Leak at Kakrapar N-plant in Gujarat moderately large, may be continuing, apprehends top nuclear expert
Dr A Gopalakrishnan, former chairman of the Atomic Energy Regulatory Board (AERB) has accused Government of India's three arms handling nuclear energy – Department of Atomic Energy (DAE) , Nuclear Power Corporation of India Ltd (NPCIL), Atomic Energy Commission (AEC) and AERB – of “total lack of transparency”, allowing experts to conjecture what might have happened at the Kakrapar nuclear power plant, which “leaked” on March 11.
“Public have a need to know and, therefore, the AEC and its sub-ordinate organizations need to promptly release status reports on the progressing safety incident which could affect their lives, to alleviate their concerns and anxieties”, the top nuclear scientist says.
He adds, “It is a series of such lapses in communication over the years which has built up the ever-increasing trust deficit in the DAE system among the general public.”
Insisting that “all future plans for expanding the civilian nuclear power sector should be put on hold until a truly independent nuclear safety regulator is put in place”, Gopalakrishnan says, the AEC and the Prime Minister’s Office (PMO) should be singularly “answerable to the public on all civilian nuclear power matters.”
Writing on the Kakrapar Unit-1 PHWR Primary System Leakage Incident on March 11, 2016 on a well-known anti-nuclear campaign portal, dianuke.org, Gopalakrishnan said, “The Kakrapar Unit-I nuclear reactor in Gujarat is undergoing a moderately large leakage of heavy water from its Primary Heat Transport (PHT) system since 9.00 AM on March 11, 2016.”
Yet, he adds, “Till 7.00 pm on March 12, 2016, the DAE officials had no clue as to where exactly the PHT leak is located and how big is the rate of irradiated heavy water that is leaking into the reactor containment.”
Referring to reports that the containment has been vented to the atmosphere at least once, the top nuclear expert says, “I suspect this indicates a tendency for pressure build up in that closed space due to release of hot heavy water and steam into the containment housing.”
“If this is true”, Gopalakrishnan says, “The leak is not small, but moderately large, and is still continuing.”
In fact, according to him, “No one confirms that any one has entered the containment (in protective clothing) for a quick physical assessment of the situation”, which suggests that “perhaps it is not safe to do so because of the high radiation fields inside.”
“When NPCIL officials state that the reactor cooling is maintained, I believe what they may be doing is to allow the heavy water or light water stored in the emergency cooling tanks to run once through the system and continue to pour through the leak into the containment floor through the break”, says Gopalakrishnan.
“All this points to the likelihood that what Kakrapar Unit-1 is undergoing is a small Loss-of-Coolant Accident (LOCA) in progress. It is most likely that one or more pressure tubes (PT) in the reactor (which contain the fuel bundles) have cracked open, leaking hot primary system heavy-water coolant into the containment housing”, he further says.
“The reactor cooling is said to be maintained which, in view of the PT breach, can only be by supply of heavy water or light water from the storage tanks of the emergency cooling systems. While it may perhaps ensure bulk coolant temperatures in the PHT system to be well under control, it could still mean fuel centreline temperatures in the channel which may have a breach could be quite high”, Gopalakrishhnan apprehends.
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