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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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.
Hiroshi Motoda
Nuclear Science and Engineering | Volume 46 | Number 1 | October 1971 | Pages 88-111
Technical Paper | doi.org/10.13182/NSE71-A22338
Articles are hosted by Taylor and Francis Online.
A generalized treatment for investigating the effects of various refueling schemes on the optimal control rod programming that maximizes the average burnup of discharged fuels in a two-region, radially one-dimensional light water moderated nuclear reactor is presented and applied to a boiling water reactor having uranium fuel of a single 235U enrichment. It is assumed that the refueling scheme has reached an equilibrium fuel cycle, and the analysis by burnup space is applied, which helps in interpreting geometrically the coupled effect of the control rod programming and the fuel burnup by the trajectory drawn in this space. Three refueling schemes are considered: parallel, series out-in, and series in-out. Scatter loading is assumed in each region and the batch number and volume fraction of each region are varied as the refueling parameters. Fuel management and poison management constitute a hierarchy relation, and the effect of the refueling schemes on burnup maximization or enrichment minimization is several times greater than that of the control rod programmings. However, the policy of the optimal control rod programming strongly depends on the refueling scheme. The power density of the inner region should be as high as possible for out-in scheme (inner high policy) and vice versa for in-out scheme (outer high policy). However, either policy can be optimal, depending on the refueling parameters for parallel schemes, and in some cases the optimal control rod programming is not unique (degenerate policy). Optimal control rod programming increases the discharge burnup or decreases the enrichment of the feed fuels by about 0 to 4% over the conventional constant power shape operation. The difference is mainly determined by the reactor design and the refueling scheme. Optimal refueling should be chosen from among parallel schemes, which have much larger freedom than series schemes.
