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 Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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.
Youji Someya, Kenji Tobita, Hiroyasu Utoh, Nobuyuki Asakura, Yoshiteru Sakamoto, Kazuo Hoshino, Makoto Nakamura, Shinsuke Tokunaga
Fusion Science and Technology | Volume 68 | Number 2 | September 2015 | Pages 423-427
Technical Paper | Proceedings of TOFE-2014 | doi.org/10.13182/FST15-101
Articles are hosted by Taylor and Francis Online.
We have considered a strategy for reducing the radioactive waste generated by the replacement of in-vessel components, such as blanket segments and divertor cassettes, for the fusion DEMO reactor. In the basic case, the main parameters of the DEMO reactor are a major radius of 8.2 m and a fusion power of 1.35 GW. Blanket segments and divertor cassettes should be replaced independently, as their lifetimes differ. A blanket segment comprises several blanket modules mounted to a back-plate. The total weight of an in-vessel component is estimated to be about 6,648 ton (1,575, 3,777, 372, and 924 ton of blanket module, back-plate, conducting shell, and divertor cassette, respectively). The lifetimes of a blanket segment and a divertor cassette are assumed to be 2.2 years and 0.6 years, respectively, and 52,487 tons of waste is generated over a plant life of 20 years. Therefore, there is a concern that the contamination-control area for radioactive waste may need to increase due to the amount of waste generated from every replacement. This paper proposes a management scenario to reduce radioactive waste. When feasible and relevant, back-plates of blanket segment and divertor cassette bodies (628 ton) should be reused. Using the three-dimensional neutron transportation code MCNP, the displacement per atom (DPA) of the SUS316LN back-plates is 0.2 DPA/year and that of the F82H cassette bodies is 0.6 DPA/year. Therefore, the reuse of back-plates and cassette bodies would be possible if re-welding points are arranged under neutron shielding. We found that radioactive waste could be reduced to 20 % when tritium breeding materials are recycled. Finally, we propose a design for the DEMO building that uses a hot cell and temporary storage.