New American and Canadian nuclear reactor designs are undergoing technical review and seeking certification by both countries’ regulatory agencies, with one set to be the first subjected to a joint U.S./Canadian technical assessment of reactor technologies under a binational cooperation agreement reached in August.

The U.S. Nuclear Regulatory Commission (NRC) and the Canadian Nuclear Safety Commission (CNSC) agreed to collaborate on technical reviews of advanced reactor and small modular reactor technologies. Eight vendors now are in CNSC design review, including six that are active and two pending by year-end.

The first is likely to be Terrestrial Energy’s advanced Integral Molten Salt Reactor, according to the Ontario-based company.

It employs Generation IV molten-salt technology with a power output of 195 MWe and is currently under separate regulatory review in both Canada and the U.S. CNSC has been receiving vendor submissions for Phase 2 of the design review since December 2018, with NRC involved in pre-licensing review since February, supported by U.S. Energy Dept. grant funding.

NuScale Power LLC’s small modular reactor is the American entry. The firm, majority owned by Fluor Corp., announced on Dec. 12 that its Generation III+ light-water integral SMR design, which has been in NRC certification review since late 2016, was approved to begin Phases 5 and 6, with completion expected by September 2020.

It will be commercially available after approval is published in the Federal Register. “We are actively marketing in the U.S., Romania and Jordan,” notes Chris Colbert, NuScale Power chief strategy officer. CNSC says NuScale’s integral pressurized water reactor will begin Phase 2 review by the end of 2019. It is not likely to undergo joint review, Colbert adds.

NuScale says the global market for SMRs could reach $100 billion by 2035, according to a report by Paris-based Nuclear Energy Authority.

Support for nuclear power generation faded in some western countries following the catastrophic accidents at Three Mile Island, Chernobyl and Fukushima. But its carbon-free generation has gained favor as climate change concern rises.

Reactor technologies have advanced through Generation III+ and now Generation IV with scalable small modular designs and improvements in operational safety. A variety of technology proposals featuring reactors from 3 MWe to 300 MWe are lining up for regulatory approval.

Each new design must run a regulatory gauntlet before approval. In Canada, CNSC approval comes in stages of review; in the U.S., NRC grants approval after completing review of the entire design. Having a joint technical review would streamline the process by coordinating and sharing information between Canadian and U.S. technical reviews.

When implemented, the proposed joint review “will help the two agencies understand the similarities of their individual reviews," says Marcus Nichol, director of new reactor deployment at the Nuclear Energy Institute. “This has the potential to reduce review times in one country for designs that have already been approved by the other.”

Terrestrial Energy’s reactor uses a liquid fuel—thermally stable molten salt—rather than the solid fuel of conventional reactors. The molten-salt reactor is one of six designs selected by the Generation IV International Forum for further research and development. “A key element of the design is that it uses a replaceable seven-year reactor core that solves material lifetime challenges often cited as impediments to molten-salt reactor development in the past,” says Jarret Adams, Terrestrial Energy spokesman. The reactors also “have considerable promise for the minimization of radiotoxic nuclear waste,” the Forum has stated.

“The early feedback I got from my staff is there is very strong alignment between the two agencies,” CNSC President Rumina Velshi told the International Framework for Nuclear Energy Cooperation’s Global Ministerial conference, held in Washington, D.C., in November.

There is “commitment to optimize the opportunities to minimize duplication of effort and make regulatory reviews less onerous, with more predictable outcomes and increased safety,” she added. The agencies agreed to terms of reference to help guide their work and discussed developing common guidance for review of small nuclear reactor license applications.