Chennai, April 16 (IANS) It will take not less than one month to restart generation from Madras Atomic Power Station (MAPS) second unit that tripped Monday due to fire in a transformer, a senior plant official said.
“We are checking whether fault is outside the transformer or inside. If it is an outside fault, then the unit can be restarted in a month’s time. On the other hand if the fault is inside the transformer, then it may take more time to sort it out,” MAPS station director T.J. Kotteeswaran told IANS over phone from Kalpakkam, around 70 km from here.
He said the Atomic Energy Regulatory Board (AERB) has been notified about the accident.
The MAPS, run by the Nuclear Power Corporation of India Ltd. (NPCIL), has two reactors of 220 MW each, but they have been functioning below their rated capacity owing to paucity of fuel.
The second unit was restarted Sunday after a 40-day maintenance shutdown. On Monday morning when the reactor was operating at 110 MW, the unit tripped due to a fault in the generator transformer high voltage bushing and the reactor was shut down.
Due to the generator transformer failure, the reactor turbine stopped and the reactor was gradually shut down following due procedure.
According to Kotteeswaran, there was no damage to the turbine due to its sudden stoppage.
He said the plant and machinery have been insured with a government owned general insurance company.
Kotteeswaran said the first unit is operating normally, feeding 170 MW to the grid.
In August 2012, two reactors at MAPS shut down automatically after a critical component (breaker) in the 230 KV switchyard tripped, resulting in power supply failure to the reactors.
Both reactors shut down their operations and restarted a couple of days later.
According to Kotteeswaran, the MAPS’ operational licence is valid till 2014.
Every nuclear power plant in India has to renew its operational licence once in five years.
With the accident in Fukushima reactors in Japan, additional safety measures have been suggested by the AERB to NPCIL for its units. The NPCIL has also been asked for an implementation roadmap and till such time the units are given limited period licence.