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.
Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Jae-Jun Jeong, Isabelle Dor, Dominique Bestion
Nuclear Technology | Volume 117 | Number 3 | March 1997 | Pages 267-280
Technical Paper | Nuclear Reactor Safety | doi.org/10.13182/NT97-A35341
Articles are hosted by Taylor and Francis Online.
The CATHARE 2 three-dimensional module is assessed in comparison with the Upper Plenum Test Facility downcomer test 7, which was performed to obtain full-scale data on downcomer and lower plenum refill behavior during the refill phase of a loss-of-coolant accident. New discretizations for the equation of motion, named Mods. D and R, are suggested and implemented in the three-dimensional module. Mod. A is also investigated, which defines a new junction void fraction used to calculate interfacial friction. Using the standard and the modified three-dimensional modules, the four experiments, test 7 runs 200 through 203, are simulated with the downcomer nodalized as an 8 × 1 × 8 mesh. Sensitivity calculations associated with interfacial friction, condensation, and nodalization are also performed. The calculation results show that the discretization of the momentum convection is very important in strongly heterogeneous flow conditions. Mod. D + A gives the best results so far, and Mod. R + A yields the smallest scatter in the predicted water deliveries to the lower plenum. The results of the sensitivity calculations show that the interfacial friction coefficient of CATHARE 2 is somewhat overestimated and the 8 × 1 × 8 mesh downcomer is fine enough for test 7.
