Green Energy-Multiplier. Subcritical-technology Thermal-spectrum Accelerator-driven Recycling-reactor. (my version of acronym)

Transcription

1 GEM STAR 1 Green Energy-Multiplier Subcritical-technology Thermal-spectrum Accelerator-driven Recycling-reactor (my version of acronym) Transforming the Nuclear Landscape Bruce Vogelaar (Virginia Tech) September 27, 2010 ADNA and Virginia GEM*STAR Consortium

2 The Urgency 2 Population Growth: billion billion Energy Availability vs poverty: Sweden 15,000 kwh e /(person-yr) Tanzania 100 kwh e / (person-yr) ½ live in poverty; 1/5 th under nourished Energy Source: 1.6 billion no electricity 2.4 billion traditional biomass Advanced Society Energy Consumption: 0.9 GJ / day / person 10.4 kw /person 32 kg coal / day / person 100 kg CO 2 / day / person

3 Global Warming is happening now STAR M S GEM 3

4 These are shared challenges either directly or indirectly nuclear energy already accounts for 17% of global electricity production 4

5 Nuclear Issues Are (and will remain) Unavoidable At least 40 developing countries have recently approached U.N. officials here to signal interest in starting nuclear power programs At least half a dozen countries are specifically planning to conduct enrichment or reprocessing of nuclear fuel Joby Warrick, Washington Post, May 12,

6 Classic Associations with Nuclear Energy 6 no CO 2 low-cost electricity (current fleet) engineered safety IAEA oversight Incremental improvements will not break all these associations be they real or imagined, each is a proven show stopper weapons enrichment reprocessing waste costly political ramifications truly catastrophic failure scenarios NIMBY

7 Invent the Future Invent Solutions to the Realities of Today 7

8 Can accelerators really make the difference? Enrichment Uranium Ore Fuel Fabrication Light Water Reactor Fuel Separation Transmutation Fuel Fabrication Fission Products and Process Losses Advanced Burner Reactor Transmutation Reprocessing High- Level Waste Repository Strontium, Cesium and Uranium Storage Low- Level Waste Disposal 8 NOT if incremental, or pursued in an unmotivated context.

9 ADNA: re re-frame the question What would an optimized accelerator-based nuclear-energy program look like? 9

10 graphically Enrichment Uranium Ore Recycling Liquid-fuel Subcritical Reactor Accelerator or fusion neutrons Fuel Fabrication Light Water Reactor Fluorination Fuel Separation Transmutation Fuel Fabrication Fission Products and Process Losses reduce and defer waste Advanced Burner Reactor Transmutation Reprocessing High- Level Waste Repository Strontium, Cesium and Uranium Storage Low- Level Waste Disposal 10

11 the advances and understanding di which h make this possible now despite the real challenges of currently being outside traditional programs 11

12 1.00E E+11 Electrostatic tandem with stopping length deuterium target ($ per gram m) Ne eutron cost 1.00E E E E E+06 Electron linac with W target LAMPF with W target GEM*STAR sc. with U SNS with GEM*STAR Hg target mass prod. 1.00E Year 12

13 Accelerators Study of a 10-MW Continuous Spallation Neutron Source (BNL, 2003) Comparison of Super-Conducting Linacs and operation power costs. STAR M S 13GEM

14 14 ADS Technology Readiness Assessment Front End System Performance Reliability Accelerating RF Structure Development System and Performance Linac Cost Optimization Reliability RF Plant Performance Cost Optimization Reliability Beam Delivery Performance Target Systems Performance Reliability Instrumentation Performance and Control Beam Dynamics Emittance/halo growth/beamloss Lattice design Reliability Rapid SCL Fault Recovery System Reliability Engineering Analysis Transmutation GEM*STAR Industrial Scale Power Demonstration Transmutation Generation Green: ready, Yellow: may be ready, but demonstration or further analysis is required, Red: more development is required.

