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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.
George Tessler, Ben R. Beaudoin, William J. Beggs, Louis B. Freeman, Albert C. Kahler, William C. Schick, Jr.
Nuclear Technology | Volume 82 | Number 3 | September 1988 | Pages 275-289
Technical Paper | Nuclear Fuel | doi.org/10.13182/NT88-A34129
Articles are hosted by Taylor and Francis Online.
The light water breeder reactor (LWBR) was developed by the Bettis Atomic Power Laboratory under the technical direction of the Office of Naval Reactors, U.S. Department of Energy. The LWBR operated successfully in the Shippingport Atomic Power Station from 1977 to 1982, producing more than 29 000 equivalent full-power hours. Because of the small breeding gain (1.35%) predicted for this selfsustaining breeder, proof of breeding required accurate nondestructive assay of expended fuel from the LWBR. The fact that breeding has been proven in the LWBR means that this reactor provides a vast alternative energy resource using plentiful thorium fuel. A gauge, called the production irradiated fuel assay gauge (PIFAG), was developed to nondestructively assay whole irradiated fuel rods from the LWBR. The gauge uses the method of active interrogation with 252Cf source neutrons and delayed neutron counting. It is remotely operated inside a hot cell and has the capability to interrogate fuel rods with two different neutron energy spectra, one with primarily low-energy (<0.625-eV) neutrons and the second with the lowenergy neutrons removed. In addition to delayed neutron counting, the PIFAG has provision for counting 252Cf source neutrons close to the surface of a fuel rod during interrogation, and for gamma scanning the fuel rod. These data are used to calculate a selfshielding correction to the delayed neutron data. A description is given of the PIFAG, its calibration, and its application to the assay of irradiated LWBR fuel rods. A comparison of the PIFAG results with destructive assay results for 17 irradiated LWBR fuel rods shows that the two methods are in excellent agreement, differing by 0.069 and 0.162% for the lowand high-energy PIFAG interrogation spectra, respectively.
