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A Path for Nuclear Power

A novel but tested technology, the pebble-bed reactor, can make fission energy safe.

Lee S. Langston

Back to the Path not Taken

The high-temperature, gas-cooled reactor technology path pioneered by Daniels needs to be rejoined. Three Mile Island and Fukushima have shown the near-catastrophic effects that loss of coolant can have on water-cooled nuclear reactors. Nuclear power will not see a major rebound unless the new designs are clearly safer than what exists now. What is needed is an industry-sponsored, public–private partnership to develop gas turbine, pebble bed–type reactors as truly failsafe sources of carbon- free electricity. There are still questions to answer, and problems to solve.

Some experts in the nuclear industry feel that pebble bed reactors have not yet shown sufficient operational efficiency: It is unclear whether their costs would be competitive with other types of nuclear reactors, much less natural gas, over their full life span. Another criticism is that pebbles moving through the reactor could create contaminated graphite dust. Although pebbles can be decommissioned individually, breaking up the task of storing nuclear waste, the overall magnitude of waste from the combined mass of pebbles might be greater than from other reactor designs.

Meanwhile, other nuclear technology is not sitting still. One intriguing, newer concept is to use molten salts instead of helium as the cooling agent. Liquid salts increase heat transfer and raise efficiency, and consequently reduce the size and the cost of the reactor, but are also inherently fail-safe. Physicists at the University of California at Berkeley and Oak Ridge have developed designs for a liquid-salt-cooled pebble bed reactor.

There may be a few twists on the path to next-generation nuclear power. But it is clear to me that the path is worth following.


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