Wednesday, February 15, 2012

After Fukushima Third-generation nuclear reactor designed


The United States has approved construction of new nuclear reactors for the first time in three decades. The two new reactors approved today (Feb. 9) for Georgia would represent the first U.S. versions of next-generation reactor designs that have begun appearing in China.

These "third-generation" reactors are said to be safer, with longer-lasting batteries and passive cooling systems powered by gravity so that they can survive longer during emergencies without outside power.

The Nuclear Regulatory Commission approved construction of the two reactors at an existing nuclear power plant in Vogtle, Ga., in a 4-1 vote.

"The last plant that got to this stage of the [approval] process did so in 1978," said Harold McFarlane, manager of the nuclear science and technology directorate at Idaho National Laboratory. "We think it's a very significant step going forward. It is the first of the new generation."

The U.S. froze construction of nuclear power plants after the partial core meltdown at Three Mile Island, Pa., in 1979. Consequently, the 104 nuclear plants still operating in the country have designs dating to the 1960s and 1970s. Meanwhile, the first of the third-generation plants were designed in the 1990s and were updated throughout the new millennium.

Following the devastating earthquake and tsunami that led to the meltdown at Japan's Fukushima Plant last March, Germany, Switzerland and Spain halted construction of any new nuclear power plants. However, energy-hungry China has pressed ahead with adding new, third-generation nuclear reactors.

The newly approved AP1000 reactors for the Vogtle plant to be made by Westinghouse have safety features that would give people "days instead of hours" to restore electric power in a Fukushima scenario, McFarlane told InnovationNewsDaily. The Fukushima reactors suffered a meltdown after the lack of electricity knocked out their cooling systems.

In the new models, which Westinghouse already has built for China, "the water needed to cool the reactors is stored inside the containment building rather than outside of containment," explained Robert Buell, a risk analyst at Idaho National Laboratory. "You use physics and natural circulation along the containment walls to cool the reactors instead of relying on mechanical systems."

The Fukushima disaster did not go unmentioned during the Nuclear Regulatory Commission vote. According to the news service Reuters, NRC chairman Gregory Jaczko cast the lone vote against the new reactors, arguing that the commission should delay approval until it requires all nuclear plant operators to include "Fukushima enhancements" safety and operational lessons learned from the meltdown

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