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NRC approves TerraPower construction permit
Today, the Nuclear Regulatory Commission announced that it has approved TerraPower’s construction permit application for Kemmerer Unit 1, the company’s first deployment of Natrium, its flagship sodium fast reactor.
This approval is a significant milestone on three fronts. For TerraPower, it represents another step forward in demonstrating its technology. For the Department of Energy, it reflects progress (despite delays) for the Advanced Reactor Demonstration Program (ARDP). For the NRC, it is the first approval granted to a commercial reactor in nearly a decade—and the first approval of a commercial non–light water reactor in more than 40 years.
Yeon Sang Jung, Won Sik Yang
Nuclear Science and Engineering | Volume 185 | Number 2 | February 2017 | Pages 307-324
Technical Paper | doi.org/10.1080/00295639.2016.1272369
Articles are hosted by Taylor and Francis Online.
This paper presents the method and performance of a coarse-mesh finite difference (CMFD) scheme for accelerating neutron transport calculations based on the finite element method (FEM). The transport solution based on FEM does not satisfy the neutron balance exactly because FEM yields a nonconservative discretization. A modified CMFD formulation has been developed to correct the limitation of the conventional CMFD that is applicable only to neutronics solvers with a conservative discretization. A consistent CMFD problem for the transport solution based on FEM is constructed by enforcing the neutron balance in each coarse mesh by introducing a pseudo absorption cross section, and the well-established alternating solution process of CMFD and transport calculations is employed to accelerate source convergence. The applicability of the modified CMFD scheme to transport calculation based on FEM was first tested for a one-dimensional, discrete ordinates (SN), discontinuous FEM. The performance of CMFD acceleration was then investigated with a two-dimensional/three-dimensional method of characteristic transport solver for thermal and fast reactor problems with various core sizes. It was observed that the consistent CMFD scheme could improve the computational efficiency of eigenvalue calculation significantly in the framework of a transport solver with fission source iteration.