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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
Seok-Ki Choi, Myung-Hwan Wi, Won-Dae Jeon, Seong-O Kim
Nuclear Technology | Volume 152 | Number 2 | November 2005 | Pages 223-238
Technical Paper | Nuclear Reactor Thermal Hydraulics | doi.org/10.13182/NT05-A3672
Articles are hosted by Taylor and Francis Online.
A computational study of thermal striping in an upper plenum of the Korea Advanced Liquid-Metal Reactor (KALIMER) was performed. The primary objective of the present study was to find the distribution of the amplitude of temperature fluctuation in the hot pool of KALIMER. The computations were performed using the CFX-4 code with the differential stress and flux turbulence model and the Van Leer convection scheme. Two cases with different outlet velocity of the control rod fuel assemblies are considered. The distributions of the velocity vector, temperature, and temperature fluctuation were obtained from the calculation. In order to quantitatively understand the amplitude of temperature fluctuation at the bottom wall of the upper internal structure (UIS), the amplitude of the fluctuation of temperature in the radial and angular directions was investigated. The amplitude of temperature fluctuation at the UIS bottom plate was largely dependent on the magnitude of the outlet velocity of the control rod fuel assemblies. From the calculated results, it was found that the largest temperature fluctuation occurred at the radial edge of the UIS bottom in the KALIMER design. Since thermal striping is dependent on the amplitude of temperature fluctuations and frequency, the region of the UIS bottom edge needs to be analyzed with a detailed unsteady calculation.
