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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 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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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
P. A. Ombrellaro, F. D. Federighi
Nuclear Science and Engineering | Volume 16 | Number 4 | August 1963 | Pages 343-356
Technical Paper | doi.org/10.13182/NSE63-A26544
Articles are hosted by Taylor and Francis Online.
A variational procedure for calculating fast energy few group constants is described. For a given medium, the method permits one to express the flux and current solutions of the Boltzmann equation, treated according to P − 1 slowing down theory in each group of a few group scheme, as a linear combination of base flux spectra to obtain the group flux and as a linear combination of base current spectra to obtain the group current. The coefficients for combining the base spectra are provided by the theory and depend only on the concentrations of the component elements of the medium. Once the flux and current spectra in each group are calculated, the group constants for the medium can be easily calculated from base flux spectra weighted library microscopic cross sections. Group constants calculated in this manner agree well with those obtained from the MUFT V program.
