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Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Jacopo Buongiorno, James W. Sterbentz, Philip E. MacDonald
Nuclear Technology | Volume 153 | Number 3 | March 2006 | Pages 282-303
Technical Paper | Fission Reactors | doi.org/10.13182/NT06-A3708
Articles are hosted by Taylor and Francis Online.
The supercritical water-cooled nuclear reactor (SCWR) concept offers potential for superior economics due to its high thermal efficiency and plant simplification. However, design of a thermal-spectrum core for such a reactor is complicated by the relatively low density of the water coolant and therefore reduced moderation. This requires the SCWR design to include a dedicated moderator. One solution explored worldwide is based on the use of water rods. In this paper we assess the feasibility of a different approach based on solid moderators, which has some potential advantages including increased core thermal capacity, reduced coolant worth, and simplified vessel internals. The neutronic performance of several solid moderators was evaluated and compared to that of water rods. It was found that the only acceptable solid moderator is zirconium hydride. Axial and local peaking can be readily suppressed by modest variations of the enrichment in a manner similar to the boiling water reactor practice. The Doppler and coolant reactivity coefficients are both negative and in the range of light water reactor experience. The use of zirconium hydride as a stable structural core component was evaluated and found to be acceptable under steady-state and accident conditions. In addition to its chemical and mechanical stability, zirconium hydride can also be fabricated with existing technology. However, its impact on the SCWR cost of electricity generation is deemed significant.