The green body said the risk of accidents increase with age in CANDU reactors.
Greenpeace India on Tuesday demanded a probe by independent experts into all "aging" heavy water reactors in the country even and alleged the country's nuclear regulator has failed to ascertain the reason behind the recent "serious" incident at Kakrapar Atomic Power Station in Gujarat.
One of the two 220 MW units of Kakrapar Atomic Power Station (KAPS) in Surat district was shut down on March 11 after leakage of heavy water and a temporary emergency situation was declared but there was no radioactive leak and all workers were safe.
"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.
"We need independent expert investigation into the Kakrapar accident and the immediate inspection of all other aging heavy water reactors," said Hozefa Merchant, Greenpeace campaigner.
Greenpeace India said, "The demand for investigation comes as the Indian nuclear regulator failed to identify the leak within 72 hours of the accident."
The NGO said although the reactor was shut down, the Atomic Energy Regulatory Board (AERB) had stated that the leak was significant enough to be considered a level 1 accident on the International Nuclear Event Scale (INES).
It said the Kakrapar unit 1, a pressurised heavy water reactor (PHWRs) based on CANDU (CANada Deuterium Uranium) design, is over 20 years old and seven others, out of the current 18 in India, are of similar design and as old.
"Any mishap in these reactors could endanger the lives of over four million people living around a 30 km-radius around these eight reactors," it said.
The population within the 30 km radius around Kakrapar is close to a million people, it said, adding, four of the oldest reactors are located in Rawatbhata in Rajasthan and Chennai in Tamil Nadu.
The green body said the risk of accidents increase with age in CANDU reactors, with the inevitable degradation of hundreds of pipes that hold the fuel and transport heavy water.
"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 said.
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