NPC confident of safety at multiple reactor sites

Seeking to allay fears about safety at nuclear plants with multiple reactors, state-run Nuclear Power Corporation (NPC) said the design adopted in reactors built in India is such that all safety systems are provided unit-wise and there are no shared systems between units.

Chairman and managing director S K Jain told Business Standard: “Every unit has got its own independent power supply system starting from the off-site power, emergency power from diesel generators, uninterrupted supplies from inverters and DC power supply from batteries. Similarly, all emergency core cooling systems, and cooling water systems for safety-related equipment are provided separately for each unit. Provision of heat sinks are also unit-based. The systems related to the reactor and its auxiliaries are housed separately and, hence, are independent of each other. Occurrence of any event in one of the reactors will not have any bearing on the safety of the other reactor in the complex.”

Jain’s statement comes on the heels of Union environment minister Jairam Ramesh’s suggestion that safety applications at Indian nuclear plants not be interlinked, given the way the Fukushima Daiichi nuclear disaster at Japan unfolded. Jairam said Fukushima was a wake-up call and safety applications at the proposed 10,000 Mw Jaitapur project in Maharashtra (six reactors of 1,650 Mw each), in particular, should be independent. NPC is currently operating 20 plants with generation capacity of 4,780 Mw in all. The number of reactors at these plants ranges from one to six each.

Jain said the purpose of having more units at a site is only to ensure optimum utilisation of common resources, like material stores, finance and human resources development functions, township facilities, medical facilities and similar functions. Having more units will also help in complementing of technical expertise and augmentation of general resources during maintenance outages.

“Since enough design margins are provided in all power supply systems and safety systems, it is felt that common cause failures due to natural events affecting core cooling is least probable,” Jain said.