Thorium reactor - International Atomic Energy Agency

Thorium reactor: Issues on environmental stressors Susan Sipaun Malaysian Nuclear Agency IAEA INPRO TECHNICAL MEETING, MAY 24-26, 2016, VIENNA “TOWARDS NUCLEAR ENERGY SYSTEM SUSTAINABILITY-WASTE MANAGEMENT AND ENVIRONMENTAL STRESSORS”

Background  





Malaysia, Nuclear Energy System (NES) and Sustainability Thorium based fuel cycle (including reactors) is currently in the development or R&D stage globally, hence opportunity for Malaysia to join this global venture, including through INPRO R&D: Development of Innovative Nuclear Reactor Technology – With The Spin-Off Based on Thorium (FP0214D052 DSTIN) Period : 2014 – 2018 Relate how advance reactors such as thorium molten salt reactor (MSR) would be evaluated using the INPRO methodology

NES Case Study: Thorium molten salt reactor and related facility Consideration: IAEA TECDOC 1434

 

Stage of Development of Innovative Nuclear Energy System (INS) (or a component thereof)

Level of maturity Level of of an INS Uncertainty of (or component) Judgement

Most important (Not all) components of the INS have been theoretically demonstrated or experimentally verified, and there is theoretical evidence that this INS could meet all the Criteria.

Conceptual Feasibility Established

High

Objective: Preliminary evaluation of long term sustainability of selected NES and its related facility Molten salt reactors, in which the salt is at the same time the fuel and the cooling liquid e.g. flouride salts + Th-232 + U-233 (U-235)

Causal Chain from Source to Effects for Thorium Processing and Molten Salt Reactor Test Facility Thorium Molten Salt Reactor Test Facility

Radioactivity

Waste Management

Chemical Toxins

Sources Tin-tailing (Amang) Plant Thorium Extraction and Purification Plant

Stressors Heat and Acid Rain Heavy metal contamination SO2, NOx, ammonia & fluorine gasses

Air

Ecosystems:

Surface Water

Aquatic

Ecological: Populations of sensitive species

Terrestrial

Pathways Groundwater

Receptors Human: Public

Habitat

Workers

Endpoints Effects Human: Health Property Values Politics Infrastructure

Malaysia Case 

   

Environmental impact study on a selected NES in Peninsular Malaysia is divided into two parts:  Radiological  Non-radiological Radiological impact assessment calls for the study of the potential radiological impacts on human health and on non-human species Non-radiological impact assessment looks at the potential impact on the environment other than human or non-human species In Malaysia, the radiological impact assessment (RIA) is under the jurisdiction of the Atomic Energy Licensing Board (AELB) The non-radiological impact assessment i.e. Detailed Environmental Impact Assessment (dEIA) is under the jurisdiction of the Malaysian Department of Environment (DOE)

Authorities involved in regulating NPP in Malaysia

AELB: Atomic Energy Licensing Board EC: Energy Commission DOE; Dept. of Environment DOSH: Dept. of Safety & Health MHLG: Ministry of Local Housing & Local Gov.

INPRO Method: Environmental impact of stressors Basic Principle: The expected adverse environmental effects of a nuclear energy system shall be well within the performance envelope of current nuclear energy system delivering similar energy product  User Requirement (UR): UR1 Controllability of environmental stressors UR2 Reduction of total environmental impact of emitted radioactivity UR3 Optimisation of the measures to reduce environmental impact 

Desktop assessment of thorium processing and molten salt reactor technology UR1

Criterion

Indicator (IN) Acceptance Limit (AL)

Controllability of environmental stressors NES Related Facility: Small Amang Factory (any factory processing tin tailings/amang)

CR1.1 Radiation exposure of the public

IN1.1 : Exposure of ionizing radiation to the whole body of a worker not exceeding 20 mSv/y (AELB Regulations) Public 1mSv/y AL1.1: 0.2 mSv/y for all other nuclear facilities of the NES related facility e.g. Annual dose to an Amang factory worker was estimated to be approximately 1.5mSv/yr (Location: Kinta Valley & Selangor) Data in year 2008

NES: Small Modular Reactor based on MSR technology (dEIA, ) Current Research Reactor(TRIGA PUSPATI)

IN1.1 :Basic Safety Radiation Protection, annual dose limit for members of public is 1 mSv/yr AL1.1: 0.2 mSv/y for all other nuclear facilities of the NES assessed Normal range for area classification: Clean (0 to 0.5µSv/hr; Supervised (0.5 to 3µSv/hr; Controlled (>3µSv)

Desktop assessment of thorium processing and molten salt reactor (continued..) UR1

Criterion


Controllability of environmental stressors

CR1.2 Radiation exposure of non-human species

IN1.2 : Dose limit of 1 mSv/y and Operational Limit (Dose constraint) of 18 mSv/y and ALARA principle AL1.2: Malaysia: 1 Bq/g clearance limit for naturally occurring radionuclides from series of uranium and thorium For airborne contamination monitoring, the activity concentration shall not exceed 0.01 Bq m3 for uranium and 0.001 Bq m3 for thorium dust. e.g. TIN TAILING (AMANG): U-238: 0.219Bq/g, Th-232: 1.41Bq/g

NES Related Facility: Small Amang Factory (any factory processing tin tailings/amang) NES: Small Modular Reactor based on MSR technology

TIN SLAG: U-238:1.122Bq/g, Th-232:0.834 Bq/g


Criterion


Controllability of environmental stressors

CR1.3 Impact of chemicals and other nonradiation NES Related Facility: environmental Thorium Extraction stressors and Purification Plant

IN1.3 : Eight-hour time-weighted average airborne concentration e.g. Tributylphosphate(TBP) 0.2ppm, 2.2mg/m3 (solvent for extraction and purification of rare earth metals from their ores) Nitric acid 2ppm, 5.2mg/m3

NES: Small Modular Reactor based on MSR technology

AL1.3: Depends on chemical UF4, ThF4 and fission by-products ThF4 dissolved in a medium of LiFBeF2


Criterion


Reduction of total environmental impact of emitted radioactivity

CR2.1. Reduction of environmental impact of radiation

IN.2.1: Total radiotoxicity of radionuclides AL2.1:Estimated amount of long-lived radiotoxic waste generated by LFTR is