Small Modular Nuclear Quickly Becoming a Reality in the Quest for Net Zero

August 3, 2022

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SMR reactor-module — NuScale's VOYGR small modular reactor has received regulatory approval in the U.S. (Image credit: Nuscale Power LLC)

Small Modular Reactors or SMRs may revive the nuclear fission reactor industry around the world. These nuclear power plants are a fraction of the size of existing facilities. They take less time to build and have safety features that make a Fukushima or Chornobyl-like event next to impossible.

As the world pivots from burning fossil fuels to generating electricity and heat, SMRs may have a role to play to get the global economy to carbon neutrality or what is referred to as the net zero 2050 target date.

Here in North America, a number of interesting developments are underway including feasibility studies, contracts, and regulatory approvals for SMR builds and deployment.

Let’s take a look.

Canadian Forces Do SMR Feasibility Study

In June, the Canadian Forces Base at Petawawa, Ontario, announced the armed forces were doing a feasibility study on deploying SMRs. The military base is one of Canada’s largest containing over 400 buildings housing 7,000 personnel. It currently receives electricity from the grid and uses three natural-gas boilers and a steam distribution network for heating and hot water.

With projected energy demand expected to increase by 59% for electricity and 9% for thermal heating, it is believed that two 20 Megawatt SMRs would cover 45-55% of the base’s energy requirements during peak periods, and 90-100% in off-peak hours. The base plans to supplement the SMRs with solar and battery systems.

The SMRs being considered would be classified as microreactors with very small footprints and much of the construction being done offsite. Microreactors are seen as flexible, and easy to assemble, install, and maintain. Those being proposed for Petawawa would be assembled at Chalk River Laboratories, a nuclear research centre adjacent to the base. There is resident expertise since Chalk River has been an ongoing centre since 1944 when it was established as Canada’s contribution to the Manhattan Project.

At Chalk River, the CANDU nuclear reactor was conceived. This heavy-water reactor is in use in Canada and other sites around the world. But CANDUs require significantly more material resources than SMRs with their smaller footprint and potential portability.

In the feasibility analysis, the Canadian forces are looking at how SMRs like the ones for Petawaw could be deployed for use in remote off-grid locations where today diesel generators are used. For Northern Canada and other remote locales, SMRs like these would be a good fit. And they could be used for more than just power production. They could be:

portable to be deployed on ships, or delivered by air to disaster areas where grid rebuilds could take months.
assembled at remote sites for heating, industrial steam, seawater desalination, and hydrogen production.

In the armed forces announcement, Fred Dermarkar, President and CEO of Atomic Energy of Canada Limited is quoted stating,

“Small modular reactors have the potential to make a significant contribution to reducing greenhouse gas emissions and meeting net zero goals. They are also ideally suited to service small remote communities where today diesel is the only practical option.”

Ontario to Close a CANDU Site and Build an SMR

Pickering, Ontario is the site of Canada’s oldest CANDU power plant. It is soon to be decommissioned. Today it supplies 14% of the province’s electricity. With its closure, it leaves the province with two remaining sites: Bruce Nuclear and Darlington. At the latter site, the province is building its first grid-scale SMR designed to deliver 300 Megawatts of power. Its completion date is 2028.

This SMR is the BWRX-300 developed by General Electric Hitachi. BWRX is an acronym for Boil Water Reactor with design safety features that allow for indefinite cooling in the event of major power loss. It will be one-tenth the size of the large nuclear plants Ontario is operating today. As SMRs go, it would be considered a big brother to those being studied for Petawawa.

U.S. to Give SMRs the Regulatory Okay

SMRs are getting the blessing of the U.S. Nuclear Regulatory Commission. The first to be built is the NuScale VOYGR SMR. VOYGR stands 23 metres (76 feet) tall and is 4.6 metres (15 feet) wide. It uses pressurized water and passive processes to generate heat. Each can deliver 50 Megawatts of power. VOYGR is manufactured off site and the modules can be daisy-chained in groups of four, six, and twelve. It has taken six years for VOYGR to receive regulatory approval.

So what makes VOYGR an attractive SMR option? Each module has an unlimited coping period, that is it can shut down and cool with no need for power, or additional water, a first in light water reactor technology. It uses helical coils to create its large heat transfer surface confined within a small space. It uses 5% of the fuel needed by conventional nuclear fission reactors. It doesn’t require a containment building, the concrete monoliths that are seen at current sites. The internal vacuum maintained in the reactor vessel, which is submerged in a pool of water, limits heat loss, the presence of oxygen which would be corrosive, and minimizes the potential for dangerous events such as loss-of-coolant as was experienced at Three Mile Island, Chornobyl, and Fukushima.

Concerns About SMRs Remain

Is it all good news? No. There is trepidation about nuclear in general, most often expressed by Green parties around the world. Why?

Because SMRs use nuclear fission to generate heat and as a result of radioactive decay leave spent fuels that require safe storage for tens of thousands to hundreds of thousands of years. The difference is that SMRs use far less fuel but if deployed as the industry projects would be found in thousands of locations rather than the 439 nuclear power station sites today.
SMRs don’t use containment buildings like large reactors which give nuclear industry traditionalists the willies.
SMRs are not fusion reactors, ultimately the safest bet for the nuclear industry’s future because this technology would produce no greenhouse gas emissions, and no radioactive waste making it a good fit to achieve net zero while leaving no radioactive waste.

Despite these three issues, many startups and big engineering firms are entering the SMR market because they see the upside of the technology in the next few decades of the 21st century.