US Certifies First Small Modular Nuclear Reactor

(Credit: NuScale Power) The US Nuclear Regulatory Commission (NRC) has certified the design for the country’s first-ever small modular nuclear reactor. In the Federal Register on Thursday, the NRC established a rule allowing the so-called “NuScale reactor” to be used within the US beginning on Feb. 21, 2023. The rule paves the way for companies to construct reactors that require less space, capital, and labor than their conventional counterparts.

The design is courtesy of Oregon-based NuScale Power, which has been working to certify a small modular reactor (SMR) design since 2007. At the NuScale’s core are up to 12 power modules, or natural circulation light water reactors that each consist of a reactor core, a pressurizer, and two steam generators housed in steel. Each of these power modules generates 160 megawatts of thermal output (MWt) and 50 megawatts of electrical output (MWe). The lower portion of each power module is submerged in a below-ground pool that functions as a heat sink, thus precluding the need for emergency diesel generators (for power outages) or water injectors (to cool the reactor after an accident).

The NuScale reactor is the seventh nuclear reactor design to achieve certification in the US. The others are all considered conventional nuclear reactors. SMRs are significantly smaller than their conventional predecessors, making them more suitable for geographical locations in which large nuclear plants would not be possible. Their size also translates to easier construction and lower upfront costs, while their modular design allows them to be deployed incrementally as energy demand fluctuates.

A mock-up of a future control room (Credit: NuScale Power)

Proponents of SMRs argue that these factors, along with SMRs’ alleged safety benefits, make designs like the NuScale vital to the country’s increasingly dire need for carbon-free energy. SMRs rely more on passive safety systems and built-in leak prevention mechanisms than conventional reactors, which means there’s less room for human error in the case of an emergency. SMRs’ smaller physical footprint means they’re less susceptible to damage during earthquakes and other natural disasters. The NuScale in particular surrounds its power modules with 4.6-meter-wide steel vessels, which can withstand far greater pressure than the 40-meter-wide concrete containment vessels found in the average power plant.

Still, not everyone is on board with SMRs. A Stanford University study from last year found that SMRs will likely exacerbate existing nuclear waste concerns. A conventional nuclear power plant produces radioactive waste that has to be isolated for hundreds of thousands of years. SMRs could end up increasing the volume of this waste “by factors of 2 to 30,” requiring more management and disposal than the US currently has plans for. Some scientists believe this alone negates SMRs’ other benefits.

The NRC’s new rule will allow nuclear power plant operators to pursue construction of the NuScale reactor and apply for a corresponding license with the NRC next month. Because the reactor is officially certified for use, third parties will not be able to legally challenge individual license applications. NuScale, meanwhile, is beginning the approval process for a larger SMR design capable of 77 MWe per module.

Now Read:

• US Department of Energy Confirms ‘Landmark’ Nuclear Fusion Reaction
• Engineers Use Lasers to Direct Lightning Strikes to Safe Targets
• Researchers Find 17-Pound Meteorite During Antarctica Expedition