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The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
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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.
Yasunori Bessho, Takafumi Anegawa, Osamu Yokomizo, Yuichiro Yoshimoto, Masao Chaki, Motoo Aoyama, Takanori Fukahori
Nuclear Technology | Volume 127 | Number 1 | July 1999 | Pages 49-65
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT99-A2983
Articles are hosted by Taylor and Francis Online.
In the stability licensing analysis and evaluation of boiling water reactors (BWRs), frequency-domain stability analysis programs have been used in Japan. To back up the licensing analysis and evaluation, time-domain, multiregional analysis programs have been used because more detailed analytical results can be obtained by these programs with little more computer time than that used by the frequency-domain stability analysis programs. In the backup calculation by time-domain, multiregional analysis programs, many trial-and-error experiments and much expertise on the reactor core radial regional division and on the initial disturbance input are necessary to analyze properly the stability of the BWR core, particularly its regional nuclear thermal-hydraulic stability.A three-dimensional time-domain core dynamics analysis program called SUPER-STANDY was developed with a detailed mesh division that makes various trial-and-error procedures and experience-based expertise unnecessary and that can treat the stability peculiar to the BWR core accurately. The program was applied to a plant where regional instability was observed, and the results were qualified. They showed that BWR stability can be analyzed using SUPER-STANDY by adding only the core uniform initial disturbance input without considering the reactor core radial regional division.It was determined that core regional mode instability can be properly analyzed by the multiregional analysis program (a) by dividing the core into six or more radial regions, (b) by specifying the hot fuel bundle as one region, and (c) by specifying the surrounding fuel bundles around the hot fuel bundle as one region.A visual display system was also developed for a huge number of stability data and core nuclear thermal-hydraulic characteristics, which are connected to each other in a complex way. These are obtained by the SUPER-STANDY program.
