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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.
Kazuki Kuwagaki, Jun Nishiyama, Toru Obara
Nuclear Science and Engineering | Volume 191 | Number 2 | August 2018 | Pages 178-186
Technical Note | doi.org/10.1080/00295639.2018.1463744
Articles are hosted by Taylor and Francis Online.
In the breed and burn (B&B) strategy, low-reactivity fuels are loaded in a core. It is difficult to keep criticality in operating a small core. To enhance the potential for achieving criticality, the neutron economy in a core should be improved. One improvement method is to increase the core size and reduce neutron leakage. If it is necessary to avoid the large-sized core, another method is to locate high-reactivity fuels in high-neutron-importance region continuously through an equilibrium burnup state. On the other hand, to stabilize the change of neutron flux and power distribution during the operation, the B&B regions need to be kept stationary in the same region.
In this study, a rotational fuel-shuffling concept was proposed. In this concept, fuel assemblies are moved to the next position step by step in a divided symmetry core region. Fresh fuel is loaded from the periphery and moved toward the center region, then moved outward and discharged. If the core could achieve an equilibrium state at which high-reactivity fuels are continuously placed in the core center region, it would be possible to keep the B&B regions stationary. In this kind of equilibrium state, high-reactivity fuels are placed in high-neutron-importance region stably. Simulations for this concept were performed using the continuous-energy Monte Carlo code MVP/MVP-BURN. A small lead-bismuth-cooled fast reactor with metallic fuel was adopted as the core design. As a result, a core with rotational fuel shuffling achieved an equilibrium cycle at criticality, and the change of multiplication factors in the equilibrium cycle was less than 0.1%. The neutron flux and power distributions were almost unchanged during the operation. In addition, high-reactivity fuels were constantly placed in the high-neutron-flux region. It was found that this concept can achieve criticality and a stable power profile.