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Robotics & Remote Systems
The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
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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.
Anil Kumar
Nuclear Science and Engineering | Volume 82 | Number 3 | December 1982 | Pages 354-358
Technical Note | doi.org/10.13182/NSE82-A19396
Articles are hosted by Taylor and Francis Online.
In the considerations of recriticality of molten fuel assemblies, the presence of bubbles in the fuel plays an important role. In such a situation, there are two opposing contributions to reactivity from (a) the phenomenon of neutron streaming in bubbles (negative contribution) and (b) the phenomenon of changing neutron self-multiplication in the fuel (positive contribution). It is not possible to accurately calculate the individual reactivity contributions of the two phenomena using multidimensional transport theory or Monte Carlo codes. A simple diffusion theory expression given by Nicholson and Goldsmith for estimating reactivity contribution due to neutron streaming alone has been used extensively. As a part of the present contribution, first an attempt has been made to improve the applicability of the Nicholson-Goldsmith work by expressing extrapolation length in terms of the root-mean-square free path in the assembly. It is found that the application of the Trombay criticality formula, particularly its “modified Wigner rational variant,” leads to an expression for bubble reactivity worth, due to neutron streaming alone, that yields the closest agreement with the bubble worth values computed from the two-dimensional transport theory code TWOTRAN and the Monte Carlo code KENO.