Malfunctioning of four Russian valves, critical to the back-up safety system, held back the operationalisation of the first unit of Kudankulam Nuclear Power Plant (KNPP) of 1000 MW capacity, Indian nuclear regulator has disclosed.
“These four valves are integral part of the back-up safety system, required to cool down the core of the nuclear reactor in case of extreme emergency,” S S Bajaj, Chairman of the Atomic Energy Regulatory Board (AERB), told Deccan Herald.
The faults were found recently when officials were checking the components and systems of the nuclear reactor, as a part of the pre-commissioning activity.
“While checking thousands of valves installed in the plant, the performances of four valves of a particular type were found deficient,” AERB Secretary R Bhattacharya said.
As these valves were imported from Russia, the Nuclear Power Corporation of India Ltd (NPCIL) had to arrange for their replacement which took time.
“The replacement valves have arrived and are now being tested by the NPCIL. Once these valves are installed, the AERB will inspect the plant again,” Bajaj said.
But neither Bajaj nor Bhattacharya, in their carefully drafted statement, disclosed when the valve malfunction was spotted and corrective action suggested.
In the absence of a definitive time-line from the AERB, it is not clear on whose advice Prime Minister Manmohan Singh, in the last week of March, told Russian president Vladimir Putin that the first unit of the plant would be operational within a month’s time, which seems unlikely at present.
The Indo-Russian nuclear power plant has missed many deadlines announced by the Department of Atomic Energy. The latest dateline set by the NPCIL is May 2013 for the first unit and December 2013 for the second.
The AERB had granted the clearance for initial fuel loading in the KNPP unit-1 in September 2012. The purpose was to check whether the plant is capable of achieving the design objectives and meet safety requirements.
Between September 19 and October 2, as many as 163 bundles of enriched uranium fuel were loaded into the reactor. Subsequently, the AERB began inspection for commissioning.
Commissioning of the first unit of the project was originally scheduled for December 2011 but had to be put off due to intense protests.
At present, the NPCIL operates 19 nuclear reactors across the country that generate about 4,680 MW electricity. One nuclear reactor at Rawat Bhata in Rajasthan–RAPS 1–is under extended shutdown.