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The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
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2023 ANS Annual Meeting
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Indianapolis, IN|Marriott Indianapolis Downtown
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Destruction of Ukrainian dam threatens Zaporizhzhia
A Soviet-era dam downstream from the Zaporizhzhia nuclear power plant in southeastern Ukraine collapsed last evening, causing the water level of the Kakhovka Reservoir north of the dam to drop and raising new concerns over the already jeopardized safety of the Russian-occupied nuclear facility, Europe’s largest. The reservoir supplies water for, among other things, Zaporizhzhia’s cooling systems.
Thomas M. Evans, Kevin T. Clarno, Jim E. Morel
Nuclear Science and Engineering | Volume 165 | Number 3 | July 2010 | Pages 292-304
Technical Paper | doi.org/10.13182/NSE09-28
Articles are hosted by Taylor and Francis Online.
We have developed a modification of the two-grid upscatter acceleration scheme of Adams and Morel. The modified scheme uses a low-angular-order discrete ordinates equation to accelerate Gauss-Seidel multigroup iteration. This modification ensures that the scheme does not suffer from consistency problems that can affect diffusion-accelerated methods in multidimensional, multimaterial problems. The new transport two-grid scheme is very simple to implement for different spatial discretizations because it uses the same transport operator. The scheme has also been demonstrated to be very effective on three-dimensional, multimaterial problems. On simple one-dimensional graphite and heavy-water slabs modeled in three dimensions with reflecting boundary conditions, we see reductions in the number of Gauss-Seidel iterations by factors of 75 to 1000. We have also demonstrated the effectiveness of the new method on neutron well-logging problems. For forward problems, the new acceleration scheme reduces the number of Gauss-Seidel iterations by more than an order of magnitude with a corresponding reduction in the run time. For adjoint problems, the speedup is not as dramatic, but the new method still reduces the run time by greater than a factor of 6.