CHALLENGES & DIRECTIONS IN FUEL CYCLE RESEARCH AND DEVELOPMENT

Transcription

1 CHALLENGES & DIRECTIONS IN FUEL CYCLE RESEARCH AND DEVELOPMENT Anil Kakodkar Department of Atomic Energy INDIA 1

2 INTRODUCTION New Technologies & Approaches needed for for the Growth of of Nuclear Power Innovative nuclear energy systems i) i) INPRO project (15 (15nations, including India) India) methodology for for assessing innovations in in reactor systems as as well as as fuel cycles being established) ii) ii) GIF --Generation IV IV International Forum 10 10Nations, 6 Reactor concepts (4 (4 of of these are are fast fast reactors) 2

3 INTRODUCTION Fuel Fuel Cycle: A vital vital & integral component of of nuclear technologies It It is is intimately linked to to a) a) choice of of the the reactor systems & b) b) national policies CLOSED FUEL CYCLE ALONE CAN PROVIDE SUSTAINABLE NUCLEAR ENERGY OVER LONG TERM WITH REDUCED IMPACT ON ON ENVIRONMENT THREE STAGES OF INDIAN NUCLEAR POWER PROGRAMME Natural Uranium PHWR 10 GWe, 40 y ELECTRICITY Th Depleted U Pu Pu FUELLED FAST BREEDERS 530 GWe, 100 y ELECTRICITY Th 150,000 Gwe y 3 Pu U-233 U-233 FUELLED BREEDERS U-233 ELECTRICITY STAGE 1 STAGE 2 STAGE 3

4 Key Performance Indices for Nuclear Fuel Cycle BENEFIT TO SOCIETY Safety ECONOMY SUSTAINABILITY through CLOSED FUEL CYCLE with MINIMUM IMPACT ON ENVIRONMENT PROLIFERATION RESISTANCE Economy Environmental impact IMPROVEMENTS IN SAFETY IMPROVEMENTS IN WASTE MANAGEMENT Sustainability & Proliferation resistance 4

5 R&D TARGETS FOR IMPROVING FUEL CYCLE Increase in in burn-up to to reduce mining milling and other processing requirements better economy and sustainability and less impact on on environment Increased remotisation of of fuel cycle operations to to permit processing of of short cooled // recycled fuel Partitioning and transmutation of of minor actinides & long lived fission products and recovery of of fission products of of commercial value (eg Cs, Sr Srand noble metals) to to reduce long term radiation hazards and create wealth from waste 5

6 R&D TARGETS FOR IMPROVING FUEL CYCLE Cumulative worldwide spent fuel arisings, reprocessing and storage (IAEA) 6 Compact plants, simplified processes, higher emphasis on on automation and co-location of of facilities to to improve economy of of fuel cycle New processes and approaches to to minimise waste and reduce secondary waste generation R & D to to augment strategies to to enhance public acceptance of of waste management philosophies: Robust process and matrix for for immobilization of of waste, technologies for for surveillance of of waste, comprehensive modeling to to ensure long term stability

7 Pu in LIGHT WATER REACTORS BWR fuel subassembly, TARAPUR Large scale deployment of of uranium, plutonium mixed oxide fuel is is one of of the directions in in utilization of of Pu Pu stockpile in in water reactors 7 Sol-gel facility for MOX fuel This demands R&D for for critical evaluation of of novel recycle technologies (co-precipitation, sol-gel microsphere pelletisation, coating // impregnation, remote fabrication, etc) to to reduce waste generation and reduce man-rem exposure

8 25 GWd/t 50 GWd/t 100 GWd/t FAST REACTORS IMPORTANT CANDIDATES FOR NEXT GENERATION REACTORS Development of clad and structural components for increasing the burn-up to a value of 200,000 MWd/t Integrated fuel cycle facilities to reduce cost and enhance proliferation resistance Development and Demonstration of matrices for deep burning of Pu Improved aqueous reprocessing schemes for processing high burn-up short-cooled fuel Development of pyrochemical processing route on industrial scale for oxide, metallic & other fuels Development and performance evaluation of Vibro-pac fuels: towards reduction in waste and man-rem exposure 8 MICROGRAPHS OF IRRADIATED (U, Pu) MIXED CARBIDE (70 % Pu) FUEL AT DIFFERENT BURN-UPS FBTR Fuel subassembly

9 R & D TARGETS for FBRs METALLIC FUELS WITH PYROCHEMICAL PROCESSING Higher burn-ups (up (up to to at at % achieved) Greater degree of of Passive safety Potential for for high breeding High resistance to to proliferation PYROPROCESSING PROCESS AT JPC, TOKAI, JAPAN 9

10 R & D Targets related to Metallic fuels for Fast Reactors Development of of comprehensive data base on on physicochemical properties of of metallic fuel Modeling Safety studies on on reactor size optimization Transmutation of of minor actinides characterisation and chemistry of of recycled fuel to to be be studied Injection casting in Glove Box 10

11 Pyrochemical Processing Lower Melting & Less Expensive Electrolytes UO 2 CATHODE DEPOSIT PARTIALLY DISSOLVED UO 2 PELLETS ANODE Developmental needs: Corrosion-resistant materials Remote handling techniques Characterization techniques & Waste management 11 PYRO-ELECTRO-METALLURICAL PROCESS FOR UO 2

12 THORIUM BASED FUELS Salient features of of thorium based fuels Thorium is is an an excellent host for for Pu Pu Makes the fuel cycle more sustainable and proliferation resistant Enables much deeper plutonium burning with manageable reactor characteristics even when the entire core is is loaded with Pu Pu bearing fuel assemblies Th-U fuel cycle has the advantage of of absence of of production of of minor (heavy) actinides 12

