Small nuclear reactors on Clinch River could power several cities the size of Oak Ridge

Clinch-River-Site-Bear-Creek-Road-Entrance-March-27-2016

The small nuclear reactors that could be built along the Clinch River could provide enough electricity to power several cities the size of Oak Ridge. The Bear Creek Road entrance to the Clinch River Site, where the reactors could be built by the Tennessee Valley Authority, is pictured above on Sunday, March 27, 2016. (Photo by John Huotari/Oak Ridge Today)

The small nuclear reactors that could be built along the Clinch River could provide enough electricity to power several cities the size of Oak Ridge. They could also be, depending upon the timing, the first commercial reactors of their type in the United States.

They’re known as small modular reactors, or SMRs. They could generate 80 to 200 megawatts each. One hundred megawatts is enough to power about 60,000 homes. Oak Ridge has about 12,000 homes.

Several companies are working on SMR designs, but so far none have been certified by the U.S. Nuclear Regulatory Commission, said Jim Hopson, public relations manager for the Tennessee Valley Authority.

By May 12, TVA plans to submit an application to the NRC for what is known as an early site permit to build SMRs on the Clinch River Site in west Oak Ridge. Hopson likened an early site permit, or ESP, to a pre-approval for a home loan, although he said that is an oversimplification.

“It’s similar to pre-approving yourself for a loan,” Hopson said Friday. “You get the preliminaries out of the way.”

The ESP would allow site characterization and an evaluation of the suitability of the 1,200-acre Clinch River Site. The site is in west Oak Ridge just north of the Clinch River and Interstate 40, south of the East Tennessee Technology Park (the former K-25 site), and between Highway 95 and Highway 58 in a bend of the Clinch River. (See a map and a link to a satellite view below.)

The NRC will have a public meeting on April 12 in Oak Ridge to discuss the TVA application for the early site permit. There will be two sessions that day, one in the afternoon and another in the evening.

It’s not clear yet how many SMRs could be built in Oak Ridge, but it could range between two and six. Hopson said SMRs are designed to be used in groups, but no decision has been made about the number that could be built here.

Before the SMRs could be built in Oak Ridge, though, the NRC would have to approve an early site permit, certify a design, and approve a construction and operating permit. Also, the TVA board would have to give the go-ahead.

There has been talk of building a small modular reactor in Oak Ridge for a number of years. At one point, TVA was looking at a proposed project timeline that would have an SMR in Oak Ridge as early as 2022.

But Hopson said that timeline depended upon the SMR design being further along.

Conceptual drawing of an underground containment structure housing two B&W mPower reactor modules. (File image from August 2013 courtesy of B&W)

At one time, Babcock and Wilcox, or B&W, was the lead designer on what is called an mPower design. But B&W decided to slow down its investment about two years ago, Hopson said. However, TVA and the U.S. Department of Energy didn’t want to slow down their work, so the focus was shifted to the early site permit. All the designs now fit a fairly generic site envelope that can be used for the site permit and refined later, Hopson said.

Shifting to the early site permit freed TVA from any particular reactor design, allowing the public utility to consider any design, Hopson said. B&W is still working on mPower, but Hopson said the company is not directly involved with TVA at this point. He said TVA is working with at least three companies on SMR design.

It will probably be a few years, at the earliest, before one of those designs is submitted to the NRC for certification, Hopson said. But he is optimistic that a feasible design will emerge; it’s just a question of when.

The SMR project in Oak Ridge now involves just TVA, although other entities such as DOE and Oak Ridge National Laboratory continue to have a strong interest in it.

Hopson said TVA has already done a lot of work at the Clinch River Site dating back to the Clinch River Breeder Reactor, which was canceled by Congress in the early 1980s. That work has included gathering meteorological and geological data, which is being used as a baseline now. There has been a meteorological station at the Clinch River Site for decades.

“We actually have decades worth of data,” Hopson said.

Other early site permit work would include hydrological studies, emergency and population planning, and safety considerations.

