Maintenance and radiation protection issues of the CREST reactor

Yoshiyuki Asaoka, Kunihiko Okano, Tomoaki Yoshida, Ken Tomabechi, Seiji Mori, Hideo Ise

Research output: Contribution to journalConference articlepeer-review

3 Citations (Scopus)


A maintenance approach of the Compact Reversed Shear Tokamak (CREST) for high availability is proposed. Full sector removal through horizontal ports for easy maintenance is adopted in order to increase availability. Cask type sector removal machines are used to transfer the blanket/divertor sectors. Achievable availability is estimated with a maintenance period and its interval. The proposed maintenance approach allows, at least, the similar availability to that of the present nuclear plants. The estimated availability is acceptable from an economical viewpoint. Safety concerns related to the super-heated direct steam cycle are also examined. One of the unique concerns is due to nitrogen-16 production in the coolant. The super-heated steam must flow through the turbines within several 10 s after leaving the blanket. The requirements for shielding on the heat transfer systems are declared. Another concern is the confinement and recovery of tritium in the coolant, because a high temperature blanket may have a large tritium permeation rate. Water detritiation system proposed here would be able to control the tritium concentration in the coolant within an allowable range.

Original languageEnglish
Pages (from-to)461-466
Number of pages6
JournalFusion Engineering and Design
Publication statusPublished - 2000 Nov
Event5th Interantional Symposium on Fusion Technology - Rome, Italy
Duration: 2000 Sept 192000 Sept 24

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • General Materials Science
  • Mechanical Engineering


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