Remote Leak Sealing of Biological Shield Cooling System of FBTR

The BSC system of FBTR at Kalpakkam, India, is meant for maintaining the integrity of the concrete that surrounds the reactor vessel. Demineralized water is circulated through the BSC coils that are embedded in the concrete to maintain the concrete temperature below 800C. Water leak of 18 l/h from A3 sub loop of BSC system was first observed In Aug 2000. The chemical sealants required were developed at BARC and the methodology at IGCAR and using this, four leaking sub-loops of BSC system were sealed during 2007-2008 remotely. This paper details the salient features of this remote leak sealing technology.