%), Re5+ (27.8%), and Re7+ (55.8%) species were found on the a-ReO2 surface under the same conditions. These findings suggest that low-temperature reductive co-precipitation method can incorporate 99Tc (or Re) into the SnO2 structure which limits the 99 Tc (or Re) re-oxidation and solubility.

208

RHENIUM BEHAVIOR IN A MOLTEN BOROSILICATE GLASS A. Laplace, E. Régnier, M. Neyret, I. Giboire, N. El Jeaidi, J.C. Laugier, M. Chartier, V. Ansault, C. Vallat, O. Pinet

CEA, DEN, DE2D/SEVT/LDMC - Marcoule, F-30207 Bagnols-sur-Cèze, France e-mail: [email protected]

In the literature, the complex behavior of technetium in a vitrification process has been addressed. Technetium and its surrogate rhenium present a low retention in the glass and interact both with alkaline ions such as Cs, Na, K [1, 2]. In order to acquire basic data on rhenium behavior in a specific borosilicate glass, glass thermal treatments above Tg have been conducted. This paper presents the comparison between two borosilicate glasses; the first one containing Re whereas the latter one is without Re. Both have been thermal treated in the range of 700 – 1100 °C for different amounts of time. The glasses have been further characterized (SEMEDS, TOF-SIMS, bubble gas analysis). The Re containing glass exhibits bubbles production with a maximum around 800 °C. Those observations have been related to the presence of rhenium, which is confirmed by the different performed analyzes. Those results are compared with the available thermodynamics data on Rhenium.

References 1. Darab, J.G. and Smith, P.A., 1996. Chemistry of Technetium and Rhenium Species during Low-Level Radioactive Waste Vitrification. Chemistry of Materials, 8(5): 10041021. 2. Kim, D. and Kruger, A.A., 2018. Volatile species of technetium and rhenium during waste vitrification. Journal of Non-Crystalline Solids, 481: 41-50.

209

DIFFUSION RESTREINTE

Rhenium behavior in a molten borosilicate glass A. Laplace, E. Régnier, M. Neyret, I. Giboire-Bardez, N. El Jeaidi, J.C. Laugier, M. Chartier, V. Ansault, C. Vallat, O. Pinet

Commissariat à l’Énergie Atomique, Nuclear Energy Division, Marcoule, F-30207 Bagnols sur Cèze, France

Point sur les gangues 19/10/2012 ISTR | October, 3-6, 2018, Moscow | A.F. Laplace

CONTEXT Nuclear waste vitrification Vitrification of the fission products solutions Borosilicate glass Re used as Tc surrogate

Thermodynamic data on Re and Tc Re and Tc redox state in the molten glass The oxygen fugacity (fO2) of our specific glass is above 10-1 atm (1100°C)  Re and Tc are under the same oxydation state : ReVII and mostly TcVII [1-3]

Volatility Oxides volatility: Re2O7 and Tc2O7 boiling point below 360°C Alkali perrhenate and pertechnetate volatility (M(Tc,Re)O4 for M = Li, Na, K, Rb, Cs) [4-6] - Fusion température of such salts :  300 - 600°C - Vaporisation without decomposition Tc and Re retention in the glass is dependent of the waste composition, chemistry and elaboration parameters [7]

Objective of the study Acquire basic data on rhenium behavior in a specific borosilicate glass – on going study [1] Russel C. et. al., Physics and Chemistry of Glasses, 30(2), 62-68 (1989) [2] Lukens W. et. al., Chemistry of Materials, 19(3), 559-566 (2007) [3] Muller, I. et. al., Procedia Materials Science, 7, 53-59 (2014) [4] Kim D. et. al., Journal of Non-Crystalline Solids, 481, 41-50 (2018) [5] J. Darab et. al., Chemistry of Materials, 8 (5), 1004-1021 (1996) [6] S.M. Shugurov, S.I. Lopatin,Russian Journal of General Chemistry,78(10):1882-1888 (2008) [7] Pegg I., Journal of Radioanalytical and Nuclear Chemistry, 305(1), 287-292 (2015)

210

| PAGE 2


METHODOLOGY Oxides

Experimental procedure Considered glasses Elaborated glasses - Glass A containing rhenium (0,25% ReO2 ) - Glass B : same composition without Re

Thermal treatment of the two glasses Glass isothermal treatment without agitation

Wt. %

SiO2

43,3

B2O3

12,8

Na2O

9,7

Al2O3

5,0

CaO

3,7

Li2O, Rb2O, Cs2O

3,3

ReO2

0,25

Others

- Al2O3 crucible (50mm )

21,95 Glass A composition

- 130g of crushed glass - Temperature : 700, 800, 850, 900, 1000 and 1100°C - Duration : 0,5, 1, 3 and 68h - “Quenching”

Analytical technics Post-mortem analyzes SEM-EDS TOF-SIMS for surface analysis Bubble gas analysis | PAGE 3

RESULTS Isothermal treatments post-mortem observation Crucible longitudinal section No difference at 700°C and 1100°C Glass / T and Duration

700°C / 3h

1100°C / 3h

Glass B (without Re)

Glass A (with Re)

| PAGE 4

211


RESULTS Isothermal treatments post-mortem observation Between 800 and 900°C, the glass with Re exhibits much more bubbles than the glass without Re Glass / T and Duration

850°C / 1h

850°C / 3h

850°C / 68h

Glass B (without Re)

Glass A (with Re)

5 | PAGE 5

RESULTS Isothermal treatments post-mortem observation Above 1000°C, there is almost no bubbles anymore

Glass / T and Duration

1100°C / 30 min

1100°C / 1h

1100°C / 3h

Glass A (with Re)

Impact of rhenium??

| PAGE 6

212


RESULTS - ANALYZES Gas bubble post-mortem analysis Bubbles are broken under vacuum and gases are analyzed by mass-spectroscopy Glass A with Re fused à 850°C (3h)

% N2 % CO2 % O2 % Ar

Sample 1_1

Sample 1_2

Sample 1_3

Sample 1_4

Sample 1_5

98.3 1.2 < 0.1 0.4

88.7 0.3 9.8 1.1

25.7 73.7 0.2 0.3

86.0 12.7 0.2 1.0

27.8 71.8 < 0.1 0.3



Analyzed bubbles contain air

 In situ, bubbles contain air and condensable gases The bubble composition may evoluate during the thermal treatment [8]

TOF-SIMS surface analysis (Time-of-Flight Secondary Ion Mass Spectrometry) Surface analysis for the first nm  in order to analyze the condensed gases at the bubble surface 1 to 10 µm nodules containing mostly Cs, Rb and Re oxides Na and Li are not analyzed | PAGE 7 K et de Cl detection 500

500

400

400

300

300

200

200

100

 In situ, bubbles contain air and volatile alkali

100

0

µm

perrhenates

μm

0

0

200

µm

400

μm 0

K+, Cs+, Rb+

200

400

SiOx-, ReOx-, Cl-

Various ions maps superposition

[8] F. Pigeonneau, International Journal of Heat and Mass Transfer 54 (2011) 1448–1455)

RESULTS INTERPRETATION Between 800 and 900°C, the glass with Re exhibits bubbles compared to the glass without Re Bubbles are due to perrhenates volatilization above 800°C In between 800 and 900°C, the bubbles remain in the glass because of its high viscosity Hadamard-Rybczynski equation for a spherical bubble velocity in a fluid With ρ the density μ the viscosity of the bubble (b) and the fluid (0)

2000

Air bubbles’ shifts for 1h (0,5 mm Ø)

Calculated Viscosity

1800

- At 800°C : < 5 mm

Measured viscosity

1600

- At 900°C : ~ 5 cm ~ glass height

1400

- At 1000°C : > 20 cm

Viscosity (dPa.s)

1200 1000

Above 1000°C, volatilization is still present but the bubbles evacuate the glass Impact of temperature on the combination of the different equilibrium (perrhenates formation, volatilization) ?

800 600 400 200 0 800

850

900

950

1000

1050

1100

1150

Temperature (°C)

1200

1250

1300

| PAGE 8

29 OCTOBRE 2018

213

1350

1400


CONCLUSIONS AND PERSPECTIVES Conclusions Glass thermal treatments have been performed with two different glasses; one containing Re and the other without Re The glass containing rhenium and alkaline ions exhibits alkali perrhenate volatilization above 800°C Probably M(Tc,Re)O4 (with M=Na, Cs, Rb) which is coherent which - Re(VII) oxidation state in the glass - Thermodynamic and literature data on perrhenates In between 800 and 900°C, the bubbles remain in the glass because of its high viscosity

Perspectives Re volatilization rate determination Chemical analyzes of the thermal treated glasses - Various temperatures and times Study of the Re incorporation mechanism in the glass XANES and EXAFS studies

29 OCTOBRE 2018

| PAGE 9

Acknowledgments - Glass thermal treatments at CEA Marcoule E. Régnier, N. El Jeaidi, J.C. Laugier, M. Chartier

- Characterization team at CEA Marcoule (SEM, viscosity) V. Ansault, C. Vallat, M. Neyret

- Gaz and TOF-SIMS bubbles analyzes Philips and Tescan Analytics

- Our partner ORANO

Thank you for your attention

29 OCTOBRE 2018

Contact information: [email protected]

| PAGE 10

214


Thank you for your attention

| PAGE 11

CEA | 10 AVRIL 2012

| PAGE 11

215

IMMISCIBILITY AND VOLATILITY OF RHENIUM IN VITRIFICATION PROCESS OF SIMULATED PUREX RAFFINATE

K. Uruga, T. Usami, T. Tsukada Central Research Institute of Electric Power Industry 2-11-1 Iwadokita, Komae-shi, Tokyo 201-8511, Japan e-mail: [email protected]

Technetium is one of the problematic elements during vitrification of high-level radioactive raffinate generated from PUREX process due to its high volatility and low solubility in glass. In this study, behavior of Re (alternate of Tc) was investigated through non-radioactive vitrification tests using a small-scale Joule-heating melter. Simulated PUREX raffinate and glass material were fed onto molten glass loaded in the melter. Re was vitrified only less than 10% of the addition mass and the other Re was transferred to off-gas. About half of the transferred Re passed through off-gas conditioning system such as a vapor condenser and a wet scrubber without trapped, while other volatile elements such as Cs, Ru and Te were more preferably trapped by those equipment. This low recovery of Re at the off-gas system might be due to not only high volatility even at low temperature but also smaller particle formation after re-condensation of the Re vapor. By the continuous feeding of the raffinate and the glass material into the melter, roundshape calcined composite which is usually called “cold-cap” was constantly formed on the surface of the molten glass. Several cold-cap specimens were obtained and elemental distribution of the vertical section of them were determined by an electron microscope. The distribution pattern of Re was very specific and only mostly correspond with the pattern of Cs. Thus it was presumed that Re mainly formed salt with Cs such as CsReO4. Another similar anionic element, Mo, was also formed salts with mainly Na in the coldcap. These molybdate salts have also low solubility in glass and potentially remain in the vitrified glass as problematic secondary phase, so-called “yellow phase”. Actual yellow phase sometimes includes Tc. However, from our observation, Re and Mo two salts were independent each other at least at the initial generation stage in the cold-cap. Interaction of these two salts might happen at later stage during convection of the molten glass. This work was carried out as a part of the basic research programs of vitrification technology for waste volume reduction supported by the Ministry of Economy, Trade and Industry, Japan.

216

Immiscibility and volatility of rhenium in vitrification process of simulated PUREX raffinate Kazuyoshi Uruga, Tsuyoshi Usami, Takeshi Tsukada Central Research Institute of Electric Power Industry ISTR2018, Moscow, Russia October 4, 2018 This work was carried out as a part of the basic research programs of vitrification technology for waste volume reduction supported by the Ministry of Economy, Trade and Industry, Japan.

HLW Vitrification and Glass Melter Liquid Fed Ceramic Melter (LFCM)

Glass beads (Si, B, Al, Na, Ca, Li, Zn) + High-Level Liquid Waste (PUREX raffinate) Na, Cr, Mn, Fe, Ni, Sr, Zr, Mo, Tc, Ru, Rh, Pd, Cs, Ba, Ln, An, S, F, P etc.

(Rokkasho Reprocessing Plant)

Liquid waste

Cold-cap (function: reactor) - Water evaporation and denitration on the top (100~500°C) - Reaction among denitrates and/or between denitrate-glass in the middle - Dissolution in molten glass at the bottom (~1150°C)

Glass material

Electrode

Molten glass (function: dissolver, homogenizer) - By thermal convection, the wastes and glass were mixing and homogenizing.

Electrode Drain nozzle

Coil Vitrified waste

2

217

Yellow Phase Yellow Phase (YP) is, - Water soluble compounds mainly composed from molybdate. Major component is sodium molybdate Na2MoO4. - Other low solubility and slow dissolution kinetic elements such as highly radioactive Cs and long lived nucleus Tc, etc are also included. - It may affect on the mobility of radioactive nuclei during repository under ground and safety of the disposal. Thus the generation of YP must be avoided. However, - The mechanisms of YP generation during the vitrification process have not been fully clarified. - We are on a way actively investigating to reveal the generation mechanisms1) and also developing appropriate operation methods of glass melter to address this YP issue2). Pale yellow spots are YP which are on black waste glass

1) K. Uruga, T. Usami, T. Tsukada,”Study for Generation of Yellow Phase Using Small-Scale Joule Heating Melter”, GLOBAL2015, 2015/9/24, Paris, France. 2) K. Uruga, T. Usami, T. Tsukada, “Operation and Future Challenges of Small-Scale Glass Melter”, GLOBAL2017, 2017/9/25, Seoul, South Korea.

