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
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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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Nuclear Science and Engineering
May 2025
Nuclear Technology
Fusion Science and Technology
Latest News
TerraPower begins U.K. regulatory approval process
Seattle-based TerraPower signaled its interest this week in building its Natrium small modular reactor in the United Kingdom, the company announced.
TerraPower sent a letter to the U.K.’s Department for Energy Security and Net Zero, formally establishing its intention to enter the U.K. generic design assessment (GDA) process. This is TerraPower’s first step in deployment of its Natrium technology—a 345-MW sodium fast reactor coupled with a molten salt energy storage unit—on the international stage.
Charles W. Bagnal, Jr., Gerard P. Cavanaugh, Robert P. Harris, Regis A. Matzie, Laszlo B. Tarko
Nuclear Technology | Volume 68 | Number 1 | January 1985 | Pages 7-17
Technical Paper | Fission Reactor | doi.org/10.13182/NT85-A33562
Articles are hosted by Taylor and Francis Online.
Fuel management and core periphery modifications are examined for slowing pressurized water reactor (PWR) pressure vessel embrittlement by reducing the incident fast flux to the vessel Such strategies can help to mitigate the consequences of pressurized thermal shock, a current licensing concern. For most operating PWRs, a factor of 2 reduction in fast flux to the reactor vessel critical welds can be achieved with little or no penalty in power peaking (3% or less), which implies only a small degradation in thermal margin. This can be accomplished with low leakage fuel management, which places twice-burned fuel near these welds. To achieve higher reduction factors, materials with good fast neutron attenuation properties must be used in conjunction with low leakage fuel management. For example, a reduction factor of 3 implies a limited use of dummy stainless steel assemblies (with an associated increase in power peaking of at least 8%) or the use of stainless steel patches between the core and the vessel In general, a factor of 3 reduction in fast flux is a practical upper limit to what can be reasonably achieved without significant degradation of thermal margin. A factor of 5 reduction may be possible in some cases, but would require the liberal use of dummy assemblies and/or stainless steel patches; a fast flux reduction by a factor of >5 would most likely require power derating.