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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Latest News
NNSA awards BWXT $1.5B defense fuels contract
The Department of Energy’s National Nuclear Security Administration has awarded BWX Technologies a contract valued at $1.5 billion to build a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant in Tennessee in support of the administration’s efforts to build out a domestic supply of unobligated enriched uranium for defense-related nuclear fuel.
Hiroki Takezawa, Delgersaikhan Tuya, Toru Obara
Nuclear Science and Engineering | Volume 195 | Number 11 | November 2021 | Pages 1236-1246
Technical Note | doi.org/10.1080/00295639.2021.1920797
Articles are hosted by Taylor and Francis Online.
This study introduces new methodologies for integrating fission reactions induced by delayed neutrons into the Multi-Region Integral Kinetic (MIK) code by using a Monte Carlo neutron transport calculation. First, it was confirmed that it is feasible to solve the Integral Kinetic Model (IKM) with delayed neutrons by the forward Euler discretization method in terms of the number of time steps. This can be done with the help of the law of radioactive decay to reflect the delay in the emission of delayed neutrons in the discretized IKM. Second, a new Monte Carlo–based methodology was introduced for calculating the cumulative distribution functions of secondary fission induced by prompt and delayed neutrons. These functions are necessary for the discretized IKM. The results of preliminary verification using the Godiva reactor confirmed the applicability of the new Monte Carlo–based methodology. A new MIK code that has the capability of calculating the fission reaction rates for delayed neutrons is currently under development. Based on the preliminary verification results, future studies will verify the discretized IKM with delayed neutrons using kinetic analyses and compare them to experimental results for prompt and delayed supercritical transients in diverse reactor configurations.