Small modular reactors can be a competitively priced source of carbon-free energy for Washington state in coming years, a study funded by the U.S. Department of Energy says.
Driving the study—issued May 17 and co-authored by the Pacific Northwest National Laboratory and Massachusetts Institute of Technology—was passage of Washington's Clean Energy Transformation Act in 2019, which requires the state's electricity supply to be free of coal-fired generation by 2025, carbon-neutral by 2030 and carbon-free by 2045.
"Nuclear energy is a reliable source of baseload electricity, and our findings show that advanced small modular reactors could be economically competitive in a future carbon-free electricity sector," said Ali Zbib, co-author and PNNL's manager for nuclear power systems, in a statement. "They're well-suited to play an important role in an energy market that requires more flexibility."
Electricity demand will likely grow as the state electrifies different sectors of its economy, including transportation, and as the region's population grows, said Zbib. And while variable energy resources such as wind and solar will fill some of the load, a complementary source of flexible power will also be needed, he said.
The study focused on the SMR designs of NuScale and of GE Hitachi Nuclear Energy's (GEH's) BWRX-300, and explored the viability of deploying the reactors at the Hanford and Centralia sites, as well as the Idaho National Laboratory, where the Utah Associated Municipal Power Systems plans to develop NuScale's SMR.
Each site has advantages, such as the trained nuclear workforce and the availability of an unfinished nuclear project at Hanford, as well as the existing infrastructure at Centralia.
The report indicates that deployment of advanced SMRs would be competitive if they can achieve their projected levelized cost of energy.
For NuScale's design, a LCOE for an nth-of-a-kind (NOAK) SMR—where all the challenges of new technology and infrastructure have been addressed—was calculated to be in the range of $51-$54/MWh using the company's estimates.
A LCOE in the range of $44-$51/MWh was calculated for the BWRX-300 using GEH's design-to-cost and target pricing input.
(All results are in 2019 dollars with the exception of UAMPS's price of $55/MWh, which is in 2018 dollars.)
The study notes that these estimates are not intended to be directly compared, because NuScale's is based on its current design, while GEH is using a "design-to-cost methodology with target pricing that is being confirmed as the design matures." Assessing the suitability of an SMR at a given site will depend on a host of other factors.
These factors include the levels of RECs and cost-effective conservation projects—which under CETA can offset up to 20 percent of a utility's obligation through 2045—and the amount of emitting resources Washington utilities must replace. In addition, the level of subsidies needed for the initial installations should be considered.
Building a plant at the Hanford Site, according to the report, could help cut costs in several ways. Much of the licensing and assessments required to build a nuclear power plant have already been completed—seismic risks and analyses of other vulnerabilities were carried out when the partially complete plants were under construction in the 1980s.
Nearly $140 million could be saved by using standing structures, according to a 2014 study commissioned by the Tri-City Development Council, and the project schedule could be shortened, resulting in additional cost savings. In additions, a trained workforce familiar with nuclear reactors that works at the nearby Columbia Generating Station offers another advantage, the study noted.
At the Centralia site—which under a 2011 agreement with the state will close all coal-fired boilers by 2025—the existing infrastructure could be used, the facility is already connected to the grid and a new plant could replace jobs lost from the closure.
For the Idaho site, UAMPS has suggested an additional savings by way of an exchange agreement with BPA to reduce current pancaking transmission costs. With BPA's potential entry into the Western EIM, the potential for a Western Electricity Coordinating Council areawide market and assuming the potential one balancing authority like the Midwest ISO, the probability of having a larger wholesale power market increases.
SMRs may face competition from other firm power sources, the study says, such as geothermal and natural gas combined-cycle power. The Energy Information Administration estimates geothermal entering the market in 2025 at $37/MWh (2019$), while advanced geothermal is estimated to cost $47/MWh (2019$); both could benefit from a $2/MWh tax credit. And natural gas combined-cycle power could be purchased between 2030 and 2045 at a penalty price of $97/MWh under CETA, the study estimates.
However, near-firm renewable resources could provide a portion of the energy required by the time the first SMR reaches commercial operation. Variable renewable resources with batteries or other storage could provide approximately 4 percent of the firm power requirements at current prices. According to two MIT studies, wind-plus-battery could provide between 16 and 95 percent of firm power requirements in the future at battery prices of about $150/MWh.
With a wider wholesale power market, the study says, energy could move inexpensively from other EIM areas with an abundance of solar and wind at significantly reduced transmission costs. Only one transmission cost would be applied rather than pancaking the transmission costs.
One issue that will need to be understood is how the state of Washington will handle the mix of electricity coming over the transmission system, which will include carbon-emitting resources. The benefits of the EIM could be exemplified by the UAMPS shipping power to Washington, which the study estimates would reduce overall transmission costs from Idaho to BPA from $24/MWh to $4/MWh.
The study did not consider other SMRs with possible presences in Washington. DOE recently announced awards for TerraPower's Natrium reactor, a 345 MWe sodium-cooled fast reactor and X-Energy's Xe-100 reactor, a 320 MWe high-temperature gas reactor.
Energy Northwest has formed alliances with both companies, and in April entered into a memorandum of understanding with Grant County PUD and X-Energy to investigate siting the Xe-100 SMR in central Washington (CU No. 1998 ).
In addition, the PUD announced May 26 it had entered into a MOU with NuScale to study the feasibility of deploying the company's SMR.