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Division Spotlight
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.
Meeting Spotlight
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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Latest News
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.
Masaoki Komata
Nuclear Science and Engineering | Volume 47 | Number 4 | April 1972 | Pages 489-493
Technical Note | doi.org/10.13182/NSE72-A22442
Articles are hosted by Taylor and Francis Online.
The perturbation formula of Usachev-Gandini for a ratio of reaction rates is newly explained by (a) a formal functional treatment of perturbation theory and (b) the variational principle. At the outset a time-dependent problem is considered, and a perturbation formula of a reaction number ratio is obtained. In a static problem this formula directly turns to a formula of a reaction rate ratio which reduces to the Usachev-Gandini formula when an adiabatic approximation is introduced. It is shown that there is no need to solve iterative equations of successive neutron generations.
