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Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
TerraPower begins U.K. regulatory approval process
Seattle-based TerraPower signaled its interest this week in building its Natrium small modular reactor in the United Kingdom, the company announced.
TerraPower sent a letter to the U.K.’s Department for Energy Security and Net Zero, formally establishing its intention to enter the U.K. generic design assessment (GDA) process. This is TerraPower’s first step in deployment of its Natrium technology—a 345-MW sodium fast reactor coupled with a molten salt energy storage unit—on the international stage.
D. P. Roux, A. R. Buhl
Nuclear Technology | Volume 12 | Number 1 | September 1971 | Pages 137-140
Technical Note | Reactor | doi.org/10.13182/NT71-A15906
Articles are hosted by Taylor and Francis Online.
As a result of the effect of residual gamma radiation on neutron detectors in shutdown reactors, the precision of subcriticality measurements by noise analysis is degraded. An equation for this gamma degradation effect was developed for application to fast reactors. The gamma degradation factor D and the detection efficiency Wn were evaluated for 10B, 3He, and 235U detectors for application in the Fast Flux Test Facility (FFTF), and it was concluded that the 235U, the least sensitive of the three detectors, is the best choice. The 235U detector is 40 times less efficient than the 3He detector, but it should experience only a slight degradation in the FFTF. By contrast, degradation factors varying between 100 and a few thousand are anticipated for the 3He detector through the shutdotvn range of -1 to -10 dollars. Furthermore, D is unity up to 106 R/h and is independent of p for the fission chamber when used as a counter.
