Saturday, April 23, 2011

Safety of nuclear power plants: India takes up seismic qualification programme

By Syed Akbar
Hyderabad, April 22: The Department of Atomic Energy has finally taken up "seismic qualification" programme to find out in real scenario whether nuclear power plants in the country are capable of withstanding earthquakes of greater magnitude.
Though the technology has been in existence for almost 20 years, this is the first time that India is testing whether the nuclear power plants are of earthquake or seismic grade. The Nuclear Power Corporation of India has been claiming that its power plants have withstood earthquakes in the neighbourhood. But seismic qualification programme will enable the NPCIL to know whether its claim is true.
In seismic qualification, a prototype nuclear power plant is subjected to earthquake loading through artificial means i.e. put on an "earthquake shaking table" to find out if the nuclear safety parameters are under control. If the nuclear power plants pass the seismic qualification, they are safe from the point of earthquakes. Other methods adopted for seismic qualification are "numerical analysis" or reference to databases of 
previously qualified nuclear plants.
The DAE presented the safety status of its nuclear power plants, and its regulatory and safety review system at the Convention of Nuclear Safety (CNS) held recently in Vienna. Releasing the details of the presentation, the DAE points out that "the CNS was informed that India is developing a seismic qualification program by experience data base which is nearing completion. Contracting parties appreciated the work as a pioneering
effort by India".
An official statement by Atomic Energy Regulatory Board said India also informed the CNS about the initiatives taken to ensure safety in nuclear power plants in the wake of Fukushima accident. The measures include the  formation of a high level committee by AERB to re-examine the capability of nuclear power plants to withstand external events and adequacy of  provisions available to ensure safety in such events.
Once a nuclear power plant is seismically qualified, the reactor shut down safely in the  event of earthquake, and the residual heat is safely removed, thus preventing release of  radioactive substances into the atmosphere. The historical data on earthquakes within a  radius of 200 km is taken into account for seismic qualification studies.

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