Thorium-Plutonium LWR Fuel

Transcription

1 Thorium-Plutonium LWR Fuel Irradiation Testing Imminent October 2012 Julian F. Kelly, Chief Technology Officer What Why How

2 Overview Testing ceramic (Th,Pu)O2 fuel with prototypical LWR composition & microstructure Experiment primed to produce new and valuable data high Pu content for high burnup high density including some Th-U material flexibly designed support to other Th development projects (HTGR, ADTR...)

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4 Status Testing ceramic (Th,Pu)O2 fuel with prototypical LWR composition & microstructure Status planning complete pellet / material procurement finalized Consortium assembled & in place transport underway Imminent Irradiation in the Halden HBWR loading Jan 2013 highly instrumented test-pins 3 different 'phases' involving different samples of (Th,Pu)O 2

5 Experiment Objective. to yield data that can be used to demonstrate the safe, long term performance of ceramic thoriumplutonium oxide fuels, and that this information can directly support the planning and approval of a commercial irradiation for such a fuel.. Regulator & Operator Audience: & not purely academic

6 LWR Th-MOX fuel is both a catalyst and a technology springboard for further Th-deployment HI-CONVERSION Thorium Fuels Thorium-Plutonium LWR Oxide Fuel Power from stockpile Pu Thorium energy share Technology development option using breeding potential of Th (eg, RBWRs, PHWRs) Familiar fuel material Reactor-operable Safety margin benefit Technology development option Optimizable (BU, CR) Achievable in forseeable future Existing infrastructure - Not a zero-sum Th game - Possible to get commercial buy-in Hi-BURNUP Thorium Fuels using matrix properties of ThO2 eg, deep burn Th fuels with SiC clad, actinide transmutation focus (2ndgen MOX Pu, WG-Pu, MAs)

7 LWR Th-MOX fuel is both a catalyst and a technology springboard for further Th-deployment HI-CONVERSION Thorium Fuels Thorium-Plutonium LWR Oxide Fuel Power from stockpile Pu Thorium energy share Technology development option using breeding potential of Th (eg, RBWRs, PHWRs) Familiar fuel material Reactor-operable Safety margin benefit Technology development option Optimizable (BU, CR) Achievable in forseeable future Existing infrastructure - Not a zero-sum Th game - Possible to get commercial buy-in Hi-BURNUP Thorium Fuels using matrix properties of ThO2 eg, deep burn Th fuels with SiC clad, actinide transmutation focus (2ndgen MOX Pu, WG-Pu, MAs)

8 LWR Th-MOX fuel must adapt to current fuel cycle imperatives Viable thorium fuel technologies for the near term will be those of the high burn-up type & not those aiming for breeding ratios. In-situ conversion and use of 233U is vastly more attractive than proposals involving radio-chemical processing. LWR thorium technologies can address Pu management issues LWR thorium fuel technologies can integrate well with future fast reactor use LWR thorium fuel technologies can integrate very well with future accident-tolerant fuels & claddings

9 The How A fuel testing campaign requires a lot of preparatory work and carries risk Programmatic $$ Consortium building Material procurement (including transport) Technical Rig design Pellet specifications & manufacture Instrumentation PIE - Post-Irrad Examination

10 Behaviours to Characterize Pellet properties evolve as fuel burns the most important changes to know about are: Temperature & Thermal Property Changes temperature, conductivity decrease, expansion, heat capacity Fission Gas Release amount, onset and composition Mechanical Interactions densification, swelling Chemical Interactions SCC, oxygen movement expect later onset for ThO2, more I? may be less creep but more swelling for ThO2 O stoichiometry different in ThO2 I yield higher (released?) ultimately, will cladding integrity be challenged?

11 To Be Measured Experiment design involves compromises & risk assessment On-Line Measurables temperature: centerline & coolant pellet stack elongation clad elongation rod internal pressure PCMI FGR swelling densification Post-Irradiation Examination fission gas analysis microscopy: optical, SEM, TEM, EPMA conductivity microstructure FP behaviour radiography fuel matrix properties microhardness γ scanning

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13 Calibration valve for power calibration of test assembly Neutron detectors vanadium Outlet turbine for power calibration of test assembly Stainless steel shield plug Inlet turbine assembly for power calibration of test assembly Fuel stack elongation detector for measuring densification / swelling of fuel Fuel rod thermocouple Fuel rod thermocouple outlet steam holes for coolant Test fuel rod, active section (Orange) Fuel rod pressure transducer Extension tube Top seal assembly, sealing against the reactor top lid

14 - Jan 2013 ITU - May Phase 1b rig schematic

15 Pellet Properties Test-fuel ceramic must represent that which can be deployed commercially. Pu content effects things cf U Microstructure density / porosity & pore size distribution grain size & grain distribution c Pu homogeneity Composition impurities: metals, non-metals stoichiometry Shaping dishing, L/D a b R d Shoulder width Chamfer width Chamfer depth Chamfer angle Dishing depth Dishing radius a b c d R

16 Thorium Fuel Ceramic Studies Thoria-Ceria Pellets: as analogs for thorium-mox Microstructure: different phases, significant 20100μm porosity, carbon. next = binderless Will Serve Model Development: thermal conductivity & dependence on O/M, grainsize, etc

17 Experiment Execution Just a few more things to cover... Rod Design pellet-clad gap, fill gas Power Roadmap starting LHGR

18 Conclusion: Thorium Fuel Testing. Ready to Go Still welcoming new Consortium partners Thanks to current Members: STL, NNL, IFE, Westinghouse, NFR, Fortum, ITU The nuclear industry is not set up for attracting innovation financing Uranium IS cheap, and could stay that way

19 Conclusion: Thorium Fuel Testing. Ready to Go Still welcoming new Consortium partners Thanks to current Members: STL, NNL, IFE, Westinghouse, NFR, Fortum, ITU FINAL THOUGHTS: The nuclear industry is not set up for attracting innovation financing Uranium IS cheap, and could stay that way