Wednesday, February 24, 2010

The sad story of the pebble bed reactor

Pebble-bed nuclear reactor gets pulled : Nature News

South Africa has stopped funding for the development of its own pebble bed reactor. (Actually, I thought there was a recent announcement of some energy funding to SA from Obama, and that it might have been going to help with the pebble bed demonstration reactor. But maybe that was just my guess.)

Anyhow, Nature explains what went wrong with the project in South Africa:
Runaway costs and technical problems helped to doom the project, says Thomas. "In 1998, they were saying that they would have the demo plant online in 2003" at a cost of 2 billion rands, he says. "The final estimate was that the demo plant would be online in 2018 and it would cost 30 billion rands." Furthermore, he adds, the PBMR has never been held to account for why costs rose every year, why the completion date was continually pushed back or the nature of its design problems.

In a final twist, the PBMR announced last year that it was indefinitely shelving plans to build a demonstration plant. The programme's demise will not help South Africa's goal of doubling its 35,000-megawatt power-generating capacity by 2025.

One problem was that the design became too ambitious, says John Walmsley, past president of the South African branch of the Nuclear Institute, a professional society for nuclear engineers. The PBMR hoped to push the reactor's operating temperature as high as possible to enable not just electricity generation, but also 'process heat' applications such as turning coal into liquid fuels, he says. It also aimed to boost the power output to the very limits of the design to make the reactor more economical. "They tried to build a BMW when they maybe should have started with a Morris Minor," he says.

Even the passive safety feature of the design may have been overstated, it appears:

Although many scientists had hoped that the safety system of the pebble-bed design would win over opponents of nuclear power, a 2008 report from the Jülich Research Centre cast doubt on those claims, suggesting that core temperatures could rise even higher than the safe threshold.

Tsinghua University in Beijing now hosts the only operational prototype pebble-bed reactor, although similar reactors are being developed in the United States and the Netherlands. But the PBMR's problems are not unique, says Thomas. "Every nuclear nation in the world has had a programme to commercialize this type of reactor, and they all got nowhere."
Well, I'm not giving up yet, as long as some company somewhere is still looking at them.

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