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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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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.
Guillaume Giudicelli, Kord Smith, Benoit Forget
Nuclear Science and Engineering | Volume 194 | Number 11 | November 2020 | Pages 1044-1055
Technical Paper | doi.org/10.1080/00295639.2020.1765606
Articles are hosted by Taylor and Francis Online.
A recent hybrid stochastic-deterministic calculation scheme using Monte Carlo–tallied group cross sections in a deterministic solver uses the best of both worlds for accurate and fast reactor agnostic transport simulations. However, neglecting the angular dependence of group cross sections induces large self-shielding errors in resonance groups, causing a large reactivity bias up to 300 pcm in light water reactors. To recover this error, we introduce a two-scale assembly transport calculation scheme: cross sections are tallied at the assembly level, while equivalence parameters are computed in a two-dimensional (2-D) pin cell system. We validate a novel equivalence method based on jump conditions on angular fluxes by comparing to the well-established superhomogenization method for 2-D and three-dimensional (3-D) linear source method of characteristics calculations. Test cases include 2-D and 3-D assemblies of two different enrichments with homogeneous and discretized cross-section discretizations. The linear source approximation enables using coarse source-region discretization for these hot zero-power problems. Both equivalence techniques perform similarly, recover the reactivity bias, and achieve near preservation of reaction rates, supporting this multiscale approach to equivalence.