Indian n-reactors have extra cushioning in case of emergency

New Delhi: Officials of India's sole nuclear power utility, the Nuclear Power Corporation of India Ltd (NPCIL), say that the country's 20 commercial nuclear reactors, including the oldest two in Tarapur, are better equipped to tackle a Fukushima-type scenario.

At Fukushima all power was lost after the shutdown of the reactors as a magnitude 9.0 earthquake and a follow-on tsunami wave knocked out power systems and back-up generators.

With power systems knocked out by the earthquake and seawater seeping into diesel generators meant to supply back-up power, an overheating of the reactors' cores resulted and the process ultimately escalated into a crisis with hydrogen explosions and radiation leaks.

Incidentally, the twin Tarapur reactors are of the same generic design as the Fukushima reactors (boiling water reactors) and actually of an older vintage, being installed in 1963. The twin 160 MWe units were the first such reactors to be installed in Asia.

The Nuclear Power Corporation of India Ltd (NPCIL) has now conducting safety audits to determine the reliability of backup systems featuring in Indian reactors.

A shutdown of a nuclear reactor merely stops fission chain reactions but the core continues to produce heat from the decay of fission products. This is known as 'decay heat.'