15 Solid Fuel Issues non-uniform fuel consumption fuel repositioning to optimize burn-up up fraction fission-product build-up significant inventory of radioactive gasses difficult and expensive process to qualify new fuels typical fission distribution for driven systems 15

16 Molten Salt Eutectic Fuel 568 o 850 ThF 4 Uranium or Thorium fluorides form eutectic mixture with 7 LiF salt o High boiling point low vapor pressure Proven compatible with modified Hastelloy-N for operation up to 750C. (ORNL MSRE) 565 o o LiF 845 o 490 o LiF : UF 4 UF o 16

17 Liquid fuel enables operation with constant and uniform isotope fractions including fission products consider isotope N 1 present in molten-salt feed: feed absorption overflow dn 1 /dt = F(v/V) - N 1 a1 N 1 (v/v) =0 define neutron fluence: F = (V/v); then in equilibrium N 1 = F / [1 + F a1 ] 1 [ a1] and its n capture and β decay daughters are given by N i = N 1 j=2,i {F c(j-1) /[1 + F aj ]} i 2 j, c(j ) aj do this for all actinides present in molten-salt feed and add together th the results 17 note: feed rate is determined by power extracted

18 extracts many times more fission energy, without additional long-lived lived actinides Feed material: LWR spent fuel 20 GWy Acc 1 40 GWy Acc 2 60 GWy etc 18 major reduction and deferral of waste

19 Thermal Spectrum ev 19 highest tolerance for fission products: neutron s-wave strength low for fission products f ( 239 Pu)/ c (f.p.)~ p) 100 (versus ~ 10 at 50 kev) resonance spacing large compared to width of neutron spectrum 151 Sm (transmuted rapidly to low c nuclei); 135 Xe (continuously removed as a gas) more than compensates for slower fission of heavy actinides

20 New Graphite Results (ADNA) Cross section (barns) 7 6 Diffraction elastic scattering for granular graphite Neutron energy (ev) Duke LANL Measurements of Thermal Neutron Diffraction and Inelastic Scattering in Reactor-Grade Graphite Nuclear Science and Engineering Vol. 159 No. 2 June 2008 Reducing Parasitic Thermal Neutron Absorption in Graphite Reactors by 30% Nuclear Science and Engineering Vol. 161, No. 1, January

21 K room temperature results (HP graphite) x 1000 x g K 600K 400K 296K standard MCNP5 predictions Neutron energy (ev) Discovered and measured a commercial graphite source with: 24% increase in room temperature thermal diffusion length ( HP manufacturing process creates distorted crystals reducing coherent scattering) boron contamination less than 2 parts in 10 7 significant reduction in parasitic neutron absorption 21

22 Invent the Future Typical GEM STAR System ADN NA & Virgin nia Te ech GREEN Power Local Grid p sub-critical REACTOR p two proton beams from accelerators (50% efficient) 44% conversion efficiency Electrical Power Multiplication baseline target: 30 meaning: 8 MW green power gives 240 MW net output 22 GEM STAR

23 Protons -vs- Electrons protons MeV): P P beam input n E ( MV MeV ) fission 1 n 1 k s E( MeV) fissioni P P electric thermal MeV MeV electrons (@50 MeV): MeV MeV n per 1 p 1n per 60 e MeV MeV proton accelerator ~ ¼ capital cost M 27 23

24 STAR M S GEM 24 Functional Components

25 GEM STAR 25 Conceptual Design

26 Unique Target Considerations 26 Existing Oak Ridge SNS Molten Hg target heat removal; diffuse/ multiple beam targets neutron absorption local core reactivity primary n production thermal n escape, fast n fission maintenance spent target disposal Uranium seems ideal

27 ectrical Multip plication El Fuel: Natural Uranium running at peak gives 91% Pu-239 plutonium equiv. to a LWR GEM*STAR Split Design burning 0.5% of natural uranium Traditional Graphite Fluence running at x30 gives 70% Pu-239 plutonium Fluence (n/b) Fissioned Fraction (%) 27

28 80.00 Fuel: un-reprocessed Light-Water-Reactor spent fuel GEM*STAR split design Elec trical Multiplic cation running at x70 gives 45% Pu-239 plutonium Super Critical Regime Traditional Graphite 100 * keff - 50 Fluence feed LWR spent fuel fission product fraction /b) Fluence (n/ Additional Fission Fraction (%) 28

