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Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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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
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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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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.
David D. Lanning
Nuclear Technology | Volume 88 | Number 2 | November 1989 | Pages 139-156
Technical Paper | NSF Workshop on the Research Needs of the Next Generation Nuclear Power Technology / Fission Reactor | doi.org/10.13182/NT89-A34321
Articles are hosted by Taylor and Francis Online.
The modular high-temperature gas-cooled reactor (MHTGR) is modularized primarily to provide the passive safety that will prevent fuel damage over a wide spectrum of accidents. Specifically, this range of safety includes the simultaneous accidental loss of primary coolant flow, depressurization of the coolant system, and failure to trip control mechanisms. The high-temperature capability of the fuel to retain fission products provides a safe margin over this broad spectrum. The passive safety feature of the MHTGR allows elimination of active safety-related cooling components (e.g., pump and valves). The result is a savings in capital cost and an important simplification of management and operator requirements for surveillance of the reactor system. Safety is also less affected by human error. Other advantages of modularization include cost reduction and quality control by factory fabrication and possibilities for stepwise additions to a power plant to follow load growth. A new approach to licensing has been initiated as part of the MHTGR development. This concept includes a system to bridge between the integrated approach to the MHTGR design requirements and the regulatory licensing process. The projected busbar costs (mills per kilowatthour) are estimated to be competitive with coal-fired plants of the same size when two or more MHTGR modules are utilized. Designs with the passive safety features are discussed. Some incentives and impediments for deployment of the MHTGR are examined. In addition, suggestions for university research related to MHTGR are presented.