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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.
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2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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
Countering the nuclear workforce shortage narrative
James Chamberlain, director of the Nuclear, Utilities, and Energy Sector at Rullion, has declared that the nuclear industry will not have workforce challenges going forward. “It’s time to challenge the scarcity narrative,” he wrote in a recent online article. “Nuclear isn't short of talent; it’s short of imagination in how it attracts, trains, and supports the workforce of the future.”
W. Seifritz, P. Wydler
Nuclear Science and Engineering | Volume 72 | Number 2 | November 1979 | Pages 272-276
Technical Note | doi.org/10.13182/NSE79-A19473
Articles are hosted by Taylor and Francis Online.
The physics parameters of a bare sphere of metallic 237Np have been investigated. The calculations indicate that a chain reaction can be sustained with fast neutrons. The predicted critical radius is 8.86 cm, and the corresponding critical mass is 59.7 kg. Kinetic parameters such as the prompt neutron lifetime, l, the prompt neutron decay constant at delayed criticality, αc, and the effective delayed neutron fraction, βeff, were also calculated. With respect to the last quantity, the phenomenon of the so-called “vanishing dollar” in systems consisting of even-neutron nuclei is discussed. Some remarks concerning the possible utilization of 237Np, which is produced in nuclear power reactors as a by-product, are appended.
