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
Robotics & Remote Systems
The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
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.
Kune Y. Suh
Nuclear Technology | Volume 106 | Number 3 | June 1994 | Pages 274-291
Technical Paper | Nuclear Reactor Safety | doi.org/10.13182/NT94-A34958
Articles are hosted by Taylor and Francis Online.
A fast-running computational model has been developed that deals with the nuclear steam supply system heat sink as a two-dimensional slice of steel with its inner and outer surfaces subjected to different thermal and material boundary conditions imposed by such surrounding media as core material, steel layer, water, and gas. This model is generally applicable to two- or one-dimensional heat sinks in the process of heatup and cooldown including liquefaction and resolidification. The numerical model and its solution technique were validated against a set of well-defined initial and boundary value problems. The computer model was applied to analyzing the temperature response of the lower head in a pressurized water reactor large-break loss of coolant accident (LOCA) with ex-vessel cooling. It was of importance to properly account for radiative heat transfer between the two exposed surfaces of the heat sink and the debris bed in the lower plenum, incorporating the physically based view factors, and to allow the heat sink to melt and relocate to the lower plenum. The model was also applied to analyzing the thermal behavior of the lower head in a boiling water reactor large-break LOCA without ex-vessel cooling. It was indicated that the vessel lower head could undergo a noticeable ablation due to the decay power generated from the debris bed in the absence of external cooling. The computer model was demonstrated to produce consistent results for the applications of practical interest in the severe accident arena.