Perspectives of Partitioning and Transmutation Technology. H. Oigawa Japan Atomic Energy Agency

Transcription

1 Perspectives of Partitioning and Transmutation Technology H. Oigawa Japan Atomic Energy Agency 1

2 Partitioning and Transmutation (P&T) Spent fuel Reprocessing FP MA U Pu MA (Np, Am, Cm) Geological disposal (Glass waste form) Recycle Conventional scheme P&T technology Transmutation by FR and/or ADS Partitioning (Example) PGM (Ru, Rh, Pd) Heat generator (Sr, Cs) Utilization and/or disposal Geological disposal after cooling and/or utilization (Calcined waste form) MA: Minor Actinides FP: Fission Products PGM: Platinum Group Metal FR: Fast Reactor ADS: Accelerator Driven System Remaining elements Geological disposal (high-density glass waste form) 2

3 Possible Benefits of P&T Reduction of long-term radiological toxicity Reduction of dose for future inhabitants To mitigate difficulties caused by long-term nature of radioactivity Reduction of amount of HLW Reduction of repository size To extend capacity of a repository Recovery of valuable materials from wastes. Enhancement of sustainability of nuclear power 3

4 Types of Transmutation System and their Transition Phase toward Sustainable Nuclear Energy Homogeneous route Homo. FR MA < 5% Homo. FR MA < 5% (a) Transient phase from LWR to homogeneous FR with all actinide recycling (b) Homogeneous FR with all actinide recycling MOX-LWR Pu Present situation Heterogeneous route Pu+Np Am, Cm Hetero. FR Driver: U, Pu(,Np) Target: Am Cm Am, Cm Pu, (Np) Hetero. FR Driver: U, Pu(,Np) Target: Am Cm Am, Cm Pu, (Np) (c) Transient phase from LWR to heterogeneous FR with MA target (d) Heterogeneous FR with MA target Pu Am, Cm MOX-LWR Pu+Np Am, Cm Homo. FR MA < 1% Pu, Np Homo. FR MA < 1% Pu, (Np) Am, Cm ADS MA ~ 60% ADS MA ~ 60% ADS MA ~ 60% Double Strata (e) Transient phase from LWR to Doublestrata with MOX-LWR for Pu burning and ADS for MA transmutation (f) Transient phase from LWR to Doublestrata with FR for Pu recycling and ADS for MA transmutation (g) Double-strata with FR for Pu recycling and ADS for MA transmutation 4

5 Check and Review (C&R) by Japan Atomic Energy Commission (JAEC) The second C&R was conducted by JAEC in The final report mentioned that the significance of the P&T technology is in three points: reduction of the potential hazard, mitigation of the requirement for geological repository site, and enhancement of the options in the design of the whole system of waste disposal. The current technology levels of the P&T were evaluated. Although the technology levels of some parts of the FBR cycle system are between basic research and engineering demonstration, the P&T technology in general is still in the basic research because of the lack of experimental data for MA It was, therefore, strongly recommended to accumulate the experimental data for MA as a common basis for both FBR and ADS. 5

6 Concept for MA Recycle Test in JAEA TEF-P (Critical / subcritical experiments) AGF (Fabrication of oxide fuel) NUCEF (Fabrication of nitride fuel) feedstock-pu/ma (g-order) Recoverd MA (g-order) CPF MMF-2 feedstock MA sample Irradiated MA sample and Fuel sampe (Reprocessing by pyrochemical and fabrication of MA sample) UPuZr Fuel PFRF sample (Fabrication of U- Pu-Zr) JOYO (MA sample and MA fuel irradiation) FMF, AGF (PIE) Irradiated MA sample Spent MOX Fuel NUCEF (Recovering of MA) CPF (Reprocessing of spent fuel) Oxide Fuel for FBR Metal Fuel for FBR NitrideFuelfor ADS 6

7 P&T for Sustainable Nuclear Energy Despite of various nuclear policies, the burden of HLW management is a common issue. P&T is interdisciplinary and integrated technology to enhance the sustainability of nuclear energy utilization. Since it is difficult to develop whole areas of the technology by one country, R&D coordination by international network is of great importance. Future Sustainable Nuclear Energy System (, MOX-LWR, FBR, Advanced Reprocessing, Waste Disposal, ets.) Items of Performance Targets Safety Economy Environmental friendliness Resource saving Proliferation resistance Domestic network Proposal of innovative concept and assessment of system performance Contribution to improve performance of future nuclear energy system Partitioning & Transmutation Accumulation of basic data for partitioning (Separation of MA and Sr-Cs, Utilization of PGM, etc.) International network Accumulation of basic data for transmutation (ADS, Nuclear data, New experimental facility, etc.) Nonproliferation Waste disposal Separation Actinide science Nuclear data Reactor physics Materials Thermal-hydraulics Structural analysis Accelerator Relevant basic technology 7

8 Concluding Remarks To mitigate the burden for the management of spent nuclear fuels, P&T technology should be continuously promoted by consolidating state-of-the-art technology of various scientific and engineering fields. It is of great importance to coordinate world s R&D activities under an international network. In particular, the small-scale demonstration of MA recycling should be the next target to break through the barrier for the realization of P&T technology. 8