3

Objective  Influence of Tc (Re) on YP generation  Due to the similar properties of Mo and Re, - Anionic elements (MoO42- and ReO4-) - Low solubility in borosilicate glass (MoO3: 1~6wt%, Re2O7: 0.6~1wt%) Re may affect positive/negative effect on the generation amount of YP.  It is also important to investigate the reaction and relationship of Mo and Re in the cold-cap.  Behavior of Tc (Re) in the Melter  Most of rhenium oxides and rhenates have high volatility. The fraction of Re to be vitrified and volatilized is important for design and operation of vitrification facility.

4

218

Small-Scale Test Melter Concept

History

2013

-Continuous feeding of simulated liquid waste and glass beads -Joule heating system -Melter body made by ceramic bricks (chromia based K-3) -Removable of molten glass from melter during continuous operation -Shape and size of melter: Cuboid 15×15×20cm (about 1/100 surface area of the Rokkasho melter) 2011 Design 2012 Fabrication, installation and trial operation 2013-2018 Feeding experiment using simulated liquid waste

5

Small-Scale Test Melter

6

219

Small-Scale Test Melter

Large View Windows

7

Cold-Cap Formation and Sampling

(Movie of cold-cap and its sampling) 8

220

Simulated Liquid Wastes Composition of simulated liquid wastes (g/L) Standard solution 32.6 0.48 2.39 0.79 1.25 0.90 3.46 8.12 0.33 2.78 0.63 1.66 0.36 4.91 2.41 3.58 6.09 2.64 10.1 1.53 6.43 0.70 94.2

Na2O Cr2O3 Fe2O3 NiO SrO Y2O3 ZrO2 MoO3 MnO2 RuO2 Rh2O3 PdO TeO2 Cs2O BaO La2O3 Ce2O3 Pr2O3 Nd2O3 Sm2O3 Gd2O3 Re2O7 others SUM

Re solution 32.5 0.49 2.41 0.80 1.26 0.90 3.49 6.15 0.33 2.80 0.63 1.67 0.36 4.96 2.43 3.61 6.15 2.66 10.2 1.54 6.49 3.42 0.70 95.9

 In order to clarify the influence of Re on YP, two simulated solutions were prepared.  As for “Re solution”, 23mol% of Mo in the “STD solution ” was substituted by Re.

9

Melter Operation Waste solution 0.65L/h

Glass material 141g/h

Cold-cap Sampling

Off gas

Off gas

Top lid

Top lid

Glass pool (5kg)

Top lid

7.2h

Ceiling heater

Electrode

Off gas View window

View window

Cold-cap

Electrode

Current

Ceiling heater

Production of 1.5kg Glass

Electrode

Plug rod

Electrode

Plug rod

4.8kW Drain heater

Drain heater

Plug rod

Remained Glass (5kg) Canister

Experimental conditions Glass Temperature 1100-1200 °C Feed time

7.2h

Glass production amount

1.5kg

Batch

3 batches/solution Glass draining 10

221

1.5kg Glass

Balance

Vitrified product

YP amount in 1.5kg glass product (mg)

Amount of YP in Vitrified Products 700 600 500 400 300 200 100 0 STD1

STD2

STD3

Re1

Re2

Re3

 Very few amounts of YP were detected from all the STD glasses, while significant amount of YP was generated at “Re-1” experiment.  However, the other two Re-glasses contained only slight YP. No reproducibility was obtained. Further investigation is required to clarify the influence of Re on the generation amount of YP. 11

YP Composition B2O3 CaO Cr2O3 Li2O MoO3 Na2O Re2O7

YP floated on surface B2O3

Drained glass “Re-1”

CaO Cr2O3 Li2O MoO3 Na2O Re2O7

YP contained in glass

 Compositions of the surface and inside YPs were analyzed separately.  Almost no Re was included in the YP on the glass surface, while Re2O7 was included 10wt% in the YP contained in the glass. The fraction of the other components were nearly the same.  This result indicated that Re might behave independently from the other YP components in the melter. 12

222

SEM Image of Cold-Cap Samples “Re-1” Sample

1cm

Si

Mo

Cs

Re

 Mo and Re were separated each other in the cold-cap. Re was rather distributed with Cs. 13

Composition of Drained Glass Conc. [wt%] SiO2 B2O3 CaO Al2O3 ZnO Li2O Na2O Cr2O3 MnO2 Fe2O3 NiO SrO Y2O3 ZrO2 MoO3 RuO2 Rh2O3 PdO TeO2 Cs2O BaO La2O3 Ce2O3 Pr2O3 Nd2O3 Sm2O3 Gd2O3 Re2O7 SUM Waste loading

STD1 40.8 12.2 2.94 5.02 2.58 2.61 12.7 0.31 0.72 1.54 0.69 0.10 0.07 2.64 2.35 0.18 0.02 0.02 0.06 1.03 0.52 1.91 2.54 0.83 2.88 0.18 0.63 98.1 19.6

STD2 40.2 12.1 2.88 4.91 2.52 2.61 13.1 0.32 0.64 1.44 0.63 0.19 0.14 2.34 2.46 0.26 0.03 0.16 0.06 1.14 0.60 1.74 2.28 0.85 2.93 0.23 1.01 97.8 19.9

STD3 40.1 12.1 2.92 4.65 2.51 2.56 12.9 0.31 0.34 1.18 0.56 0.23 0.17 2.06 2.39 0.53 0.13 0.32 0.06 1.12 0.63 1.58 2.12 0.84 2.95 0.35 1.27 96.9 19.7

Re1 40.1 12.0 2.89 4.57 2.48 2.35 12.2 0.31 0.29 1.12 0.50 0.29 0.21 1.87 2.35 0.62 0.15 0.35 0.07 1.02 0.69 1.50 2.13 0.88 3.02 0.44 1.54 0.02 95.9 20.2

Re2 39.4 11.9 2.88 4.61 2.47 2.60 14.0 0.36 0.26 1.08 0.54 0.32 0.23 1.74 2.27 0.55 0.13 0.34 0.08 1.06 0.73 1.43 2.06 0.88 3.09 0.39 1.72 0.03 97.2 19.8

Re3 39.4 11.9 2.87 4.55 2.46 2.49 13.5 0.34 0.23 1.06 0.51 0.36 0.27 1.66 2.21 0.50 0.08 0.30 0.08 1.01 0.78 1.41 2.02 0.91 3.23 0.45 1.93 0.04 96.6 20.1

14

223

Meas./Ideal [%] 99 98 113 109 97 99 97 264 107 102 106 104 105 98 89 83 72 72 85 68 100 91 83 95 88 99 111 7

 The ratios of the Meas./Ideal composition for volatile elements were relatively small.  Especially the ratio of Re was less than 10%. The other Re was considered to be volatilized and transferred to the off-gas.

Off-Gas System Inside deposits Off-gas pipe

Glass material

Waste solution

Chiller (Vapor condenser)

Scrubber

HEPA filter

Off-gas 100L/min

View window Top lid

Ceiling heater

Cold-cap Current Plug rod

Condensed solution

Scrubber solution

15

Off-Gas Transfer 45

Transfer to off-gas (%)

40 35 30 25 20 15 10 5 Si B Al Ca Li Zn Na Mn Fe Ni Sr Y Zr Rh Pd Ba La Ce Pr Nd Sm Gd Mo Ru Te Cs Re

0 Glass components

Non-volatiles

Volatiles

 Transfer of each elements to the off-gas was calculated with [collected mass at off-gas pipe, chiller and scrubber]/[feed mass]  About 5% of fed non-volatile elements were transferred to the off-gas. Those were carried by mists of the liquid wastes. Thus those values were larger than that of the glass components.  Transfer of Re was the largest, more than 40%. Considering the mass balance, about half of Re were not trapped by scrubber and traveled farther to the HEPA filter. 16

224

Off-Gas Transfer Distribution in off-gas system

100% 90%

Scrubber

80% 70% 60%

Chiller

50% 40% 30% 20%

Off-gas pipe

10%

Si B Al Ca Li Zn Na Mn Fe Ni Sr Y Zr Rh Pd Ba La Ce Pr Nd Sm Gd Mo Ru Te Cs Re

0%

 About half of the transferred non-volatiles were collected from the pipe. The distribution ratio was pipe > chiller > scrubber.  In terms of volatiles, the distribution to the chiller and the scrubber increased. The ratio of Re was nearly pipe = chiller = scrubber. This result implies the difficulty of trapping and recovery of volatilized Tc (Re) from the off-gas. 17

Summary •

Influence of Re on the YP generation and behavior of Re during vitrification process were investigated using small-scale glass melter.

•

Existence of Re in the liquid waste would potentially increase the amount of YP in the vitrified product. However, no obvious interaction between Re and Mo was observed, at least, at generation stage of YP in the cold-cap.

•

Only less than 10% of the fed Re was vitrified and the other was volatilized. The volatilized Re traveled the off-gas system farther than the other volatile elements.

•

Further runs and investigation are scheduled within years to elucidate the influence of Re on YP and to develop countermeasure for the Tc volatilization will be developed.

18

225


SPECTROSCOPIC AND BATCH STUDIES OF TECHNETIUM UPTAKE BY SIDERITE K. Schmeide1, A. Rossberg2, S. Weiss1, A.C. Scheinost2 1

Helmholtz-Zentrum Dresden - Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany 2 The Rossendorf Beamline at ESRF, F-38043 Grenoble, France e-mail: [email protected]

Tc is a long-lived (t1/2 = 2.1 × 105 years) β-emitter formed during the fission of U and is of major concern for radioactive waste disposal. Its environmental mobility is primarily governed by the oxidation states VII and IV, with TcVII forming the highly mobile TcO4− aquo anion, whereas TcIV is rather immobile due to the low solubility of its hydrolysis products [1]. Redox processes, which are able to convert TcVII into TcIV, are hence of paramount importance for the safety of radioactive waste repositories. FeII-bearing minerals, ubiquitous in nature but also forming as corrosion products of the steel canisters foreseen as a possible first enclosure of radioactive waste, play a vital role in these redox reactions due to their high redox reactivity and high sorption capacity, as has been shown not only for Tc, but also for Se, U, Np and Pu. 99

We studied the TcVII uptake by siderite (FeCO3), a typical FeII mineral in carbonate-rich environments, in the relevant pH range 7 – 12.6 under anoxic conditions by means of batch sorption experiments and by X-ray absorption spectroscopy. Sorption experiments showed that Tc retention by siderite is fast and efficient (log Rd ∼6) across the investigated pH range and independent of ionic strength (0.1 – 1 M NaCl). Tc K-edge X-ray absorption near-edge structure (XANES) data confirmed that the Tc immobilization is due to the surface-mediated reduction of TcVII to TcIV. The local structure of TcIV in Tc siderite sorption samples and Tc siderite coprecipitates probed by extended X-ray absorption fine-structure (EXAFS) spectroscopy revealed three different species: In the pH range 7.8 to 11.8, TcO2-dimers form inner-sphere sorption complexes at the surface of the initial siderite phase as well as on secondary magnetite or green rust formed during the redox reaction. Between pH 11.9 and 12.6, a mixed Fe/Tc hydroxocarbonate precipitate (chukanovite-like) is formed. The results showed that siderite contributes effectively to the retention of Tc under repository conditions through formation of strong sorption complexes and precipitation of hydroxocarbonate phases with low solubility. Reference 1. Eriksen et al.: The solubility of TcO2×nH2O in neutral to alkaline solutions under constant pCO2. Radiochim. Acta 58-9, 67 (1992).

226

Spectroscopic and batch studies of technetium uptake by siderite

Katja Schmeide, André Rossberg, Stefan Weiss, Andreas C. Scheinost

10th International Symposium on Technetium and Rhenium – Science and Utilization 03.-06.10.2018, Moscow, Russia page 1

Member of the Helmholtz Association InstituteofofResource ResourceEcology EcologyI I www.hzdr.de www.hzdr.de Katja Schmeide I Institute

Motivation and Objective (I)  Disposal of high-level nuclear waste is planned in deep geological formations behind multiple barriers.

Multiple-barrier system of a nuclear waste repository (based on [2])

Geo-engineered barrier

[1] www.bfs.de/de/endlager

Engineered barrier Geological barrier

Siderite and pyrite occur ubiquitously in clay rocks (Opalinus clay, Boom clay, MX80 bentonite)

Steel containers will gradually corrode under near-field conditions. → Formation of magnetite, siderite, chukanovite, FeII sulfides …

Siderite (FeIICO3) is relevant for the near-field of nuclear waste repositories as well as for the far-field. [2] BfS (2012). Handbuch Reaktorsicherheit und Strahlenschutz. BfS, Salzgitter. page 2

Member of the Helmholtz Association Katja Schmeide I Institute of Resource Ecology I www.hzdr.de

227

Motivation and Objective (II) Technetium (99Tc)  Tc is a β-emitting fission product with a long half-life (2.1·10 5 years) and a high content in radioactive waste.  Tc is redox-sensitive (oxidation states from –I to +VII)  Under oxic conditions: highly mobile TcVII (TcO4ˉ)  Under anoxic conditions and in presence of a reducing solid phase: TcIV forms sparingly soluble hydrous oxides (TcO2xH2O(s)) and is strongly retained by mineral surfaces. Anoxic conditions!

TcO4ˉ + 4H+ + 3eˉ  TcO2xH2O(s) + (2-x)H2O

Dissolved TcVII ions

Formation of secondary minerals

TcIV

(magnetite (FeIIFeIII2O4), … ?)

