Development plan of high burnup fuel for high temperature gas-cooled reactors in future

将来の高温ガス炉のための高燃焼度燃料の開発計画

相原 純 ; 植田 祥平   ; 本田 真樹*; Blynskiy, P.*; Gizatulin, S.*; 坂場 成昭 ; 橘 幸男 

Aihara, Jun; Ueta, Shohei; Honda, Masaki*; Blynskiy, P.*; Gizatulin, S.*; Sakaba, Nariaki; Tachibana, Yukio

小型高温ガス炉(HTGR)HTR50Sの第I期第2ステップの炉心(第2次炉心)のための被覆燃料粒子(CFP)及び燃料コンパクトについて計画と現状を述べた。R&Dのリスクを減らすため、既存の高燃焼度用CFP (HTR50S2型CFP)の仕様をCFPの仕様とした。HTR50S2型CFPは高温工学試験研究炉(HTTR)プロジェクトで培った技術に基づいて製造された。HTR50S2型CFPの最初の照射試験を現在実施中である。HTR50S2型CFP中の燃料核の体積割合はかなり小さいので、燃料コンパクトの高充填率化のR&Dもまた必要である。以上に加え、HTR50Sの第II期炉心及び実用高温ガス炉のためのR&D計画の概要も述べた。

Plan and status of research and development (R&D) were described on coated fuel particle (CFP) and fuel compacts for core of small sized high temperature gas-cooled reactor (HTGR) HTR50S at 2nd step of phase I (second core of HTR50S). Specifications of existing CFPs for high burnup (HTR50S2-type-CFPs) were adopted as specifications of CFPs, to reduce the R&D. HTR50S2-type-CFPs were fabricated based on technology developed in High Temperature Engineering Test Reactor (HTTR) project. First irradiation test of HTR50S2-type-CFPs is now being carried out. In addition, R&D for fuel compact with high packing fraction is needed, because volume fraction of fuel kernel to whole of HTR50S2-type-CFP is rather smaller than that of the HTTR-type-CFP. In addition, we describe outline of R&D plans for core of HTR50S in phase II and naturally safe HTGR.