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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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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
T. M. John, Om Pal Singh
Nuclear Science and Engineering | Volume 85 | Number 4 | December 1983 | Pages 362-370
Technical Paper | doi.org/10.13182/NSE83-A18383
Articles are hosted by Taylor and Francis Online.
The results of a theoretical study of noise transmission characteristics of multiplying media and neutron noise source localization in liquid-metal fast breeder reactors (LMFBRs) by using the neutron wave propagation technique is reported. The study was carried out using one-group as well as multigroup diffusion theory. Both theories show that the noise transmission characteristics are quite sensitive to the multiplication factor k of the medium. For k very close to unity, the response of the out-of-core detectors is found to be the same irrespective of the location of the neutron noise source in the multiplying medium. However, for a highly subcritical reactor, the response of the out-of-core detectors is sensitive to the location of the neutron noise source, and from the point of view of the noise transmission characteristics, the medium behaves like a nonmultiplying medium. The analytical results of one-group theory that are fully supported by the multigroup multiregion theory clearly indicate that the neutron noise signal at detector locations can be assumed to be made up of two components—the first (local) is insensitive to the multiplication factor, and the second (global) is very sensitive to the multiplication factor of the system. If the local component can be separated from the total out-of-core detector signal, then a proper calibration of the local component with respect to the various locations of neutron noise source may help in finding the location of the neutron noise source in LMFBR cores. Further, it is observed that, as in the case of nonmultiplying media, noise transmission through largely subcritical multiplying media occurs with equal attenuation for all frequencies w < (υ∑t)min, where υ is the speed of the neutrons and ∑t is the total removal cross section, and for w > (υ ∑,t)min, the attenuation increases with frequency. However, for a critical system, the global component in a multiplying medium is maximum at lower frequencies and decreases rapidly for higher frequencies, and the local component remains the same as in the case of largely subcritical systems.
