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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
Kenji Yokoyama, Makoto Ishikawa
Nuclear Science and Engineering | Volume 178 | Number 3 | November 2014 | Pages 350-362
Technical Paper | doi.org/10.13182/NSE14-11
Articles are hosted by Taylor and Francis Online.
To provide a reactor physics benchmark for burnup reactivity coefficients, experimental data, showing the relationship between excess reactivity and accumulated thermal power acquired during the experimental fast reactor JOYO MK-I duty power operation in the late 1970s, have been evaluated and analyzed. To improve the prediction accuracy of nuclear characteristics through the use of integral experimental data, nominal values and uncertainties, including correlations of the experimental data, were evaluated. All possible uncertainty factors were evaluated and quantified by utilizing knowledge obtained after the MK-I duty power operation and calculation results based on the latest reactor physics analysis methods. Meanwhile, the present evaluated data have been reviewed and approved by the International Reactor Physics Experiment Evaluation Project, with the expectation that these data will be widely used. In the present paper, the evaluation of nominal values and uncertainties is described with a focus on the measurement technique uncertainty, which is a dominant uncertainty factor of the burnup reactivity coefficient. In addition, new analysis results of the benchmark problem are shown by the use of the latest Japanese evaluated nuclear data JENDL-4.0.