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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
Ariz. governor vetoes “fast track” bill for nuclear
Gov. Katie Hobbs put the brakes on legislation that would have eliminated some of Arizona’s regulations and oversight of small modular reactors, technology that is largely under consideration by data centers and heavy industrial power users.
M. G. Silbert, J. R. Berreth
Nuclear Science and Engineering | Volume 52 | Number 2 | October 1973 | Pages 187-200
Technical Paper | doi.org/10.13182/NSE73-A28188
Articles are hosted by Taylor and Francis Online.
The radiative capture cross section of 238Pu has been measured from 18-eV to 200-keV neutron energy. A time-of-flight experiment with a 306-m flight path was carried out in conjunction with the underground nuclear explosion Persimmon. Fission-fragment detectors viewed a thin 238Pu target to measure the fission cross section, while modified Moxon-Rae detectors viewed a second, thicker 238Pu target to measure the gamma-ray emission. Subtraction of the fission gamma-ray contribution from the Moxon-Rae signal yielded the contribution due to radiative capture. Single-level area analysis of the measured fission and capture cross sections gave values for the neutron and fission widths of 49 resonances below 500 eV, under the assumption of a known, constant radiative capture width. The s-wave neutron strength function was determined to be (1.27 ± 0.25) × 10-4. The derived fission widths exhibit a distinct maximum near 300-eV neutron energy. At higher energies, the fission-to-capture ratio shows pronounced intermediate-structure peaks attributed to second-well effects in the fission barrier.
