Small American reactors want to bring nuclear into a new era

A new generation to come of small American nuclear reactors is attracting communities and elected officials, as far away as Europe, but the road to commercialization and operation is still strewn with pitfalls, regulatory and financial.

During a congressional hearing a few days ago, the US Secretary of Energy, Jennifer Granholm, reaffirmed the “importance of nuclear energy” in the supply of electricity in the coming years to the States -United.

In the absence of new traditional power plant projects and with the aging of the existing fleet, the future of industry rests on small new-generation reactors, SMRs (small modular reactors).

“I spoke to many heads of public utilities and (…) many say they want to build SMRs and not large reactors,” explains William Freebairn, sector specialist at S&P Global.

According to him, it is often a question of replacing coal-fired power stations in remote regions, where “the possibility of installing a conventional reactor is very limited”.

The momentum is encouraged by the American government, whose tax package IRA (Inflation Reduction Act), passed last year, provides for tax credits reaching up to 30% of investments.

Several American companies are currently developing their own SMR, less expensive than their big brothers and, a priori, with a tighter construction time and less fuel requirements, therefore potentially less nuclear waste.

Only one of them, the model of the start-up NuScale, has nevertheless been, at this stage, validated by the American Nuclear Regulatory Commission (NRC), last January, six years after the filing of its application.

“Other countries in the world that are interested in (nuclear) are watching closely what is happening in the United States and are ready to (place an order) once the NRC has given its authorization”, underlines Bahram Nassersharif, director of the nuclear engineering program at the University of Rhode Island.

Based in Portland (Oregon), NuScale initially expected the first commissioning of its small reactor with a capacity of 77 megawatts, compared to around 1,000 for standard power plants, in 2026 in Idaho Falls (Idaho, northwest), but he had to push the deadline to 2030.

Time is running out, because in addition to American competitors, other countries, notably France and South Korea, are working on the production of SMR. Some 70 to 80 projects coexist around the world.

The bill for the NuScale plant was recently revised upwards by 75%, to 9.3 billion dollars, of which 4.2 will be covered by various public mechanisms.

The group of local authorities under contract with NuScale has lost members and must imperatively commit to absorbing a minimum level of production by the end of the year, failing which the project could be purely and simply cancelled.

“We are thoroughly in the search for new participants and we also aim to obtain current members that they increase their commitments”, indicates Stephen Handy, spokesman of the group, baptized UAMPS.

“The initial project is always the most difficult”, summarizes Chris Levesque, general manager of TerraPower, which must soon start construction of a prototype of its reactor, called Natrium and developed in collaboration with GE Hitachi, in Kemmerer, Wyoming, on the site of a coal-fired power plant.

“There is the design cost, which will not have to be paid for the following ones, the regulatory authorizations and the experience to be acquired, because it is the first time”, explains the manager of this company created by a group of investors led by Bill Gates.

Unlike the NuScale prototype, which uses pressurized water like conventional reactors, the Natrium uses so-called molten salt technology, which poses no risk of explosion and does not require a bulky containment enclosure.

To succeed in commissioning a reactor from 2027 in Champagne (Illinois), another American start-up, Ultra Safe Nuclear Corporation (USNC), has chosen a regulatory approach that allows it to have the various elements of its installation approved over time. of its construction rather than an a priori validation of the whole project.

In the longer term, USNC wants to offer reactors made up of standardized elements, capable of being produced in the factory and then transported to the site, which would significantly reduce costs and lead times, explains Daniel Stout, nuclear manager of the Seattle company ( Washington State).

Americans remain divided on the use of nuclear energy, even if the proportion of those who oppose it has declined since 2016, from 54% to 47% in 2022, according to a poll by the Gallup institute.

The new players in the American nuclear industry present their SMRs as little or not at all susceptible to serious incidents and to irradiation or contamination, due to their small size and the technologies used, which in particular exclude the melting of the reactor core.

“We want to prove to regulators that we don’t need massive evacuation plans,” claims Daniel Stout, “because our design excludes an accident that would justify it.”

“Major accidents as well as more minor incidents have allowed a lot to be learned, and these lessons have been incorporated into the new models”, according to Baham Nassersharif, for whom “the new reactors are generally much safer than those of the previous generation. “.

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