Power outages at Kudankulam nuclear plant dangerous: finds a new study

Courtesy: Times of India

nuclear cartoonAccording to a study based on analysis of grid data, there have been 21 power outages at Kudankulam Nuclear Power Plant (KKNPP) from Oct 22, 2013, to Oct 22, 2014. Of these 21 outages, 14 are “scrams” or trips caused by faulty equipment or poor oversight, or both, and, according to experts, can be potentially catastrophic.

The first part of the study published in academia.edu, an online research community, points out that the maximum permitted trip rate — calculated per 7,000 reactor hours — is 0.37 for reactors across the world. Alarmingly, in Kudankulam (in its 4,701 hours of operation), the trip rate is projected at 20.8 per 7,000 reactor hours. In the US, a plant with 25 scrams during a 7,000-hour period is issued a “red” citation and will be forced to shut down.

The study was conducted by a team of researchers led by Cochin University of Science and Technology (CUSAT) scientist M J Joseph, Society of Science Environment and Ethics (SoSEE) chairman V T Padmanabhan and Dr R Ramesh, a medical practitioner, who has authored books on the geology of Kudankulam and is a member of Doctors for Safer Environment.

The main reason for the ‘scrams’ is old equipment, including reactor pressure vessels, turbines and polar cranes at KKNP, all imported from post-Chernobyl Soviet Union.

“Trip rate for KKNPP is 20.8 per 7,000 reactor hours, which is too high and can trigger an explosion leading to a nuclear disaster. It is due to the use of old equipment imported after Chernobyl nuclear disaster when the erstwhile Soviet Union cancelled the VVER-1000 reactors, a Russian version of the Pressurized Water Reactor,” Prof Joseph said.

CUSAT scientist Prof M Sabir said, “If substandard materials are used in a nuclear reactor and if quality checks are not maintained, obviously chances of a disaster are high”. He said that an earlier study conducted by scientists from CUSAT, Bremen University, Sussex University and based on official documents from Atomic Energy Regulatory Board, Nuclear Power Corporation of India Ltd and their Russian counterparts had concluded that major equipment at KKNPP like the reactor pressure vessel and polar crane are outdated.

“Though China discarded such equipment after initial imports, India continued importing such equipment for KKNPP,” Prof Joseph said.

Incidentally, a turbine generator system imported from Russian firm Silmash was involved in eight of the 14 trips reported at KKNPP. Three other trips and the pipe burst accident on May 14 this year (officially known as “warm water incident”) were related to the feed water system. Both the feed water system and the turbine are located in the same auxiliary building.

According to the scientists, what could hamper remedial measures is the secretive manner in which relevant information is treated. At KKNPP, all documents related to functioning of the nuclear reactor are property of the Russian firm Atomstroy, which exports all nuclear power machinery.

Officials of the Department of Atomic Energy and AERB were unavailable for comment.

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