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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.
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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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A look inside NIST’s work to optimize cancer treatment and radiation dosimetry
In an article just published by the Taking Measure blog of the National Institute of Standards and Technology, Stephen Russek—who leads the Imaging Physics Project in the Magnetic Imaging Group at NIST and codirects the MRI Biomarker Measurement Service—describes his team’s work using phantom stand-ins for human tissue.
Yoshiro Asahi, Keisuke Okumura, Yasuo Ose
Nuclear Science and Engineering | Volume 139 | Number 1 | September 2001 | Pages 78-95
Technical Paper | doi.org/10.13182/NSE01-A2223
Articles are hosted by Taylor and Francis Online.
The rate equation for neutronic population is derived from the transient neutron diffusion equation. Neutronic imbalance is defined as the difference between the solution of the rate equation and the neutronic population obtained by spatial kinetics. If the transient neutron diffusion equation in the fully implicit formulation is discretized in such a manner as to satisfy the Gauss theorem and to retain a conservation form, neutronic imbalance decreases as the convergence criteria become strict. The iterative implicit method for neutronics and thermal hydraulics requires continuity of all the variables involved, which, in turn, facilitates the automatic time-step width control. From the viewpoints not only of well-posedness of a transient problem but also of code verification, a transient code should be capable of a null transient analysis for stable systems. Sample calculations are performed for a pressurized water reactor main-steam-line-break accident. An overall thermal-hydraulic trend model is conjectured to help compare and explain the calculated results. Spatial kinetics is found to clearly influence even the temporal behaviors of the secondary system.