Sorption of species at surface

Identification of Tc retention mechanisms on a molecular scale

Siderite (FeIICO3)

Precipitation of TcIV species on surface

Incorporation of TcIV in siderite

page 3


Siderite Synthesis: 0.4 M FeCl2 solution + 0.8 M Na2CO3 solution Characterization:  Raman spectroscopic measurements: purity of siderite [1]  Zeta potential measurements: isoelectric point at 10.1 [1]

Batch sorption experiments [TcVII]ini = 10-5 M, S/L = 0.2 g/L, 0.1 M NaCl, N2

7 -1

log (Rd / L kg )

100

Tc uptake [%]

[TcVII]ini = 10-5 M, S/L = 0.2 g/L, N2

8

95

pH 8.6

90

6 5

0.1 M NaCl 1 M NaCl

4 3 2 1

0

1

10

0

100

Contact time [h]

7

8

9

10

11

12

13

pH

 Tc retention by siderite occurs almost instantly and completely.  Tc retention is independent of pH value and ionic strength (0.1 and 1 M NaCl).  log Rd  6 → points to TcVII to TcIV reduction [1] Scheinost et al., Environ. Sci. Technol. 50, 10413 (2016). page 4


228

X-ray absorption spectroscopy (XANES, EXAFS)  Oxidation state of radionuclides  Type and number of near neighboring atoms, bond distances

Tc loaded siderite samples Sorption experiments

Coprecipitation experiments

addition of TcVII to siderite suspensions

coprecipitation of Tc with Na2CO3 and FeCl2

Variation of the following parameters:  Tc loading (700 – 6600 ppm)  pH value (7.8 – 12.6)  carbonate concentration (up to 0.3 M)  contact time (2 – 230 d) XAS measurements - Rossendorf Beamline at ESRF (Grenoble, France) - Samples were kept at 15 K in a closed-cycle He cryostat. - Spectra were acquired in fluorescence mode at the Tc K-edge (21 044 eV).

page 5

www.esrf.fr


Sample 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Contact Electrolyte Carbonate time (NaCl)

TcVII initial

S/L-ratio

[mol/L]

[g/L]

[mol/L]

[mol/L]

[d]

5.1E-04 2.5E-04 5.5E-05 5.1E-04 5.5E-05 1.6E-04 8.0E-05 8.0E-05 5.5E-05 8.0E-05 1.6E-04 5.1E-04 2.5E-04 5.1E-04 8.0E-05 8.0E-05 2.5E-04 5.5E-05 5.5E-05 5.5E-05 1.6E-04 5.5E-05 1.6E-04 8.0E-05 8.0E-05 2.5E-04 5.5E-05

7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5

0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

0 0 0 0 0 0.3 0.3 0.3 0 0.3 0.3 0 0 0 0.3 0.3 0 0 0.3 1 0.3 1 0.3 0.3 0.3 0 0

2 2 46 26 46 15 15 224 43 21 21 25 13 2 22 232 2 46 12 12 22 9 20 20 229 13 46

page 6

pH End 7.75 7.82 8.73 9.09 10.00 10.10 10.10 10.08 10.72 11.00 11.01 11.05 11.12 11.83 11.87 11.84 11.91 11.97 12.06 12.07 12.07 12.55 12.58 12.58 12.60 12.63 12.64

Eh

Loading

[mV]

[ppm]

-294 -456 -437

-519 -559

-600 -703 -732 -558 -653

-705

6645 3317 724 6654 724 2095 1047 1046 720 1049 2101 6636 3326 6619 1050 1051 3329 724 723 724 2101 724 2101 1049 1051 3328 724

Tc siderite sorption samples

Anoxic conditions (N2)


229

Tc K-edge XANES spectra of Tc siderite sorption samples pH

a)

7.8

VII Tc O4 (aq)

0 1

 Shape and position of the XANES white-line is similar for all samples (absorption edge: 21 058 eV, no pre-edge).  Large difference to XANES spectrum of TcO4- (no pre-edge at 21 050 eV).

-5

 Complete reduction of TcVII to TcIV.  Energy and white-line shape comparable to that of TcO2xH2O reference sample and to TcIV in TcIV/FeII oxide systems [1-3].

-10

Normalized Fluorescence [a.u.]

Normalized Fluorescence [a.u.]

XANES: #1

#27

0

TcIV magnetite [1] TcIVO2 xH2O (s)

-1

-2

12.6

21.05

[1] Yalçintaş et al., Dalton Trans. 45, 17874 (2016). [2] Yalçintaş et al., Radiochim. Acta 103, 57 (2015). [3] Marshall et al., Environ. Sci. Technol. 48, 11853 (2014)

21.05 21.10 21.15

Photon Energy [keV]

page 7

21.10

21.15

Photon Energy [keV]


Tc K-edge EXAFS spectra of Tc siderite sorption samples b)

c)

experiment 3 PC reconstr.

0

pH 7.8

0

Fourier Transform Magnitude

EXAFS:

(k) k

3

-100

 Iterative target-transformation factor analysis (ITFA), using a code developed by A. Rossberg [1,2].

-4

 Reconstruction: 3 PCs → good fit of data, esp. EXAFS → all spectra are mixtures of three components → extraction of EXAFS spectra of endmember species was not possible

-8

-200

 Self-Organizing Maps (SOM) to isolate endmember species -12

2

4

6

8

10 -1

k [Å ]

12

14

0

1

2

3

4

5

6

7

R+R [Å]

8

12.6 [1] Rossberg et al., Anal. Bioanal. Chem. 376, 631 (2003). [2] Rossberg et al., Environ. Sci. Technol. 43, 1400 (2009).

page 8


230

Counter-Propagation Self-Organizing Maps (SOM) •

Modified artificial neural network for clustering and blind source separation (spectral decomposition of spectral mixtures into spectral components and their fractions)

pH Species distribution

•

Each point corresponds to one of the 900 neurons (left)

•

Each neuron contains one spectrum and corresponding physicochemical parameter (pH, concentration, …fractions)

•

Numbers of the samples are drawn at best matching neurons with respect to their content

•

Fractions are refined during clustering process, content of not matching neurons is interpolated

•

Corresponding pH distribution (right)

Stojkovi, G., et al., Chemometrics and Intelligent Laboratory Systems 102 (2010), 123–129. Domaschke, K., et al., ESANN 2014 proceedings, Computational Intelligence and Machine Learning (2014), 277-282. page 9


Three TcIV species identified

page 10


231

Species 1: TcIV dimers sorbed to siderite O

Fourier transform

3

5

(k) k

0.15

0 -5

0.10

-10

4

Tc

6

8

10

12

14

k [Å]

Fe 1

0.05

magnitude exp. imagin. exp. magnitude fit imagin. fit

Fe 2 0.00

Tc-Tc dimers: RTc-Tc = 2.45 Å, CN of 1 0

2

4 R + R [Å]

6

8

2 Tc-Fe paths with low CN ( 6.5. In this case, the improvement on the Tc reduction is not only due to Fe2+ presence, but also to the surface properties of alumina, triggering heterogeneous reduction of Tc by high Fe2+ surface coverage or possible LDH formation. This work has been developed in the frame of VESPA II project (02E11607B), supported by the German Federal Ministry of Economy and Energy (BMWi). References 1. 2. 3. 4. 5.

Kobayashi, T. et al. Radiochimica Acta. 2013, (5) 323–32. Livens, F.R. et al. Journal of Environmental Radioactivity 2014, (74) 211–19. T. Peretyazhko, et al. Geochim. Cosmochim. Acta. 2008, (72) 1521–1539; T. Peretyazhko, et al. Environ. Sci. Technol. 2008, 42(15): 5499–5506. E. Yalçıntaş, et al. Dalton Trans. 2016, (21) 8916–36.

237

99Tc

retention in pyrite and alumina: The effect of Fe2+ D. M. Rodríguez, N. Mayordomo, K. Müller & T. Stumpf

VESPA II PROJECT 02E11607B

Diana M. Rodríguez I Institute of Resource Ecology I www.hzdr.de

 Long half-life

(2.13×105 years)  O2 atmosphere: Tc(VII)  Very low retention on geo-technical barriers (almost inert)  High mobility expected

Technetium-99: Fission product

Mobilized Pertechnetate Access of water Image from: “Radioactive Wastes in the UK”, NDA/ST/STY(11)0050, 2010 Page 2

Member of the Helmholtz Association Diana M. Rodríguez I Institute of Resource Ecology I [email protected]

238

Tc(VII) Fe2+

Tc(IV)

Lower solubility and lower mobility!

Fe3+

[1] Zachara J. et al., Geochim. et Cosmo. Acta, 71, 2137 (2007) Page 3


In this work…

Iron sulfide Fe2S (mixture pyrite – marcasite)

γ-alumina with pre-addition of iron.

Page 4


239

CASE 1: Iron sulfide Fe2S (mixture pyrite – marcasite)

by D. Rodríguez Page 5


Why pyrite? •

Redox sensitive Fe(II) Sulphur mineral.

•

Simple common mineral.

•

Due to the repository conditions, FeS2 will be formed as pyrite and marcasite [7].

[7] Roberts W.M.B. et al., Mineral. Deposita (Bed.), 4, 18 (1969) Page 6


240

Relative Intensity (Arbitrary Units)

Pyrite was synthetized [8] and characterized:

Pyrite Marcasite Sample

1.0

BET: 5.3 ± 0.4 m2g-1 0.5

0.0

20

40

60

80

2(deg) 30 2000

10

Size (nm)

Z Potential (mV)

20

0 -10 -20

1000

7.4

-30 -40

4

6

1500

8

500

10

4

pH

6

8

10

pH

[8] Huo L. et al. Chemosphere 174, 456 (2017) Page 7


Tc sorption 1. Kinetics

% Tcremoved

100 80

-

Fast kinetics (50% removal in just one day)

-

Almost complete retention reached after 7 days

60 40 20 0 0.1

1

10

t (days) FeS2 dosage= 1.33 g/L [Tc(VII)]0= 5.07x10-6 M pH = 6.5 Page 8


241

Tc sorption

log ([Tc]removed/g) (mol/g)

2. Isotherm -4

-

-5 -6

Linear trend (m = 0.5) suggest single reaction mechanism: sorption on one site or precipitation of Tc(IV)

-7 -10

-8

-6

-4

-2

log ([Tc]solution ) (mol/L) FeS2 dosage= 1.57 g/L pH = 6.5 Contact time: 7 days Page 9


Tc sorption  3. Batch experiments TcO-4/TcO2 by [3]

80

H2O - Complete Tc retention for pH 0.2 0.1 M NaCl 6.5. – 9, then retention decreases again

Eh (V)

% Tcremoved

0.4

100

60

0.0

-0.2

40

TcO2

H2O 0.1 M NaCl

20 4

5

6

7

8

9

10

- Similar trend in water and TcO in -4 0.1 M NaCl

-0.4

11

4

5

6

7

8

9

10

11

pH

pH FeS2 dosage= 1.28 g/L [Tc(VII)]0= 5.07x10-6 M Contact time: 7 days [4] Meyer, R. E. et al. Radiochimica Acta, 55, 11 (1991) Page 10


242

1. SEM images of the mineral without Technetium

50.0 μm

1.0 μm

2.0 μm

2. SEM images of the mineral with Technetium

High surface dynamics. Incorporation?? 50.0 μm Images by E. Christalle. FWIZ – A. HZDR Page 11

1.0 μm

2.0 μm


Conclusions

Sorption

Sorbed colloids Organic coating Precipitation

Biofilm Microorganisms

Redox triggered Incorporation sorption

Page 12

 Pyrite is capable to remove Tc:  100 % removal after 7 days  Retention increases linearly with [Tc(VII)]  Not affected by NaCl 0.1 M  The retention mechanism is not clear:  Sorption on the surface?  Precipitation?  Incorporation?


243

CASE 2: Tc retention on gamma alumina (gAl2O3) in absence and presence of Fe2+

by N. Mayordomo [email protected] Page 13


gAl2O3    

Model for more complex minerals High specific surface area ≈ 130 m2/g High Point of Zero Charge (pH 9) Good anion sorbent [2]

gAl2O3

2- Retention of Tc on the ternary system gAl2O3 + Fe2+ + Tc(VII)

1- Retention of Tc on the binary system gAl2O3 + Tc(VII)

+ Fe2+ + Tc(VII)

+ Tc(VII) gAl2O3

[2] Mayordomo N. et al., ES&T, 52, 581 (2018) Page 14


244

Retention of Tc(VII) on the binary system 100

+ Tc(VII) % Tcsorbed

80

gAl2O3

 Retention mechanism: Sorption by surface complexation TcO4

OH2+

OH

0.01 M NaCl Isotherm Al2O3 + Tc(VII) pH 4.5

60 40 20 0

-7

-6

-5

-4

-3

log ([Tc]solution(mol/L))

O

6.5 % Tc is sorbed! More than is considered in the conservative safety analysis

Page 15


Retention of Tc(VII) on the ternary system

Fe2+

+ Fe2+ + Tc(VII)

gAl 2O3

 Similar approach for corundum (a-Al2O3) and diaspore (a-AlO(OH)) [3]

[3] Peretyazhko, T. et al., Environ. Sci. Technol., 42, 5499 (2008). Page 16


245

Tc sorption 1. Batch experiments 0.6 100

0.4

60 40

0.0 -0.2

H2O 0.25 M NaCl

20 0

   

0.2

Eh / V

% Tcremoved

80

-0.4 -0.6

4

5

6

7

8

9

10

11

4

Tc uptake

TcO-4/TcO2 by [3] H2O depends onNaCl pH 0.25 M

Increases with pH Complete pH > 6.5

TcO-4

Tc uptake slightly depends on ionic strength for pH 7  Not affected by NaCl  Removal mechanism  Complex: involves several factors (LDH phases, other Fe minerals, retention mechanisms, etc)


248

Page 23


2)- Retention of Tc(VII) on the ternary system Methodology and experimental set-up

FeCl2 in H2O pH Fe2+

Step 1) Al2O3 addition

O2 and CO2 free [Fe2+] = 6 10-5 M [Al2O3] = 0.5 g/L [TcO4-] = 5 10-6 M Page 24

Step 2) TcO4- addition After 2 days of Fe2+/Al2O3 interaction Fe2+ and TcO4- in solution 1) Centrifugation 2) Supernatant analysis (UV-vis and LSC)

Blank system Kinetically monitoring pH and Eh → UV-vis, [Fe2+] Ferrozine assay, Fe2+ selective Ternary system Kinetically monitoring pH and Eh [Tc] → LSC [Fe2+]sol → UV-vis Ferrozine assay, Fe2+ selective Redissolved Fe2+ (sorbed+ solution+ possible solid dissolution) 1) Suspension acidified 2) Centrifugation 3) Supernatant analysis (UV-Vis)


249

EDX

Images by E. Christalle. FWIZ – A. HZDR Page 25


EDX

Page 26


250

Tc electrochemistry (Tc 1mN + HNO3 1M) 0.6

Absorbance

0.4 0.2 0.0 -0.2 -0.4

Tc Initial -100 mV 30 min -200 mV 20 min -350 mV 30 min -550 mV 30 min NEXT DAY

-0.6 -0.8 -1.0 -1.2

200

400

600

800

1000

Wavelenght (nm) Page 27


Tc electrochemistry (Tc 1mN + HNO3 1M) Tc Initial -100 mV 30 min

-200 mV 20 min

-200 mV 20 min

0.2

-350 mV 30 min -550 mV 30 min NEXT DAY

0.2

0.0

-350 mV 30 min

Absorbance

Absorbance

0.4

Tc Initial -100 mV 30 min

-550 mV 30 min NEXT DAY

0.0 -0.2 240 250 260 270 280 290 300

400

Wavelenght

Tc (VII) peak increases!

