Nuclear Power Could See Revival

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A major theme in new designs is to simplify the reactor and reduce the number of moving parts, both literal and metaphorical. As well, the builders have looked at passive safety systems that engage automatically rather than those requiring operators to take action.

Westinghouse is producing a reactor called the AP1000, which is cooled by air flow around the containment vessel. The idea is to allow the warm air to rise, just as it does in a chimney, which cools the reactor vessel. In addition, the containment vessel can be examined from the outside, so any corrosion is apparent. In this way, cooling the reactor requires less input from the operators.

Thus far the AP1000 is probably closest to coming online in the U.S., as it is the type of plant Westinghouse plans to build in Georgia. The company is already building a similar plant in China.

Meanwhile Areva has chosen to go with tweaking more traditional light water reactors, with its European Pressurized Reactor, or EPR. An EPR uses pressurized water to transfer the heat from the reactor vessel to a steam generator; such reactors are the most common design Western Europe and the U.S.

The Areva design is much like its cousins. Jarrett Adams, a spokesman, says the changes are mostly in strengthening the containment building and the efficiency with which it uses fuel.

General Electric is offering the Economic Simplified Boiling Water Reactor, which as the name implies simplifies earlier boiling water reactor designs. A boiling water reactor pumps water through the reactor core, using the heat to generate steam which powers the turbines.

The ESBWR reduces the number of pumps. When water is heated into steam it rises, and when it condenses it falls, creating a natural circulation. Earlier designs would pump water.

Another feature is the cooling from pools above the level of the reactor core. If the water level in the core drops the pools are designed to empty into the core, keeping it cool. The reaction is also designed to stop on its own, rather than having to have an operator do it.

The designs aren't without their detractors. Arnie Gundersen, a consultant at Fairwinds, a firm that often advises environmental groups, said the biggest issue with the AP1000 is what happens if there is a leak in the containment vessel. He maintains that the coatings used on it will not prevent corrosion which could damage it. Gundersen has appeared before the ACRS, a separate body from the NRC that writes recommendations for the NRC's rulemaking, most recently in late June.

At the NRC, Eileen McKenna, branch chief of the AP 1000 projects at the office of new reactors, said the staff at the agency has looked at that possibility and decided the design was adequate.

Westinghouse has made some revisions to the AP 1000 design, as all builders do as the NRC makes recommendations during the approval process. McKenna said thus far none she was aware of addressed the issue Gundersen raised. There have been changes in the shield building, which is now designed to withstand an airplane crashing into it.

There are still other questions surrounding nuclear power. It reduces carbon emissions when stacked up against coal, but there is an environmental cost to mining uranium for the fuel. Costs are another factor. The fact that loan guarantees were needed to get the private sector to build the plants is worrying to some economists.

Waste disposal has also been a hot-button issue. In 2001 the DOE estimated there are some 100 million gallons of radioactive waste and 2,500 metric tons of spent fuel. Currently nuclear power plants store much of the waste on-site. Currently the only site approved is at Yucca Mountain in Nevada, but the Obama administration has said it would oppose further funding and no new site has been proposed.