Decarbonising electricity production is a critical step in the fight against global warming. Solar, wind and geothermal are all being touted as important solutions, and some argue nuclear energy is as well. While nuclear energy gets a bad rap in some environmental circles, many energy experts and policymakers agree that splitting atoms is going to be an indispensable part of the solution. While traditional reactors are known for being large and dangerous, an Oregon-based startup is busy envisioning a better future for nuclear energy.
Tucked away in a corner of the Oregon State University campus is a small company that has been experimenting with a revolutionary prototype Small Modular Reactor (SMR). NuScale hopes their reactor represents a new chapter in the controversial, politically bedeviled saga of nuclear power plants.
Currently, there are 98 nuclear reactors in the United States, however the majority are approaching the end of their regulatory lifetime. Only two new reactors are under construction in the US, but they’re billions of dollars over budget and years behind schedule. As nuclear energy provides the US with 60% of its green energy, closing reactors will put a temporary strain on the other sources of energy. At least until new reactors are up and running, or other sources are added to the mix.
This is where NuScale comes in. Unlike traditional reactors, the company’s prototype won’t need massive cooling towers or sprawling emergency zones. It can be built in a factory and shipped to any location, no matter how remote. Extensive simulations suggest it can handle almost any emergency without a meltdown. At 65 feet tall and just 9 feet in diameter, this small reactor also uses much less nuclear fuel than existing reactors. It is also modular, giving it the ability to be adaptable – Need a modest amount of energy? Install just a few modules. Want to fuel a sprawling city? Tack on several more.
The only similarity between NuScale and traditional reactors is that they are both light water reactors. Light water reactors make use of pure H2O as the coolant and moderator (slowing the speed of atomic reactions) for the nuclear rods. When the rods are cooled, they produce steam that powers turbines to generate electricity. The other type of reactors are heavy water reactors – Which use water which is made from a special slightly heavier isotope of hydrogen called deuterium, which is more effective in slowing down atomic reactions . Despite their small size, these reactors can crank out 60 megawatts of energy, which is about one-tenth the smallest operational reactor in the US today.
On average, a traditional nuclear power plant can produce 1gigawatt of power everyday, but usually they do not run at full capacity all the time. Each power plant has a lifespan between 20-40 years. The biggest challenge with traditional plants, however, is the need for a buffer zone, sometimes as large as 20 miles to avoid exposure to nuclear radiation in case of an accident. Since the 1986 accident at Chernobyl in the Ukraine, a 1,000 sq. mile exclusion zone around the plant has been set up. The area will remain uninhabitable for up to 20,000 years.
Going small has big advantages. Smaller reactors can sit in underground pools of water, so should there be a leak, the heat can diffuse into the pool. Unlike traditional reactors, the ground acts as a containment measure, reducing the risk of radioactive transmission in the atmosphere.
That also means the reactors could be built closer to the places where their power is needed, without the 10-mile safety buffer a conventional plant must have.
The safety buffer is in place to ensure that life isn’t immediately threatened, in case of an accident like in Chernobyl or Fukushima.
The US Department of Energy (DoE) is also investigating using microreactors, like the one NuScale has designed. These microreactors are not just ideal for industries, but their “plug and play” nature also makes them ideal for smaller energy needs – like a temporary military base or remote community. Such reactors can be factory- fabricated, are easy to transport and are easier to maintain due to their simple design.
The DoE in December 2019 provided a permit to Oklo, a secretive nuclear startup to build a microreactor. Dubbed ‘Aurora’, this 1.5-megawatt microreactor will be built at the Idaho National Lab. There are several other regulatory hurdles though, as well as challenges around cost.
Small reactors will still need to prove they can be cost-competitive, says Steve Fetter, a professor of public policy at the University of Maryland. With the price of renewables like wind and solar rapidly falling and ample natural gas available, smaller, svelter reactors may never find their niche. Especially if a prime motivator is climate change, whose pace is exceeding that of regulatory approvals.
Since 2016, the Nuclear Regulatory Commission since 2016 has been reviewing NuScale’s design, but due to the brutal and complex regulatory process, it could be another year before the company can build its first commercial system. Expecting approval by the end of 2020, the company says it is on track to break ground for its 12-reactor plant at the Idaho National Laboratory within two years. The plant could be up and running in 2026 and supply energy to communities in the Western states.