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
NRC proposes changes to its rules on nuclear materials
In response to Executive Order 14300, “Ordering the Reform of the Nuclear Regulatory Commission,” the NRC is proposing sweeping changes to its rules governing the use of nuclear materials that are widely used in industry, medicine, and research. The changes would amend NRC regulations for the licensing of nuclear byproduct material, some source material, and some special nuclear material.
As published in the May 18 Federal Register, the NRC is seeking public comment on this proposed rule and draft interim guidance until July 2.
Post Critical Heat Transfer Predictions Using a Modified RELAP5/MOD2 Computer Code
Nuclear Science and Engineering | Volume 103 | Number 1 | September 1989 | Pages 70-80
Technical Paper | doi.org/10.13182/NSE89-A23661
Articles are hosted by Taylor and Francis Online.
A new modified version of the RELAP5/MOD2 computer code for the analysis of the reflood phase after a hypothetical large-break loss-of-coolant accident is developed. Various rewetting correlations are examined and compared with full-length emergency core heat transfer separate-effects and system-effects test (FLECHT-SEASET) experimental reflood data. The RELAP5 prediction of vapor temperatures is low in comparison with the data. The use of a new interfacial heat transfer between droplets and steam results in a reasonable prediction of vapor superheats. A revised dispersed flow film boiling correlation, which accounts for the enhancement of steam convective cooling by droplet-induced turbulence, is incorporated in the code. Comparison of the current results with data shows significant improvement in the prediction of clad temperature time histories over previous RELAP5 calculations.