By Venkatachari Jagannathan
Chennai, April 11 (IANS) The Nuclear Power Corporation of India Ltd (NPCIL) has started investigating the reasons for leak of heavy water at its 220 MW reactor at Kakrapar Atomic Power Station (KAPS) in Gujarat, said a senior official.
"We have started our investigations and corrective action will be done after that," L.K. Jain, site director, Gujarat, told IANS over phone on Monday.
On restarting of power generation, he said it will take some time but not very long.
On the morning of March 11, the first reactor at KAPS shut down automatically following leakage of heavy water from its coolant channel. The leak was plugged ten days later.
Once the inspection of the affected reactor is done, then the channel has to be cut and sent to a lab for testing.
A senior official of Atomic Energy Regulatory Board (AERB) told IANS that the coolant channel has to be cut without disturbing the leak spot.
Queried whether NPCIL can restart the reactor with or without new coolant channel, AERB chairman S.A. Bhardwaj had earlier told IANS: "Both options are possible. The affected channel is low power one."
As the reactor has 306 channels and each channel has 12 fuel bundles, the absence of one channel and a bundle will not cut down the power output if the reactor is restarted, he said.
The NPCIL has the take the call as it has to complete its probe into the leakage of heavy water and the kind of damage that the coolant channel has suffered, Bhardwaj had said.
As the affected channel is in the reactor's core area, it has to be removed carefully due to radiation and transported to a lab following the laid down procedures.
The affected channel needs radiation shielding. The equipments have to be brought in and set up for removing the affected channel.
Most probably, the coolant channel will be sent to Bhabha Atomic Research Centre (BARC) in Mumbai for study.
The coolant channel at the affected reactor was changed only in 2011.
At present, KAPS Unit 1 is in cold shut-down state.
India's atomic power plant operator NPCIL has two 220 MW units at KAPS. The second unit is under maintenance shut-down since July 2015.
