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Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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Nuclear Science and Engineering
Fusion Science and Technology
Fund to spur new nuclear projects launched in U.K.
The U.K. government is providing £120 million (about $149.9 million) for a new fund designed to support the development of new nuclear energy projects, stimulate competition in the industry, and unlock investment.
Yoshitaka Naito, Kazuo Azekura
Nuclear Technology | Volume 204 | Number 1 | October 2018 | Pages 94-100
Technical Paper | dx.doi.org/10.1080/00295450.2018.1469344
Articles are hosted by Taylor and Francis Online.
In this paper, a method is proposed to evaluate the extent of subcriticality of an accident-damaged nuclear reactor. With this method the activity ratio of two fission product (FP) rare gas nuclides and is measured. From the measured value, the value of the nuclides in the fuel region is estimated by correcting for the time lag incurred when the gases diffuse from the fuel region to the measuring point. A simple expression for an effective multiplication factor has been derived that uses the corrected -to- activity ratio and the -to- fission yield ratios of and but that does not require information on the amount or distribution of the fuel material, making the proposed method very simple. This method has the advantage that FP rare gases can easily leak from the reactor core through many openings and gaps, reaching germanium counters without reacting with other materials.