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May 31–June 3, 2026
Denver, CO|Sheraton Denver
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Modernizing I&C for operations and maintenance, one phase at a time
The two reactors at Dominion Energy’s Surry plant are among the oldest in the U.S. nuclear fleet. Yet when the plant celebrated its 50th anniversary in 2023, staff could raise a toast to the future. Surry was one of the first plants to file a subsequent license renewal (SLR) application, and in May 2021, it became official: the plant was licensed to operate for a full 80 years, extending its reactors’ lifespans into 2052 and 2053.
Ang Zhu, Yunlin Xu, Thomas Downar
Nuclear Science and Engineering | Volume 182 | Number 4 | April 2016 | Pages 435-451
Technical Paper | doi.org/10.13182/NSE15-39
Articles are hosted by Taylor and Francis Online.
Three-dimensional (3D), full-core transport modeling with pin-resolved detail for reactor dynamic simulation is important for some multiphysics reactor applications. However, it can be computationally intensive due to the difficulty in maintaining accuracy while minimizing the number of time steps. An innovative Predictor-Corrector Quasi-static Method (PCQM) is introduced that is based on a Transient MultiLevel (TML) methodology. Two levels of couplings are used between 3D-transport/3D-CMFD (coarse-mesh finite difference) and 3D-CMFD/EPKE (exact point-kinetics equation). In each level, the original flux equation is solved in the coarse predictor step and then is factorized as an amplitude and a shape function in the corrector step, where the predicted solution is adjusted using multiple fine steps. In the first-level 3D-transport/3D-CMFD coupling, the angular and subpin flux shape functions in the Boltzmann transport equation are assumed to vary slowly over time, and the CMFD cellwise amplitude function is solved using multiple steps by the 3D-CMFD transient equation. In the second level, the CMFD scalar flux calculated in the last step is further corrected by a whole-core-wise amplitude function generated by the EPKE solver. The utilization of hierarchical multilevel neutronics transient solvers achieves the goal to balance the numerical accuracy and computational efficiency. In addition, a new iteration scheme with pin-resolve thermal-hydraulic feedback and theoretical proof for the accuracy of PCQM are also presented. Finally, a stripe assembly case adopted from the SPERT (Special Power Excursion Reactor Test) transient tests is used to demonstrate the accuracy and efficiency of the TML method.