ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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.”
Rei Kimura, Kazuhito Asano
Nuclear Science and Engineering | Volume 194 | Number 3 | March 2020 | Pages 213-220
Technical Paper | doi.org/10.1080/00295639.2019.1685352
Articles are hosted by Taylor and Francis Online.
Nuclear energy has been one of the sustainable energy sources, but after the Fukushima Daiichi nuclear accident, large-scale light water reactors are losing price competitiveness due to the rising costs to meet elevated safety standards. On the other hand, small modular reactors (SMRs) have been developed by various teams and are expected to provide not only electricity but also heat for small communities, chemical plants, factories, mines, and hydrogen production. Since 2017, a multipurpose very small modular reactor (vSMR), namely, Mobile-Very-small reactor for Local Utility in X-mark (MoveluXTM), has been studied at Toshiba Energy Systems and Solutions Corporation as a feasible distributed energy source. The main concept to MoveluX is a heat pipe–cooled calcium hydride–moderated core to simplify the reactor system while increasing inherent safety and nuclear security. Portable vSMRs are useful for remote places; therefore, criticality safety during their transport is essential for vSMRs to gain popularity. In a previous paper, we discuss positive temperature reactivity coefficients of the hydride-moderated core and its control method. The phenomenon is caused by thermal-neutron spectrum shifts at increased temperatures. In the current paper, we show that a positive temperature reactivity coefficient can be utilized to maintain subcriticality during transport. The reactor core requires preheating to achieve criticality, which means the core does not become critical even though safety rods have been extracted in the low-temperature range. The positive reactivity in the low-temperature range establishes inherent criticality safety during transport of the reactor system.