Page 28

600

Wavelenght

Formation of other Tc oxidation states!


251

Tc electrochemistry (Tc 1mN + HNO3 1M) Tc(VII); Tc(IV) and Tc(III) in [CO3-] = 0,7M. pH=8,981 Tc Initial -100 mV 30 min -200 mV 20 min

0.2

Absorbance

-350 mV 30 min -550 mV 30 min NEXT DAY

0.0

400

600

Wavelenght

This peak could show the Tc(IV) formation! 1.

I. Alliot; C. Alliot; P. Vitorge; M. Fattahi; Environ. Sci. Technol. 43(2009), 9174

Page 29


Tc electrochemistry (Tc 1mN + HNO3 1M)

0.2

Absorbance

But, what are this peaks?? Are them due to the HNO3 reduction? 0.0

Mal sehen! 330 340 350 360 370 380 390 400

Wavelenght

Page 30


252

VOLATILITY MECHANISM STUDY IN THE WASTE VITRIFICATION PROCESS A. Ledoux, Jf. Hollebecque, C. Michel, S. Schuller, E. Sauvage, M. Delaunay, V-Labe, S. Lemonnier, L. Meslin1, A. Rodrigues2

CEA, DEN, DE2D, SEVT, LDPV, BP 17171 F-30207 Bagnols-sur-Cèze, France 1 LCV, ORANO Marcoule, BP 17171, 30207 Bagnols-Sur-Cèze Cedex, France 2 - ORANO BUR / DT / DRDP, Tour AREVA, 1 place Jean Millier, 92084 Paris La Défense, France

Gases released during high level liquid waste vitrification are treated into a specific unit, which allows to stop and recycle aerosol particles coming out from the vitrification process. We will enhance the understanding of the volatility, condensation and recombination mechanisms of sprays, containing Cs and Re (Tc surrogate). The study will be realized on an experimental mock-up, to be developed and instrumented. It will have to link the aerosol particles characterization with the various elementary process steps. The studies will be performed on simplified borosilicate glasses in which the impact of specific chemical elements will be investigated. Various additional characterization techniques, such as LIBS (Laser-induced breakdown spectroscopy), mass spectrometry, scanning electron microscope, thermal differential analysis, will be used. The applied methodology should ultimately allow to optimize the design of new decontamination equipment for future vitrification processes.

253

VOLATILITY OF PERTECHNETATES K. E. German1, V. F. Peretrukhin1, Ya.A. Obruchnikova2, A.V. Afanasiev1,3, S.N. Ryagin1,3 A.N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS, Leninsky pr. 31, 117091, Moscow Russia. e-mail: [email protected] 2 Mendeleev University of Chemical Technology, Moscow, Russia 3 Medical University REAVIZ, Moscow branch, Russia

DOI: 10.13140/RG.2.2.13446.42561 Technetium volatility have been widely discussed in a number of reviews [1 – 3] the principle attention given to Tc(VII), pertechnetate (TcO4-), the most dominant species in oxidizing conditions. But the direct experimental data on this item is very scattered. Volatility data on 99 Tc(VII) compounds are of high importance for two main reasons. The first is the understanding of Tc behavior in the procedures of radioactive wastes vitrification. The second is the basis for estimating of possible environmental contamination during accidental nuclear reactors. The data on the Tc rejects from Chernobyl accident are sometimes contradictory [1] and indicate the importance of more systematic study of sublimation and volatilization of different 99Tc species under high temperature conditions. Among the Tc compounds, the volatility of oxides is the best studied. At low concentrations of Tc formation of TcO3 was postulated [2], while at relatively high concentrations, Tc forms Tc2O7 with high volatility starting from 100 °C. During vitrification of radioactive wastes the Tc should be considered semi-volatile, a large fraction of this radionuclide evaporates in the melter, which operates at a nominal temperature of 1150 °C [5,8,9]. Small-scale melter tests with simulated Hanford LAW glass feeds have shown that the fraction retained in glass (referred to as “retention”) varied from 18% to 66% for Tc (tested with Tc-99m, a short-lived isotope as a surrogate for Tc-99) and from 1% to 56% for I (tested with nonradioactive I) depending on the feed composition [10–13]. A large fraction of volatilized I is expected to pass through the primary WTP off-gas treatment system (i.e., submerged bed scrubber and wet electrostatic precipitator) [5]. This I fraction will be captured downstream in other off-gas treatment system components (e.g., carbon beds) and sent to the IDF [14]. On the other hand, almost all (> 98%) of the Tc that leaves the melter is expected to be captured by the primary offgas system. Some kinetic data are available on oxidation of Tc metal [3] and sublimation of TcO3 from UO2 ceramics [4]. Volatile Tc oxides and hydroxides are discussed in [5]. The data on sublimation of KTcO4 at 1000°C without decomposition is due to terminology misusing in [6] (in fact they observed evaporation) because the congruent fusion temperature of KTcO4 is 803 K [7]. For NaTcO4 and CsTcO4 fusion points are at 1063 K [8] and 863 K [9] correspondingly. Considerable information is found on volatility of Tc during radioactive wastes vitrification [10, 11, 12]. Data on the volatility of technetium salts are limited by a few works: evaporation rate for NaTcO4 was reported to be 0.37 mg∙cm-2∙min-1 at 700 °C and increased to 3.2 mg∙cm-2∙min-1 at 1050°C [13]. Kuranov with coauthors has determined by effusion mass-spectrometry from Knudsen camera that ∆Hevap (KTcO4) = 213 kJ/M and ∆Hevap ((KTcO4)2) = 282 kJ/M [14]. Gibson has confirmed that evaporation gives gaseous KTcO4 and (KTcO4)2 in vacuum at 500 - 550 °C [15]. We studied the high-temperature evaporation of MTcO4 (M = K, Cs) from chemically pure compounds by thermogravimetry analyses (TGA) using a Q-1500D derivatograph (system F.Paulik-J.Paulik-L.Erday) in 300 – 1300 K temperature region. Dynamic and quazi-isothermal modes were used. Some experiments were also carried out by effusion mass-spectrometry (EMS). In TGA tests (with lower sensitivity if compared to EMS), no evaporation of solid KTcO4 and CsTcO4 from crucible was noted. The detectable changes in the KTcO4 and CsTcO4 sample

254

masses were noted only after 995 K and 950 K correspondingly (that means after salt fusion) while the Tc2O7 oxide is known to exhibit noticeable volatility even at 475 K.

Fig.1. Experimental weight losses of CsTcO4 and CsI samples during its thermogrammometric tests in dynamic TGA mode (pre-fused samples, temperature increase rate 10 deg/min, sample evaporating surface 1 cm2, initial sample mass 200 mg) with permission from [2]. X-ray diffraction test of the rest in the crucible was done after evaporation 20% of the sample. The patterns were identified as identical to initial compounds, i.e. KTcO4 and CsTcO4. The same composition was found by X-ray diffraction after condensation of vapors. The KTcO4 and CsTcO4 evaporation rate increase monotonically with temperature. For comparison similar tests were carried out with CsI sample (Fig. 2).

Fig.2. Evaporation rate and its linearization for fused salt sample of CsI and CsTcO4 in dynamic TGA mode (pre-fused samples, temperature increase rate 10 deg/min, sample evaporating surface 1 cm2, initial sample mass 200 mg) References 1. Aarkrog A., Carlsson L., Chen Q.J., Dahlgaard H., Holm E., Huynh-Ngoc L., Jensen L.H., Nielsen S.P., Nies H. Origin of technetium-99 and its use as a marine tracer. Nature. 1988. Vol. 335. P.338-340. 2. Steffen A., Bachman K. // Talanta. 1978. V.25, No 10. P.551-556. 3. Spitsyn V.I., Bukov K.G., Emel’yanenko et. al. Russ. J. Inorgan. Chem. 1988. V.33, No 10. pp. 2449-2452. 4. Eichler B., Domanov V.P. // J. Radioanal. Chem. 1975. V.28 . P.143-152.

255

5. Gibson J.K. High temperature oxide and hydroxide vapor species of technetium. Radiochim. acta. 1993, v.60, p.121- 126. 6. Spitsyn V.I. Kuzina A.F. Technetium. Moscow, Nauka Publ. 1983. 143 p. 7. Gilbert, R. A., Busey, R. H., “The heat of fusion and melting point of KTcO4”, Tech. Rep. ORNL-3832, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA, 1965, 119 p. 8. German, K. E., Grushevschkaya, L. N., Kryutchkov, S. V., Pustovalov, V. A., Obruchikov, V. V., “Investigation of phase trans-itions and other physico-chemical properties of pertechnetates and perrhenates of alkali and organic cations”, Radiochim. Acta, 63 (1993) 221–224. 9. Kanellakopulos, B., “Zur Kenntnis der Hochtemperaturmodifikation einiger Verbindungen des Typs Me I XO4 (Me=Cs, Tl; X=Re, Tc, Cl)”, J. Inorg. Nucl. Chem., 28 (1966) 813–816, in German.]. 10. Migge, H., “Simultaneous evaporation of Cs and Tc during vitrification, -a thermochemical approach”, in: “Sci. Basis Nucl. Waste Manage. XIII, held November 1989 in Boston”, vol. 176 of Mat. Res. Soc. Symp. Proc., 1990, pp. 411–417. In : Oversby, V.M. (ed.),Brown, P.W. (ed.) Materials Research Society, Pittsburgh, PA (USA), Materials Research Society, 1990, 748 p. 11. Brodda B.G., Lammertz H., Merz E. Radiochim.acta, 1983, v.32, p.139-52. 12. Demin A.V., Matyunin Yu.I., Polyakov A.S., Fedorova M.I. Localization of platinum 13. group elements and technetium under solidification of liquid HLW with preparation of phosphate and borosilicate materials. Proceedings of the 3-d Conference of the Nuclear Society, 1993, Nizhny Novgorod, Russia p.678. 14. German K.E., Peretrukhin V.F. Sublimation of Tc in form of pertechnetates of alkali metals and oxides. In: 12th Radiochemical Conference, Marianske Lazne, May 7 - 11, 1990 , p. 24 15. Kuranov K.,Semenov G. et all., 4-th USSR conf. on mass-spectr. , Sumy, 1986, Book of Abstracts. No 3, p.89(1986). 16. Gibson J.K. Radiochimica acta, 1993, v.62, p. 127 - 132

The work was carried out with partial funding by the Ministry of Science and Higher Education of the Russian Federation (subject No. AAAA-A16-116110910010-3)

256

IMMOBILIZATION OF ReO4– BY A FAMILY OF RARE-EARTH PLUMBITE PERCHLORATES BASED ON SINGLE CRYSTAL-TOSINGLE CRYSTAL TRANSFORMATION J. Lin1, L. Zhu2, J.-Q. Wang1, S. Wang2 1

Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, People’s Republic of China, e-mail: [email protected] 2 School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University, 199 Ren’ai Road, Suzhou 215123, People’s Republic of China

Effective removal of fission product 99Tc in the form of TcO4− from nuclear waste is highly desirable but of significant challenge in the modern nuclear fuel cycle. In this study, a large family of cationic rare-earth plumbite perchlorate (RPP) materials has been synthesized. The structures of RPP are based on [(RE6O8)Pb18O34] (RE = Sm to Ho, and Y) or [(RE6O8)Pb15O32] (RE = Er to Yb) cationic polynuclear clusters with ClO4– as counterions. Anion exchange experiments were conducted with ReO4– (surrogate of TcO4–) and RPP are capable of removing ReO4– with a capacity of 294 mg/g, which is among the highest for inorganic materials. More importantly, RPP can selectively remove ReO4− in the presence of 100 times excesses of NO3−. The uptake mechanism is elucidated by the single crystal structure of ReO4––exchanged RPP, suggesting it is based on an anion exchange process via a path way of single crystal-to-single crystal transformation (Figure 1). This work presents the promise of using cationic polynuclear cluster materials as scavengers for treating radionuclide 99Tc.

