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Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Argala Srivastava, K. P. Singh, S. B. Degweker
Nuclear Science and Engineering | Volume 189 | Number 2 | February 2018 | Pages 152-170
Technical Paper | doi.org/10.1080/00295639.2017.1388091
Articles are hosted by Taylor and Francis Online.
The use of the Monte Carlo (MC) method for space-time reactor kinetics is expected to be much more accurate than the presently used deterministic methods largely based on few-group diffusion theory. However, the development of the MC method for space-time reactor kinetics poses challenges because of the vastly different timescales of neutrons and delayed neutron precursors and their vastly different populations that also change with time by several orders of magnitude. In order to meet these challenges in MC-based space kinetics, we propose various new schemes such as deterministic decay of precursors in each time step, adjustment of weights of neutrons and precursors for population control, use of mean number of secondaries per collision, and particle splitting/Russian roulette to reduce the variance in neutron power. The efficacy of these measures is first tested in a simpler point-kinetics version of the MC method against analytical or accurate numerical solutions of point-kinetics equations. The ideas are then extended to space-dependent MC kinetics and are validated against a transport theory/MC transient benchmark. We have also tested our methods by comparison with results of realistic space-time kinetics benchmarks/studies involving multiregion reactors, energy dependence, movement of control rods, and feedback—most of which are based on few-group diffusion theory treated by the finite difference method. To facilitate exact comparison with such benchmarks, we have implemented the schemes described above for space-time reactor kinetics based on finite difference diffusion MC, a method developed by us earlier in a different context.