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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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ANS joins others in seeking to discuss SNF/HLW impasse
The American Nuclear Society joined seven other organizations to send a letter to Energy Secretary Christopher Wright on July 8, asking to meet with him to discuss “the restoration of a highly functioning program to meet DOE’s legal responsibility to manage and dispose of the nation’s commercial and legacy defense spent nuclear fuel (SNF) and high-level radioactive waste (HLW).”
Hyung Jin Shim, Chang Hyo Kim
Nuclear Science and Engineering | Volume 157 | Number 2 | October 2007 | Pages 132-141
Technical Paper | doi.org/10.13182/NSE06-33
Articles are hosted by Taylor and Francis Online.
Two new stopping criteria designed to terminate automatically inactive cycle runs in Monte Carlo (MC) neutronics eigenvalue calculations are derived in terms of the covariance matrix of stochastic error components inherent in the stationary fission source distribution (FSD) from each stationary MC cycle run. A practical way to determine the covariance matrix using nonstationary FSD in the course of inactive cycle MC runs is presented. The effectiveness of the new stopping criteria including the way to calculate the covariance matrix is examined through continuous energy MC neutronics calculations for ten pressurized water reactor test problems with varying dominance ratios. It is shown that the empiricism-free new stopping criteria stop inactive cycle MC runs effectively and that FSDs from the termination of inactive MC runs are stationary consistent with the available posterior source convergence diagnosis.