Part 2 of 2 Parts (Please read Part 1 first)
NuScale’s SMR design is the first such reactor to gain the approval of the NRC. It will take more than a year before it can be put into operation, said Edwin Lyman. Lyman is the director of nuclear power safety at the Union of Concerned Scientists. According to Lyman, many of the proposed microreactor applications are inappropriate applications of nuclear energy. This includes the microreactor being designed at Argonne. Lyman said, “The Department of Energy is desperately trying to think of applications for all sorts of nuclear reactors, no matter how improbable or impractical they are, and I think this is a good example.”
The Argonne researchers insist that their microreactor design would be safe and efficient if constructed. The design incorporates an energy storage system that could store excess energy in the form of heat. That stored energy could be used to supplement the output of the microreactor at times of high demand where a lot of trucks need to be charged in a short period of time.
The Argonne microreactor is purposely designed to need little maintenance, according to Kultgen. They intend to use a layered fuel called TRISO (tristructural isotropic). The U.S. Department of Energy considers TRISO to be, “the most robust nuclear fuel on Earth.” Kultgen pointed out that in the Argonne design, the radioactive material would be fully secured within the microreactor.
Jacopo Buongiorno is the director of the Center for Advanced Nuclear Energy Systems at the Massachusetts Institute of Technology. He said, “TRISO is often adopted almost automatically for this kind of applications because it's exceptionally robust.”
Rick Mihelic is the director of emerging technologies at the North American Council for Freight Efficiency. He remarked that while it is reasonable to consider the use of microreactors to charge EV semitrucks, there are a number of issues that will have to be addressed before such charging microreactors could be deployed to truck stops across the U.S.
General opposition to nuclear power could impede the deployment of microreactors according to Mihelic. A network of microreactors would also contribute to the growing problem of disposing of the spent nuclear fuel generated by U.S. nuclear power reactors. He went on to say that it may be difficult to construct microreactors economical. In order to deal with that problem, the designers would have to find a way to mass-produce them. “If they are deployed each a little differently, each built at a different location with a different workforce, then achieving good economics may prove hopeless,” he said.
Despite the stamp of approval for the safety of the NuScale SMR from the NRC, Lyman said that the actual security arrangements for the SMRs have not yet been fully developed. He said, “It's clear that these reactors would require a higher level of security, and that would add to the cost and inconvenience.”
Kultgen hopes that he will be able to develop a model that could be standardized and mass-produced to significantly reduce construction costs for microreactors. In addition, the cost of electricity from microreactors will need to be competitive in the energy market. He said, “Our priority is to have a safe design, but also an economical one and to be able to compete with the electrical grid.”
The Argonne researchers are working on a model that will require minimal on-site assembly, he said. If the Argonne project can raise enough addition funding, Kultgen says that their design could be ready for construction within five years. He said, “The licensing and regulatory steps required may increase these estimated time frames.”
In spite of the potential challenges, the deployment of nuclear microreactors could be a bold new opportunity for lowering the carbon emissions of U.S. transportation.