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.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Mar 2026
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
March 2026
Nuclear Technology
February 2026
Fusion Science and Technology
April 2026
Latest News
NRC approves TerraPower construction permit
Today, the Nuclear Regulatory Commission announced that it has approved TerraPower’s construction permit application for Kemmerer Unit 1, the company’s first deployment of Natrium, its flagship sodium fast reactor.
This approval is a significant milestone on three fronts. For TerraPower, it represents another step forward in demonstrating its technology. For the Department of Energy, it reflects progress (despite delays) for the Advanced Reactor Demonstration Program (ARDP). For the NRC, it is the first approval granted to a commercial reactor in nearly a decade—and the first approval of a commercial non–light water reactor in more than 40 years.
August W. Cronenberg, E. L. Tolman
Nuclear Technology | Volume 87 | Number 1 | August 1989 | Pages 273-282
Technical Paper | TMI-2: Materials Behavior / Nuclear Safety | doi.org/10.13182/NT89-A27654
Articles are hosted by Taylor and Francis Online.
Inspection of the Three Mile Island Unit 2 (TMI-2) reactor vessel has yielded a wealth of information on core melt debris thermal interactions with vessel internal structures. The observed damage state of such structures is summarized and an analysis is presented to further the understanding of governing physical processes. Specifically, thermal damage is assessed for the baffle plates surrounding the core periphery, the core former plates, the bottom head instrument penetrations, and the lower head. Analysis indicates that differences in damage characteristics to such structures are due largely to differences in contact time with molten corium, the heat capacity of the various structures, and exposure to coolant. Vessel and debris examinations corroborate the present understanding of melt debris/structural interactions during the melt relocation phase of the TMI-2 accident.