Transmutation of Minor Actinides in Fast Reactors (LFR and SFR)

1. Transmutation of Minor Actinides in Fast Reactors (LFR and SFR) Kamil Tucek, Johan Carlsson, Dragan Vidovic and Hartmut Wider European Commission, Joint Research Center / Institute for Energy, The Netherlands COE-INES2

2. Nuclear Renaissance – existing and planned reactors. Source: World Nuclear Association (WNA) August 2006 Existing Power Reactors 442 - 370 GWe Reactors under construction 28 - 22 GWe On order or planned 52 - 58 GWe Proposed152 - 107 GWE These additional 187 GWe look only like a 50% increase – but e.g. the US Industry talks already about 50% increase in GWe by 2030 (recent ANS meeting in Albuquerque) – in the WNA report it was only 25% etc. COE-INES2

3. INPRO8 Steering Committee: DESAE calculations • “Uranium 2003” by OECD/NEA and IAEA • Known conventional 4.6 Million Tons • Undiscovered conventional (by adding speculative & others) 14.4 Million Tons • Unconventional (in phosphate deposits) 22 Million Tons • Current consumption = 68,000 Ton/year for 360GWe R/P with comfortable Margin at least until 2050 • Exploration and mining activities must be initiated to support global expansion of nuclear power. – But to be on the safe side fast reactors should be built earlier 16 Million Ton case Hypothetical case disregarding market activities to recover unconventional resources COE-INES2

4. INPRO8 Steering Com.:DESAE calc.with Fast Reactors COE-INES2

5. European poll on Nuclear Waste in the EU “BAROMETER” 37 % in favor + 38% of 55% initially opposed= 58 % in favor 31 % against COE-INES2

6. Design parameters of SFR and LFR self-breeder cores COE-INES2

7. Homogeneous Burning of MAs of LWRs in LFRs + SFRs + Heterogeneous Burning in Blankets including Breeding of Pu in both cases → Sustainability The entire TRUs from spent LWR fuel are used in oxide fuels together with depleted uranium. 5% MAs can be used due to the insertion of moderating pins (BeO or UZrH1.6 or CaH2) which improve the safety coefficients. An alternate or better an additional approach is the French proposal to burn the MAs in external Blankets which is no proliferation problem since they include initially 10% MAs The future aqueous reprocessing for MA-fuel is GANEX (Global Actinide Extraction) or nearer term: PUREX – DIAMEX – SANEX COE-INES2

8. Different Design Options SFR LFR MAs only in the core no blankets MAs only in blankets MA in the core & blankets MAs only in the core no blankets MA only in the blanketsex ( in) core MA in the core & blankets Pu generated (kg/y) 12 +198 +150 +14 +145 (+78) +110 MA consumed (kg/y) 66 65 131 67 -15 (-63) 104 Key results on burning MAs and the simultaneous breeding of new plutonium COE-INES2

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12. MA burn-up = 2.4 times that generated by an EPR COE-INES2

13. 233 U Fissile 234 U T : 2.14e6y 1/2 via Pa233 T :87.7y 1/2 235 U Th T :2.5e4y 1/2 236 T :6.5e3y U 1/2 237 237 U Np 6.7d T :432.9y 1/2 238 238 238 U Np Pu 2000d 70% Fissile T :162.9d 1/2 239 239 Np Pu Transmutation chain for TRUs, G. Rimpault, CEA 2300d Fissile T :30y 1/2 240 Pu 241 241 Pu Am 14.4y T :9e5y Fissile 1/2 242 242 242 Pu Am Cm < 30d < 30d T :7e3y 242m Am 1/2 Fissile 243 243 243 Pu Am Cm 5h T :18.1y 1/2 g 244 244 (n, ) Am Cm < 30d b - decay b + decay g decay 244m 245 T :8.4e3y Am Cm 1/2 (n, 0) < 30d y Fissile a deca y (n, 2n) 246 Bk Cm Pu242/243 (7.4e3y/1.6e7y) COE-INES2 247 Cm

14. 600 MWe LFR and SFR unprotected LOF ULOF in LFR – the natural circulation is so good that accident can be overcome by a 150K outlet temperature increase (EAC2 + STAR-CD) In SFR natural circulation not good enough and feedbacks not strong enough to prevent boiling + 50% core melting COE-INES2

15. 600 MWe LFR – unprotected Loss-of Heat Sink Na has shorter grace time (r•cp = 0.7 of that of Pb) Na boiling could start In reactivity accidents leading to pin failures molten fuel gets swept out by equally heavy Pb COE-INES2

16. Economics Apects • ANL STAR-LM Design (Secure Transportable Autonomous Reactor) • All components withdrawable • No Redan, no inlet sommier since low-pressure drop core • Heat exchangers in primary • pool • No concerns about leaks + fires, no major concerns on water + air ingress COE-INES2

17. A Nuclear Renaissance is already starting – but in many countries there are still major concerns about the spent fuel disposal and about reactor safety, also fissile resources are becoming more expensive Conclusions • let’s use the “waste” as a fuel for fast reactors, and thus, resolve the waste problem and improve the sustainability by simultaneously breeding new plutonium • The key for burning 5% MAs in the core is due to the novel use of thermalizing pins for softening the spectrum. Also the use of MAs in blankets helps a great deal COE-INES2

18. Conclusions 2 • Fuel with an oxide matrix with Pu and 5% MAs is stable and currently feasible as is the reprocessing of the burnt-up fuel – at least in Europe • SFRs have advantages regarding the amount of burning and breeding and have only half the critical mass – but LFRs have a better burn-up swing, can store more MAs and Pu, are more robust regarding safety and rather certainly also more economical COE-INES2