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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
HyeonTae Kim, Woosong Kim, Yonghee Kim
Nuclear Science and Engineering | Volume 193 | Number 5 | May 2019 | Pages 441-452
Technical Paper | doi.org/10.1080/00295639.2018.1542867
Articles are hosted by Taylor and Francis Online.
This paper suggests novel approaches to generate exact discontinuity factors (DFs) for transverse-integrated nodal analyses with a two-by-two node configuration in a homogenized fuel assembly (FA). We have shown that the conventional DF calculation scheme cannot generate exact DFs with the nodal expansion method (NEM) calculation when a FA is subdivided into two-by-two nodes due to the inherent discrepancy between the transport-based heterogeneous analysis and the diffusion-based NEM calculation. In order to overcome the difference, an iterative, two-node NEM sweeping method is proposed. In addition, three different formulations to define a single representative DF per assembly surface for the two-by-two NEM are suggested for convenient application for the existing nodal codes while maintaining enough accuracy. Numerical assessments with a colorset model and small modular reactor cores with 16 × by × 16 FAs show that the iterative two-node NEM sweep method successfully corrects the error caused by an inherent discrepancy between the transport and the diffusion method. Among the candidates of a single representative DF, the net current weighted average DFs are found to be the most adequate.