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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.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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
College students help develop waste-measuring device at Hanford
A partnership between Washington River Protection Solutions (WRPS) and Washington State University has resulted in the development of a device to measure radioactive and chemical tank waste at the Hanford Site. WRPS is the contractor at Hanford for the Department of Energy’s Office of Environmental Management.
Jeffrey C. King, Leonardo de Holanda Mencarini
Nuclear Technology | Volume 208 | Number 7 | July 2022 | Pages 1137-1148
Technical Paper | doi.org/10.1080/00295450.2021.2004870
Articles are hosted by Taylor and Francis Online.
A low-enriched-uranium (LEU)–fueled space reactor could avoid the security and proliferation concerns inherent with highly enriched uranium (HEU)–fueled space nuclear reactors. Recent LEU-fueled space reactor designs include a moderator to reduce the size and mass of the reactor core. This paper considers shadow shield options for an unmoderated HEU-fueled space reactor and a moderated LEU-fueled space reactor. Both reactors are kilowatt-class reactors, producing 15 kW(thermal) of thermal power over a 5-year operational lifetime. Based on the shielding required to meet established dose limits [a neutron fluence of less than 1014 n/cm2 (1 MeV equivalent in silicon) and a gamma-ray dose of less then 1 Mrad in silicon], the moderated LEU-fueled space reactor will require a thicker shadow shield than the unmoderated HEU-fueled space reactor. The thinner reflector of the moderated LEU-fueled reactor results in more neutrons reaching the shadow shield at higher energies compared to the unmoderated HEU-fueled reactor. The presence of a significant reflector in most space reactor designs means that the core spectrum is relatively unimportant in terms of shadow shield design, as the reflector thickness has a much stronger impact on the neutrons and gamma rays reaching the shadow shield. Based on the results presented in this paper, the mass optimization of moderated LEU-fueled space nuclear reactors should always consider the coupled effects of the core, the reflector, and the shielding.