[ RadSafe ] Risks to Nuclear Reactors Scrutinized in Tsunami´s Wake

[Marcel Schouwenburg]

News from IAEA.
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Risks to Nuclear Reactors Scrutinized in Tsunami´s Wake
International Workshop on Hazards of External Flooding to Convene in India
Staff Report
16 August 2005

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)

Story Resources Kalpakkam Nuclear Power Plant
IAEA Nuclear Installation Safety
Reassessing "What if" Factor at NPPs
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 Installation Safety,
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.
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Marcel Schouwenburg
RadSafe moderator & listowner