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
Aug 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
Nuclear Dirigo
On April 22, 1959, Rear Admiral George J. King, superintendent of the Maine Maritime Academy, announced that following the completion of the 1960 training cruise, cadets would begin the study of nuclear engineering. Courses at that time included radiation physics, reactor control and instrumentation, reactor theory and engineering, thermodynamics, shielding, core design, reactor maintenance, and nuclear aspects.
Lianfa Wang, Mingjun Wang, Suizheng Qiu, Guanghui Su, Wenxi Tian (Xi’an Jiaotong Univ)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 33-43
The lateral flow in top core region and upper plenum is detrimental for power control. The temperature heterogeneity in hot-legs induces the deviation of estimation of power level. Therefore, to investigate the lateral flow at the core outlet and temperature heterogeneity in the hot-legs of AP1000, a CFD analysis of the domain from the core inlet to hot-leg outlet was conducted. The core region was simulated by introducing additional source term in the momentum equations instead of being reconstructed in detail. A volumetric power density of hot full power derived from AP1000 middle of life was applied to the active core zone. The main internal components including control guide tubes with eight large opening windows on it and support columns were kept, while other little components including control rod assemblies were omitted to decrease the total mesh quantity. The Reynolds-averaged Navier-Stokes equations was solved with Realizable k-? turbulence model using commercial CFD code FLUENT. The coolant temperature map at the core outlet and the extent of the hot-leg suction effect on the top core region were obtained. Compared with the temperature field at core outlet, the maximum temperature difference at the entrance of the hot-leg drops 10K after the mixing in the upper plenum. The hotter coolant from central fuel assemblies remains at the upper part of the hot-leg, while the cooler coolant from peripheral fuel assemblies stays in the lower part of the hot-leg. The temperature heterogeneity and its evolvement along the hot-leg were analyzed.