29 Depleted U 600,000 tons Th 14 MWe solar array HEU W-Pu 7 MWe accelerator input power Day 7 MWe Night U GEM*STAR 210 MWe five cycles over 200 yrs Up to 300-year interim underground storage in Hastelloy Naval reactor spent fuel 10,000 tons? Commercial reactor spent fuel 60,000 tons Hydrogen DOE U 60,000 tons 217 MWe day 203 MWe night 100,000 homes Coal Production of transportation fuel for cars, trucks, trains, airplanes Solar output t 6.5 % during daylight 29 Regional geologic storage beginning in 500 years?

30 Next: 60 (120) MW e Demonstration Facility e Santa Fe Hill road Acc. 1 Reactor Acc. 2 LANSCE Los Alamos canyon 30 a potential site at Los Alamos

31 Acc. 1 Reactor Acc a potential site in Virginia

32 GEM STAR System intrinsic safety: no critical mass ever present no high-pressure containment vessel thermal neutrons: better tolerance to fission products exceptional neutron economy: allows deeper burning higher thermal to electric conversion efficiency no enrichment; no reprocessing; can burn multiple fuels including LWR spent fuel 32

33 current prices for electricity (estimated by Black and Veatch, Overland Park, Kansas) cents/kwh t/k Coal without CO 2 capture 7.8 Natural gas at high efficiency 10.6 Old nuclear 3.5 New nuclear 10.8 Wind in stand alone 9.9 Wind with the necessary base line back-up 12.1 Solar source for steam-driven electricity 21.0 Solar voltaic cells; higher than solar steam electricity *NYT, Sunday (3/29/09) by Matthew Wald 33

34 E lectricity production cost (cen ts/kwh) Thorium $50/kg Depleted uranium $30/kg Natural uranium + thorium $75/kg Natural uranium $100/kg Practical limit to accelerator Today's accelerator cost cost reduction? Accelerator cost reduction factor 34

35 cost (cent ts/kwh) El lectricity production Spent fuel + thorium Spent fuel + depleted uranium Spent fuel + natural uranium Spent fuel alone Accelerator cost reduction factor 35

36 Coal-Fired Plant Conversion to Half Nuclear Cap-and-Trade Neutralized 1000 MWe Coal Steam boiler GEM*STAR 250 MWe Electric multiplication by 30 each Steam Generator Natural uranium fuel 24 tons fed per year each Steam 550 C Original turbine/generator recouperator Before 1000 MWe Coal only Production and capital cost $0.060/KWH After 1000 MWe Coal-Nuclear Prod. and capital costs combined $0.050/KWH because existing plant infrastructure reduces GEM*STAR capital 36 Natural UF 4 fuel $5.0 million/year Electricity 7 /KWH $550 million/year CO 2 credits transferred internally

37 Diesel and Gasoline from GEM*STAR CO 2 GEM*STAR 500 MWt Coal Water Electricity and steam 6H 2 O + 3C 3CO 2 + 6H 2 2(-CH 2 -) + 4 H 2 O + CO 2 Modified Fischer-Tropsch Fuel Estimate of Diesel Price at the Pump Steam and electricity from GEM*STAR $ 0.53/gallon Feed $100/ton (twice the current price) 0.37 Conversion facility operations costs 0.19 Construction mortgage payments for conv. facil Liquid fuel production 15 % 0.19 Water (680,000 gallons/d) Wholesale price $ 1.43/gallon + Coal (3000 tons/d Distribution and sales 0.24 Federal excise tax* 0.25 Diesel (680,000 gallons/d State excise tax* CO 2 (1000 tons/d C (1/3 of feed)) Total $2.14/gallon Obviously railroad site required *U. S. Energy Information Administration averages for the U. S. 37

38 GEM STAR will transform the nuclear policy landscape: not a niche, but rather base-line capable (green) energy source no enrichment necessary burns Light-Water-Reactor spent fuel directly (including fission products and actinides) burns multiple-fuels (including Th) low-cost electricity ect c ty for consumer significant international and non-proliferation implications 38