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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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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. R. Bierman, B. M. Durst, E. D. Clayton
Nuclear Science and Engineering | Volume 65 | Number 1 | January 1978 | Pages 41-48
Technical Paper | doi.org/10.13182/NSE78-A27124
Articles are hosted by Taylor and Francis Online.
There is a continuing interest in the use of fixed neutron absorbers (poisons) for criticality control, since their use would permit safely handling larger quantities of nuclear materials with reduced probability of criticality. The effectiveness of such absorbers as neutron poisons depends on self-shielding effects, which in turn are determined by the magnitude of the absorption cross sections and their variation with energy, the thickness of material, and the neutron energy spectrum. Criticality experiments were performed to obtain data on the reactivity worths of several thicknesses of the following materials in two different neutron energy spectra: Boral Cadmium Type 304-L stainless steel containing 1.6 wt% boron Type 304-L stainless steel containing 1.1 wt% boron Type 304-L stainless steel Uranium depleted to 0.2 wt% 235U Lead. The measurement data reported are limited to a single region of a given absorber material in each critical assembly. Combinations of absorber materials or multiregions were not investigated; however, material thicknesses were varied from 0 to ∼60 mm. The data are presented as sets of clean, well-defined, poisoned critical assemblies that can be used to check calculational techniques and cross-section data in two different neutron energy spectra. The materials are listed above in the order of their measured relative worth as fixed poisons in either neutron energy spectrum.