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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.
Jian-Yu Zhu, Hao-Wei Dai, Wen-Xiong Xie
Nuclear Technology | Volume 192 | Number 2 | November 2015 | Pages 172-180
Technical Paper | Radiation Measurements and General Instrumentation | doi.org/10.13182/NT14-115
Articles are hosted by Taylor and Francis Online.
Algorithms for locating the neutron source by neutron time-of-flight (TOF) measurement are established and discussed for monoenergetic and multienergetic neutrons in this paper. For the monoenergetic neutron source, the location of the source could be estimated by locating the position where the variance between the actual TOF and the calculation gains its minimum. For multienergetic neutrons the maximum likelihood (ML) method has been applied to process the time-correlation measurement. The efficiencies of location estimations are studies with simulations. In the simulations, the TOFs are acquired by time-correlation measurement of three neutron detectors surrounding the suspected area of the neutron source. The results indicate that the location of monoenergetic neutron sources could be estimated by the neutron TOF acquired by three detectors, while for multienergetic neutron sources, the likelihood method could be used to locate the most probable location, as well as its possible distribution of location. As the result of large-scale simulation and comparison, the ML estimation method is more effective than traditional methods, especially in conditions of low count rates or low resolution.