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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.
Doonyapong Wongsawaeng, Donald Olander
Nuclear Technology | Volume 159 | Number 3 | September 2007 | Pages 279-291
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT07-A3876
Articles are hosted by Taylor and Francis Online.
A liquid metal (LM) consisting of one-third weight fraction each of Pb, Sn, and Bi has been investigated as the bonding substance in place of He in the pellet-cladding gap of light water reactor fuel elements. The LM bond eliminates the large T over the preclosure gap that is characteristic of helium-bonded fuel elements. Because the LM does not wet either UO2 or Zircaloy, simply loading fuel pellets into a cladding tube containing LM at atmospheric pressure leaves unfilled regions (voids) in the bond, which lead to local fuel hot spots. Voids were eliminated during fabrication by first evacuating the rod loaded with solid alloy and a fuel stack, melting the alloy, pushing down the fuel stack to drive the LM into the gap, and finally applying at least 5 atm He overpressure. Fabrication of a 4-m-long full-scale fuel rod using this technique was successfully demonstrated. A destructive examination revealed numerous breaks in the frozen alloy bond, but all of these appeared to result from handling the fuel rod. Application to commercial fuel manufacturing should require only minor modifications to existing fabrication lines. The most suitable nondestructive examination technique utilizes a collimated X-ray beam to probe edge-on the region between the pellet surface and the cladding inside diameter.