Mock-up recovery operations to be done at the leaking reactor at KAPS

Mock-up reactor recovery operations will be carried out before starting the actual activities at the first unit at Gujarat's Kakrapar Atomic Power Station (KAPS) which was shut down on early on March 11 due to heavy water leak in the coolant system, said a top official at the plant site.

"We do mock-up of all activities in our field. Similarly mock-up activities will be done for recovery of the reactor," KAPS site director L.K.Jain told IANS over phone on Friday.

According to him, the reactor core is being cooled down and the source of leak has to be isolated.

"The reactor temperature has been maintained at less than 30 degrees centigrade. There is no increase in the radiation levels. We are carrying necessary operations," Jain said.

According to the sectoral regulator Atomic Energy Regulatory Board (AERB), the first unit in KAPS is in cold shut down state and the reactor is continuously cooled by the shutdown cooling system.

The regulator has given its sanction to the plant operator, Nuclear Power Corporation of India Ltd's (NPCIL) action plan for isolating the leak with necessary precautions.

"The investigations for identifying the nature of the leak and its causes can begin after isolating the leak and normalising the coolant system. However, it is expected that these investigations could take considerable time," the AERB had said

An AERB official told IANS that NPCIL has to go ahead with precaution as errors should be avoided even though it may take some more time.

"We do not want a time bound activity given the fact that safety is important," said the official who did not want to be identified.

According to him, the leak is in one of the coolant channels and the fuel has to be removed first safely.

"Special tools are needed for the purpose. These are factored into the design stage of the reactor," he said.

Speaking to IANS on the condition of anonymity, a senior NPCIL official said the leaking channel has to be blocked first and it is not a major issue while the cooling of the reactor is being maintained.

Meanwhile the failure investigations will also look at the component or the components that had failed and the reasons for its failure.

The coolant channel was replaced couple of years ago as a part of planned activity.

According to NPCIL officials, the pressured heavy water reactor (PHWR) and its components are made in India.

The Indian atomic power plant operator has two PHWR 220 MW units at KAPS. The second unit is under shut down since July 2015.

However NPCIL officials at the headquarters were not available for clarifications despite several attempts by IANS.