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
Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver 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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
Fusion Science and Technology
Latest News
TerraPower begins U.K. regulatory approval process
Seattle-based TerraPower signaled its interest this week in building its Natrium small modular reactor in the United Kingdom, the company announced.
TerraPower sent a letter to the U.K.’s Department for Energy Security and Net Zero, formally establishing its intention to enter the U.K. generic design assessment (GDA) process. This is TerraPower’s first step in deployment of its Natrium technology—a 345-MW sodium fast reactor coupled with a molten salt energy storage unit—on the international stage.
Reuben Rainisch, Victor R. Fricke
Nuclear Technology | Volume 87 | Number 2 | October 1989 | Pages 478-485
Technical Paper | TMI-2: Health Physics and Environmental Release / Nuclear Safety | doi.org/10.13182/NT89-A27740
Articles are hosted by Taylor and Francis Online.
During the accident at Three Mile Island Unit 2, a significant mass of core debris relocated to the bottom head of the reactor vessel. Subsequently, defueling activities in the core area redistributed the fuel and caused further core debris to relocate to the lower head region. An analytical approach is presented for determining the relative increase in lower plenum debris bed mass from observed changes in ex-core neutron detector readings. The neutron source magnitude of the fuel in the lower reactor vessel plenum and the degree of subcritical multiplication of neutrons in the lower head are investigated. Based on the mathematical relation formulated, it is estimated that during lower core area defueling (September 1986 to November 1987), between 12 and 23.5 additional tonnes of core materials relocated to the lower head.
