Risks to Nuclear Reactors Scrutinized in Tsunami's Wake
The December 26, 2004 earthquake was the most powerful in decades. This month the international nuclear community will share lessons learned from the tsunami and previous flood events. (Photo credit: AP)
Scientists are re-examining the potential dangers to nuclear power plants in the wake of the catastrophic earthquake that struck the Indian Ocean last December, triggering a massive tsunami.
India's Kalpakkam nuclear power plant withstood the giant waves, which engulfed its small township, home to India´s centre for atomic research. Battered but safe, the plant shut down automatically after detectors tripped it as the water level rose. There was no release of radioactivity. The reactor was restarted 1 January 2005, six days after the catastrophic waves struck India´s east coast.
"There are scores of nuclear power plants operating in coastal areas and some of these may need to take a renewed look at this external hazard," IAEA Director of Nuclear Power, Mr. Akira Omoto said. "It is also true for plants presently under construction." It is common for nuclear power plants to be built in coastal areas, drawing the seawater to cool the reactor.
Specialists from around the world will scrutinize the potential impact of natural disasters on nuclear reactors, at the IAEA organized International Workshop on External Flooding Hazards at Nuclear Power Plant Sites. From 29 August - 2 September 2005 the world´s nuclear community will gather at the Kalpakkam nuclear complex to share latest knowledge and research developments and take home lessons learned, from this tsunami, and past flood events.
The IAEA has stringent safety standards designed to guard nuclear power plants against natural calamities like earthquakes, volcanoes, flooding, tsunamis and cyclones. The non-legally binding guidelines cover site and design requirements for nuclear reactors, as well as appropriate monitoring and warning systems.
The IAEA issued the Kalpakkam reactor a clean bill of health in the tsunami´s wake, rating the event a "zero" or of "no safety significance" on the International Nuclear Events Scale. Around 3.5 cubic metres of seawater, sludge and muck entered a construction pit, where the foundations for a new 500 MWe Fast Breeder Reactor were being built. Water also entered a pump house for cooling water, tripping the nuclear power plant to shut down.
Mr. S.N. Ahmad, Executive Director, Corporate Services, Indian Department of Atomic Energy, said natural calamities like Tsunamis were considered when selecting the site and design of nuclear reactors. "Man must live with natural calamities. Wisdom lies in effectively meeting the challenges of such situations and ensuring safety of human life and property. In nuclear power plants the whole spectrum of such natural calamities and highly improbable accident conditions are factored in site selection and design," Mr. Ahmad said.
Japan, a country were earthquakes and Tsunamis regularly strike, has developed systems to evaluate and protect reactors. It will be among the seventeen countries at the workshop to provide guidance and share its experiences. "Learning from the lessons of this latest Tsunami as well as from other flood events that occurred in the past will allow the review, revision and expansion, as appropriate of the Agency Safety Standards on external flooding hazards," IAEA Director of Nuclear Safety and Nuclear Installation, Mr. Ken Brockman said.
In particular, recent events highlighted some technical difficulties in the hazard assessment for such scenarios where combinations of different events may take place, such as tide, storm surge, waves and cyclonic winds.
Topics on the five-day agenda include case studies on flooding hazards to be presented by countries including France, whose "Le Blayais" reactor was assaulted by severe storms in December 1999. See Story Resources for further details.