From Wikipedia, the free encyclopedia
Jump to: navigation, search

Interesting Items[edit]
Articles I've Done Significant Work On[edit]

(though not necessarily recently)

I made this image showing waypoints for Linnaeus' Lapland expedition.

By 1946, only eight years after the discovery of nuclear fission, three fissile isotopes had been publicly identified for use as nuclear fuel:[1][2]

Th-232, U-235 and U-238 are primordial nuclides, having existed in their current form for over 4.5 billion years, predating the formation of the Earth; they were forged in the cores of dying stars through the r-process and scattered across the galaxy by supernovas.[4] Their radioactive decay produces about half of the earth's internal heat.[5]

For technical (outlined in a section below) and historical reasons, the three are each associated with different reactor types. U-235 is the world's primary nuclear fuel and is usually used in light water reactors. U-238/Pu-239 has found the most use in liquid sodium fast breeder reactors. Th-232/U-233 is best suited to molten salt reactors (MSR).[3]

Alvin M. Weinberg pioneered the use of the MSR at Oak Ridge National Laboratory. The Aircraft Reactor Experiment in 1954 and Molten-Salt Reactor Experiment from 1965 to 1969 both used liquid fluoride salts; the latter notably demonstrated the use of U-233 as a fuel source.[6] Unfortunately for MSR research, Weinberg was fired and the MSR program closed down in the early 1970s,[7] after which research stagnated in the United States.[8][9]


External Links[edit]
Selected Pictures I've Taken[edit]
RFID chip
  1. ^ UP (29 September 1946). "Atomic Energy 'Secret' Put into Language That Public Can Understand". Pittsburgh Press. Retrieved 18 October 2011. 
  2. ^ UP (21 October 1946). "Third Nuclear Source Bared". The Tuscaloosa News. Retrieved 18 October 2011. 
  3. ^ a b Hargraves, Robert; Moir, Ralph (2010). "Liquid Fluoride Thorium Reactors" (PDF). American Scientist 98 (4): 304–313.  Unknown parameter |month= ignored (|date= suggested) (help)
  4. ^ Synthesis of heavy elements
  5. ^ The KamLAND Collaboration (2011-07-17). "Partial radiogenic heat model for Earth revealed by geoneutrino measurements". Nature Geoscience 4: 647–651. doi:10.1038/ngeo1205. 
  6. ^ Rosenthal, M.; Briggs, R.; Haubenreich, P., Molten-Salt Reactor Program: Semiannual Progress Report for Period Ending August 31, 1971 (PDF), ORNL-4728, Oak Ridge National Laboratory 
  7. ^ H. G. MacPherson (1985-08-01). "The Molten Salt Reactor Adventure". Nuclear Science and Engineering 90: 374–380. 
  8. ^ Weinberg, Alvin (1997). The First Nuclear Era: The Life and Times of a Technological Fixer. Springer. ISBN 978-1563963582. Retrieved 12 November 2011. 
  9. ^ "ORNL: THE FIRST 50 YEARS--CHAPTER 6: RESPONDING TO SOCIAL NEEDS". Retrieved 12 November 2011.