Authorities in the Indian state of Gujarat are investigating and a 220-MW nuclear reactor remains shut down after Unit 1 of the Kakrapar Atomic Power Station began leaking heavy water on March 11.
Heavy water is used to cool the core in CANDU reactors, and loss of coolant in any nuclear plant can lead to a catastrophic failure. At Kakrapar, Site Director LK Jain said the faulty coolant channel was isolated, its nuclear fuel bundles were removed, and the leak was plugged.
Officials declared a temporary site emergency when the leak was discovered, but the country’s Atomic Energy Regulatory Board has consistently reported normal radiation levels surrounding the plant and no hazard for plant employees.
“No worker involved in the operations was exposed to any undue radiation. The radiological conditions remain normal and cooling is being maintained in all the remaining channels,” Jain said. “The investigation will now be carried out to find the cause of the failure.”
Four days after the leak, Greenpeace India called for an independent review of all the country’s “aging” heavy water reactors, noting that the cause of the “serious” accident at Kakrapar had not been determined. Greenpeace pointed out that eight of the country’s 18 reactors, including Kakrapar, are now more than 20 years old.
“Due to increasing accident risks, CANDU reactors typically need to be shut down and completely retubed after about 25 years of operation in order to continue operating safely,” Greenpeace India stated.
“The Kakrapar accident was likely caused by degrading components and we’re concerned similar aging effects could cause accidents at other aging heavy water reactors,” added campaigner Hozefa Merchant. “We need independent expert investigation into the Kakrapar accident and the immediate inspection of all other aging heavy water reactors.”
“The impacts of aging are not entirely well understood, so it is vital to adopt a precautionary approach to protect public safety,” agreed Greenpeace Canada spokesperson Shawn-Patrick Stensil, a specialist in the CANDU (Canada-Deuterium-Uranium) design.
In a commentary on the fifth day of the leak, Kumar Sundaram fumed about the limited public information available on an incident at plant that has had a history of performance problems. “Ever since it was commissioned in 1993, the Kakrapar nuclear plant has had several accidents, including a major one in 1994 when the reactor was flooded and water reached inside the reactor building,” he wrote. This time, he charged, the leak occurred in the morning but wasn’t announced until evening, by which time it was becoming common knowledge in nearby communities.
“It’s not easy to get the picture with incomplete information,” Sundaram wrote. “When the Fukushima accident happened, sitting in Delhi I got live radiation counts from the operator’s website, where counts from devices installed in all directions of the plant were updated live. That’s how we came to know of the extent of the accident in initial days.” But “in India, non-transparency is national security and sanity is sedition.”
In January 2003, the CANDU Owners Group had declared the Kakrapar complex its best-performing pressurized heavy water facility, Wikipedia reports. By that time, construction costs had more than tripled from 382.52 to 1,335 crore (a crore equals 10 million rupees, or US$157,000). (h/t to the Ontario Clean Air Alliance for pointing us to this story)
