Save the nukes

The Economist looks at the prospects for nuclear energy with new and safer designs including the meltdown-proof “pebble bed” reactor:

Yet political interest in nuclear power is reviving across the world, thanks in part to concerns about global warming and energy security. Already, some 441 commercial reactors operate in 31 countries and provide 17% of the planet's electricity, according to America's Department of Energy. Until recently, the talk was of how to retire these reactors gracefully. Now it is of how to extend their lives. In addition, another 32 reactors are being built, mostly in India, China and their neighbours. These new power stations belong to what has been called the third generation of reactors, designs that have been informed by experience and that are considered by their creators to be advanced. But will these new stations really be safer than their predecessors?

Clearly, modern designs need to be less accident prone. The most important feature of a safe design is that it “fails safe”. For a reactor, this means that if its control systems stop working it shuts down automatically, safely dissipates the heat produced by the reactions in its core, and stops both the fuel and the radioactive waste produced by nuclear reactions from escaping by keeping them within some sort of containment vessel. Reactors that follow such rules are called “passive”. Most modern designs are passive to some extent and some newer ones are truly so. However, some of the genuinely passive reactors are also likely to be more expensive to run.

Although cheaper than a blackout.