ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Mathematics & Computation
Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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!
Latest Magazine Issues
Sep 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
November 2024
Nuclear Technology
October 2024
Fusion Science and Technology
Latest News
Demolition work continues near former Hanford processing facility
Workers with the Department of Energy Office of Environmental Management’s contractor Central Plateau Cleanup Company recently demolished the Reduction Oxidation Plant, one of five former plutonium production facilities at the Hanford Site in Washington state.
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.