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Snap-Together Nuclear Power

Energy Department picks a design and a builder for small modular reactor power plants

by Jeff Johnson
December 10, 2012 | A version of this story appeared in Volume 90, Issue 50

Credit: Babcock & Wilcox
Shown in this depiction is a 360-MW, two-reactor, small modular nuclear power plant that will be buried 150 feet underground, covered by a 10-foot concrete slab, and will look like a 30-acre WalMart store from the surface, B&W says.
This is a graphic of Babcock & Wilcox’s nuclear  power plant using a small modular reactor.
Credit: Babcock & Wilcox
Shown in this depiction is a 360-MW, two-reactor, small modular nuclear power plant that will be buried 150 feet underground, covered by a 10-foot concrete slab, and will look like a 30-acre WalMart store from the surface, B&W says.

The U.S. moved further along last month on an experiment to build a new generation of nuclear power plant reactors. Supporters hope these physically smaller reactors will have more flexible applications and incur less financial risk and construction cost than the nation’s current fleet of 104 large and aging nuclear power plants.

In late November, the Department of Energy announced that engineering firm Babcock & Wilcox (B&W) will receive funding to design, license, and commercialize the first small modular reactor for the U.S. market. Small modular reactors, including the B&W design, would generate less than one-third the electrical output of today’s 1,000-MW nuclear power plants. They would be built in a factory and hauled by train, truck, or barge to a site where they would be placed in the ground and wired up to generate electricity for at least 60 years.

The reactors could be grouped together for a large-scale utility application or could operate separately to provide electricity for a remote community or an industrial facility, such as a chemical plant or petrochemical complex, explains Christofer M. Mowry, president of B&W mPower, a subsidiary of B&W. The firm has been developing the concept for four years, Mowry says, and hopes to submit a complete design to the Nuclear Regulatory Commission (NRC) for approval within 18 months for a 180-MW unit. The design is a modification of a technology—a light-water reactor—basic to every large nuclear plant today. Advocates say the underground design protects the reactors from threats such as hurricanes and terrorists, but critics worry that it increases vulnerability to other hazards such as floods.

DOE’s November announcement follows its solicitation in March to support development of two modular reactor designs over the next five years. Some $450 million in support was offered, which had to be matched by industry. Four companies submitted proposals, including B&W.

However, DOE ended up selecting only one project and the specific funding amount is being left to negotiations. This lack of a second design and other details for the award concerns both the nuclear industry and its critics, who worry DOE may have thought the other proposed designs were unsatisfactory or may be backing off on support during this time of federal austerity.

The modular reactor program at DOE has an annual operating budget of about $65 million, a DOE official says, but adds that new funding opportunities may appear in the future, which would be needed to hit the amount listed in the solicitation.

DOE’s goal for the project is clear and ambitious: It wants B&W to begin com­mercial modular reactor operations by 2022.

B&W’s project will be managed by a team, Mowry says, including the Tennessee Valley Authority, a federally owned electric utility, and Bechtel International, a global construction company. TVA is preparing an application to NRC for a license to operate up to four 180-MW B&W reactors at its Clinch River site in Oak Ridge, Tenn. To meet DOE’s goal, Mowry says, B&W’s intention is to install two units by 2022.

The selection of B&W’s proposal, according to Mowry, signals DOE’s willingness to enter a partnership. The size of the award is not the issue, he says, noting the company is negotiating with DOE over the exact amount. “It is full speed ahead for us as it has been for four years. This is an ongoing effort,” he says, noting that B&W has more than 300 people working on the project.

The smaller “bite-sized” reactors, he explains, have several advantages, such as lowering the financial risk of deploying these technologies. The key, however, is to keep the cost per kilowatt for construction to a level no higher than that of a large reactor, despite the loss of economies of scale.

“We are changing the game,” he says. “Historically, 70% of the cost of a nuclear plant is construction at the job site, and 30% is in a factory environment. We want to turn that on its head.”

By building the plant in a more controlled factory environment, he hopes to keep costs predictable and under control. Mowry says the 180-MW size will cost around $1 billion to build and was selected because it is the biggest B&W can construct and still put on a railcar. Also it is the building-block size a utility likes, he says, and it is the size of a typical coal- or gas-fired power plant B&W hopes to replace.

Its location underground is safe, Mowry says, but opponents have their doubts.

“Being underground is a double-edged sword,” says Edwin Lyman, senior scientist with the advocacy group Union of Concerned Scientists. “You do reduce many threats, but you increase the vulnerability to flooding, and being underground makes it much harder for operators to gain access to manual equipment whether during an emergency.”

Lyman also questions whether the small reactors will be financially competitive. To shave costs, companies such as B&W will be forced to rely heavily on passive safety systems and reduce backup support and staffing for emergencies



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