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Division Spotlight
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
NRC cuts fees by 50 percent for advanced reactor applicants
The Nuclear Regulatory Commission has announced it has amended regulations for the licensing, inspection, special projects, and annual fees it will charge applicants and licensees for fiscal year 2025.
P. R. Fields, G. L. Pyle, M. G. Inghram, H. Diamond, M. H. Studier, W. M. Manning
Nuclear Science and Engineering | Volume 1 | Number 1 | March 1956 | Pages 62-67
Technical Paper | doi.org/10.13182/NSE56-A17658
Articles are hosted by Taylor and Francis Online.
The effective pile neutron capture cross sections of the heavier Pu isotopes have been measured by irradiations, in the Chalk River Reactor (NRX) and in the Materials Testing Reactor. The values in barns for Pu240, Pu241, Pu242, Pu243, Pu244, and Pu245 were found to be: 530 ± 50, 390 ± 80, 30 ± 10, 170 ± 90, 1.5 ± 0.3, and 260 ± 145, respectively. In addition, a thermal neutron absorption cross section of 1450 ± 250 barns was found for Pu241 and a thermal neutron fission cross section of 1060 ± 210 barns for Pu241. Using these cross sections and an assumed flux of 3 × 1014 cm-2 sec-1, curves were calculated and plotted showing the variation in composition of plutonium as a function of integrated flux.
