IT0200164 ENTE PER LE NUOVE TECNOLOGIE, L'ENERGIA E L'AMBIENTE
ISSN/1124/7932
Serie Energia
SP-FISPACT2001 A COMPUTER CODE FOR ACTIVATION AND DECAY CALCULATIONS FOR INTERMEDIATE ENERGIES. A CONNECTION OF FISPACT WITH MCNPX
CARLO PETROVICH ENEA • Divistone Sistemi Energetici Ecosostenibili Centro Ricerche "Ezio Clemente!, Bologna
RT/ERG/2001/10
ENTE PER LE NUOVE TECNOLOGIE, L'ENERGIA E L'AMBIENTE Serie Energia
SP-FISPACT2001 A COMPUTER CODE FOR ACTIVATION AND DECAY CALCULATIONS FOR INTERMEDIATE ENERGIES. A CONNECTION OF FISPACT WITH MCNPX
CARLO PETROVICH ENEA - Divisione Sistemi Energetici Ecosostenibili Centro Ricerche "Ezio Clementel, Bologna
RT/ERG/2001/10
I contenuti tecnico-scientifici dei rapporti tecnici dell'ENEA rispecchiano l'opinione degli autori e non necessariamente quella dell'Ente. The technical and scientific contents of these reports express the opinion of the authors but not necessarily those of ENEA.
SP-FTSPACT2001 A COMPUTER CODE FOR ACTIVATION AND DECAY CALCULATIONS FOR INTERMEDIATE ENERGIES. A CONNECTION OF FISPACT WITH MCNPX Riassunto In fase di design di sistemi ADS (Accelerator Driven Systems), di strutture con acceleratori quali quelli finalizzate alla produzione di fasci di ioni radioattivi o a sorgenti neutroniche di spallazione è necessario calcolare la composizione e l'attività di materiali a seguito di interazioni nucleari con energie fino a qualche GeV. Oltre la radioattività dei materiali, questi calcoli permettono di prevedere la formazione di elementi gassosi attivi e possibili problemi di corrosione. Le energie delle particelle qui coinvolte sono più alte di quelle usate in tipici reattori nucleari ed in dispositivi finalizzati alla fusione, per i quali sono già disponibili diversi codici. Questi tipi di calcoli possono essere eseguiti accoppiando due codici differenti: MCNPX e SP-FISPACT. MCNPX trasporta particelle con metodo Montecarlo fino ad energie di alcuni GeV. SP-FISPACT è il risultato di una modifica di FISPACT, un codice creato per calcoli di attivazione indotta da neutroni per energie minori di 20MeV, finalizzati a progetti di fusione nucleare. In tal modo è possibile eseguire un calcolo "ibrido": vengono utilizzati dati neutronici di attivazione per interazioni neutroniche ad energie minori di 20MeV e modelli fisici ad energie intermedie per tutte le altre interazioni nucleari,. Parole chiave: attivazione, codice di calcolo, energie intermedie, prodotti di spallazione, mcnpx. Abstract The calculation of the number of atoms and the activity of materials following nuclear interactions at incident energies up to several GeV is necessary in the design of Accelerator Driven Systems, Radioactive Ion Beam and proton accelerator facilities such as spoliation neutron sources. As well as the radioactivity of the materials, this allows the evaluation of the formation of active gaseous elements and the assessment of possible corrosion problems. The particle energies involved here are higher than those used in typical nuclear reactors and fusion devices for which many codes already exist These calculations can be performed by coupling two different computer codes: MCNPX and SP-FISPACT. MCNPX performs Monte Carlo particle transport up to energies of several GeV. SP-FISPACT is a modification of FISPACT, a code designed for fusion applications and able to calculate neutron activation for energies +CLEA*SPLI&',4) >c > c 20 MeV C.Petrovich. Added in the previous line: >c *CURR*TARG*ATTA*TCOL*HCOL 775c787,791 < *1170,1180),J > * 1175,1177,1185,1190,1195,1170,1180),J >c > c 20 MeV C.Petrovich. Added in the previous line: >c 1175,1177,1185,1190,1195, >c
776a793 >C 1052al070,1076 >c > c begin >20MeV CPetrovich >c > CPFLUX=FLUX2 >c > c end >20MeV CPetrovich >c 2403a2428,2456 >c
> c begin >20MeV CPetrovich
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> c New code words to be input in the preliminary input for collapsing >c CURR > c proton current > 1175 ICHK=NEWDEC(1) > CURR=FLDEC(O) > GO TO 100 >c TARG > c material number > 1177 ICHK=NEWDEC(1) > IDTARG=INDEC(0) > GOTO 100 >c ATTARGET... > c number of atoms of the material number TARG > 1185 ICHK=NEWDEC(1) > ATTARG=FLDEC(O)/1E24 > GOTO 100 >c total collapse...TCOL > c FLAG for collapsing all energies > 1190 FLAGCP=1 > GO TO 410 >c high collapse....HCOL... > c FLAG for collapsing only interactions >20MeV > 1195 FLAGCP=2 > GO TO 410 >c > c end >20MeV CPetrovich Since the modifications to the subroutines col*.f are very similar, only the modifications to the subroutine col 175 .fare shown. 29,31c29,41 < DIMENSION NUCL(1950),FLUX(176),XSECT(176),ZSECT(24000)5 < + ZSEKT(15000),MREAC(114),NP(24000),ND(24000), .< + NP2(15000),ND2(15000),JPAR(1000) >c > c begin >20MeV C. Petrovich >c > c before: DIMENSION NUCL(1950),FLUX(176),XSECT(176),ZSECT(24000), >c + ZSEKT(15000),MREAC(114),NP(24000),ND(24000), >c • + NP2(15000),ND2(15000),JPAR(1000) > DIMENSION NUCL(1950),FLUX(176),XSECT(176),ZSECT(24000), > + MREAC(114),NP(24000),ND(24000),JPAR(1000)
