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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
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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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
L. R. Bunney, D. Sam
Nuclear Science and Engineering | Volume 39 | Number 1 | January 1970 | Pages 81-91
Technical Paper | doi.org/10.13182/NSE70-A21173
Articles are hosted by Taylor and Francis Online.
Experimental measurements of the gamma-ray spectra emitted by the products of thermal-neutron fission of 235U have been made at nine selected times (¼, ½, 1, 2, 5, 10, 24, 48, and 72 h) after fission. A calibrated and highly collimated 5- × 5-in. NaI(T1) detector was used. The 100-energy-bin γ-ray spectra were unfolded from the pulse-height distributions by means of an iterative method. Extensive use was made of machine computation. The number of fissions in each sample was determined radiochemically. Significant differences between this work and calculated spectra were found. At the earlier times the experimental photon emission rate is higher than the calculated rate by as much as 40%. At later times the experimental rate is 20% lower than the calculated rate. Surprisingly large differences (as much as 33%) were found between the photon emission rates of products of fission by slow neutrons and by fast neutrons.