TVA intends to be ready when an SMR design is certified. Then, the TVA board can make a decision about whether it wants to proceed with the project, Hopson said.

“You’re got the early work taken care of,” he said of the early site permit work.

Oak Ridge Today asked why the Clinch River Site was chosen. Hopson said previous work has shown that the site is suitable for this type of facility, and DOE, which has several other facilities in the area, including ORNL, is interested in the project. Also, TVA already owns the Clinch River property.

“Those things combined to make this location very attractive for this type of facility,” Hopson said.

He described nuclear power as the only source of carbon-free power that can be used 24 hours a day, seven days per week. It’s an attractive way of addressing carbon concerns without sacrificing electrical reliability or cost, Hopson said. It can also reduce the nation’s “carbon footprint,” he said.

“We believe that nuclear power plays an continuing role in maintaining low-cost reliable electricity, but does so without increasing the output of carbon generation,” Hopson said.

The SMRs produce considerably less power than a traditional nuclear power plant. All of TVA’s traditional nuclear power plants generate at least 1,100 megawatts, compared to the 80-200 megawatts of a proposed SMR.

Officials say the traditional large, expensive nuclear power plants are great for providing base load power. They are designed to stay at 100 percent power throughout the fuel cycle.

But they have to be built on location and aren’t scalable. And it takes about five to 10 years to bring one online, and that requires projecting power needs a decade or more into the future, Hopson said.

In contrast, the lower-output SMRs are designed to be brought online in sequence. Investments in those nuclear plants can be phased in in smaller, more manageable chunks, Hopson said.

The NRC meetings on April 12 are scheduled in the auditorium of the Pollard Technology Conference Center at 210 Badger Avenue in Oak Ridge. The first is scheduled from 1-4 p.m. Tuesday, April 12, and the second is scheduled from 6-9 p.m. Prior to each formal session, there will be an informal one-hour open house to give the public an opportunity to speak informally with the NRC staff.

“A key topic to be discussed is how and when the public may participate in the NRC review process, if desired,” a NRC meeting notice said. “The public is encouraged to ask questions about the NRC review process for this ESP application.”

The public is invited to participate by providing comments and asking questions throughout the meeting.

Hopson encouraged the public to attend the NRC meetings. He said TVA personnel will be at those meetings.

View an Energy Department infographic on small modular reactors here.

The Clinch River Site in west Oak Ridge. (Photo courtesy TVA)

TVA energy generation portfolio

Hopson also shared some insight about how TVA’s energy generation portfolio has changed and could continue to change. The demand for electricity is still there, but it is being offset to some extent by improvements in energy efficiency, Hopson said. TVA is not seeing the large-scale need for electrical increases that it saw even as recently as the early 2000s.

TVA has coal plants and will continue to operate some. But the utility has moved from 50 percent coal to 30 percent coal during the past 15 years. And over the next five to 10 years, it will be down to 20 percent or less coal, Hopson said.

TVA also uses widely available natural gas as a low-cost source of power. It’s much cleaner than coal, about 50 percent cleaner than an equivalent coal plant, Hopson said. TVA is also adding more solar and wind power sources, but they are intermittent power sources. In addition, TVA is modernizing its hydroelectric sources, squeezing about another 400 megawatts out of its 29 hydroelectric dams, where the power source (water) is free, Hopson said. Four hundred megawatts is equivalent to about half of a power plant.

With the Watts Bar 2 nuclear plant coming online in Spring City, nearly 40 percent of TVA’s power will be carbon-free, Hopson said. Add in the 12 percent from hydroelectric dams, wind, and solar, and nearly half of TVA’s power comes from carbon-free sources, Hopson said.

“That’s a major element in something that we feel is important for the TVA Valley and also the world,” he said.

TVA supplies electricity to nine million people in parts of seven southeastern states.

The Clinch River Site is in the horseshoe bend of the Clinch River below.

You can see an aerial view of the Clinch River Site here. It’s in the horseshoe bend in the Clinch River.