–

ReO4

Figure 1. The scheme is of the anion exchange process of trapping ReO4– via via a path way of single crystal-to-single crystal transformation.

257

Shanghai Institute of Applied Physics Chinese Academy of Sciences

中国科学院上海应用物理研究所

Immobilization of ReO4– by a Family of RareEarth Plumbite Perchlorates Based on Single Crystal-to-Single Crystal Transformation Jian Lin Associate Professor Thorium Molten Salt Reactor Center (TMSR) Shanghai Institute of Applied Physics (SINAP) Chinese Academy of Sciences

Shanghai Institute of Applied Physics (SINAP) One of the 104 research institutes under Chinese Academy of Sciences (CAS). Founded in 1959, 1300 employees, and 500 graduate students Research areas: photon sci., nuclear sci. and tech., biological physics, environmental tech., etc. Two campuses, Shanghai Synchrotron Radiation Facility (SSRF) and Thorium Molten Salt Reactor System (TMSR) campus

SINAP-SSRF Campus 232

90Th

SINAP-TMSR Campus

258

Fuel

History of MSR and TMSR@ SINAP

ARE ORNL

1954

MSRE ORNL

1965

Zero-power coldstate MSR

SINAP

1970

FHR

Break off 40 Years

2002

TMSR SINAP

2010

2011

• CAS initiated the TMSR project with 2.1 billion CNY (~$300 million)

2013

• National-Energy Major R&D projects of Chinese National Energy Administration (CNEA)

2016

• Shanghai local government start a major new-Energy project to support the TMSR project

2017

• A 2 MW TMSR is under construction in Gansu Province by SINAP

2020

Research Interests Coordination Chemistry of Actinides and Lanthanides

Functional Materials based on Lanthanides and Actinides Radionuclides adsorption Photoluminescence Photocatalysis Chemsensor

Hydrolysis, nucleation, and condensation of actinides Periodic trend of lanthanides on their crystal structures and rare earth separations

Lin, J.; et.al, Inorg. Chem. 2016, 55, 10098-10101. Lin, J*.; Wang J-Q*, Inorg. Chem. 2017,56, 14198-14205. Qie, M; Lin, J*, et. al, Inorg. Chem., 2018, 57, 1676. Lin, J.*; Wang J-Q*, Inorg. Chem., 2018, 57, 6753-6761.

Lin J.*, et.al, Inorg. Chem., 2018, 57, 6778-6782 Yue, Z; Lin J.*, Wang J-Q*, Dalton Trans., 2018, ASAP Yue, Z; Lin J.*, Environ Sci Technol Lett, submitted

259

Motivation : t1/2 211,000 y, a long-term disposal of HLW 0.6~1 kg 99Tc in 1 ton of PWR fuel High solubility: 11.3 M at 20 oC Tc2O7 is volatile, vitrification T ≥ 1000 oC

Hanford LAW Melter Recycle

99Tc

SRS HLW solution

(NH4)2CO3

4.30E-05

Free NaOH

1.33E+00

NH4Cl

6.39E-02

Total NaNO3

2.60E+00

(NH4)2SO4

6.64E-06

NaAl(OH)4

4.29E-01

NH4NO3

5.96E-02

NaNO2

1.34E-01

KNO3

3.03E-03

Na2SO4

5.21E-01

Ca(NO3)4H2O

5.43E-04

Na2CO3

2.60E-02

NaNO2

1.66E-01

Total Na

5.6

NH4TcO4

1.94E-04

NH4TcO4

7.92E-05

Total NO3-

6.07E-02 Molar Ratio

Molar Ratio

NO3-/TcO4-

314

NO3-/TcO4-

32819

SO42-/TcO4-

0.034

SO42-/TcO4-

328

Report SRNL-STI-2016-00619 99Tc

is one of the most difficult contaminants to address at HLW5

Chem. Mater. 1996, 8, 1004-1021

Possible Solutions Solid phase extraction vs. solvent extraction Typical materials for solid phase extraction of TcO4− : Cationic inorganic frameworks (a) Layered double hydroxides (LDHs) (b) Metal organic frameworks (MOFs) (c,d) Cationic polymeric networks (e)

SCU-CPN-1

Angew. Chem. Int. Ed., 2010, 49, 1057. Environ. Sci. Technol., 2017, 55, 3721.

Environ. Sci. Technol., 2017, 51, 8606. Nat. Commun., 2018, 9, 3007.

260

J. Am. Chem. Soc., 2017, 139, 14873.

6

Representative Works of TcO4- Remediation done by Prof. Shuao Wang at Soochow University (SCU) SCU-100

SCU-100

ReO4-

NO3Environ Sci Technol Lett, 2017, 4, 316.

Environ. Sci. Technol., 2017, 51, 3471.

SCU-101

SCU-CPN-1

99TcO 4

NO3J. Am. Chem. Soc., 2017, 139, 14873.

Nat. Commun., 2018, 9, 3007

7

Our Strategy Hyperpolarizable oxo-anions Hyperpolarizabilities are taken from SHG measurements Quantify the movement of electron density d0 transition metal oxoanions (e.g. Mo6+, W6+, V5+) and oxoanions with long-pair electrons (Te4+, Se4+, Pb2+) Ability to adopt multiple coordination geometries Ability to polymerize

Halasyamani, Chem. Mater., 2002, 14, 3174.

8

Te6O132−

Te7O176−

261

Our Strategy Lanthanides

Hyperpolarizable oxo-anions

Te6O132−

High coordination number (6-12) Various coordination geometries High charge density

Te7O176−

9

Experiment Design Synthesis: solid state /hydrothermal condition Ln4+/ Ln3+

Chargebalancing anions

Oxoanions

Characterization Single Crystal X-Rays Diffraction SEM-EDS UV-VIS; IR spectroscopy ICP-OES or ICP-MS Extended X-ray absorption fine structure (EXAFS) spectroscopy

10

262

Lanthanide-Tellurite-Halide System 4 CeIIIX3 + 14 TeO2 + 4 H2O + O2 → 2 [CeIV2Te7O17]X2 + 8 HX 4 CeIIICl3 + 8 TeO2 + 4 H2O + O2 → 2 [CeIV2Te4O11]Cl2 + 8 HCl

(X = Cl, Br)

2 ZrX 4 + 4 TeO2 + 3 H2O → [Zr2Te4O11]X2 + 6 HX 2 PuO2 + 4 TeO2 + 2 HCl → [Pu2Te4O11]Cl2 + H2O

Ce-Cl

Ce-Br

Ce-Cl

Zr-Cl

Zr-Br

Pu-Cl

200 µm

11 Lin, J.; et.al, Inorg. Chem. 2012, 51, 11949-11954.

Lin, J.; et.al, Inorg. Chem. 2012, 51, 10083-10085.

Lanthanide-Tellurite-Halide System



263

Lanthanide-Tellurite-Halide System

[CeIV2Te7O17]X2 (X = Cl, Br)

[M2Te4O11]X2 (M = Pu/Ce/Zr)



Lanthanide-Plumbite-Perchlorate System Replacing halides (Cl−) with perchlorate (ClO4−) Replacing tellurites (TeO32−) with plumbites (PbO34−)

[(Ln6O8)Pb18O34](ClO4)11(H3O)8 (Ln = Eu, Sm, Gd, Tb, Dy, Ho)

[(Ln6O8)Pb15O32](ClO4)12(H3O)5 (Ln = Er, Tm, Yb) Jian Lin,* et. al, unpublished result

264

Lanthanide-Plumbite-Perchlorate System Typical Polyoxometalates (POMs)

Mo6O2−19

V10O6−28

H2W 12O10−42

X2M18On−62

XM12On−40

A Brand New Family of POMs Ln6Pb18

Ln6Pb12

Anion Exchange Studies ReO4-

265

YPbOClO4

280 240 200 160 120 80 40

Removal percentage (%)

msorbent/Vsolution =1 g/L; 12h; C0(Re): 400 ppm 267

320

-

q (mg ReO4 /g sorbent)

Effect of pH and Adsorption Kinetic for YPbOClO4 100

60

2

4

6

pH

8

10

20

capacity (mg/g)

28 ppm Re; pH 8; 1 g/L

0

12

Re(VII) Adsorption

Sorbents

YPbOClO4

40

-20

0

~8h

80

0

300

600

900

1200

pH

Sample

Removal rate % (NO3:ReO4-=100:1)

1

541

~7

SCU-100 1

73.2%

SCU-1012

217

~7

SCU-1012

54.4%

SCU-102 3

291

~7

SBN

~7

SCU-102 3

93.8%

786

LDHs

130

~7

SCU-POP-1

90.8%

YPbOClO4

267

YPbOClO4

80.1%

SCU-100

1Environ.

~6 2J.

Sci. Technol., 2017, 51, 8606.

1500

Contact time (min)

Am. Chem. Soc., 2017, 139, 14873.

3Environ.

Sci. Technol., 2017, 55, 3721

Effect of NO3- and SO42-

Removal rate (%)

YPbOClO4 80 60 40 20 0


100

100 80 60 40 20 0

0:1

1:1

5:1

10:1

-

20:1

100:1 -

Molar ratio between NO3 and ReO4

YPbOClO4

0:1

1:1

10:1

100:1 1000:1 6000:1 2-

-

Molar ratio between SO4 and ReO4

Effect of the concentration of (a) NO3- and (b) SO42- on the anion exchange of ReO4- by YPbOClO4

266

ErPbOClO4

280 240 200

294

msorbent/Vsolution =1 g/L; 12h;C0(Re): 400 ppm

160 120 80 40 0

2

4

6

8

10


Highest among inorganic materials

320

-

q (mg ReO4 /g sorbent)

Effect of pH and Adsorption Kinetic for ErPbOClO4 100

ErPbOClO4

60 40 20

28 ppm Re; pH 8; 1g/L

0 -20

12

~8h

80

0

300

Re(VII) Adsorption

Sorbents

600

900

1200

capacity (mg/g)

pH

Sample

Removal rate % (NO3:ReO4-=100:1)

SCU-100 1

541

~7

SCU-100 1

73.2 %

SCU-1012

217

~7

SCU-1012

54.4 %

SCU-102 3

291

~7

SBN

SCU-102 3

93.8 %

786

~7

LDHs

130

~7

SCU-POP-1

90.8 %

ErPbOClO4

294

ErPbOClO4

82.7 %

1Environ.

1500

Contact time (min)

pH

~8 2J.

Sci. Technol., 2017, 51, 8606.

Am. Chem. Soc., 2017, 139, 14873.

3Environ.

19

Sci. Technol., 2017, 55, 3721

Effect of NO3- and SO42-

Removal rate (%)

ErPbOClO4 80 60 40 20 0

0:1

1:1

5:1

10:1


100

100 80 60 40 20 0

-

20:1

100:1

Molar ratio between NO3 and ReO4

-

ErPbOClO4

0:1

1:1

10:1

100:1 1000:1 6000:1 2-

-

Molar ratio between SO4 and ReO4

Effect of the concentration of (a) NO3- and (b) SO42- on the anion exchange of ReO4- by ErPbOClO4

267

Adsorption Mechanism

ReO4-

Single Crystal-to-Single Crystal Transformation

Ln6Pb18

Ln6Pb12

2 × Ln6Pb18

21

Conclusions A brand new family of polyoxometalate species LnPbOClO4-1 and LnPbOClO4-2 were synthesized. ErPbOClO4-2 demonstrates exceptional adsorption capacity toward ReO4− (294 mg/g), which is the highest among all inorganic materials. The sorption mechanism is based on a single crystal-tosingle crystal structural transformation from LnPbOClO4-2 to a purely Ln6Pb18 containing perrhenate complex. Problems: lead is environmental pollutant; perchlorate is explosive when reacted with organic materials.

22

268

Acknowledgement

Prof. Thomas E. Albrecht-Schmitt at Florida State University Prof. Jianqiang Wang at SINAP Prof. Shuao Wang at Soochow University National Natural Science Foundation of China (21876182, 21701184) and Shanghai Pujiang Talent Program (17PJ1410600)

SINAP-SSRF Campus

SINAP-TMSR Campus

269

RHENIUM SPECIATION IN SODIUM ALUMINO(IRON) PHOSPHATE GLASSES S.V. Stefanovsky, B.S. Nikonov,1 A.L. Trigub2 Frumkin Institute of Physical Chemistry and Electrochemistry RAS Institute of Geology of Ore Deposits, Mineralogy, Petrography, and Geochemistry RAS 2 NRC Kurchatov Institute

1

While Tc speciation in borosilicate glasses is well-known [1,2], no data on Tc in alumino(iron) phosphate glasses have been found. Re is the best surrogate for Tc including the study of nuclear waste vitrification. Four glasses with chemical compositions (mol.%) 40 Na2O, 20 Al2O3, 40 P2O5 (Re-1 and Re-2) and 40 Na2O, 10 Al2O3, 10 Fe2O3, 40 P2O5 (Re-3 and Re-4) each doped with 1 mol.% ReO2 were prepared under oxidizing (Re-1 and Re-3) and reducing (Re2 and Re-4) conditions using a quenching method. The samples Re-1 and Re-2 were predominantly amorphous but contained minor AlPO4 phase (phosphotridymite) and aggregated (Re-1) or individual (Re-2) crystals of metallic Re. Residual Re content in glass was low. The samples Re3 and Re-4 were fully amorphous. All the Re was found to be dissolved in glass where its concentration reached 1.6-1.8 wt.%. Infrared spectra consisted of the bands typical of stretching and bending modes in phosphorus-oxygen glass network. No effect of Re was found due to its low content in glasses. XANES Re L3 edge demonstrated predominantly Re(VII) with some admixture of Re(0) in the samples Re-1 and Re-2. No Re(IV) has been found that is consistent well with reference data on Re in borosilicate glass [3]. References 1. M. Antonini et al. EXAFS and Near Edge Structure, Springer, 1983, pp. 261-264. 2. M. Antonini et al. J. Non-Cryst. Solids. 71 (1985) 219. 3. W.W. Lukens et al. Chem. Mater. 19 (2007) 559.

