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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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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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Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
J. T. Mihalczo
Nuclear Science and Engineering | Volume 60 | Number 3 | July 1976 | Pages 262-275
Technical Paper | doi.org/10.13182/NSE76-4
Articles are hosted by Taylor and Francis Online.
The effective delayed neutron fraction from fission was determined for an unreflected uranium (93.2 wt% 235U) metal sphere from the ratio of time-correlated counts in a randomly pulsed neutron measurement to those in a Rossi-α measurement. In the randomly pulsed neutron measurements, a 252Cf source was placed in the sphere which contained a fission counter that, because of its location, did not count neutrons directly from the source. Neutrons from spontaneous fission of 252Cf initiated fission chains in the sphere, and the fission counter detected events from the interaction of neutrons from these fission chains with the uranium of the fission counter. A Type I time analyzer was triggered each time a 252Cf nucleus fissioned and recorded the time distribution of neutrons from the fission chains initiated by neutrons from californium at t = 0. The delayed neutron fraction by this method (60.2 ± 0.8 × 10−4) is ∼11% lower than that from other measurements or calculations that are all in agreement. This low value may be due to an improper theoretical formulation for the correction of point kinetics for spatial effects. The value of this correction factor estimated by another theoretical formulation is 30% larger. An 11% larger correction for spatial effects would produce agreement between this measurement and previously measured results.
