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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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DOE issues new NEPA rule and procedures—and accelerates DOME reactor testing
Meeting a deadline set in President Trump’s May 23 executive order “Reforming Nuclear Reactor Testing at the Department of Energy,” the DOE on June 30 updated information on its National Environmental Policy Act (NEPA) rulemaking and implementation procedures and published on its website an interim final rule that rescinds existing regulations alongside new implementing procedures.
Jin-Young Cho, Jae-Seung Song, Chung-Chan Lee, Sung-Quun Zee, Jae-Il Lee, Kil-Sup Um
Nuclear Technology | Volume 161 | Number 1 | January 2008 | Pages 57-68
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT08-A3913
Articles are hosted by Taylor and Francis Online.
A lumped-refined multichannel analysis scheme is developed for a high-fidelity thermal-hydraulic (T-H) calculation through neutronics code coupling and applied to a control element assembly (CEA) ejection accident of the Ulchin Unit 3 nuclear power plant to quantify the conservatism of the conventional scheme. The high-fidelity core minimum departure from nucleate boiling (DNB) ratio calculation is realized by coupling more than two TORC dynamic link libraries (DLLs) under the control of the neutronics code, one for the lumped multichannel calculation and the others for the refined subchannel calculations. Realistic radial boundary conditions are supplied from the lumped multichannel calculation to the refined TORC DLL through the neutronics code. The CEA ejection accident problem is simulated from the DNB limiting conditions for operation condition, which is searched by adjusting the core radial peaking factor at a 30% axial offset power shape. The results indicate that the simplified hot-channel model contains ~15 and 5% conservatism in the core minimum DNB ratio and in the number of failed fuel rods, respectively, and reveals that those conservatisms are mainly due to the unrealistic isolated boundary condition. Therefore, it is concluded that the developed scheme can be effectively used to quantify the conservatism of a conventional DNB evaluation scheme.