GE GE Aerospace

By Daniel Michaels 

The nuclear power industry is trying to bounce back after shrinking for decades, and shrunken nuclear reactors could be one key to success.

Combining new technologies, advanced engineering and a market-friendly approach, reactor manufacturers are developing new systems that produce less power but are much smaller and less costly than existing nuclear reactors.

The pitch: small modular reactors, or SMRs, that can be housed in compact containment structures and operate safely with less shielding and oversight. SMRs could allow power plants to shed their huge hourglass-shaped cooling towers and, in some designs, the reactors would be immersed in water to prevent overheating.

Dozens of designs are now on the table, with a handful under preliminary U.S. and Canadian regulatory review following several billion dollars of investment by private and government entities. A Utah utility hopes to run the first U.S. SMR by the end of the decade. China is investing heavily in SMR development, and Russia last year fired up an SMR on a ship, touting it as a portable power station.

SMRs may not be an easy sell, given concerns over the safety and environmental impact of nuclear power. But proponents of the new technology are pitching competitively priced, potentially limitless electricity that yields no greenhouse gas emissions -- unlike power plants that burn fossil fuels -- and that is more reliable than wind or solar power.

Utilities could retrofit existing power plants by substituting climate-friendly SMRs for aging, climate-unfriendly coal- or gas-fired burners, boosters say. SMRs could also power municipal heating systems, turn water to hydrogen for fuel or electrify remote locations, all without any emissions.

SMRs would produce up to 300 megawatts of power, compared with more than 1,000 megawatts for some big power plants now in operation. But because the devices are inherently modular -- many of their components can be mass-produced in factories rather than being constructed on site -- SMRs could be combined in increments to boost capacity.

"It's not just about making things smaller," says Jay Wileman, chief executive of GE Hitachi Nuclear Energy, an alliance of General Electric Co. and Hitachi Ltd. that is developing and marketing SMRs. "It's about making things simpler."

Like conventional nuclear reactors, SMRs split atoms to heat water and produce steam, which turns a generator to produce electricity. Because of their compact size, their proponents say, SMRs can operate safely with reduced need for the thick shielding, complex safety systems and intensive maintenance regimens required for the reactors in traditional nuclear power plants.

A Tiny Nuclear Reactor Could Power Future Space Colonies

By Robert Lee Hotz and Alberto Cervantes

As NASA plans for bases one day on the moon and Mars, agency engineers know they'll need power -- lots of it. A reliable power system will be essential for lighting, water and oxygen, as well as for running experiments and making fuel for the journey home.

NASA is developing a nuclear power plant whose reactor is about the size of a garbage can. Called Kilopower, this fission power system could provide up to 10 kilowatts of electrical power continuously for at least 10 years -- enough to run several households. Four Kilopower units could sustain a lunar or Martian outpost.

The high cost of building and maintaining conventional reactors has stymied the development of new nuclear power plants since the 1980s and led to the decommissioning of nuclear power plants in many countries.

SMR developers aim to reverse these trends by rethinking reactor design. It's a bid for industrial survival with overtones of the Cold War rivalries that can be traced back to the dawn of the Atomic Age, when President Eisenhower offered his "Atoms for Peace" plan for the widespread development of nuclear power.

Eisenhower's plan, outlined in a 1953 speech to the United Nations, ushered in decades of nuclear power plant construction and a race with the Soviet Union to energize the world. Today, Russia and China are competing with the U.S. and Europe in the downscaled market.

Global rivalries are just one concern for reactor makers. Next-generation nuclear must overcome public wariness of the technology engendered by the terrifying mishaps at Three Mile Island, Chernobyl and, most recently, Fukushima. Then there is the challenge of making a compelling case for nuclear power as the cost of electricity from natural gas, wind and solar is plunging.

Rather than offering up SMRs as a replacement for renewables, proponents of the devices say they can play a complementary role in the smart grid of the future -- replacing coal- and gas-fired plants and operating alongside wind and solar.

Most utilities rely on a variety of electricity sources, with differing costs, emissions and capacity to provide the constant flow that power grids need for stability, says Tom Mundy, chief commercial officer at SMR developer NuScale Power LLC. "Our technology is a great complement to renewable power systems," he says.

