Improvement of thermal insulation materials for the expansion joint of the steam plumbing for Reprocessing Plants

Komatsu, Seiji; Nishida, Tetsuro; Kawasaki, Ichio ; Gunji, Hikaru; Nishino, Shohei; Kambara, Takashi*; Miura, Hirohito*; Suzuki, Takaichi*; Kinoshita, Masato*; Kanei, Tatsuya*

Steam used for process and air conditioning in each facility at the Nuclear Fuel Cycle Engineering Institute is generated by a water tube boiler installed in the Institute's central control room and supplied to each facility via underground trenches. There are three steam supply pipelines (A, B, and C) to each facility, with two of these (A and B) designated for the reprocessing facility. The steam pipelines, including expansion joints and steam traps, are covered with insulation. The two steam pipelines for the reprocessing facility (A and B) are laid parallel, creating a structure that makes inspection and maintenance difficult. In particular, the expansion joints are spaced very closely between the A and B lines, making insulation removal difficult, which has been a challenge in performing visual inspections of the expansion joint bodies. This paper reports on the features and effects of an improved insulation system designed to allow for easy removal and installation.