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Division Spotlight
Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
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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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.
T. T. Anderson
Nuclear Technology | Volume 9 | Number 3 | September 1970 | Pages 422-433
Technique | Symposium on Theoretical Models for Predicting In-Reactor Performance of Fuel and Cladding Material | doi.org/10.13182/NT70-A28797
Articles are hosted by Taylor and Francis Online.
The hydrodynamics of coolant flow in a natural circulation, nuclear-heated boiler are dependent upon interactions of the generated heat, the available driving head of vapor in the two-phase mixture, and flow of the coolant. Where at steady operating conditions a slight increase in heat generation will induce unstable flow, circulation hydrodynamics can be investigated by small-signal techniques of control system theory. The flow-pressure interaction can be described in terms of the hydraulic impedance which is the frequency-transformed ratio of two perturbed quantities, differential pressure over flow rate. The hydraulic impedance is analogous to acoustic impedance (acoustic pressure/particle velocity) of compressible media and to mechanical impedance (force applied to structure/resulting velocity) of rigid body mechanics. Measurements of the flow-vapor interaction and of the flow-pressure interaction (hydraulic impedance) are compared to a simplified theory, to demonstrate how the impedance approach aids understanding of complex two-phase phenomena. As a practical application, the flow stability of a boiling loop is predicted by measured hydraulic impedances.
