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Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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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New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
R. L. Crowther, J. W. Weil
Nuclear Science and Engineering | Volume 3 | Number 6 | June 1958 | Pages 747-757
Technical Paper | doi.org/10.13182/NSE58-A25508
Articles are hosted by Taylor and Francis Online.
The presence of a large, sharp resonance at 1 ev in Pu240 results in the effective pile cross section for this isotope being very much larger than the true thermal cross section. Furthermore, the narrowness of this resonance causes the absorption of epithermal neutrons in Pu240 to be strongly self-shielded. Consequently, the effective cross section of Pu240 will be a function of reactor spectrum and of the Pu240 concentration at any given time. The significance of this effect can be appreciated by noting that the effective cross section of this isotope is frequently more than twice the effective thermal value. An approximate method of calculation has been applied to long term reactivity problems. The importance of the resonance augmentation and concentration dependence of the Pu240 cross section is particularly evident in the first few thousand Mwd/t and causes significant changes in the reactivity required to reach any longer burnout. Sample calculations are presented and comparisons with the Canadian experimental determinations of the effective Pu240 cross section are made. An effective constant Pu240 cross section is presented which will yield approximately correct burnout results when used in conventional irradiation studies.