The work was carried out with partial funding by the Ministry of Science and Higher Education of the Russian Federation (subject No. AAAA-A16-116110910010-3)

270

Rhenium Speciation in Sodium Alumino (Iron) Phosphate Glasses Sergey Stefanovsky (Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow, Russia)

October 3-6, 2018 – Moscow - Russia

Introduction • Vitrification is the most common method of HLW treatment and behavior of Tc at both HLW heating and long-term storage is one of the key aspects of safe management of Tc bearing wastes. • Rhenium is normally used as a technetium surrogate at the study of its behavior at nuclear waste processing. • Tc and Re have similar oxidation states in glasses, ionic potentials, and ionic radii, including the same radii of Me7+ ions. • While in borosilicate glasses Tc and Re speciation is studied in details, in phosphate glasses – no.

271

Experimental • Glass composition (mol.%): • • • • •

40 Na2O, 20 Al2O3, 40 P2O5 (AP) and 40 Na2O, 10 Al2O3, 10 Fe2O3, 40 P2O5 (AFP) Doped with 2 mol.% Re2O7 Chemicals: NaPO3, Al2O3, Fe2O3 и NH4ReO4 , 5 wt.% C T = 1100 C - AP, 1200 C – AFP

• Characterization: • X-ray diffraction • Scanning electron microscopy with energy dispersive Xray spectrometer • XANES – Structure Materials Science - Kurchatov Inst. (special thanks to Dr. Stefanovskaya, Dr. Shiryaev, Mr. Nikonov, Dr. Trigub)

Specified and actual oxide contents in glasses (wt.%). Sample Oxides

Re-1 Crystals

Glass Spec.

Re-2

Actual

Actual

Crystals

Glass

Re-3

Re-4

Glass

Glass

Actual

Actual

Spec.

Actual

Spec.

Actual

24.3

20.5

14.0

23.0

21.6

23.0

21.4

Spec.

Na2O

24.3

22.3

12.5

Al2O3

20.0

17.5

27.0

20.0

19.7

25.5

9.5

8.9

9.5

9.0

SiO2

-

1.8

1.5

-

1.5

1.5

-

1.2

-

1.0

58.4

59.1

58.3

59.0

52.7

53.1

52.7

52.9

-

-

-

-

14.8

13.5

14.8

14.0

2.0*

1.8

2.0*

1.7

100.00

100.0

P2O5

55.7

Fe2O3

-

Re2O7

2.0*

Total

55.7 2.0*

100.00

100.1

* Over 100 %

272

100.1

100.00

XRD: AP-1, AFP-1

AlPO4 - phosphotridymite

Re in AP and AFP glasses

Re in aluminophosphate glass is present in a metallic form

273

SEM

AP-1

AP-2

AFP-1

AFP-2

1 – Glass, 2 – dark-gray dendrite crystals – AlPO4, 3 – Re met.

FTIR spectroscopy

274

FTIR spectra – deconvolution

Band 1

Parameters Max

Samples Re-1

Re-2

Re-3

Re-4

436

422

436

453 110

FWHM

162

153

98

Max

503

503

480

FWHM

76

77

64

Max

551

551

555

FWHM

51

46

93

4 5 6

7 8 9 10

11 12 13 14 15

88 552

FWHM

26

Max

609

598

627

142

216

81

66 640

FWHM

34

Max

750

758

749

FWHM

108

103

60

55

Max

912

912

920

917

FWHM

749

83

86

101

102

Max

1017

1000

1004

FWHM

134

Max FWHM Maximum

1051

FWHM

189

Maximum

68

80

1042

1042

60

48

1094

FWHM

as PO3

591

Max

as PO4

 s POP  as POP

 as PO4

 as PO4

78

Maximum

1117

1123

1089

1080

FWHM

53

41

78

93

Maximum

1191

1174

1177

1178

FWHM

141

166

153

153

Maximum

1267

1330

1369

1359

XANES Re L2 edge Reference data

275

546

Max

FWHM

s PO4 s PO3

2

3

Assignment

 ’s PO3  as PO3  as PO2

Conclusions • Re-doped aluminophosphate glasses contained minor AlPO4 as phosphotridymite. • In Re-doped phosphate glasses Re is present in a metallic form. • Re-doped alumino-iron-phosphate glasses were homogeneous. Re is incorporated in glass. • Re solubility in glasses on aluminophosphate basis increases at Fe2O3 substitution for Al2O3. • In vitreous phases of the glasses Re is present as Re(VII). • No reduction of Re(VII) to Re (IV) was observed. • On the whole Re speciation in aluminophosphate and borosilicate glasses was found to be similar.

The work was carried out with partial funding by the Ministry of Science and Higher Education of the Russian Federation (Project No. AAAA-A16-116110910010-3)

276

CALCIUM MOLYBDATE, CaMoO4: A PROMISING TARGET MATERIAL FOR 99mTc AND ITS POTENTIAL APPLICATIONS IN NUCLEAR MEDICINE AND NUCLEAR WASTE DISPOSITION E.V. Johnstone,1,2 K.R. Czerwinski,1 T. Hartmann,3 F. Poineau,1 D.J. Bailey,4 N.C. Hyatt,4 N. Mayordomo,5 A. Nuñez,6 F.Y. Tsang, A.P. Sattelberger,7 K.E. German,8 E. J. Mausolf1,2 1

University of Nevada – Las Vegas, Chemistry and Biochemistry Department, Las Vegas, NV, USA 2 Global Medical Isotope Systems (GMIS), Las Vegas, NV, USA 3 University of Nevada – Las Vegas, Department of Mechanical Engineering, Las Vegas, NV, USA 4 University of Sheffield, Department of Materials Science and Engineering, Sheffield, UK 5 Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Dresden-Rossendorf, Germany 6 Centro de Investigaciones Energéticas. Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain 7 Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA 8 A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow, Russia

DOI: 10.13140/RG.2.2.31901.36328

Introduction Calcium molybdate (CaMoO4) is a robust, inorganic material known for its favorable physicochemical properties making it ideal for a wide scope of applications including optics (i.e., phosphors, scintillators, laser hosts, etc.) [1], nuclear waste encapsulation and disposal [2 – 5], corrosion inhibition [6], etc. Calcium molybdate occurs in nature as the mineral powellite, and the compound adopts the scheelite (CaWO4) structure-type with Mo fully oxidized in the +6-oxidation state [7]. This Mo-containing mineral phase exhibits limited solubility in aqueous environments and relative thermal stability at elevated temperatures. In the laboratory, CaMoO4 can be synthesized straightforwardly from the stoichiometric solid-state reaction of MoO3 with the respective calcium oxide or carbonate, e.g., CaO or CaCO3, at elevated temperatures, or alternatively via co-precipitation, sol-gel, or mechanochemical methods [8 - 10]. Depending on synthetic conditions, single phase nano-powders to monoliths can be generated and tailored for its successive application. Likewise, the scheelite structure type can incorporate different doping elements into the host lattice, such as Pb2+ or elements arising from the lanthanoid series, which are used for phosphor applications [11-13]. On the periodic table, Mo (Z = 42) is located on the 5th row within the transition metals and precedes the lightest, inherently radioactive element, technetium (Tc, Z = 43) [14]. Molybdenum is characterized by an assortment of naturally occurring isotopes (i.e., 92Mo 14.53%, 94Mo 9.16%, 95 Mo 15.84%, 96Mo 16.67%, 97Mo 9.60%, 98Mo 24.39%, and 100Mo 9.82%) making it a suitable starting material for the transmutation to an array of different Tc isotopes depending on isotope enrichment, particle beam type (e.g., proton, deuteron, electron, neutron, photon, etc.), and beam energy. One of the most recognized Mo-Tc radionuclidic parent-daughter couples is 99Mo-99mTc, where the daughter isotope 99mTc has been characterized as the workhorse of the nuclear diagnostic imaging industry used worldwide in 30 to 40 million procedures annually, i.e., ~ 9,000 6-day Ci at end of processing (EOP) per week [15]. As the international geopolitical attitude towards using highly enriched uranium (HEU) for the production of 99Mo begins to shift, the use of non-fission sources for the production of 99mTc is becoming increasingly more attractive, and new methods for production and separation are desperately being sought. For example, the United States of America currently has no domestic supply in place for the production of 99mTc, although it is responsible for half of the world’s usage. When considering both, the isotopic and physicochemical composition and properties of Mo and CaMoO4, strong arguments can be made to pursue the better understanding of CaMoO4 and its relationship as a host material for direct transmutation of Mo → Tc and / or post-processing integration of Tc at the atomistic level to weight percentages in its fundamental structure. In this work, the synthesis and irradiation of CaMoO4 using a modular, fusion-based neutron source and

277

its successive characterizations are reported. Further discussions are presented considering these empirical data and their context with potential applications in the realms of nuclear medicine and materials. Materials and Methods Synthesis and Characterization of CaMoO4. Equimolar mixtures of powdered of MoO3 (natural abundance of Mo isotopes) and CaO were intimately ground together as a slurry in ethanol with a mortar and pestle. The resulting powder was subdivided and pressed together as a green body pellet using an uniaxial press. The green bodies were reacted in a platinum-lined alumina crucible at 860 °C for 6 hr in a furnace under flowing argon gas or normal atmosphere. The samples were then re-homogenized, pressed into pellets, and reacted for an additional 4 hr. The resulting pellets weighed approximately 3.1 g with a total sample size of CaMoO4 for irradiation of ~ 12.1 g. Powder X-ray diffraction (PXRD) was performed on the synthesized samples using a Bruker D8 Advance diffractometer employing Cu Kα1 radiation. Representative areas from each puck were manually removed and ground with a mortar and pestle. The samples were blended with a silicon metal line standard and distributed on a low-background silicon wafer XRD sample holder. The samples were scanned in the region of 10-120° 2θ and analyzed using Topas 4.0 software. Neutron irradiation of CaMoO4. The synthesized CaMoO4 pellets were stacked within a 50 mL polypropylene centrifuge tube in between pieces of high-density polyethylene (HDPE), in so that they were located at the approximate center of the tube or roughly 12 cm from the neutron source while situated within the holder. The tube and its contents were placed in a HDPE cavity and situated adjacent to a neutron source. The point source had a neutron output of approximately 109 neutrons per second (~ 106 neutrons∙cm-2∙s-1) with energies of 2.45 MeV at the origin of production, and the CaMoO4 was irradiated for roughly 1.5 hr. Total neutron production over the irradiation period was ~ 1.54 x 1012 neutrons. Following end of bombardment (EOB) resulting 99 Mo-99mTc activities were measured on a NaI gamma spectrometer for a count time of ~ 200 s; activities were corrected for decay incurred during transfer from the point source to the spectrometer after EOB. Information on detector efficiencies nor geometric positioning on the NaI detector have been provided, instead these values in a system of 100% capture efficiencies are assumed and used for correlating subsequent production rates. Results and Discussion Synthesis and Characterization of CaMoO4 Calcium molybdate samples were synthesized using a method similar to that reported by Abdel-Rehim [8, 16]. This method yielded dense pucks that fluoresced under a UV light source as is shown in Figure 1. The effect of atmosphere on the synthesis of these materials was negligible as can be seen in Figure 2. When pulverized, the bulk material also fluoresced demonstrating an overall homogeneity within the monolith and formation of the intended compound. A quantity of these materials was removed and analyzed by PXRD. Analysis of the diffraction profiles indicated that some unreacted starting materials were still present in the sample (i.e., CaO), however, in relatively small amounts; these samples were reground with a mortar and pestle and reacted again at 860 °C for 4 hr. In Figure 3, the CaMoO4 samples and the irradiation container and configuration used for irradiation are presented.

278

Figure 1. Synthetic scheelite (CaWO4) and powellite (CaMoO4) samples observed under ambient versus UV lighting showing fluorescent properties. Left: room lighting conditions. Left: UV lamp. Figure adapted from Ref. Ошибка! Закладка не определена..

Figure 2. Comparison of synthetic powellite samples produced under an air or argon atmosphere at elevated temperatures. Left: room lighting conditions. Middle: UV light. Right: ground powder under UV lamp. Figure adapted from Ref.

Figure 3. CaMoO4 target material and irradiation containment used in this study. Ruler shown for scale. Inset: a representative pellet of CaMoO4. Phase analysis and quantification of the bulk powder CaMoO4 was performed by PXRD and subsequent Rietveld structure refinement, an example of which is shown in Figure 4. Results indicated that the composition of the bulk powder was CaMoO4 with some unreacted starting materials, depending upon the sample. The CaMoO4 was fit with the scheelite structure type with I41/a symmetry (unit cell parameters of a = 0.52266(4) nm and c = 1.1435(1) nm) consistent with

279

previous studies [7]. Phase characterization of samples produced under an inert atmosphere yielded similar results (not presented here).

