The document discusses liquid fuel nuclear reactors that use molten salt coolants with dissolved uranium and thorium fluorides. These reactors promise to generate electricity cheaper than coal. The history of nuclear reactor development is reviewed, including early experimental reactors from the 1940s-1960s. Molten salt reactors from the 1950s-60s are discussed in more detail. It is argued that liquid fluoride thorium reactors (LFTRs) could provide energy more cheaply than coal and with less nuclear waste. Developing a prototype LFTR within 5 years is proposed.

1. Liquid Fuel Nuclear Reactors Molten salt coolants with dissolved uranium and thorium fluorides promise reactors that can generate electric power cheaper than from coal. Robert Hargraves and Ralph Moir March 29, 2010

2. 1934: Hungarian physicist Leó Szilárd filed a patent for chain reaction fission.

3. Enrico Fermi sketched a lattice of graphite and uranium oxide.

4. Fermi's 1942 Chicago pile illustrated criticality.

5. Fermi's 1944 first fluid reactor measured U-235 critical mass. uranyl sulfate in water all the world's U-235 ! beryllium oxide neutron reflector http://www.fas.org/sgp/othergov/doe/lanl/pubs/00416628.pdf

6. Weinberg's PWR was heterogeneous. uranium fuel rods moderating water

7. The aqueous homogeneous reactor at Oak Ridge generated 140 kW in 1953. Richard Engel adds 300 g of uranium in 500 ml of heavy water to generate electric power for two months. National Geographic

8. LAMPRE Los Alamos Molten Plutonium Reactor Experiment 1961-1963 molten iron and plutonium fuel liquid sodium cooled

9. J J Went developed a 1 MW suspension test reactor in 1974 at KEMA, Netherlands. A homogeneous slurry of uranium and thorium particles was suspended in heavy water.

10. Weinberg had proposed the PWR to Rickover's team for naval propulsion.

11. Rickover + Shippingport  100 US PWRs.

12. Radiation, fission products, and heat damage solid fuel. Zirconium cladding must contain fuel for centuries.

13. Spent fuel contains fission products , fissile fuel , and fertile uranium . trace % minor actinides Np, Am, Cm, … Enriched uranium fuel 96.5% U-238 3.5% U-235 3% fission products 1% plutonium 0.50% Pu-239 FUEL 0.25% Pu-240 future FUEL 0.15% Pu-241 FUEL 96% uranium 0.83% U-235 FUEL 0.40% U-236 future FUEL 94.77% U-238 future FUEL WASTE Power reactor

14. France reprocesses some spent fuel. in temporary or permanent storage http://spectrum.ieee.org/print/4891 1450 T fresh fuel (for 59 reactors) 100 T MOX spent fuel 500 T UOx spent fuel 850 T UOx spent fuel Reprocessing Plant separates U, Pu radioactive wastes 300 T re-enriched in Russia U 505 T U stockpiled 37 T radioactive waste vitrified 100 T MOX 92 T depleted U 8 T Pu 1050 T enriched UOx

15. Actinides fission or absorb neutrons to form new actinides, which ....

16. LMFBR LFTR PWR Two breeding technologies provide 10 2 X more energy than 0.7% U-235.

17. All five US LMFBRs were shut down, as was the Integral Fast Reactor project. Fission product wastes Oxides to metals Future fast reactors Current thermal reactors Fissionable U, Np, Pu, Am, Cm, … kept together Electrorefining New fuel rod casting Metals + - Cadmium etc

18. In LFTR the liquid Th-232 blanket becomes the U-233 liquid fuel.

19. Weinberg and Oak Ridge developed the first molten salt nuclear reactor in 1954. 860 C Red hot! 100 hours 2.5 MW

20. 235 UF 4 fuel in molten NaF and ZrF 4 salt flowed through beryllium moderators. intrinsic reactivity stability automatically adjusted power without control rods corrosion resistant

22. 1.4 m diameter NaK metal would transfer 200 MW thermal power to jet engines.

23. The Molten Salt Reactor Experiment ran until 1965. Salt flowed through channels in this graphite core.

28. Weinberg had envisioned LFTR ever since the 1943 Wigner aqueous design. " humankind's whole future depended upon this "

29. Global warming, overpopulation, and resources competition are increasing.

30. Dennis Meadows’ Limits to Growth showed effects of finite resources. http://www.aspoitalia.net/images/stories/aspo5presentations/Meadows_ASPO5.pdf Resources Population Food Pollution Industrial Output 2010 1972

31. Energy cheaper than from coal is important.

32. Energy cheaper than from coal is important. Copenhagen failed.

33. Energy cheaper than from coal is important. Copenhagen failed. Coal costs $40 a ton – $0.02 / kWh just for the coal.

34. Population is stable in developed nations. http://caliban.sourceoecd.org/vl=1260748/cl=17/nw=1/rpsv/factbook/010101.htm US World OECD 6.7 billion 2008 http://www.oecd.org/dataoecd/13/38/16587241.pdf

35. Prosperity stabilizes population. https://www.cia.gov/library/publications/the-world-factbook/docs/rankorderguide.html GDP per capita Children per woman 82 nations with populations over 10 million.

36. Prosperity stabilizes population. https://www.cia.gov/library/publications/the-world-factbook/docs/rankorderguide.html GDP per capita Children per woman 82 nations with populations over 10 million.  Stable replacement rate

37. Prosperity stabilizes population. https://www.cia.gov/library/publications/the-world-factbook/docs/rankorderguide.html GDP per capita Children per woman 82 nations with populations over 10 million.  Stable replacement rate Prosperity

38. Prosperity depends on energy. https://www.cia.gov/library/publications/the-world-factbook/rankorder/2042rank.html GDP per capita Annual kWh per capita Nations with populations over 10 million.

