NuScale Power: Rethinking nuclear reactors
NuScale Power, which is headquartered in Portland and also has a presence in Corvallis, is on track to become the first company in the world to receive federal approval that will allow its design for a small modular reactor to be used in a nuclear power plant slated to be built in Idaho.
The company is touting its design as the shot in the arm that the nuclear power industry desperately needs.
Although nuclear energy represented 17.6 percent of electricity consumed globally in 1996, it has lost ground in recent years. The cost to build a nuclear power plant with conventional reactors sits in the billions of dollars, while the cost of energy from renewable sources such as wind and solar has dropped, making those options more attractive.
Meanwhile, concerns abound about how to handle radioactive waste from nuclear power plants. So do worries about safety — especially after a tsunami in March 2011 disabled a power supply and cooling capacity at Fukushima Daiichi, leading to a meltdown of three reactor cores at the Japanese nuclear power plant.
NuScale's team, however, is touting its small module reactor technology as a safer and more affordable solution to conventional reactors.
For starters, NuScale's design calls for its modules to be fabricated off-site and then shipped by rail or truck to the plant location. Because the fabrication of the modules and the building of the physical plant occur simultaneously, the modules can be installed as soon as they arrive, requiring less construction time, less labor and less money.
The modules — each capable of producing 60 megawatts of energy, which is enough to power 45,000 homes — also allow a plant to scale up as needed, with a maximum capacity of 12 modules for a total of 720 megawatts.
The biggest difference between NuScale's technology and conventional reactors, however, may well reside in the area of safety. Traditional reactors feature valves and pumps — all of which can fail.
By tapping gravity, conduction and convection, NuScale has been able to come up with a design that has eliminated the pumps and valves used in traditional reactors to move and heat water to produce steam, which turbines then use to produce electricity. Fewer moving parts mean less chance for failure.
Traditional reactors also require electricity to secure the reactors in case of a shut down along with an additional water source that can be used to cool the reactor cores and spent rods in case of an emergency.
NuScale's design, however, calls for the modules at a plant to sit completely immersed in a pool of water, which serves to cool down the module reactor cores and rods in the case of an emergency.
"It doesn't need power to make the safety systems work," Ross Snuggerud, a NuScale plant operations supervisor, said. "It shuts down and self-cools indefinitely, without the need for operator intervention."
The technology behind NuScale's reactor design can be traced back to 2000, when the U.S. Department of Energy provided money for research into the development of a small nuclear power plant model that could be used for multiple purposes. The Idaho National Engineering and Environmental Laboratory led the research project, with support from a team at Oregon State university that included professor Jose Reyes.
In 2003, when the research project ended, Reyes and his team of scientists continued to work on a small, multi-application water reactor. Reyes envisioned the reactor as being built in a factory and then installed in a plant. The reactor would operate for seven or eight years and then could be replaced, which would eliminate the need for on-site refueling.
The idea would go on to become the current technology behind — and in — the small modular reactor design that's the focus of NuScale. Reyes, who co-founded the company, now serves as its chief technology officer.
He isn't the only one at NuScale who has ties to the early incarnation of the company's current design.
Eric Young, who received his master's and doctorate degrees in nuclear engineering from OSU, worked with Reyes on early research from 2000 to 2003. Young was invited to join NuScale in March, 2008 and now oversees the NuScale Integral System Test, which provides data for validation of the software that will be used to monitor modules once they're installed and operating
"(When I joined NuScale), there were only six individuals working at the company," Young said. "It's grown a bit since then.
NuScale's employee roster currently numbers 333. Twenty-four people work at the company's headquarters in Portland. Another 66 are spread among offices in North Carolina, Virginia, Washington state, Maryland and a United Kingdom location in London. The remaining 243 work at the company's Corvallis location, where the majority of the design, research and development work takes place.
One entire room in the Corvallis space, for example, contains a mock-up of what the operations office will look like in an Idaho plant that is expected to be the first to use NuScale's small modular reactors once the design receives approval from the U.S. Nuclear Regulatory Commission.
The commission has established rules regarding how many operators are required to run a plant based on the size. NuScale, however, has used the simulated operations room to show the commission that a fully scaled, 12-module plant can run with a maximum of six operators, which Snuggerud said is far fewer than would be needed for a conventional plant with similar energy generation.
Part of that ability to scale down manpower rests in a system that uses color codes to allow an operator to scan oversized wall monitors for each module to determine with a glance if operations are proceeding normally.
The safety features also make it possible to reduce the number of operators. In a conventional plant, an emergency shut-down situation requires all of the operators to make manual adjustments in order to cool down the reactor core and rods to avoid a meltdown.
The NuScale design, however, requires no such intervention from operators. Because the modules are submerged in a room filled with approximately seven million gallons of water, the liquid absorbs the heat automatically without need for operator intervention.
If the shutdown is prolonged, by the time the water in the pool is gone, the reactor cores and rods will have reached a temperature that the air will be sufficient to finish the cool-down process, according to Snuggerud.
"Getting rid of waste heat after a shut down, normally that heat goes into a river or lake or even the ocean (via pumps)," he said. "In NuScale's plant, that big pool represents the ultimate heat sink."
Sharing the wealth
Before a new reactor design came be used in a nuclear power plant, the design must be approved by the U.S. Nuclear Regulatory Commission. In 2017, NuScale became the first company to submit a Design Certification Application for a small modular reactor. The company expects to receive a final decision from the commission in September 2020.
Although NuScale Power is still a few years away from full manufacturing mode to produce a small modular reactor for the market, the process to get to that point already is providing a boost for other companies.
NuScale has produced a mock-up of the upper one-third of the module that serves as an educational piece to explain how the design works. The mock up was fabricated by two Oregon companies: Oregon Ironworks and Greenberry Industrial.
A Virginia-based company is providing engineering to guide the eventual construction and installation of the modules. NuScale spent 18 months interviewing 83 companies from 10 countries before settling on BWXT Technologies as the firm of choice.
NuScale eventually will issue a call for companies interested in actually building the modules. However, the company does not have a timeline for when that might occur, a spokeswoman for NuScale said.