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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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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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A wave of new U.S.-U.K. deals ahead of Trump’s state visit
President Trump will arrive in the United Kingdom this week for a state visit that promises to include the usual pomp and ceremony alongside the signing of a landmark new agreement on U.S.-U.K. nuclear collaboration.
Robert B. Hayes
Nuclear Technology | Volume 207 | Number 3 | March 2021 | Pages 460-467
Technical Note | doi.org/10.1080/00295450.2020.1762472
Articles are hosted by Taylor and Francis Online.
The standard approach in nuclear criticality safety analysis is to rely quite heavily—and in some cases exclusively—on passive controls, such as assuming all worst-case conditions are by default attained. This means assumptions are made such as no poison, optimum moderation, and pure fissile actinide content at the maximum mass with optimum full reflection. What is clearly attainable is something less than any of these extremal conditions, but how can one rely on a limit based on assuming less than the worst case without some controls ensuring those assumptions are not challenged? This technical note discusses various options for approaching a defendable realistic technical basis for safety analysis by associating probabilities with conservative assumptions.