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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.
Milorad Dusic, Mark Dutton, Horst Glaeser, Joachim Herb, Javier Hortal, Rafael Mendizábal, Fernando Pelayo
Nuclear Technology | Volume 188 | Number 1 | October 2014 | Pages 63-77
Technical Paper | Reactor Safety | doi.org/10.13182/NT13-16
Articles are hosted by Taylor and Francis Online.
In 2009 the International Atomic Energy Agency (IAEA) published “Deterministic Safety Analysis for Nuclear Power Plants Specific Safety Guide,” Specific Safety Guide No. SSG-2 (hereinafter referred to as SSG-2). SSG-2 addresses four options for the application of deterministic safety analyses. Option 1, which has been used since the early days of civil nuclear power and is still used today, uses conservative codes/models and conservative initial and boundary (I&B) conditions. Option 2, which is frequently used worldwide, uses realistic codes/models but with conservative I&B conditions. Option 3 uses realistic codes/models and realistic I&B conditions and therefore needs also to consider the associated uncertainties. Today, option 3 is known as the Best Estimate Plus Uncertainty option. Option 4 is not developed in SSG-2 and only indicates that option 4 is an attempt to combine insights from probabilistic safety analyses with a deterministic approach, which results in a risk-informed safety analysis. In options 1, 2, and 3, the availability of safety systems is based on conservative assumptions, whereas in option 4, the availability of safety systems is derived by probabilistic means. This paper explains in more detail the approach proposed for option 4 and provides illustrative examples for its application, recognizing the fact that option 4 is still a research option and will remain so for some time.