"...a less well-known side of nuclear power: It requires great amounts of cool water to keep reactors operating at safe temperatures. That is worrying if the rivers and reservoirs which many power plants rely on for water are hot or depleted because of steadily rising air temperatures.
"If temperatures soar above average this summer - let alone steadily increase in years to come, as many scientists predict - many nuclear plants could face a dilemma: Either cut output or break environmental rules, in either case hurting their reputation with customers and the public."Governments and the energy industry are just starting to grasp the vulnerabilities of water-hungry power plants. If the complications prove serious in countries where inland sources of water are growing scarce, where seafront nuclear stations are unwelcome or impractical and where alternative cooling technologies are too expensive, it could take the bloom off of nuclear as a source of clean energy and leave it more unclear than ever where sizable new power supplies might come from.
"'We're going to have to solve the climate-change problem if we're going to have nuclear power, not the other way around,' said David Lochbaum, a nuclear engineer who is with the Union of Concerned Scientists.
"'As the climate warms up, nuclear power plants are less able to deliver,'" he said.
"The French company operates 58 reactors - the majority on ecologically sensitive rivers like the Loire.
"During the extreme heat of 2003 in France, 17 nuclear reactors operated at reduced capacity or were turned off. Électricité de France was forced to buy power from neighboring countries on the open market, where demand drove the price of a megawatt hour as high as €1,000, or $1,350. Average prices in France during summer months ordinarily are about €95 per megawatt hour.
"The heat wave cost Électricité de France an extra €300 million. The state-owned company 'swallowed it as a one-off cost of doing business in extreme circumstances,' Philippe Huet, an executive vice president at Électricité de France, said.
"The company was not allowed to pass along price surges to customers.
"Huet said the company was preparing for this summer on several fronts. The company is stocking more water in reservoirs, offering lower priced contracts to large users in exchange for the right to cut supplies and using more sophisticated forecasting tools for weather and river temperatures, he said.
"'If this year is the same as in 2003 we will handle it better,' Huet said. 'But we cannot exclude difficulties if the summer is even warmer and drier than 2003.'"
Source and more details: Climate change puts nuclear energy into hot water - International Herald Tribune
(via Green Car Congress and Treehugger ).
Even this story might be over-optimistic. It claims that if you put nuclear power stations by the sea, then you have no problem. Yet ocean temperatures are rising due to climate change, too. Granted, oceans heat up much more slowly than smaller bodies of water, so ocean temperatures may be unlikely to affect nuclear power operations in the short term. But the increase in sea levels due to melting ice, plus more frequent severe storms, could endanger any shoreline installation. What would happen if a Katrina-sized hurricane hit a nuclear power station?
Finally, we have already learned in many painful ways that the oceans, too, are finite. Increasing ocean temperatures to cool nuclear power stations might not be as benign as it may seem.