Figure 4. PXRD analysis of reaction products from MoO3 and CaO at elevated temperature under air after 6 hours reaction time. Silicon is used as an internal standard. Figure adapted from Ref. Neutron Irradiation of CaMoO4 and 99Mo-99mTc Production The samples of CaMoO4 and canister design were placed into a moderating block and irradiated adjacent to a neutron point source of ~109 n/s for 1.5 hr. The resulting samples were analyzed for activated products and more specifically for 99Mo and 99mTc and the respective activity of each. In Figure 5 and Figure 6, the gamma spectra of the irradiated samples are presented at different times after EOP.

Figure 5. Gamma spectrograph of irradiated CaMoO4 indicating 99Mo and 99mTc measured 10 hr after EOP. Other unlabeled peaks are associated with unidentified, short-lived impurities in the matrix and background contributions, e.g., 40K.

280

Figure 6. Gamma spectrograph of irradiated with identified 99Mo and 99mTc approximately 21 hr after EOB. Other unlabeled peaks are associated with unidentified, short-lived impurities in the matrix and background contributions, e.g., 40K. Encapsulation and Immobilization of 99Tc Nuclear Wastes Technetium-99 is a long-lived (t½ = 214,000 yrs) nuclear byproduct of 235U (~ 6% yield) fission, where it is found associated with the epsilon (ɛ) phase which contains, most notably, MoTc-Ru-Rh-Pd. This metallic phase is highly resistant to corrosion, though Mo and Tc can be removed during nitric acid reprocessing activities [17]. Previous research has shown that these particles can be selectively separated using fluorine containing compounds in an inert atmosphere at elevated temperature [18]. They are difficult to recover due to their sub-nano radius and are found as colloidal inclusions that are removed by filtration and/or centrifugation after fuel dissolution. In direct-heated melter systems for waste glass fabrication, the formation of metallic globules can clog waste glass draining and the associated heat dissipation in the area of the bottom drain of the melter, resulting in lower melt temperature and higher viscosities. Due to the high melting point of these particles, methods such as plasma arc melting or induction techniques are required to process metallic billets greater than 10 g. These particles have also been shown to be associated with iodine (I) retention before uranium oxide, e.g., UO2, dissolution occurs. This result suggests that these compounds could play an important repository role in slowing the rate of both 99 Tc as pertechnetate ([TcO4]-) and 129I as diatomic iodine (I2) via the with interaction Ag and Pd nano-particles [19]. Tc is also problematic during glass melting processes where oxidizing conditions promote the formation of volatile Tc oxides and hydroxides that must be trapped in the off-gas scrubbing system and reprocessed back into a final waste form [20]. In nuclear spent fuel reprocessing, the spent fuel is dissolved in nitric acid and [TcO4]- and uranyl ([UO2]2+) are co-extracted in tributylphosphate (TBP) (30 vol%) in dodecane or kerosene. Following extraction, Tc and U are both back-extracted into dilute nitric acid, and an anion exchange resin is used for the final separation of Tc from [UO2]2+. Thereafter, Tc is transformed into a robust material, such as metal / alloy or a glass, for final disposition [21]. The Closed Endto-End (CETE) demonstration was an exercise that applied the Uranium Extraction (UREX) process to yield mg quantities of Tc metal via hydrogen reduction post fuel dissolution. This Tc was eventually incorporated into stainless steel (SS-316)/Zirconium (Zr), SS-316 [Pd-Rh-Ru], and pure epsilon phases (Mo-Tc-Ru-Rh-Pd) [22]. These phases have been shown to be robust wasteforms for Tc and possibly I when fuel is stored via the “once-through cycle” after placed in a hypothesized geological long-term repository. Particularly problematic is the highly soluble and mobile form of Tc, the pertechnetate anion [TcO4]-, which is a byproduct of reprocessing and nuclear medicine scenarios and a potential

281

hazard to the biosphere when released in an uncontrolled fashion. Methods to encapsulate soluble [TcO4]- have been explored using large and / or bulky organics containing soft-base donor ligands, primarily comprised of carbon and nitrogen. Although this form is suitable for subsequent processing into metal, it is not feasible to process most legacy waste, nor low specific activity (LSA) ground state Tc wastes biologically rejected from patients undergoing 99mTc SPECT imaging via urine. Specifically for Tc, due to the cost and volume burdens of the waste, it does not seem economically viable to recover low activity 99Tc from these patients; however, the introduction of an element, which only occurs in ultra-trace quantities naturally, into the environment is not advisable and should be avoided. Therefore, it is proposed that the coprecipitation of CaMoO4 and Ca(TcO4)2 could be explored as a method to specifically encapsulate Tc into a glass, ceramic, or metallic waste form precursor across all waste classes. It is expected that Ca(TcO4)2∙xH2O would have a range of solubilities over a range of Ca concentrations – this is particularly important when considering charge balance in transmuted samples associated with Mo(VI) → Tc(VII) where a cationic excess would be present. Additionally, several [TcO4]- salts with monocationic metals exhibit the scheelite-type structure and theoretically would be ideal for incorporation [22]; however, density functional theory (DFT) calculations have demonstrated that Tc would occupy the interstitial sites in the CaMoO4 and CaWO4 structures. To date, there is a significant gap in the literature associated with the solidstate synthesis of the mixed phases via co-precipitation of the compounds discussed in this paper. Production and Separation of 99Mo-99mTc. The first (serendipitous) demonstration of using a Mo target for the production of Tc was the experiment performed via the international collaboration of American and Italian scientists Ernest Lawrence, Emilio Segre, and Carlos Perrier where molybdenum metal foil, a component of the Berkley cyclotron, was activated by the bombardment with a deuteron beam. Subsequent analysis of the radioactive Mo yielded the undiscovered, missing element Z = 43, which was later named technetium, alluding to the Greek word “τεχνητός” meaning “artificial” [23]. The use of Mo and Mo-containing targets for the production of 99Mo-99mTc specifically was later applied for the use in the emerging field of nuclear medicine and has since rapidly expanded with the development in detection methods, radiolabeling, etc. Whereas this was the original pathway for 99 Mo-99mTc production in the first protype generators, it was soon replaced by the use of highly enriched uranium (HEU) fission-based 99Mo, which eventually became the “gold standard” for the radiopharmaceutical community. This change in direction was primarily driven by the fact that greater yields of 99Mo could be produced with higher specific activities; processing and separation protocols were developed and have sustained the industry for several decades since this turn. However, the global community, reverting from the use of HEU, is actively pursuing alternative production methods for 99Mo-99mTc, primarily the direct irradiation of Mo and Mo-containing target sources. Concerning this, there have been several production routes identified, typically dependent upon the particle beam utilized, e.g., photon, proton, deuteron, neutron, etc. and respective energy on either natural Mo, enriched 100Mo or 98Mo, or a combination of these. Particularly problematic with this route of production is the generation of LSA 99Mo, which makes separation and radiolabeling increasingly difficult and inefficient with decreasing specific activity. To overcome this for the separation of the parent-daughter, various methods have been proposed where 99mTc in high specific activity (HSA) can be isolated from LSA 99Mo target material. The technology options include liquid-liquid extraction (LLE) with methylethyl ketone (MEK), column chromatography with aqueous biphasic extraction chromatography (ABEC) or ion exchange (IE), chemical precipitation / gel generator, and thermal chromatographic separations [24, 25]. For the latter, thermal chromatographic separations were first demonstrated in the laboratory and in the clinical environment in Hungary [26]. This method has since been adopted and improved by scientists in Japan, where the problem of low(er) yields of 99mTc milking has been vastly improved [27]. Large enhancements in the process have involved: 1) the use of a MoO3 target, in which the generated 99mTc is in its fully oxidized state in an oxygen-rich matrix allowing for the facile formation of volatile Tc oxides, and 2) complete sublimation of molten MoO3 at

282

elevated temperatures (~ 840 °C) to overcome the low diffusion rates of transmuted 99mTc from the target. Other target materials for thermal separations that have also been investigated include molybdenum carbide Mo2C and titanium molybdate [28, 29]. Some drawbacks observed for these techniques and materials have been associated with the regeneration of the Mo / Mo-containing target after thermal treatment, price of target production (enrichment increases costs significantly whether through HEU or Mo-enrichment), ease of target synthesis, and amount of Mo content available for transmutation. In consideration to the results reported here, CaMoO4 exhibits compositional stability at elevated temperatures under oxidizing environments and yields workable amounts of generated 99m Tc. Additionally, the range of synthetic routes, such as precipitation, high-temperature treatment, and mechanochemical formation, with an equally diverse possibility in material properties, like controlled nano-sized crystallization that have been reported in the literature, makes CaMoO4 an ideal candidate as a Mo-containing material for 99mTc production coupled with thermal chromatographic separation techniques for use in the nuclear medicine industry, for example as a solid-state 99mTc generator following bombardment, though this is not yet known to be viable. The applicable use of this material has been evaluated and is provided in Figure 7 for use as a 99mTc generator as it relates to the possible total ‘patient doses’ of 99mTc versus time of irradiation using neutron outputs ranging from 109 to 1015 n/s, where a ‘patient dose’ is defined as 20 mCi of 99mTc at time of use to a patient receiving a SPECT image. With approximately 40 million patient doses used annually worldwide, this is approximately 154,000 doses required daily, 5 days a week, 52 weeks a year. At EOB we correlate that over the course of the week, ~400,000 doses would be available, thus far exceeding the supply requirements of patients worldwide at the maximum neutron outputs of current day systems, i.e., reactors and spallation neutron sources. By exploiting a target of this nature, the market has room for expansion if the distribution chain does not contain the same inefficiencies of that observed from fission produced 99Mo using HEU, i.e. decay losses are minimized due to decentralization of production and distribution. Therefore, natural samples bombarded within a reactor of decent neutron fluxes will generate similar patient doses. In the heavier Tc homolog, rhenium (Re), several isotopes (186Re and 188Re) have been used for radiotherapeutic treatments. Unlike the 99Mo-99mTc couple, these isotopes are typically produced only from tungsten (W) or osmium (Os) targets, as neither of these Re isotopes nor their parent isotopes are generated in the fission process. Concerning this, literature has reported the cyclotron irradiation of mixed Mo-W and Mo-Os sulfide targets, i.e., MoS2, WS2, and OsS2, for the use as a Tc-Re generator for simultaneous radiotherapeutic-diagnostic treatments. Likewise, because of the of the scheelite solid-solution series with powellite and the similar volatile oxides formed for Tc and Re, i.e., M2O7, HMO4, etc., mixed CaMoO4-CaWO4 target materials could be used employing these thermal volatilization methods [31, 32].

283

Figure 7. Predicted patient doses of 99mTc as a function of time and neutron source output (sequentially from 109 n/s (bottom blue) to 1015 n/s (top purple)) under ideal conditions as determined from activity measured within this study and proportionally scaled up to equivalent reactor fluences. One patient does of 99ms Tc is equivalent to 20 mCi. Conclusions The use of CaMoO4 and some of its innate chemical and physical properties as a target material for the production of 99Mo-99mTc via neutron irradiation have been investigated. The material was synthesized using solid-state techniques, and upon neutron irradiation with a lowflux point source, both 99Mo and 99mTc were observed in the target material post-irradiation by gamma spectrometry. With these results, the potential applications of CaMoO4 and how they can be applied in various sectors of the nuclear industry, such waste encapsulation and disposal as well as the production of valuable radioactive isotopes for medical diagnostic and therapeutic procedures, were discussed. The authors believe that CaMoO4 and similar powellite and scheelite materials have significant implications for application in commercial and industrial setting, especially those addressing the global shortage of 99mTc. References 1. Thongtem, T.; Kungwankunakorn, S.; Kuntalue, B.; Phuruangrat, A.; Thongtem, S. “Luminescence and absorbance of highly crystalline CaMoO4, SrMoO4, CaWO4 and SrWO4 nanoparticles synthesized by co-precipitation method at room temperature,” J. Alloy. Comp. 2010, 506, pp. 475–481. 2. Kindness, A.; Lachowski, E. E.; Minocha, A. K.; Glasser, F. P. “Immobilisation and fixation of molybdenum (VI) by Portland cement,” Waste Manag. 1994, 14, pp. 97–102. 3. Taurines, T.; Boizot, B. “Synthesis of powellite-rich glasses for high level waste immobilization,” J. Non-Cryst. Sol. 2011, 357, pp. 2723 – 2725. 4. Bosbach, D.; Rabung, T.; Brandt, F.; Fanghänel, T. “Trivalent actinide coprecipitation with powellite (CaMoO4): Secondary solid solution formation during HLW borosilicate-glass dissolution,” Radiochim. Acta., 2009, 92, pp. 639—643. 5. Hand, R J.; Short, R. J.; Morgan, S.; Hyatt, N. C.; Möbus, G.; Lee, W. E., “Molybdenum in glasses containing vitrified nuclear waste,” Glass. Tech. 2005, 46, pp. 121—124.

