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The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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.
Toshihiro Yamamoto, Yoshinori Miyoshi
Nuclear Science and Engineering | Volume 142 | Number 3 | November 2002 | Pages 305-314
Technical Paper | doi.org/10.13182/NSE02-A2309
Articles are hosted by Taylor and Francis Online.
Mechanisms of a positive temperature reactivity coefficient that occurs in a dilute plutonium solution are investigated based on the perturbation theory and the four-factor formula. The temperature coefficient of a solution fuel is positive if the adjoint flux increases with neutron energy between 0.05 and 0.2 eV. As compared to 239Pu, 241Pu has a tendency to make the temperature coefficient of a plutonium solution positive because of the energy dependence of the capture cross section of 241Pu. As 241Pu in a plutonium solution decays into 241Am with time, the temperature coefficient of the solution becomes more positive. Since the capture cross sections of most neutron absorbers such as boron and gadolinium decrease with increasing neutron energy between 0.05 and 0.2 eV, soluble absorbers in a plutonium solution make the temperature coefficient positive for higher-concentration plutonium solutions. Cadmium and samarium dissolved in a dilute plutonium solution can exceptionally keep the temperature coefficient negative because of the energy dependence of the capture cross sections. A fixed neutron absorber generally makes the temperature coefficient of a plutonium solution negative regardless of the property of absorber materials.