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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
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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Fusion Science and Technology
Latest News
Taking shape: Fusion energy ecosystems built with public-private partnerships
It’s possible to describe fusion in simple terms: heat and squeeze small atoms to get abundant clean energy. But there’s nothing simple about getting fusion ready for the grid.
Private developers, national lab and university researchers, suppliers, and end users working toward that goal are developing a range of complex technologies to reach fusion temperatures and pressures, confounded by science and technology gaps linked to plasma behavior; materials, diagnostics, and electronics for extreme environments; fuel cycle sustainability; and economics.
C. D. Bowman, E. G. Bilpuch, D. C. Bowman, A. S. Crowell, C. R. Howell, K. McCabe, G. A. Smith, A. P. Tonchev, W. Tornow, V. Violet, R. B. Vogelaar, R. L. Walter, J. Yingling
Nuclear Science and Engineering | Volume 161 | Number 1 | January 2009 | Pages 68-77
Technical Paper | doi.org/10.13182/NSE161-68
Articles are hosted by Taylor and Francis Online.
The results of two experiments combined show that the diffusion length D for thermal neutrons in the graphite studied is 24% larger than expected from classical experiments and that the boron equivalent absorption is smaller than expected and consistent with zero. Taken together, the results indicate a reduction in parasitic thermal neutron absorption in heterogeneous graphite reactors by about 30%. The first experiment measured the z-dependence of thermal neutron flux in a column of 12 t of granular graphite with a neutron source at the bottom. A second measurement was made by pulsing the column with a neutron source at its center and measuring the neutron decay rate as a function of time after a pure exponential decay had been established. The diffusion coefficient D adjusted to a density of 1.60 g/cm3 is 1.05 ± 0.03 cm compared with the commonly accepted value of 0.85 ± 0.013 cm. The absorption in our graphite owing to impurities was found to be <10% of that from carbon alone. The parameter a/D that measures neutron loss was determined to be 0.000235 ± 0.000026 cm-2 for a density of 1.60 g/cm3 and may be compared with the commonly accepted value of 0.000340. The performance of graphite thermal spectrum reactors constructed using our graphite would be significantly enhanced over present expectations because neutron loss to graphite is a major factor in the neutron economy of graphite-moderated thermal reactors.