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.
Marco Cigarini, Mario Dalle Donne
Nuclear Technology | Volume 84 | Number 1 | January 1989 | Pages 33-53
Technical Paper | Nuclear Safety | doi.org/10.13182/NT89-A34194
Articles are hosted by Taylor and Francis Online.
Calculations of the reflooding phase during a loss-of-coolant accident (LOCA) have been performed for two homogeneous advanced pressurized water reactors (APWRs) with a wide [pitch-to-diameter (p/d) ratio = 1.2] and a tighter (p/d = 1.123) fuel rod lattice as well as for a reference 1300-MW(electric) pressurized water reactor (PWR). The FLUT computer code, developed by the Gesellschaft für Reaktorsicherheit in Garching for the reflooding phase of a PWR, has been improved: A new criterion for the determination of the onset of the upper quench front and a new water droplet model for the dispersed flow film boiling have been introduced in the code, as well as new friction factor correlations more suitable for the core geometry of an APWR. Finally, the interfacial drag coefficients between steam and water are not independent of the geometry as in FLUT, but rather the flow channel geometry is taken into account. The new version of the code (FLUT-FDWR) has been tested on the base of various reflooding experiments in PWR (FLECHT, FEBA, SEFLEX) as well as APWR (FLORESTAN) core geometries. In all the cases investigated, the FLUT-FDWR predictions are relatively good and generally better than with the original FLUT version. The reactor calculations with FLUT-FDWR indicate that the maximum cladding temperatures in the APWRs during the reflooding phase are lower than those for the PWR. This is due to the lower temperatures for the APWRs at the beginning of the reflooding phase and to the higher isostatic water pressure above the APWR cores, which are shorter and therefore placed in a lower position inside the reactor pressure vessel. The cladding temperatures calculated for the PWR and the two APWRs are quite acceptable and considerably lower than those calculated during the blowdown phase of the LOCA.