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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The Frisch-Peierls memorandum: A seminal document of nuclear history
The Manhattan Project is usually considered to have been initiated with Albert Einstein’s letter to President Franklin Roosevelt in October 1939. However, a lesser-known document that was just as impactful on wartime nuclear history was the so-called Frisch-Peierls memorandum. Prepared by two refugee physicists at the University of Birmingham in Britain in early 1940, this manuscript was the first technical description of nuclear weapons and their military, strategic, and ethical implications to reach high-level government officials on either side of the Atlantic. The memorandum triggered the initiation of the British wartime nuclear program, which later merged with the Manhattan Engineer District.
W.E. Browning, Jr., C.E. Miller, Jr., R.P. Shields,B.F. Roberts
Nuclear Science and Engineering | Volume 18 | Number 2 | February 1964 | Pages 151-162
Technical Paper | doi.org/10.13182/NSE64-1
Articles are hosted by Taylor and Francis Online.
A series of experiments to study the amounts and forms of fission products released during simulated reactor accidents is described. These experiments consisted of melting miniature stainless-steel-clad UO2 fuel elements in a helium atmosphere in the Oak Ridge Research Reactor and measuring the fission products released. Fission and gamma heat in the reactor raised the temperature of the miniature fuel element sufficiently high to melt the UO2 without the use of external heat. In these experiments with UO2, nearly all of the iodine, tellurium, and cesium, and more than half of the strontium, zirconium, ruthenium, barium, and cerium were released from the fuel. Release of the latter group of fission products and uranium from a zone including the fuel and surrounding heat insulators was generally less than 3%. The minimum temperature of this zone during fuel melting was 1000 C. The retention of fission products within the high-temperature zone is considered to be significant since, during an actual reactor accident, temperatures corresponding to those of the high-temperature zone would probably occur only within the immediate area in which the fuel is overheated. Analysis of the observed distributions of deposited fission products yields information about their behavior and form. Ruthenium follows the stainless-steel cladding as it melts and vaporizes. Certain fission products are associated with millimicrometer-size particles of two size groups, one centered around 22 angstroms and the second around 30 angstroms in diameter. Comparisons of the fission-product-release values from in-pile and various out-of-pile experiments indicate that the in-pile releases are greater, probably because of more extreme temperatures.
