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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.
C. O. Muehlhause
Nuclear Science and Engineering | Volume 5 | Number 4 | April 1959 | Pages 225-226
Technical Paper | doi.org/10.13182/NSE59-A25588
Articles are hosted by Taylor and Francis Online.
Values for the number of neutrons produced per thermal neutron absorbed, ηth, in the three fissile materials U233, U235, and Pu239 are reported. The measurement of these quantities was performed between the years 1951 and 1953 at the Argonne National Laboratory using the original enriched heavy water reactor, CP3', and the technique of pile oscillation. A slight revision of the data has been made on the basis of new total cross sections and f-values. The eta values at thermal energy (0.0253 ev) were found to be η23 = 2.25 ± 0.03, η25 = 2.05 ± 0.03, and η49 = 2.04 ± 0.04.
