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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.
Hideo Hirayama, Yoshiko Harima, Yukio Sakamoto, Naohiro Kurosawa, Makoto Nemoto
Nuclear Technology | Volume 168 | Number 3 | December 2009 | Pages 901-905
Dose/Dose Rate | Special Issue on the 11th International Conference on Radiation Shielding and the 15th Topical Meeting of the Radiation Protection and Shielding Division (PART 3) / Radiation Protection | doi.org/10.13182/NT09-A9325
Articles are hosted by Taylor and Francis Online.
Line-beam response function (LBRF) and conical-beam response function (CBRF) data for gamma-ray skyshine are generated using the EGS4 code in an arbitrary geometry for energies ranging from 0.1 to 10 MeV at all the emitted angles up to a distance of 2000 m from the source. The skyshine dose is calculated for the air kerma, exposure, ambient dose equivalent H*(10), and effective dose E with anterior-posterior and isotropic irradiation geometries.A response function with a four-parameter empirical formula,R(E,,x) = [fraktur R]E(/0)2 exp(a + cx/0)xb+dx/0,can be used to approximate the LBRF and CBRF with good accuracy. The values of the four parameters a, b, c, and d are determined for a given beam energy and direction by fitting the four-parameter function such that the maximum fractional deviation of the LBRF and CBRF values is minimized for a set of discrete source-to-detector distances. The parameter set is selected to realize the interpolation of LBRF and CBRF in relation to the energy and direction by the interpolation of these parameters. Consequently, discrete LBRF and CBRF data are converted to continuous data with regard to both energy and direction.The evaluation of gamma-ray skyshine dose analyses can be accomplished easily and quickly by using the four-parameter formula.These data can be downloaded in Excel format from http://rcwww.kek.jp/rc_en.html as "Data Library of Line- and Conical-Beam Response Functions and Four-Parameter Empirical Formula in Approximating Response Functions for Gamma-Ray Skyshine Dose Analyses."
