The Atomic Energy Regulatory Board (AERB) has set up a 10-member committee to examine if our 20 nuclear plants can withstand earthquakes and other external events such as tsunamis, cyclones, floods, etc. That includes checking if the arrangements are adequate to ensure safety in case of such events, both within and beyond the design.
The panel is chaired by AERB’s former chairman, S K Sharma. It first meeting is on the coming Thursday.
Committee members include representatives of AERB, Bhabha Atomic Research Centre, Nuclear Power Corporation, IIT-Madras, Indian Institute of Tropical Meteorology, Pune, and Central Water & Power Research Station, Pune.
A committee member, who did not want to be named, said Indian plants were, depending on the sites, designed for various magnitudes of earthquakes, ranging from 5.5 to 6.7 on the Richter scale.
He said during the 2004 tsunami, nuclear plants in south India were able to withstand the effects. “Our plants are almost 2,000 km away from the tectonic boundary of Sumatra. The earthquake following the tsunami in Japan was quite unprecedented and, therefore, the committee will revisit the safety applications installed in our plants.” Since the events at Fukushima are still unfolding, and full analysis and understanding would become available only in due course, the committee may consider issuing an interim report as early as possible, followed by a final report subsequently, he said.
A Nuclear Power Corporation official explained that Indian plants were located in seismic zones II, III and IV. After selection of the site, a detailed seismic survey is carried out, considering the earthquakes in that region for the past about 300 years. Based on the major data and inferred data from the history, the magnitude of possible earthquakes and ground acceleration is calculated. Further, by a formula, the magnitude of earthquake assumed is enhanced. The structures of plant and equipment inside are designed in line with the enhanced magnitudes,” he said.
Further, Indian nuclear plants have an ‘Exclusion Zone’ of 1.6 km surrounding the power station, in which no habitation is permitted. The entire area is fenced or walled and defines the boundary of the site. Beyond this is the public domain and an area of 16 km radius around the plant site is called the Off Site Emergency Planning Zone.
