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.
O. S. Gokhale, B. P. Puranik, A. K. Ghosh
Nuclear Technology | Volume 190 | Number 1 | April 2015 | Pages 52-64
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT14-31
Articles are hosted by Taylor and Francis Online.
Heat transfer characteristics of intact fuel pins under reflood conditions have been extensively studied to understand the quench behavior of a typical pressurized water reactor (PWR). Overheating of fuel pins due to loss of nucleate boiling under exposed conditions causes the clad to balloon over large portions of the fuel pin length (up to 60%). The reflood behavior of ballooned fuel pins has been studied experimentally for ballooned heater pin configurations with an up to 15% ballooned length of the total length. Substantial changes in the reflood behavior are observed for a higher extent of the ballooned region. An experimental setup is thus being developed to study the effect of the large extent of the ballooned region (up to 60% of the total length) on the reflood behavior. The experimental setup employs a 5×5 matrix of indirectly heated fuel pins surrounded by 32 dummy fuel pins. The scaling analysis carried out for the design of the experimental setup is presented here. The nondimensional π terms pertaining to the quench phenomena have been conserved as compared to the typical PWR values. The evolution of some of the nondimensional π terms under reflood conditions has been discussed for simulations done with RELAP5 for ballooned as well as nonballooned test cases. Delayed quenching is observed in the extended ballooned fuel pins due to poor heat transfer in the ballooned region.