First look at nuclear power project

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By Arin McKenna

The Los Alamos Department of Public Utilities (DPU) hosted a presentation Dec. 1 on NuScale Power’s small modular reactors. 

The Board of Public Utilities directed DPU to explore whether to add a next-generation nuclear power facility to the county’s energy generation portfolio to meet its goal to be carbon neutral by 2040.  

DPU is a member of the Utah Associated Municipal Power Systems (UAMPS), making it eligible to buy into UAMPS Carbon Free Power Project, which uses NuScale’s small modular reactor technology.

Speakers included NuScale’s Chief Commercial Officer Mike McGough, Los Alamos National Laboratory’s Director of the Office of Civilian Nuclear Programs DV Rao, and Utah Associated Municipal Power Systems (UAMPS) Chief Executive Officer Doug Hunter. 

The meeting opened with a video of Franklin Orr, Department of Energy (DOE) undersecretary for science and energy, addressing a UAMPS informational meeting. 

“My colleagues and I at DOE recognize the potential for small modular reactors (SMRs) to provide safe, clean and low cost electric power generation,” Orr said. “SMRs provide an important opportunity for America to lead the world in advancing the state of nuclear technologies. We believe SMRs will be part of the model for nuclear energy worldwide, alongside the larger reactors.”

Orr talked about the advantages of SMRs in terms of safety, providing generation output suitable to small communities, shorter construction cycles and opportunities for U.S. manufacturers to produce components.

Rao gave some history about the decline of nuclear power — largely due to falling natural gas prices — and why he believes SMRs could reverse that trend. 

According to Rao, there are three options for meeting increasingly strict carbon emission standards.

One option, supercritical (high efficiency) coal plants, is very expensive with limited carbon capture. 

Solar photovoltaic coupled with natural gas as follow-on is another option. 

The third option is new nuclear reactors. 

“Whatever scenario you look at, what you see is if we don’t start building nuclear now, its ability to impact the country and global greenhouse gas is little or very little,” Rao said. “So we have to build.”

Rao believes the lower costs associated with SMRs (as opposed to large nuclear facilities) can compete with natural gas.

“If all you care about is dollars and cents today, then natural gas is presently a very difficult computation for nuclear,” Rao said. “So the value proposition is important.”

McGough stressed DOE’s support for SMR development. NuScale has received $217 million in DOE funding to date and is applying for additional support. DOE is also paying 50 percent of eligible costs such as site permitting and development and for developing the combined operating license application. DOE is also providing a long-term lease at the preferred location at Idaho National Laboratory.

If the UAMPS project proceeds with the project, it will be NuScale’s first customer. 

McGough provided detailed information about the NuScale power plant design. 

The proposed plant would have nuclear reactor buildings with footprints about the size of a football field. Each can hold up to 12 power modules that run on nuclear fuel pellets.

Nuclear fission heats pressurized water surrounding the core to 500 degrees Fahrenheit. That water rises through riser tubes and then cascades over coiled tubes, heating the cool water inside them and turning it into the steam that runs the generating turbine. 

“In order for this plant to work, instead of those pumps and motors and valves (used in current nuclear facilities), all that electrically driven stuff, we have to have three things work: convection, conduction and gravity. And they always work,” McGough said. 

The modules sit in a 7.4-million gallon common pool of water which serves as the ultimate heat sink for cooling the modules in shutdown circumstances.

Each module has its own turbine, so they can be taken offline individually for refueling while the other modules continue to operate. 

An independent spent fuel storage facility holds spent fuels in dry cask storage until they can be taken to an interim storage facility. 

The assembly allows smaller utilities to start with fewer modules and add incrementally as load growth dictates.

Components can be built in a manufacturing plant and shipped by truck or barge. 

Increased safety is one of NuScale’s big selling points. 

In core damage frequency analysis, today’s power plants have a risk assessment of 10 to the minus sixth degree, or the chance of one core damage incident in 1 million operating reactor years. The NRC goal is 10 to the minus fourth. NuScale’s risk assessment is 2.38 times 10 to the minus ninth, or 2.38 incidents predicted in a billion operating reactor years.

“Our core damage frequency is so low that it’s not a credible event,” McGough said. 

The NuScale plant also has more barriers between the fuel and the outside world, seven as opposed to the three found in today’s nuclear reactors. 

The combination of low core damage frequency and the additional barriers allows the plant to be sited with an emergency planning zone at the site boundary. Existing nuclear power plants must have 10-mile emergency planning zones. That means NuScale plants can be located at retired coal plant sites (which are often closer than 10 miles to the nearest population), taking advantage of existing power plant infrastructures.

The most innovative safety element is a plant designed to maintain a safe condition during a worst-case scenario: the loss of offsite power, which is what caused the Fukushima nuclear disaster. 

“If that happened to a NuScale plant, our plant shuts itself down and cools itself off forever, with no operator action in the control room, with no AC or DC power and with no additional water, other than the 7.4 million gallons that the modules live in every day,” McGough said. 

“That’s never been done before. We call it the triple crown of nuclear safety. It’s one of the big reasons that the DOE selected this technology to be developed.”

At its advisory board’s insistence, the plant was also designed with follow up capabilities so it can serve as a backup for renewable energy resources. That is accomplished through individual dispatch ability for each module, so each can be shut off completely or varied up or down 40 percent per hour. The plant can also go into full turbine bypass mode, where the steam goes straight to the condenser without rotating the turbine, although “that is not a very efficient way of using nuclear fuel.”

Modules can also be used for applications such as desalification, reducing the carbon footprint of an old oil refinery, for hydrogen production or for powering mission critical facilities.

NuScale has spent $5 million testing individual components and a one-third scale facility. It has accumulated 13 years of test data since 2003. Those tests included putting kids — who will be the reactor operators when NuScale plants come online — in the control room simulator to see if they understood it. 

The test data is being assembled into NuScale’s design certification application. That application is expected to go to the Nuclear Regulatory Commission for review this month. NuScale invested $1 million to have 84 NRC staffers review the 14,000-page application to insure it is ready for submission. The review is expected to take 40 months. 

Hunter described the NuScale project as one leg of its Carbon Free Power Project, which also includes increasing energy efficiency and distributed energy production. 

“What we want to do is provide a non oil-based, coal-based, hydrocarbon-based fuel alternative for our members,” Hunter said. 

If UAMPS goes through with the project once factors such as cost/benefit have been evaluated, the goal is to have it online in 2026, about the time many of the coal generating plants its members rely on are being shut down. 

DPU will host another meeting on NuScale Jan. 12. Follow the Los Alamos Monitor for details. For more information about NuScale Power and small modular reactors visit www.nuscalepower.com.