The World Nuclear Association, a trade group, has touted "the enormous potential of SMRs" offered by their small size, construction efficiency and safety systems, which could in turn make them easier to finance than conventional nuclear power plants.

The U.S. government is lending its support to SMR development. In September, the Nuclear Regulatory Commission for the first time issued a final safety evaluation report on a SMR -- a critical step before a design can be approved -- to NuScale. The company, based in Portland, Ore., and majority-owned by the industrial engineering and construction multinational Fluor Corp., is developing its first commercial SMR for utilities in Utah and promising power by the end of the decade.

Last fall, the Energy Department awarded $210 million to 10 projects to develop technologies for SMRs and beyond, as part of its Advanced Reactor Demonstration Program. The agency had already awarded $400 million to various projects since 2014 "to accelerate the development and deployment of SMRs," it said in a statement on NuScale's safety evaluation last September.

Dozens of SMR initiatives are at various stages of development around the world, according to the World Nuclear Association. Potential buyers range from U.S. utilities trying to phase out coal-fired generators to Eastern European countries seeking energy independence.

Estonia, a reluctant part of the Soviet Union for five decades before gaining independence in 1991, sees nuclear power as a potential escape from Moscow's continued energy grip. SMRs could work there because their size best fits the country's power needs, says Kalev Kallemets, chief executive of Fermi Energia, an Estonian startup assessing SMR designs for a potential project.

GE, a pioneer in civilian nuclear power, has two main SMR offerings in the works. The first is a slimmed-down version of the traditional water-cooled reactor that the corporation has offered since 2014. GE designers slashed construction costs of the new device by reducing by 90% the amount of concrete and reinforcing metal needed, says Mr. Wileman. Rather than relying on electrical pumps to prevent dangerous overheating in the event of a mishap, the proposed reactor would be sited below ground in a tank of water.

Similarly, NuScale's reactor module would rest in a pool of water and use a safety system consisting of valves instead of electric pumps, says Mr. Mundy.

GE's second offering, a system now in development with nuclear startup TerraPower LLC, replaces water with molten salt, similar to what's used in some advanced solar-power arrays. Dubbed Natrium, the system runs hotter than water-cooled reactors but at lower pressure and with passive cooling, which eliminates piping and electrical systems while improving safety, according to TerraPower CEO Chris Levesque.

"When you have a really elegant design, you can get multiple benefits working together," Mr. Levesque says. TerraPower, established by investors including Bill Gates, received $80 million of the Energy Department funding for Natrium in October.

While proponents of SMRs tout their inherent "passive safety," the small reactors face opposition. Greenpeace, the Union of Concerned Scientists and other advocacy groups argue that nuclear power remains a dangerous technological dead-end that causes as many problems as it solves.

"Small modular reactor development is too slow to address the climate crisis," the Canadian Environmental Law Association said in a petition opposing the country's proposed funding of SMRs, which also criticized SMRs' radioactive waste and cost.

"The basic idea, from a business perspective, is flawed," M.V. Ramana, a professor of disarmament and global security at the University of British Columbia, says of SMR technology. Traditional reactors grew over time to achieve greater efficiencies of scale and lower cost per kilowatt-hour because power output rose faster than construction and operating costs. "There's no reason that's changed," he says, dismissing SMR makers' promises of lower costs and increased safety. Many proposed SMR expense reductions, such as less shielding, could ultimately increase their danger, while the combined use of several modules could create new safety risks like radioactive contamination that negate gains in individual modules, he says.

Mr. Ramana also says that the technological advances like 3-D printing and digital manufacturing that make SMRs possible are doing even more to improve green renewables. "It's a kind of treadmill race, where one treadmill is going much faster."

Even the International Atomic Energy Agency, acknowledging growing interest in the field, concluded last September that "although SMRs have lower upfront capital cost per unit, their economic competitiveness is still to be proven."

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Write to Daniel Michaels at daniel.michaels@wsj.com

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February 11, 2021 13:50 ET (18:50 GMT)

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