ANALYSIS - Nuclear Power Faces Stormy Seas Threat
Date: 01-Feb-07
Country: UK
Author: Daniel Fineren
Nuclear power plants need plentiful water for cooling so are usually near the sea or on rivers. All of the UK's operational plants, most of Japan's and many in the United States are on the coast.
Intensifying fears of climate change have boosted the popularity of nuclear power because it emits no carbon dioxide, the gas largely responsible for global warming.
With sea levels likely to rise for at least the next 1,000 years, according to a United Nations report to be published on Friday, bolstering the flood defences of the world's many coastal reactors looks set to become a more costly and time-consuming job -- one that could last for centuries.
A predicted sea level rise of less than a metre by the end of the century, alone, is not a big threat. But the prospect of more violent storms and higher seas is a cause for concern.
"In the future warmer climate there are some indications that storm surges will be larger than they are in the present day climate," said Keith Fenwick, a forecaster at the UK Met Office which has studied the threat for nuclear operator British Energy.
"In terms of the UK flood defences, it is generally the future storm surges that are cause for concern, as opposed to the general global sea level rises."
The Met Office predicts that if CO2 emissions remain at current levels, storm surge heights could increase by 1.7 metres at the Sizewell power plant in England by the end of the century.
Such concerns should not preclude building nuclear plants on the coast, because of the key role they could play in the fight against climate change, its supporters say.
"Nuclear power is part of the positive measures to reduce the impact of human activities on climate change," Antonio Godoy, the acting head of engineering safety at the International Atomic Energy Agency said.
"Although the effect of the policy measures that we take now would be in 1000 years, we should take it now."
The IAEA takes climate change seriously and requires that it be considered in all site evaluations for new plants, but nobody is really sure how big the threat is.
TSUNAMI
Ultimately, while governments and scientists argue over the gravity of the problem, the Asian tsunami of December 2004 could result in improved sea defences for nuclear plants.
After the tsunami temporarily flooded a reactor in India, the IAEA launched a global review of sea defences which could help defend against the longer-term, more persistent threat of climate change.
"We are now in the process of updating the standards on the basis of the lessons learnt from that tsunami," Godoy said.
British Energy, which runs most of the UK's ageing nuclear reactors, commissioned the Met Office study as part of preparations to defend its existing plants and assess their suitability for building a new generation of reactors.
Bulldozers already trundle up and down the beach next to British Energy's Dungeness power station every winter, repairing the constantly-eroding wall of shingle protecting the plant.
Bigger storms and higher seas could make defending Dungeness and plants like it a year-round job, or force a complete re-think.
Nor are inland river-cooled reactors invulnerable to global warming. Hot weather makes it difficult to keep them cool and operate safely. The hotter it gets, the more frequently they may have to close, just when power demand is highest.
Several European reactors have had to close or reduce output in recent summers as soaring temperatures made the water they rely on for cooling too warm to be of any use.
Cooling water problems also affect fossil-fuel fired power plants and even wind farms shut down in severe gales, so all the major power generation types face climate challenges of some kind.