284

6. Vukasovich, M. S.; Farr, J. P. G. “Molybdate in corrosion inhibition – A review,” Polyhedron, 1986, 5, pp. 551–559. 7. Senyshyn, A.; Kraus, H.; Mikhailik, V. B.; Vasylechko, L.; Knapp, M. “Thermal properties of CaMoO4: Lattice dynamics and synchrotron powder diffraction studies,” Phys. Rev. B. 2006, 73, pp. 014104-1 – 014104-9. 8. Abdel-Rehim, A. M. “Thermal analysis and X-ray diffraction of synthesis of powellite,” J. Therm. Anal. Calor. 2001, 64, pp. 1283–1296. 9. Pramanik, P. “A novel chemical route for the preparation of nanosized oxides, phosphates, vanadates, molybdates and tungstates using polymer precursors,” Bull. Mater. Sci. 1999, 22, pp. 335–339. 10. Hoseinpur, A.; Bezanaj, M. M.; Khaki, J. V. “Mechanochemical synthesis of CaMoO4 nanoparticles: Kinetics and characterization,” Int. J. Mater. Res. 2016, 107, pp. 935–941. 11. Yang, P.; Yao, G.; Lin, J. “Photoluminescence and combustion synthesis of CaMoO4 doped with Pb2+,” Inorg. Chem. Comm., 2004, 7, pp. 389—391. 12. Dutta, P. S.; Khanna, A. “Eu3+ Activated Molybdate and Tungstate Based Red Phosphors with Charge Transfer Band in Blue Region,” ECS J. of Solid St. Sci. Tech. 2013, 2(2), R3153-R3167. 13. Schmdit, M.; Heck, S.; Bosbach, D.; Ganschow, S.; Walther, C.; Stumpf, T. “Characterization of powellite-based solid solution by site-selective time resolved laser fluorescence,” Dalton Trans. 2013, 42, pp. 8387—8393. 14. Johnstone, E. V.; Yates, M. A.; Poineau, F.; Sattelberger, A. P.; Czerwinski, K. R. “Technetium: The first radioelement on the Periodic Table,” J. Chem. Educ. 2017, 94, pp. 320–326. 15. OECD Nuclear Energy Agency, “The Supply of Medical Radioisotopes: 2017 Medical Isotope Supply Review: 99Mo/99mTc Market Demand and Production Capacity Projection 2017-2022,” OECD, 2017, Paris, pp. 1—29. 16. Chernesky, W.; Johnstone, E.; Borjas, R.; Kerlin, W.; Ackerman, M.; Mayo, K.; Kim, E.; Poineau, F.; Czwerinski, K. R., “Development of fluorescent technetium compounds as a radioactive distributed source,” SDRD FY 2014 – Instruments, Detectors, and Sensors, 2014, RSLN-25-14, pp. 59—69. 17. Buck, E. C.; Mausolf, E. J.; McNamara, B. K.; Soderquist, C. Z.; Schwantes, J. M. "Nanostructure of metallic particles in light water reactor used nuclear fuel," J. Nucl. Mater., 2015, 461, pp. 236—243. 18. McNamara B. K.; Buck, E. C.; Soderquist, C. Z.; Smith, F. N.; Mausolf, E. J.; Scheele, R. D. "Separation of metallic residues from the dissolution of a high-burnup BWR fuel using nitrogen trifluoride," J. Fluor. Chem. 2014, 162, pp. 1—8. 19. Buck E. C.; Mausolf, E. J.; McNamara, B. K.; Soderquist, C. Z.; Schwantes, J. M. "Sequestration of radioactive iodine in a silver-palladium phase in commercial spent nuclear fuel," J. Nucl. Mater., 2016, 482, pp. 229—235. 20. Childs, B. C., “Volatile technetium oxides: Implications for nuclear waste vitrification,” University of Nevada – Las Vegas Thesis, 2017. 21. Mausolf, E. J., “Separation of Tc from U and development of metallic Tc waste forms,” University of Nevada – Las Vegas Thesis, 2013. 22. Ackerman, M.; Kim, E.; Weck, P. F.; Chernesky, W.; Czerwinski, K. R., “Technetium incorporation in scheelite: insights from first-principles,” Dalt. Trans. 2016, 45, pp. 18171—18176. 23. Perrier, C.; Segrè, E. “Technetium: The element of atomic number 43,” Nature, 1947, 159, pp. 24. 24. Magdalena, G. “Separation methods of cyclotron-produced 99mTc,” Nucl. Med. Bio., 2017, 58, pp. 33—41. 25. Dash, A.; Knapp, F. F., Jr.; Pillai, M. R. A. “99Mo/99mTc separation: An assessment of technology options,” Nucl. Med. Bio. 2013, 40, pp. 167—176.

285

26. Gerse, J.; Kern, J.; Imre, J.; Zsinka, L. “Examination of a portable 99Mo/99mTc isotope generator/SUBLITECH,” J. Radioanal. Nucl. Chem. Lett. 1988, 128, pp. 71—80. 27. Nagai, Y.; Kawabata, M.; Sato, N.; Hashimoto, K.; Saeki, H.; Motoishi, S. “High thermoseparation efficiency of 99mTc from molten 100MoO3 samples by repeated milking tests,” J. Phys. Soc. Jap. 2014, 83, pp. 083201-1—083201-4 28. Richards, V. N.; Mebrahtu, E.; Lapi, S. E. “Cyclotron production of 99mTc using 100Mo2C targets,” 2013, 40, pp. 939—945. 29. Zsinka, L.; Kern, J. “New, portable generator for the sublimation of technetium-99m,” IAEA-CN-45/39 Report, 1988, pp. 95—106. 30. Gott, M. D.; Hayes, C. R; Wycoff, D. E.; Balkin, E. R.; Smith, B. E.; Pauzauskie, P. J.; Fassbender, M. E.; Cutler, C. S.; Ketring, A. R.; Wilbur, D. S.; Jurisson, S. S. “Acceleratorbased production of the 99mTc-186Re diagnostic-therapeutic pair using metal disulfide targets (MoS2.,WS2, OsS2),” Appl. Rad. Iso., 2016, 114, pp. 159—166. 31. Fernadez-Gonzalez, A.; Andara, A.; Prieto, M. “Mixing properties and crystallization of the scheelite-powellite solid solution,” Cry. Grow. Des., 2007, 7, pp. 545—552. 32. Richards, V. N.; Rath, N.; Lapi, S. E., “Production and separation of 186gRe from proton bombardment of 186WC,” Nucl. Med. Bio., 2015, 42, pp. 530—535.

286

BIOSORPTION OF Re(VII) BY CYANOBACTERIA SPIRULINA PLATENSIS I. Zinicovscaia1,2,3, A. Safonov4, I. Troshkina5, I. Shirokova4, K. German4 1

2

3

Joint Institute for Nuclear Research, Joliot-Curie Str., 6, 141980 Dubna, Moscow reg., Russia. Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Reactorului Str., 30, MG-6, Bucharest - Magurele, Romania.

Institute of Chemistry of the Academy of Science of Moldova, Academiei Str., 3, 2001, Chisinau, Moldova Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky prospect, 119071, Moscow, Russia.

4

5

Dmitry Mendeleev University of Chemical Technology of Russia, Miusskaya sq. 9, 125047 Moscow, Russia

Re (VII), a rare and valuable metal, is predominantly produced from molybdenites and some copper and platinum ores [1]. Due to its special properties, rhenium is extensively used in petrochemical, metallurgy, medicine, defense, aviation, chemical, and alloy production industries. Data on the adsorption efficiency of microorganisms for rhenium are not widely reported in the literature. The biosorption and bioaccumulation of ReO4− by the bacterium Bacillus sp. GT-83 was reported by [1] and [2]. Motaghed and co-authors investigated the process of rhenium recovery from a spent refinery catalyst by bacteria Bacillus megaterium. Rhenium is the closest chemical analogue of technetium. The information on Tc behavior in the presence of microorganism could be indicative for rhenium behavior predictions. The present study evaluated the potential of Spirulina platensis biomass to remove rhenium ions from both batch solutions and industrial effluents. The concentration of rhenium ions in solutions was determined by ICP-MS and colorimetric according to Malouf and White [3]. Rhenium content in biomass was determined by means of neutron activation analysis The effects of various parameters such as pH, contact time, initial concentration, and the temperature of biosorbent treatment were investigated. The maximum biosorption capacity of lead was 142.9 mg/g at pH of 2.0, sorbent dosage=0.05 g, and temperature of biosorbent treatment 30 ºC. The Langmuir and Freundlich adsorption isotherm models were found to fit well the sorption equilibrium of the experimental data (R2 = 0.99), while the kinetic data were best described using the pseudo second-order kinetic model (R2> 0.99). FTIR spectra indicated that rhenium removal takes place through two mechanisms: ionic interactions of perrhenate anions with amide and amino-groups, and binding to organic functional groups of the cell surface. The rhenium bound to the biomass could be effectively stripped using NH4OH (8 %) and the biomass was effectively used for three sorption–desorption cycles. In the case of industrial effluents, Spirulina platensis biomass has been shown to have relatively high removal efficiency (51-55%). The study demonstrates the potential of Spirulina platensis as biosorbent to remove rhenium from industrial effluents. References 1. S. Ghorbanzadeh Mashkani, P. Tajer Mohammad Ghazvini, D. Agha Aligol, Uptake of Re(Vii) from Aqueous Solutions by Bacillus sp. GT-83-23, Bioresource Technology 2009, 100, 603–608. 2. M. Motaghed, S. M. Mousavi, S. O. Rastegar, S. A. Shojaosadati, Platinum and Rhenium Extraction from a Spent Refinery Catalyst using Bacillus megaterium as a Cyanogenic Bacterium: Statistical Modeling and Process Optimization, Bioresource Technolology 2014, 171, 401-409. 3. E. Malouf, White M, Colorimetric Determination of Rhenium, Analytical Chemistry 1951, 23(3), 497–499.

287

BIOGEOCHEMICAL IMPACT OF TECHNETIUM MIGRATION IN SUBSURFACE WATER NEAR TO RW REPOSITORY A.Safonov1, R. Aldabaev1, N. Andryshchenko1, K. Boldyrev2.3, T. Babich2 E. Zakharova1, K. German1 1

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky prospect, 119071, Moscow, Russia. 2 Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russian Federation 3 The Nuclear Safety Institute (IBRAE) Russian Academy of Sciences

DOI: 10.13140/RG.2.2.31062.50243 The paper presents data on the role of microbiological factors in behavior technetium in the upper aquifers (10-15 m) near the surface repository of radioactive waste (Russia, Tomsk region). Pollution of groundwater has been going on for 50 years and now, in addition to radionuclides, concentration of nitrate ions reached to 5000 mg/l. The presence of nitrate ions and a small amount of dissolved oxygen leads to high values of the redox potential, which creates the prerequisites for technetium high migration activity in higher oxidation states. In the samples of ground water, an active microbial community capable of using nitrate, pertechnetate ions for cell respiration was found. There were also found sulfatereducers capable to produce biogenic sulfides and Fe-reducers. All this bacteria are well known microorganism with significant role in Tc geochemistry [1-45. Laboratory modeling of the microbial stimulation process with organic substrates led to activation of microflora, consumption of nitrate ions to molecular nitrogen, reduction of pertechnetate to Tc(IV). The results of computer geochemical modeling have shown that the immobilization of technetium in the formation occurs mainly in the form of a tetravalent oxide and in a mixture with a biogenic sulphide. while biogenic sulfide ions can play the role of an antioxidant buffer in the event of ingress of new portions of the oxidant into the system. It is important to note that Tc reduction occurs only after nitrate consumption and Eh reduction to anaerobic zone. Thus microbial roles in Tc immobilization are: biogeochemical - Eh reduction due to oxidizer consumption (oxygen, nitrate, etc.); - mineralization by biogenic sulphide interaction and biochemical – dissimilatory Tc reduction due to oxidoreductaze enzymes. References 1. Peretroukhin V.F., Khizhnyak T.V., Lyalikova N.N., German K.E. Radiochemistry (Russ). 38/5: 471-475 (1996). 2. T. Peretyazhko, J.M. Zachara, S.M. Head, B.-H. Jeon, R.K. KUKKADAPU, C. LIU, D.A.

Moore, C.T. Resch, “Heterogeneous Reduction of Tc(VII) by Fe(II) at the Solid-Water Interface”, Geochimica Cosmochimica Acta 72, 1521 (2008). 3. R. Lloyd, J.A. Cole, L.E. Macaskie, “Reduction and Removal of Heptavalent Technetium from Solution by Escherichia coli”, Journal of Bacteriology 179, 2014 (1997). 4. J.R. Lloyd, H.-F. Noting, V.A. Sole, K. Bosecker, L.E. Mcaskie, “Technetium Reduction and Precipitation by Sulfate-Reducing Bacteria”, Geomicrobiology Journal 15, 45 (1998). 44 5. J.K. Fredrickson, J.M. Zachara, R. Kukkadapu, J.P. Mckinley, S.M. Heald, C. Liu, A.E. Plymale. “Reduction of TcO4- by Sediment-Associated Biogenic Fe(II)”, Geochimica et Cosmochimica Acta 68, 3171 (2004). 22.

The work was carried out with partial funding by the Ministry of Science and Higher Education of the Russian Federation (Project No. AAAA-A16-116110910010-3) 288

Biogeochemical aspects of Technetium migration in subsurface water A. Safonov, R. Aldabaev, N. Andryshchenko, K. Boldyrev, T. Babich, E. Zakharova, K. German Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky prospect, 119071, Moscow, Russia. Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russian Federation The Nuclear Safety Institute (IBRAE) Russian Academy of Sciences

Objects of research

Surface repositories of LRW and MRW of Siberian radiochemical plants Was constructed in 1960x Usage time 30-50 years High level of subsurface water pollution Under conservation due to IAEA recommendation (not for deep LRW) total square 51 400 m2 was used for RW storing 1964 - 2010 was conserved 2012 depth of water horizon is 4-6 m from the surface

289

Macrocomponents inside

C g/l

nitrates

10- 300

sulphates

≤10-20

Total salinity

20- 400

RW repository

soil Buffer grunt Porosity 10-40% Water flow Saturation zone - Eh +100 - -50 Bacterial cells Sandy aquifer

pH 7-10 (neutralized by NaOH) Metals Up to 10 g/l Mg, Ca, Fe, Ni, Cr, Zr, Al

Macrocomponents in water after filtration, mg/l Clay or stone buffer

Total

pH

Fe

Na+

Ca2+

Mg2+

NH4+

NO3-

SO42-

HCO3-

120-

7,06-

0,49

4,0

17,51-

3,64