By Debbie Carlson
Investors have embraced once-niche alternative-energy sources including solar, wind and geothermal as governments crack down on polluting and poisonous fossil fuels.
But what’s often avoided is any discussion of a reliable, carbon-free source that can scale more than any other alternative form of energy: nuclear.
Sustainable-minded investors have had an uneasy relationship with nuclear energy. Significant downsides abound: the high costs and long time spans to build plants and handling spent fuel (nuclear waste), and the potential for proliferation.
Bill Gates, Warren Buffett
However, in a time of climate triage, nuclear energy is getting a renewed look. The best-known example is Bill Gates’ advanced nuclear reactor company TerraPower, which teamed up with GE-Hitachi Nuclear Energy and Berkshire Hathaway’s /zigman2/quotes/200060694/composite BRK.B -0.44% power company, PacifiCorp, to eventually build a next-generation small nuclear reactor using new fuel technology.
Further, as the world economy struggles to rebound following last year’s lockdowns, upending traditional energy supplies and a transition to renewable energy, nuclear advocates may use this time to push it as a baseload source of clean power that can work in harmony with wind and solar energy, and as an alternative to carbon-emitting natural gas that’s often bundled with renewables.
Using nuclear energy to advance the goals of the Paris Agreement is likely to be discussed at the UN Climate Change Conference, known as the COP26 Summit, starting Oct. 31 in Scotland. In its report , the Intergovernmental Panel on Climate Change earlier this year said nuclear has “the potential for an expanded role as a cost-effective mitigation option,” but can cause “great problems” if the downsides aren’t handled carefully.
Those “great problems” are the hurdles that nuclear faces, but new nuclear technologies are trying to address some of those issues.
Smaller, safer reactors
Alex Gilbert, project manager at Nuclear Innovation Alliance, which supports commercialization of advanced nuclear energy systems, says the new designs are a fraction of the size of a conventional nuclear plant and use significantly less fuel.
Gates’ TerraPower ’s reactor would produce about 345 megawatts of thermal power. Micro reactors, similar to the module that nuclear company X-energy is planning for the Department of Defense , are small enough to put on a semi-trailer and produces 10 megawatts (MW) or less and are about the size of a wind turbine.
Comparatively, Exelon’s /zigman2/quotes/205982254/composite EXC -0.91% recently relicensed Braidwood Generating Station’s two-unit nuclear power station in Illinois generates 2,389 megawatts of power.
TerraPower and X-energy’s projects are under an advance reactor demonstration program, Gilbert says, and could possibly be online in 2029 or 2030. A third advanced reactor, from NuScale , with about 250 MW, may be ready around that time, too. Those would be three companies producing power at a utility level.
But the first to market may be a 4 MW (with 1.5 MW of electrical power) micro reactor by Oklo . The U.S. Nuclear Regulatory Commission is reviewing it now. Because of its small size, if approved, it could be built and go online as soon as 2025, Gilbert says.
The new designs of advanced reactors could more easily work with renewable energy on the electric grid, he says, noting different systems have different strategies. TerraPower has a molten-salt integrated storage system where the plant’s output can balance with the grid, while NuScale has multiple modules that can be turned on or off as needed.
Gilbert says these advanced reactors use fuel more efficiently and use much less of it. One of the fuel types being discussed is high-assay low-enriched uranium , which allows these new reactors to use up to 20% of uranium 235, the isotope that produces energy during a chain reaction, and get more power. Conventional reactors use only 5%. This design makes spent fuel less radioactive in the short- and long-term versus conventional reactors