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Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
Standards Program
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.
Henry H. Kramer and Werner H. Wahl
Nuclear Science and Engineering | Volume 22 | Number 3 | July 1965 | Pages 373-382
Technical Paper | doi.org/10.13182/NSE65-A20941
Articles are hosted by Taylor and Francis Online.
Metastable isomers of stable isotopes may be formed in a nuclear reactor by inelastic neutron scattering and photoexcitation of the stable isotopes, and by radiative neutron capture and (n,2n) reactions on neighboring stable isotopes. The relative importance of these reactions for the production of Ba137m, Cd111m, Se77m, and Sr87m was evaluated by the irradiation of normal and isotopically enriched samples of the elements in the mixed radiation field of the Union Carbide Research Reactor. Radiative neutron capture is the most important source of Cd111m, Se77m and Sr87m in samples of normal isotopic abundance. Inelastic neutron scattering is the prime contributor to the production of Ba137m and is of considerable importance in the production of Cd111m. The (n,2n) reaction appears to be significant only in the production of Ba137m. The formation of these isomers by photoexcitation by the gamma-ray flux associated with the reactor appears to be insignificant when compared with the production by the other three processes. The cross sections determined in these investigations are generally in good agreement with available published values. Reactions for which cross sections were determined and not found in the literature include: Ba137(n,n′)Ba137m, = 0.22b; Cd111 (n,n′) Cd111m, = 0.14b; Se77(n,n′)Se77m, = 0.60b;Sr87(n,n′)Sr87m, = 0.12b; Ba138(n,2n)Ba137m, = 2.0mb; and Cd112 (n,2n)Cd111m, = 0.35mb. The data indicate that, for short irradiation periods in the fluxes employed in these studies, the metastable isomers Ba137m, Cd111m, Se77m and Sr87m are the most sensitive activation-analysis indicators for these elements and give detection sensitivities in the low nanogram range.