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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.
Hiroshige Kumamaru, Yutaka Kukita, Hideaki Asaka, Ming Wang, Etsuo Ohtani
Nuclear Technology | Volume 126 | Number 3 | June 1999 | Pages 331-339
Technical Note | Thermal Hydraulics | doi.org/10.13182/NT99-A2978
Articles are hosted by Taylor and Francis Online.
The effectiveness of intentional depressurization of a pressurized water reactor primary system as a means to maintain core cooling during a small-break loss-of-coolant accident (SBLOCA) was studied. The investigation was based on experiments conducted at the Rig of Safety Assessment-V (ROSA-V) Large Scale Test Facility (LSTF) and RELAP5/MOD3 code calculations performed for LSTF geometry, together with single lumped-volume model calculations - all simulating hypothetical total failure of the high-pressure-injection system. For cold-leg breaks ≶2.5% of the leg cross-sectional area, experimental and analytical results have shown that the break discharge depressurizes the primary system to the accumulator (ACC) and low-pressure-injection (LPI) system injection pressures, and thus the core cladding temperature would be maintained below ~1000 K. For break areas ≤1.0%, on the other hand, additional depressurization means are needed to initiate the ACC injection before the core is overheated. RELAP5/MOD3 calculations have shown that steam venting through the pressurizer power-operated relief valves would be effective in depressurizing the primary system to the ACC and LPI pressures. However, for break areas <0.5%, the peak cladding temperature would finally reach the safety criterion of 1473 K.