39. Prosperity depends on energy. Prosperity https://www.cia.gov/library/publications/the-world-factbook/rankorder/2042rank.html GDP per capita Annual kWh per capita Nations with populations over 10 million.

40. LFTR can make electricity cheaper than from coal. http://www.bloomberg.com/apps/news?pid=20601080&refer=asia&sid=aV_2FPlVxISE 100 MW LFTR $ Cost $ per mo, 40 yrs, 8% $ per KWH @ 90% Construction 200,000,000 1,390,600 0.0214 100 kg U startup 1,000,000 6,953 0.000108 Thorium fuel 30,000/yr 2500 0.00000386 Decomm (½ const) 100,000,000 960 0.00000148 Operations 1,000,000/yr 83,333 0.00128 TOTAL 0.0228

41. The median of five cost estimates for molten salt reactors is < $2/watt. Estimate Year $/watt 2009 $/watt Sargent & Lundy 1962 0.650 4.64 Sargent & Lundy ORNL TM-1060 1965 0.148 1.01 ORNL-3996 1966 0.243 1.62 Engel et al, ORNL TM7207 1978 0.653 2.16 Moir 2000 1.580 1.98

42. LFTR needs no costly 160-atmosphere pressure vessel and containment dome. GE-Hitachi ABWR 39 months 1,356 MW 36 x 29 meter containment 1,000 ton crawler cranes

43. The Westinghouse Toshiba AP-1000 is massively larger than a 100 MW LFTR. AP-1000 Samen, China Jan 2010

44. The Westinghouse AP-1000 is massively larger than LFTR. 1.4 m 1.4 m AP-1000 Samen, China Jan 2010

45. LFTR relies on simple, intrinsic safety systems, not costly defense in depth. Stable reactivity. Fuel already melted. Atmospheric pressure. Salt from rupture or leak will solidify. Melting freeze plug dumps salt to tank. Freeze plug

46. High thermal energy efficiencies keep LFTR compact and low cost. Molten salt is a high thermal capacity heat exchange fluid, better than water, sodium, or helium. Carbon composite heat exchangers presage future higher temperatures.

47. Closed cycle Brayton turbine raises power conversion efficiency to 45+%. Halving rejected heat enables air cooling.

48. Boeing makes one $200 million aircraft per day.

49. The learning curve experience runs counter to economy of scale. 10% learning ratio

50. By-product U-232’ s decay chain emits gamma rays hazardous to bomb builders . neutron absorption beta decay neutron abs/decay (n,2n) nucleons Th 90 Pa 91 U 92 Np 93 235 234 233 232 231 230

51. Uranium separator Fertile Th-232 blanket Fissile U-233 core New U-233 fuel New Th-232 n n Uranium from a commercial LFTR will not be used for weapons. Breeds only as much U-233 as it consumes. Removing any will stop the LFTR.

52. Uranium separator Fertile Th-232 blanket Fissile U-233 core New U-233 fuel New Th-232 n n Uranium from a commercial LFTR will not be used for weapons. Breeds only as much U-233 as it consumes. Removing any will stop the LFTR. U-232 contamination will be 0.13%. A 5 kg sphere of it radiates 4,200 mrem/hr at 1 meter.

53. Uranium separator Fertile Th-232 blanket Fissile U-233 core New U-233 fuel New Th-232 n n Uranium from a commercial LFTR will not be used for weapons. Breeds only as much U-233 as it consumes. Removing any will stop the LFTR. U-232 contamination will be 0.13%. A 5 kg sphere of it radiates 4,200 mrem/hr at 1 meter. After 72 hours of exposure a weapons worker will likely die.

54. Uranium separator Fertile Th-232 blanket Fissile U-233 core New U-233 fuel New Th-232 n n Uranium from a commercial LFTR will not be used for weapons. Breeds only as much U-233 as it consumes. Removing any will stop the LFTR. U-232 contamination will be 0.13%. A 5 kg sphere of it radiates 4,200 mrem/hr at 1 meter. After 72 hours of exposure a weapons worker will likely die. India, Pakistan, and North Korea demonstrated far less technically challenging and costly paths.

55. LFTR produces much less long lived radiotoxic actinide waste.

56. Moir and Teller proposed LFTR R&D in 2005

57. US R&D in nuclear fission had dropped – to zero for breeders. IAEA, via Inter. Panel on Fissile Materials Feb 2010

58. A prototype LFTR could be operational in 5 years. 2010 2015 2020 Develop Scale up Produce $ 1 B $ 5 B $ 70 B per year industry Commercialize One LFTR per day Export

59. A prototype LFTR could be operational in 5 years. 2010 2015 2020 Develop Scale up Produce $ 1 B $ 5 B $ 70 B per year industry Commercialize One LFTR per day Export Rickover's Shippingport was built in 32 months . Weinberg-engineered Oak Ridge X-10 was built in 9 months .

60. Aim High! Zero emissions worldwide. http://www.eia.doe.gov/pub/international/iealf/table63.xls Install one 100 MW LFTR each day , worldwide, to replace all coal power. 2020 2058 10 billion tons CO 2 Annual emissions from coal power plants  1400 GWY

61. Aim High! Synthesize fuel and fertilizer. http://wwwtest.iri.tudelft.nl/~klooster/reports/hydro_slides_2003.pdf Dissociate water at 900 o C to make hydrogen: sulfur-iodine process. CO 2 + 3 H 2  CH 3 OH + H 2 O Methanol for gasoline Dimethyl ether for diesel Ammonia for fertilizer

62. Aim High! Check population growth, pollution, and resources use. Resources Population Food Pollution Industrial Output

63. Liquid Fuel Nuclear Reactors will be published this summer.