As corrective measures, the valve components are being replaced by NPCIL [Nuclear Power Corporation of India Limited] and their performance is further being subjected to regulatory review. Subsequent clearance will be granted by AERB only after a satisfactory review.
The Atomic Energy Regulatory Board (AERB) on Friday acknowledged that four valves were found defective during tests at the Kudankulam nuclear power plant in Tamil Nadu and said they were being replaced.
In a press release, the Board also indicated that the long overdue commissioning of the plant could be further delayed as the new valves were again being put to the test. “The test results at the current stage of commissioning for various systems are seen to be within the acceptable limits. However, during testing of thousands of valves installed in the plant, the performance of four valves of a particular type was found deficient. As corrective measures, the valve components are being replaced by NPCIL [Nuclear Power Corporation of India Limited] and their performance is further being subjected to regulatory review. Subsequent clearance will be granted by AERB only after a satisfactory review.”
Reacting to media reports, which raised the issue of quality of components originating from a particular Russian supplier, the AERB stressed that the system of quality checks, testing and reviews specified and enforced by it had the necessary depth to detect and correct deviations in quality. Elaborating on the system adopted to ensure quality, the press release issued by AERB Secretary R. Bhattacharya said multilevel checks were in place for ensuring conformance with the quality requirements. A nuclear power plant would be considered suitable for operation only after all components were found to be functioning properly. “In general, several thousand components are installed in a nuclear power plant and as is normal for all complex engineering systems, occasional variations in their performances during their commissioning trials are expected. The very intent of such commissioning trials is to identify non-conformance, if any, and take corrective actions,” the release said. Speaking to The Hindu over telephone, AERB Chairman S.S. Bajaj said the NPCIL had procured new valves for replacement and was testing them. He however, declined to comment on how long the testing would take place on the ground that it was still under way.