ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.
Michelle Pitts, Farzad Rahnema
Nuclear Science and Engineering | Volume 140 | Number 3 | March 2002 | Pages 241-266
Technical Paper | doi.org/10.13182/NSE02-A2259
Articles are hosted by Taylor and Francis Online.
The number of spent nuclear fuel assemblies taken from nuclear power plants and to be stored in existing storage pools is increasing. Therefore, there is a need to optimize the storage configurations. The computer codes and cross sections used to analyze proposed storage configurations must be validated through comparison with experimental data. Restrictive values of ksafe, caused by limited data, can prevent optimal storage utilization. As a collaborative effort between Westinghouse Safety Management Solutions, Oak Ridge National Laboratory (ORNL), Georgia Institute of Technology, and the University of Missouri Research Reactor (MURR), more than 120 experiments were performed using four highly enriched MURR fuel assemblies. The 252Cf-source-driven noise analysis technique developed at ORNL was used as the measurement method for these experiments. This method is based on calculating a specific ratio of measured auto-power and cross-power spectral densities. Twenty-two unique configurations from the MURR experimental program were analyzed for benchmarking purposes.These subcritical experiments were described and analyzed in this paper to provide new measurements to increase the amount of data available for benchmarking criticality codes and cross sections for systems that are far from critical (keff < 0.9).All aspects of the experimental apparatus designed for the experiment program are thoroughly described to enable calculational modeling. Measured and calculated results for the 22 configurations of interest are given. Thorough perturbation studies on measurement uncertainties (e.g., fuel spacing and composition) were performed to determine the uncertainty on the ratio and keff values. Inferred keff values ranged from 0.648 ± 0.005 to 0.860 ± 0.006. A simplified benchmark model is described that consists of the four fuel assemblies, four 3He detectors, detector drywells, and the water reflector. For these measurements, the calculated ratio and keff values agreed with the measurement results within the measurement uncertainty. All of the analyzed configurations were considered acceptable for validation of computer codes and cross sections.
