1. Bob Cywinski International Institute for Accelerator Applications Why thorium? Why Accelerators? PASI 13 January 2012

2. The Global Energy & Climate Crises

3. Current nuclear electricity supply Country N o. Reactors GW capacity % Total Electricity United States 104 101 20 France 58 63 75 Japan 55 47 29 United Kingdom 19 11 17 Germany 17 20 26 Russia 32 23 18 So. Korea 21 19 31 Canada 18 13 15 India 20 5 3 Sweden 10 9 37 21 Others 87 69 Totals: 441 380 14.....but this represents only 5% of global energy consumption

4. The Carbon Problem Energy source Grammes of carbon per KWh of electricity Nuclear 4 Wind 8 Hydro electric 8 Energy crops 17 17 Geothermal 79 79 Solar 133 133 Gas 430 430 Diesel 772 772 Oil 828 828 Coal 955 955 source: Government Energy Support Unit (confirmed by OECD)

5. The Uranium Fuel Cycle Enriched uranium 97% U-238, 3% U-235 Natural uranium: 99.3% U-238, 0.7% U-235

6. Uranium requirements Scenario 1 No new nuclear build Scenario 2 Maintain current nuclear capability (implies major increase in plant construction) Scenario 3 Nuclear renaissance: increase in nuclear power generation to 1500 GW capacity by 2050

7. Breeding nuclear fuel Enriched uranium 97% U-238, 3% U-235 Natural uranium: 99.3% U-238, 0.7% U-235

8. Annual global use of energy resources 5x10 9 tonnes of coal 27x10 9 barrels of oil 2.5x10 12 m 3 natural gas 65x10 3 tonnes of uranium 5x10 3 tonnes of thorium An alternative fuel?

9. Thorium resources

10. Breeding fuel from thorium Advantages Does not need processing Generates virtually no plutonium and less higher actinides 233 U has superior fissile properties Disadvantages Requires introduction of fissile seed ( 235 U or Pu) Parasitic 232 U production results in high gamma activity.

11. Advantages of thorium Thorium fuel cycle thorium reactor

12. Advantages of thorium: waste 100,000 1001,00010,000 100,000 1,000,00010,000,00010 100 1,000 10,000 100,000 1,000,000 10,000,000 100,000,000 1,000,000,000

13. Past experience with thorium “There is little chance that thorium-fuelled nuclear reactors will play a major role in meeting the UK’s future energy requirements...............No thorium reactor design has been implemented beyond relatively small, experimental systems” Baroness Tina Stowell, Government spokesman on energy and climate change House of Lords November 2011 The UK’s perspective:

14. Past experience with thorium: the reality

15. Past experience with thorium

16. The Indian thorium strategy 500 MW prototype FBR is under construction in Kalpakkam is designed to breed 233 U-from Th The FBR is expected to be operating shortly, fuelled with uranium-plutonium oxide with a blanket of thorium and uranium to breed fissile U-233 and plutonium respectively

17. Potential deployment of thorium 1. Thorium as fuel in conventional reactors:

18. Potential deployment of thorium 2. Thorium as fuel in molten salt reactors:

19. Potential deployment of thorium 3. Thorium as fuel in an energy amplifier: Rubbia et al., CERN/AT/93-47 (ET), CERN/AT/95-44 (ET) Phys Rev C73, 054610 (2006) also MSR option: C.D.Bowman, NIM A320, 336 (1992)

20. Spallation neutrons The energy spectrum of proton induced spallation neutrons. The target is a lead cylinder of diameter 20 cm At 1 Gev, approximately 24 neutrons per proton are produced

21. The Accelerator Driven Subcritical Reactor

22. Accelerator power The (thermal) power output of an ADSR is given by withN = number of spallation neutrons/sec E f = energy released/fission (~200MeV) ν = mean number of neutrons released per fission (~2) k eff = criticality factor (<1 for ADSR) So, for a thermal power of 1550MW we require Given that a 1 Gev proton produces 24 neutrons (in lead) this corresponds to a proton current of

23. Accelerator power k eff =0.95, i=33.7mA k eff =0.99 i=6.5mA To meet a constraint of a 10MW proton accelerator we need k eff >0.985

24. Safety Margins k=0.985

25. ADSR Shutdown Parks (Cambridge)

26. Evolution of the criticality value, k eff Coates, Parks (Cambridge)

27. Evolution of power output Coates, Parks (Cambridge)

28. The ADSR as an energy amplifier 10MW Accelerator 20 MW electrical 1550MW Thermal Power 600 MW Electrical Power

29. Why has no ADSR been built?...because accelerators are relatively unreliable

30. Multiple (FFAG ?) proton injection Multiple injection: - mitigates against proton beam trips and fluctuations - homogenises power distribution across ADSR core

31. IAEA support I A E A “IAEA warmly welcomes the proposed accelerator driver development programme embodied in the ThorEA project as a positive contribution to the international effort to secure the eventual global deployment of sustainable thorium- fuelled ADSR power generation systems…” Alexander Stanculescu Nuclear Power Technology Development Section International Atomic Energy Agency (IAEA) Vienna September 2009

32. Other ADSR Projects: KURRI Results show prompt and delayed neutrons, the latter from stimulated fission.

33. Other ADSR Projects: MYRRHA The MYRRHA Project Abderrahim et al., Nuclear Physics News, Vol. 20, No. 1, 2010 1b€ European project to build an ADSR for transmutation and waste management (2015)

34. STOP PRESS: 12 January 2012 GUINEVERE World’s first operation of an accelerator driven Pb-cooled fast subcritical reactor (1kW) (CNRS/CEA)

35. Other ADSR Projects: Aker/Jacobs K eff 0.995 Accelerator3MW ADSR 600MW

36. Technology Readiness Levels ADSR Thorium MOX MSR

37. “The Stone Age didn’t end because we ran out of stone”

38. Thank You! PASI 13 January 2012 www.thorea.org