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
May 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
June 2026
Nuclear Technology
Fusion Science and Technology
Latest News
NextEra, Dominion to merge in major utilities announcement
NextEra Energy is set to acquire Dominion Energy, the two utilities announced earlier today in an approximately $67 billion merger that will alter the energy landscape—including for nuclear power—in the United States.
Yong Jin Cho, Gyoo Dong Jeun
Nuclear Technology | Volume 158 | Number 3 | June 2007 | Pages 366-377
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT07-A3848
Articles are hosted by Taylor and Francis Online.
The header of a Canada deuterium uranium reactor (CANDU) is an important component in simulating the fuel channel behavior because the header's hydraulic behavior controls the feeder void fraction, which affects the fuel bundle coolability. In CANDU accident analyses, the liquid entrainment and vapor pull-through (off-take) phenomena should be considered when horizontal stratification is achieved inside the header. The current RELAP5 off-take model can treat only three directions: vertical upward, vertical downward, and side oriented junctions. In this study, the RELAP5 off-take model was modified and generalized by considering the geometric effect of branch angles. Based on Craya's approach, the critical height correlation was reconstructed by use of the branch line connection angle. The new model in RELAP5/CANDU could be applied to vertical upward, vertical downward, and angled branch. The verification and validation analyses for this new model were performed using separate effect test and integral effect test results. The verification and validation analyses show improved accuracy with the new model.