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
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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 Technology
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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.
Hideo Nagasaka, Takashi Sato, Hirohide Oikawa, Ryoichi Hamazaki, Kenji Arai, Takao Kageyama, Hiroyuki Yoshida, Hiroshi Machiba
Nuclear Technology | Volume 92 | Number 2 | November 1990 | Pages 260-268
Technical Paper | Heat Transfer and Fluid Flow | doi.org/10.13182/NT90-A34477
Articles are hosted by Taylor and Francis Online.
The TOSBWR-900P, a natural-circulation boiling water reactor design with 300-MW(electric) power emphasizing passive safety, is studied. The TOSBWR-900P has steam drums above the pressure vessel that minimize the lower drywell volume associated with a top-mounted gravity-driven control rod device. The flow to the core is controlled by the valves on the downcomer pipes. The emergency core cooling system consists of high- and low-pressure accumulators, a gravity-driven core cooling system, and an automatic depressurization system, which guard against core uncovery in case of a design-basis accident. Long-term decay heat removal is achieved passively by a drywell water wall. The gravity-driven drywell spray water can completely flood the reactor pressure vessel during a severe core damage accident.
