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
Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
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.
M. V. Speight
Nuclear Science and Engineering | Volume 37 | Number 2 | August 1969 | Pages 180-185
Technical Paper | doi.org/10.13182/NSE69-A20676
Articles are hosted by Taylor and Francis Online.
The influence of intragranular bubbles, acting as efficient trapping sites, on the migration of fission gas atoms in material under irradiation is assessed. It is considered that the bubbles are unstable due to the operation of an irradiation-induced resolution process tending to dissolve their enclosed gas. Treating an individual grain within the material as a sphere whose boundary behaves as a perfect sink, general expressions are derived for the intragranular concentrations of gas existing instantaneously within bubbles and in solution. It is shown that the relationships may be simplified for the range of irradiation times and conditions likely to be encountered in practice. Under these conditions, an expression is obtained for the quantity of gas released to the grain boundary, and this is compared with the analogous expression derived previously by Booth for the case where there are no intragranular traps. The fact that the resolution process through its effects on bubbles at the grain boundary will return some gas to the matrix and in so doing destroy the property of perfect-sink behavior is later considered. By an approximate method the appropriate modification to the formula describing the quantity of gas released to the boundary is deduced. This final expression, including the complete effects of intragranular trapping and irradiation-induced resolution on gas migration, may provide the basis on which to calculate the amount of gas which is eventually released external to the material from regions where intergranular bubbles grow so large that they interlink.