13 THORIUM BASED FUELS R& D issues Fuel Fabrication: Sol-gel derived microspheres New technologies for for the production of of U-Th and Th-Pu oxide fuels (sol-gel, Impregnation,etc.) Reduction in in sintering temperature, Improvement of of homogeneity Pu-nitrate solution Pores ThO 2 Matrix pellet Impregnated pellet Sintered (Th,Pu)O 2 pellet Impregnation chamber Fuel Reprocessing: Dissolution without use of of HF? Three component separations U,Th,Pu U clean-up (removal of of U) U) by by laser separation 13

14 ACTINIDE PARTITIONING AND TRANSMUTATION 14 Partitioning flow flow sheets Comprehensive techno-economic evaluation to to consider: i) i) Secondary waste production, ii) ii) Need for for An/Ln separation, iii) iii) Utility value of of actinides iv) iv) Simplification in in alpha waste management Transmutation Fast Fast reactors or or Accelerator driven sub-critical systems? Choice of of ADS fuel fuel cycle would be be influenced by by its its goal: Actinide Breeding // Actinide burning/ Power production Burning in in fast fast reactors choice of of fuel fuel cycle would depend on on matrix :: metal // oxide // nitride

15 AQUEOUS FUEL REPROCESSING Process Development Process Equipment NDT Techniques Fuel Fuel Reprocessing R&D R&D Chemistry, NDA & On-Line Monitoring Modeling & Simulation Waste Management Materials and Fabrication Instrumentation & Control 15

16 Mircrograph of Corrosion resistant Ti-5Ta-1.8 Nb Nitric acid loop for corrosion studies AQUEOUS FUEL REPROCESSING Increase in in plant life Use of of corrosion resistant materials to to withstand high concentrations of of nitric acid and high temperatures in in high radiation environment Systematic studies on on corrosion behaviour of of materials Development of of special coatings on on materials On-line monitoring of of health of of the equipment AFM IMAGE OF CORROSION RESISTANT NANO-COATING 16

17 AUTOMATION AND REMOTISATION OF OPERATIONS Simplified plant maintenance through development of remote handling tools Multi-link manipulator Reduction in man-rem exposure through increased remotisation of equipment and operations Pipetting Robot & Sample handling robot 17

18 AQUEOUS FUEL REPROCESSING LASER PLASMA EMISSION SAMPLE LENS SPECTROMETER LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS) FOR THE ESTIMATION OF U, Pu IN RAFFINATES, FUEL PELLETS 18 Neutron collar for on-line monitoring Reduction of of waste generation: Adoption of of salt-free processes for for reducing secondary wastes (new organic soluble reductants for for Pu; Pu; electrochemical and photochemical steps) Minimising loss of of actinides to to waste streams & discharges to to environment Development of of new extractants and resins Comprehensive on-line monitoring of of Pu Pu (at (at low low as as well as as high concentrations) to to improve process control and safety

19 New extractants: higher loadings, higher decontamination, lesser degradation & economical manufacturing. Comprehensive fuel reprocessing flow sheet: Near-Quantitative Extraction of actinides, and recovery of minor actinides &valuable fission products Variation of D Am with nitric acid concentration; Diluent: n-dodecane; Temperature: 25 C D Am M TODGA 30% TRPO 1.0M DMDBTDMA 0.2M CMPO + 1.2M TBP [HNO 3 ], M 19 C 8 H 17 N C 8 H 17 O O C 8 H 17 C O C CH 2 CH N 2 TODGA C 8 H 17

20 Variation of maximum aqueous Pu concentration inside the HC contactor: SIMPSEX results for 70%U+30%Pu flowsheet with feed concentration of 72 g.l -1 (U+Pu). Maximum Pu Conc. g/l Strip 2 (4N Acid), Base Flow Strip 1 (0.01 N Acid), Base Flow Pu loss in organic phase in HC Contactor: SIMPSEX results for 70%U+30%Pu flowsheet with feed concentration of 72 g.l -1 (U+Pu). AQUEOUS FUEL REPROCESSING Development of of comprehensive modeling capability to to design improved processes and and equipment. Development of of equipment with with reduced maintenance Constant Volume Feeders Pu loss, g/l Accurate metering of crucial streams. 20 Strip 2 (4N Acid), Base Flow Strip 1 (0.01 N Acid), Base Flow Rotary Semi-Continuous Dissolver

21 Molten glass flowing from a COLD CRUCIBLE WASTE MANAGEMENT R & D on on glass and ceramic matrices to to adapt to to fast reactor fuel reprocessing waste Processes benign to to environment: Supercritical extraction Processes which generate minimum or or no no secondary wastes Electrochemical and photochemical steps Ultrafiltration, Supported liquid membranes, Microwave techniques 21

22 INTEGRATED FUEL CYCLE FACILITIES Objectives R& D Targets 22 Reduction in in number of of process steps Minimization of of waste generation Economy of of operation Reduction in in man-rem exposure Oxide fuels: i) i) Integration of of Fuel Fabrication & Reprocessing (( by by adopting sol-gel vibro pac or or SGMP process) ii) ii) Sol-gel process to to be be demonstrated on on commercial scale Metallic fuels: i) i) Integrated fuel fabrication plant ii) ii) Very little liquid waste, iii) iii) Compact size, iv) iv) Economy

23 CONCLUSIONS Closed Fuel Cycle and Th Th utilisation sustainable long term strategy for for nuclear energy Cost Reduction of of Nuclear Fuel Cycle R & D is is vital; Key issues plant life, safety & reduced burden on on environment R & D emphasis should be be on on innovative approaches for for reactor systems as as well as as fuel cycle 23

24 24 Thanks