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2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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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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Modernizing I&C for operations and maintenance, one phase at a time
The two reactors at Dominion Energy’s Surry plant are among the oldest in the U.S. nuclear fleet. Yet when the plant celebrated its 50th anniversary in 2023, staff could raise a toast to the future. Surry was one of the first plants to file a subsequent license renewal (SLR) application, and in May 2021, it became official: the plant was licensed to operate for a full 80 years, extending its reactors’ lifespans into 2052 and 2053.
U. C. Bergmann, P. Grimm, F. Jatuff, M. F. Murphy, R. Chawla
Nuclear Science and Engineering | Volume 156 | Number 1 | May 2007 | Pages 86-95
Technical Paper | doi.org/10.13182/NSE07-A2687
Articles are hosted by Taylor and Francis Online.
The reaction-rate ratio C8/Ftot, neutron captures in 238U to total fissions, has been measured in 80 out of 96 fuel rods of a Westinghouse SVEA-96+ boiling water reactor fuel assembly. High-resolution gamma spectroscopy was performed on individual fuel rods, withdrawn from the SVEA-96+ assembly after irradiation at low power in the center of the LWR-PROTEUS reactor core. Absolute experimental errors of 1.7% and relative errors of 0.6% (for rod-to-rod ratios) were achieved. The experimental results were used as a database for validation of four different calculational tools: CASMO-4 and HELIOS as commercial assembly codes, the Paul Scherrer Institute in-house code BOXER, and the Monte Carlo transport code MCNPX. In general, on the level of a few percent, there is good agreement between experiment and calculations, the use of a recently proposed 239Np gamma-ray emission probability improving even further the agreement. However, the highly heterogeneous design of the SVEA-96+ assembly (both in terms of material compositions and neutron moderation conditions) causes some problems. Clear deviations from assembly mean values are found among the burnable absorber fuel rods that are grouped in clusters (direct neighbors), a unique feature of this assembly design. For these rods the codes overpredict C8/Ftot by several percent, including MCNPX. Additional trends, not present in the results from the Monte Carlo calculation which generally shows the best overall agreement with experiment, are identified for the deterministic codes.
