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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
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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
Westinghouse’s lunar microreactor concept gets a contract for continued R&D
Westinghouse Electric Company announced last week that NASA and the Department of Energy have awarded the company a contract to continue developing a lunar microreactor concept for the Fission Surface Power (FSP) project.
Y. S. Rana, S. B. Degweker
Nuclear Science and Engineering | Volume 169 | Number 1 | September 2011 | Pages 98-109
Technical Note | doi.org/10.13182/NSE11-A12499
Articles are hosted by Taylor and Francis Online.
Through our earlier papers, we have shown that reactor noise in accelerator-driven systems (ADS) is different from that in critical or radioactive source-driven subcritical systems due to periodically pulsed source and its non-Poisson character. We have developed a theory of reactor noise for ADS, taking into account the non-Poisson character of the source. Various noise descriptors, such as Rossi-alpha, Feynman-alpha (or variance to mean), power spectral density, and cross power spectral density, have been derived for a periodically pulsed source, including correlation between different pulses and finite pulses of different shapes. For mathematical simplicity, the theory was restricted to the case of prompt neutrons only. Recently, we extended the theory to the delayed neutron case and derived Feynman-alpha and Rossi-alpha formulae by considering the source to be a periodically pulsed non-Poisson source, without correlations between different pulses. The present paper extends the treatment to account for the possibility of correlations between pulses. Feynman-alpha and Rossi-alpha formulas are derived by considering the source to be a periodic sequence of delta function non-Poisson pulses, with exponential correlations.
