Management strategy for radioactive waste in the fusion demo reactor

Youji Someya, Kenji Tobita, Hiroyasu Utoh, Nobuyuki Asakura, Yoshiteru Sakamoto, Kazuo Hoshino, Makoto Nakamura, Shinsuke Tokunaga

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)423-427
Number of pages5
JournalFusion Science and Technology
Volume68
Issue number2
DOIs
Publication statusPublished - 2015 Jan 1
Externally publishedYes

Fingerprint

Radioactive Waste
fusion reactors
blankets
Fusion reactors
radioactive wastes
Radioactive wastes
Atoms
Neutrons
Tritium
vessels
Shielding
modules
Welding
Contamination
Fusion reactions
atoms
neutrons
life (durability)
reuse
tritium

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Materials Science(all)
  • Mechanical Engineering

Cite this

Someya, Y., Tobita, K., Utoh, H., Asakura, N., Sakamoto, Y., Hoshino, K., ... Tokunaga, S. (2015). Management strategy for radioactive waste in the fusion demo reactor. Fusion Science and Technology, 68(2), 423-427. https://doi.org/10.13182/FST15-101

Management strategy for radioactive waste in the fusion demo reactor. / Someya, Youji; Tobita, Kenji; Utoh, Hiroyasu; Asakura, Nobuyuki; Sakamoto, Yoshiteru; Hoshino, Kazuo; Nakamura, Makoto; Tokunaga, Shinsuke.

In: Fusion Science and Technology, Vol. 68, No. 2, 01.01.2015, p. 423-427.

Research output: Contribution to journalArticle

Someya, Y, Tobita, K, Utoh, H, Asakura, N, Sakamoto, Y, Hoshino, K, Nakamura, M & Tokunaga, S 2015, 'Management strategy for radioactive waste in the fusion demo reactor', Fusion Science and Technology, vol. 68, no. 2, pp. 423-427. https://doi.org/10.13182/FST15-101
Someya, Youji ; Tobita, Kenji ; Utoh, Hiroyasu ; Asakura, Nobuyuki ; Sakamoto, Yoshiteru ; Hoshino, Kazuo ; Nakamura, Makoto ; Tokunaga, Shinsuke. / Management strategy for radioactive waste in the fusion demo reactor. In: Fusion Science and Technology. 2015 ; Vol. 68, No. 2. pp. 423-427.
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