The Maintenance management of thickness measurement on the water tube boiler

Nishino, Shohei; Motohashi, Masahiro; Nishida, Tetsuro; Kawasaki, Ichio 

There are 4-boiler in Nuclear fuel Cycle engineering Laboratories (NCL). These boilers have been operated in the long term over 29 years. There are many water tube as one of many identical components which together make up a boilers. The leakage from water tube have occurred four times in recently. It was presumed that sulfur acid corrosion had caused the leakage. Therefore, to reduce generation of sulfuric acid corrosion, the operation term was changed to long, and regular inspection (non-destructive testing) have been carried out.