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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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2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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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High-temperature plumbing and advanced reactors
The use of nuclear fission power and its role in impacting climate change is hotly debated. Fission advocates argue that short-term solutions would involve the rapid deployment of Gen III+ nuclear reactors, like Vogtle-3 and -4, while long-term climate change impact would rely on the creation and implementation of Gen IV reactors, “inherently safe” reactors that use passive laws of physics and chemistry rather than active controls such as valves and pumps to operate safely. While Gen IV reactors vary in many ways, one thing unites nearly all of them: the use of exotic, high-temperature coolants. These fluids, like molten salts and liquid metals, can enable reactor engineers to design much safer nuclear reactors—ultimately because the boiling point of each fluid is extremely high. Fluids that remain liquid over large temperature ranges can provide good heat transfer through many demanding conditions, all with minimal pressurization. Although the most apparent use for these fluids is advanced fission power, they have the potential to be applied to other power generation sources such as fusion, thermal storage, solar, or high-temperature process heat.1–3
S. K. Bhattacharyya, R. B. Pond
Nuclear Science and Engineering | Volume 65 | Number 3 | March 1978 | Pages 548-553
Technical Note | doi.org/10.13182/NSE78-A27186
Articles are hosted by Taylor and Francis Online.
The Doppler effect of a small UO2 sample was determined for the temperature range from 300 to 1100 K at the core center of the Argonne National Laboratory gas-cooled fast reactor (GCFR) critical assembly. The measurement provided the first data on the important 238U Doppler effect in GCFR systems. The normalized value of the GCFR 238U Doppler effect was found to be 54% smaller than the corresponding value in an equivalent liquid-metal fast breeder reactor (LMFBR) assembly. Calculations with ENDF/B-IV data yielded a calculated/experimental (C/E) ratio of 0.83, which is considerably lower than that in LMFBR assemblies. The reason for this misprediction appears to be an underprediction of the low-energy flux, a feature that seems to be general to hard spectrum assemblies. The 238U Doppler effect was also determined in a “steam-flooded” GCFR assembly. The Doppler effect for the temperature range from 300 to 1100 K increased by 93% relative to the “dry” reference value because of spectral softening. The same calculational methods using ENDF/B-IV data resulted in the much better C/E value of 1.00.