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> COMMON /SPAL3/ NP2(15000),ND2(15000),ZSEKT(15000),MCP2 > COMMON/SPAL2/FLAGCP >c > c end >20MeV C. Petrovich >c 792a803,815 >c
>c >c >c > > > > > > >c >c >c
begin >20MeV C. Petrovich FLAGCPX) for collapsing >20MeV FLAGCP=2 not collapsing 20MeV C. Petrovich
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APPENDIX B - Definition of 'pseudo cross-sections' The number of atoms Ni of the nuclide / produced by the stable nuclide y is governed by the following equation (without considering fission)4:
where: j is the neutron flux (n cm"2 s'1) Nj(t) is the amount of nuclide./ at time t ay is the reaction cross section for reactions ony producing / (barns). If there is a fixed number of source particles per second (such as protons in an accelerator) causing an amount N, of residual nuclei to be formed in a given material, then the production of Ni (without decays) is ruled by: —— dt
= Residual nuclei Ns per source proton * Source protons per sec
(2)
where: 'Residual nuclei iV)- per source proton' is provided by the code HTAPE3X. The number of 'Source protons per sec' depends on the current used in the accelerator. This is the contribution coming from interactions >20MeV to be added in FISPACT2001. We can define a pseudo cross-section (a fictitious cross-section) such that:
_ Residual nuclei N ; per source proton * Source protons per sec*10 24
where: a is the integral neutron flux under 20MeV (n cm"2 s"1). Nj(0) is the number of atoms of the nuclidey forming the nuclide / at time t=0. In this way FISPACT will calculate:
4
The complete equation can be found in [4], page 90.
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= Residual nuclei N{ per source proton * Source protons per sec * N/t)/Nj(0). If the number of atoms of the initial material remains approximately constant (this is true in most cases, but the responsibility for checking that is left to the user), then Nj(t)/Nj(0)=l and we obtain the desired equation (2).
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Acknowledgements K.W. Burn provided fruitful discussions.
Disclaimer Neither the author nor ENEA accept responsibility for consequences arising from errors in the present report.
Contact person Feedback on the use of SP-FISPACT2001 is welcomed. Please contact the author with comments. Carlo Petrovich ENEA Via MM.Sole 4, Bologna 40129 Tel.+39-051-6098517 E-mail:
[email protected]
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References [1] Laurie S. Waters, Editor: 'MCNPJfM User's Manual', Version 2.1.5, TPO-E83-G-UG-X00001, November 14,1999 (http://mcnpx.lanl.gov/). [2] C. Rubbia, J.A. Rubio, S. Buono, F.Carminati, N. Fieter, J. Galvez, C. Gelei, Y. Kadi, R. Klapisch, P. Mandrillon, J.P. Revol and Ch. Roche, 'Conceptual Design of a Fast Neutron Operated High Power Energy Amplifier', CERN/AT/95-44(ET). [3] *SPES, Project Study of an Advanced Facility For Exotic Beams at LNV, LNL-INFN (REP) 145/99, June 1999. [4] RA Forrest and J-Ch Sublet, 'FISPACT-2001: User manual', EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, UK, March 2001 (http://www.fusion.org.uk/easy2001/). [5] J. F. Briesmeister, editor, 'MCNP™-A General Monte Carlo N-Particle Transport Code', Los Alamos National Laboratory, LA-12625-M (March 1997). (>ttp://www-xdiv.lam.gov/^CI/PROJECTS/MCNP/manual.html). [6] Yury E. Titarenko et al., Fission Products Yields in Hybrid (ADS) Target Materials induced by High-Energy Proton, Proc. of the 15th Int. Workshop on Fission Physics, Obninsk, Russia, October 2-6,2000. LA-UR-00-5848. [7] Yu. N. Shubin , V.P. Lunev, A. Yu. Konobeyev, A.I. Ditjuk, 'Cross-section data library MENDL-2 to study activation as trasmutation of materials irradiated by nucleons of intermediate energies '. report INDC(CCP)-385 (IAEA, May 1995). [8] Yu.A. Korovin, A.Yu. Konobeyev, P.E. Pereslavtsev, A.Yu. Stankovsky, C. Breeders, I. Breeders, U. Fischer, U. von Mòllendorff, 'Evaluated nuclear data files for accelerator driven systems and other intermediate and high-energy applications', Nuclear Instr. and Methods in Physics Research A 463 (2001) p.544-556. [9] RA Forrest, 'The European Activation File: EAF-2001 decay data library', UKAEA FUS 452, UK, March 2001. [10] The Berkeley Laboratory Isotopes Project's, Ernest O. Lawrence Berkeley National Laboratory, (http://ie.lbl.gov/education/isotopes.htm).
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Edito dati' Unità Comunicazione e Informazione Lungotevere Grande Ammiraglio Thaon di Revel, 76 - 00196 Roma Sito Web http://www.enea.it Stampa Laboratorio Tecnografico • C.R. Frascati Rnito di stampare nel mese di novembre 2001
