Presentation is loading. Please wait.

Presentation is loading. Please wait.

Bob Cywinski School of Applied Sciences International Institute for Accelerator Applications Accelerator Driven Subcritical Reactors with thorium fuel.

Similar presentations


Presentation on theme: "Bob Cywinski School of Applied Sciences International Institute for Accelerator Applications Accelerator Driven Subcritical Reactors with thorium fuel."— Presentation transcript:

1 Bob Cywinski School of Applied Sciences International Institute for Accelerator Applications Accelerator Driven Subcritical Reactors with thorium fuel Doctoral Training Course University of Huddersfield 11 April 2013

2 The Global Energy Crisis

3 The Carbon Problem Energy source Grams of CO 2 per KWh of electricity Nuclear 4 Wind 8 Hydro electric 8 Energy crops Geothermal Solar Gas Diesel Oil Coal source: Government Energy Technology Support Unit (confirmed by OECD)

4 Current nuclear supply Country N o. Reactors GW capacity % Total Electricity France Sweden South Korea Japan Germany United States Russia United Kingdom Canada India Others Totals: But this represents only 5% of global energy consumption To increase this by x5 would reduce carbon emissions by 25%

5 Fission

6 Conventional Reactors

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

8 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

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

10 Retaining the nuclear option the nuclear option should be retained precisely because it is an important carbon-free source of power….....but there are four unresolved problems: high relative costs perceived adverse safety, environmental, and health effects potential security risks stemming from proliferation unresolved challenges in long-term management of nuclear wastes.

11 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?

12 Thorium resources

13 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) The decay of parasitic 232 U results in high gamma activity from 208 Tl.

14 Advantages of thorium: waste 100, ,00010, ,000 1,000,00010,000, ,000 10, ,000 1,000,000 10,000, ,000,000 1,000,000,000

15 Past experience with thorium:

16 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) The decay of parasitic 232 U results in high gamma activity from 208 Tl.

17 Spallation ISIS 200kW SNS (1 MW) J-PARC (1MW)

18 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

19 Spallation neutrons Number of neutrons per unit energy of incident proton

20 The Accelerator Driven Subcritical Reactor

21 3. 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 Accelerator power 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

25 Accelerator power

26 H.M. Broeders, I. Broeders : Nuclear Engineering and Design 202 (2000) 209– Initial loss due to build- up of absorbing Pa 233 and decrease of U 233 enrichment by neutron absorption and fission Increase due to increasing U 233 enrichment from subsequent β-decay of Pa Long term decrease due to build up of neutron absorbing fission products A Thorium Fuelled ADSR

27 Evolution of the criticality value, k eff Parks (Cambridge)

28 Evolution of power output Coates, Parks (Cambridge)

29 Accelerator power

30 ADSR Shutdown Parks (Cambridge)

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

32 “A reactor needs an accelerator like a fish needs a bicycle…”

33 Waste management

34 The ADSR for waste management

35 Applications of Accelerator Driven Systems Applications of Accelerator Driven Systems Technology  Transmuting selected isotopes present in nuclear waste (e.g., actinides, fission products) to reduce the burden these isotopes place on geologic repositories.  Generating electricity and/or process heat.  Producing fissile materials for subsequent use in critical or sub- critical systems by irradiating fertile elements. Transmuting selected isotopes present in nuclear waste (e.g., actinides, fission products) to mitigate the need for geologic repositories. Generating electricity and/or process heat Producing fissile materials for use in conventional critical or novel sub-critical reactors by irradiating fertile precursors.

36 Waste management From: Hamid Aït Abderrahim (MYRRHA)

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

38 ADSR Projects: Aker/Jacobs K eff Accelerator3MW ADSR 600MW

39 ADSR Projects: Aker/Jacobs

40 Towards an ADSR ??

41 Proton drivers? Cyclotron High Current (

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

43 Why has no ADSR been built? o...because accelerators are relatively unreliable, (largely because of ion source and RF issues ) From: Ali Ahmad

44 Technology readiness assessment (US)

45 EMMA – the world’s first ns-FFAG

46

47 Multiple FFAG proton injection Multiple injection: - mitigates against proton beam trips and fluctuations - homogenises power distribution across ADSR core Patent taken out on multiple injection

48 The way forward? In 2009 Science Minister, Lord Drayson, asked ThorEA to prepare a report outlining what might be needed to deliver the technology to build the world’s first ADSR power station ThorEA delivered that report in October Interest in thorium is now growing: eg Weinberg Foundation, All Party Parliamentary Group on Thorium, Annual International Conference (IThEC)

49 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

50 Conclusions Thorium has been used in the past and could now be deployed in conventional, molten salt, ADS and even hybrid MS/ADS reactors providing an alternative, sustainable, safe, low waste and proliferation- resistant technology for nuclear power generation 780kg of thorium = 200 tonnes of uranium (as currently used) No plutonium is used and very little is produced After 70 years the radiotoxicity is 20,000 times less than an equivalent conventional nuclear power station Thorium systems provide means of burning existing legacy waste Waste can be mixed with thorium and burnt as fuel, reducing radiotoxity by orders of magnitude and turning a liability into an asset But Significant R&D has to be carried out on: Materials research (particularly for MSR systems) Improving accelerator reliability (for ADSR and hybrids) Beam, spallation target and blanket interfaces

51 Thank You! Thank you !


Download ppt "Bob Cywinski School of Applied Sciences International Institute for Accelerator Applications Accelerator Driven Subcritical Reactors with thorium fuel."

Similar presentations


Ads by Google