new delhi

The Indian Atomic Energy Commission (AEC) has admitted that eight workers were exposed to “mild radioactivity” last month. The incident happened when about six tonnes of heavy water leaked during the inspection of a coolant channel tube at the Madras Atomic Power Station.

The 220-MW reactor was under routine maintenance when the leak occurred. The incident — rated 1 on the international nuclear events scale of 0 to 7 — is the first since a fire destroyed the control room of a power reactor at Narora, 150 km from Delhi, six years ago; that rated 3 on the scale.

Neither the AEC nor the Atomic Energy Regulatory Board (AERB) reported the incident. It only came to light only after a newspaper broke the story two weeks later, quoting the workers who had been treated in hospital.

AEC chairman Rajagopalan Chidambaram dismissed the event at a press conference in Mumbai (formerly Bombay) last week as of “no safety significance”. He claimed that the workers, who were exposed to radioactive tritium, only received three times the amount of radiation they would have normally received in a week.

AERB says the leak was caused by failure of the sealing plug in the equipment used to examine the coolant channel by remote control. It says that a committee has been set up “to investigate the root cause, to review the design of the special seal plug of the inspection equipment, and to suggest remedial measures to avoid recurrence of such incidents.”