Wednesday, August 8, 2012

The nuclear approach to climate risk - Bulletin of the Atomic Scientists

From desertification in China to glacier melt in Nepal to water scarcity in South Africa, climate change is beginning to make itself felt in the developing world. As developing countries search for ways to contain carbon emissions while also maximizing economic potential, a natural focus of attention is nuclear power. But nuclear energy presents its own dangers. Below, Wang Haibin of China, Anthony Turton of South Africa, and Hira Bahadur Thapa of Nepal answer this question: "Given nuclear energy's potential to slow global warming, do its benefits outweigh its risks, or do its risks outweigh its benefits for developing countries?"

In his first Roundtable essay, Anthony Turton presented a perceptive analysis of the linkages among water scarcity, electricity demands, and climate change in South Africa. He also outlined inspiring ideas about easing that country's water constraints by using nuclear energy in the desalination of seawater. It is my view, however, that while Turton's ideas may be sound for South Africa, they have limited applicability in many other places -- including China.

If nuclear energy is to be developed in a sustainable fashion, cost-benefit ratios must always be kept clearly in mind -- and in different locations, nuclear power can present starkly different cost-benefit ratios. In developing countries with constrained water supplies and less constrained electricity supplies, it may make sense to use nuclear energy to desalinate seawater (and even to pump it to remote locations). But in developing nations where the population suffers from an urgent shortage of electricity, the idea of consuming a great deal of power to produce fresh water would seem to lack a firm economic basis.

China, a country whose economy and electricity needs are both growing rapidly, currently operates 15 nuclear reactors. More than one of these plants is used for desalinating seawater, but only when, as is the case with the Hongyanhe facility in Liaoning province, desalination is unavoidable. The pressurized water reactors at the Hongyanhe facility require a great deal of fresh water to operate, and the local supply of fresh water is inadequate for this purpose. Therefore, the plant has been designed to desalinate over 10,000 cubic meters of seawater daily for its own operation.

Significantly, the desalination technology that the plant has adopted is reverse osmosis. The choice is significant because reverse osmosis consumes less energy per unit of fresh water produced than do other desalination methods, rendering the energy needs and economic costs of desalination acceptable to the plant's operators. But -- according to an interview I recently conducted with a senior economist at China Guangdong Nuclear Power Group, the plant's owner -- the company has no plans to desalinate more seawater than the Hongyanhe facility needs for its own operation.

The company's decisions regarding desalination reflect a trade-off between water demands and power demands; such trade-offs are common in the developing world, where many countries require more water, more electricity, or both. I believe that, in a world where 1.5 billion people lack access to electricity, it is power demands that, on the whole, are more acute than water demands. More