Bill Gates and Warren Buffett want to build a new kind of nuclear reactor to generate electricity. Why? Because the wind doesn’t always blow and the sun doesn’t always shine. They intend to plunk their new toy down in the state of Wyoming on the former site of a coal-fired generating plant.
“This is our fastest and clearest course to becoming carbon negative,” says Wyoming’s governor Mark Gordon. “Nuclear power is clearly a part of my all-of-the-above strategy for energy.” Wyoming is the top coal producing state in America.
According to The Guardian, the new facility will be a joint venture between TerraPower, founded by Gates 15 years ago, and PacifiCorp, a Berkshire Hathaway-owned utility that serves customers in Wyoming, Idaho, Utah, California, Oregon, and Washington.
Small advanced reactors, which run on different fuels than traditional reactors, are regarded by some as a critical carbon-free technology that can supplement intermittent power sources like wind and solar as states strive to cut emissions that cause climate change. “We think Natrium will be a game-changer for the energy industry,” Gates told a media conference in Cheyenne, Wyoming this week.
The Guardian says the new generating station will produce 345 megawatts of electricity, but the output can be boosted by a molten salt energy storage component to 500 megawatts. The primary feature of the so-called Natrium technology is that it uses sodium to cool the reactor instead of water. Natrium is the Latin word for sodium, which is why its symbol on the periodic table of elements is Na.
Chris Levesque, TerraPower CEO, told the press this week the demonstration plant will cost about $1 billion and will take about seven years to build. “We need this kind of clean energy on the grid in the 2030s,” he told reporters. Actually, Chris, we need clean energy on the grid now, not 7+ years from now. A billion dollars would buy more than 500 MW of power and have it online, together with grid storage batteries, in a lot less time. Why wait?
I am not a nuclear engineer nor am I a rocket scientist, so I have to rely on Wikipedia to inform me about some things (I contribute $5 a month to support Wikipedia and encourage you to do the same).
Here is what I found out:
The primary advantage of liquid metal coolants, such as liquid sodium, is that metal atoms are weak neutron moderators. Water is a much stronger neutron moderator because the hydrogen atoms found in water are much lighter than metal atoms, and therefore neutrons lose more energy in collisions with hydrogen atoms.
This makes it difficult to use water as a coolant for a fast reactor because the water tends to slow (moderate) the fast neutrons into thermal neutrons (though concepts for reduced moderation water reactors exist).
Another advantage of liquid sodium coolant is that sodium melts at 371K and boils / vaporizes at 1156K, a total temperature range of 785K between solid / frozen and gas / vapor states. By comparison, the liquid temperature range of water (between ice and gas) is just 100K at normal, sea-level atmospheric pressure conditions. Despite sodium’s low specific heat (as compared to water), this enables the absorption of significant heat in the liquid phase, even allowing for safety margins. Moreover, the high thermal conductivity of sodium effectively creates a reservoir of heat capacity which provides thermal inertia against overheating.
Sodium also need not be pressurized since its boiling point is much higher than the reactor’s operating temperature, and sodium does not corrode steel reactor parts. The high temperatures reached by the coolant (the Phénix reactor outlet temperature was 560° C) permit a higher thermodynamic efficiency than in water-cooled reactors. The molten sodium, being electrically conductive, can also be pumped by electromagnetic pumps.
A disadvantage of sodium is its chemical reactivity, which requires special precautions to prevent and suppress fires. If sodium comes into contact with water it reacts to produce sodium hydroxide and hydrogen, and the hydrogen burns when in contact with air.
This was the case at the Monju Nuclear Power Plant in a 1995 accident. In addition, neutron capture causes it to become radioactive; however, activated sodium has a half-life of only 15 hours. Another problem is sodium leaks which are regarded by a critic of fast reactors, M.V. Ramana, as “pretty much impossible to prevent.”
Wikipedia adds that a natrium facility that generates less than 500 MW of electricity uses “uranium-plutonium-minor-actinide-zirconium metal alloy fuel, which is supported by a fuel cycle based on pyrometallurgical reprocessing in facilities integrated with the reactor.” I don’t know about you, but the words “uranium” and “plutonium” don’t sound like “different fuels compared to traditional nuclear reactors.”
The Guardian points out that nuclear power experts have warned that advanced reactors could have higher risks than conventional ones. Fuel for many advanced reactors would have to be enriched at a much higher rate than conventional fuel, meaning the fuel supply chain could be an attractive target for militants looking to create a crude nuclear weapon. And don’t even be concerned about Russian hackers. We know those malefactors only like to interrupt gasoline pipelines and beef processing plants. Pooty Poot and his henchmen would never stoop so low as to hack a nuclear power plant…would they?
People always rush to criticize Tesla for selling emissions credits, but no one wants to talk about the $80 million the US Department of Energy has already invested in TerraPower with millions more coming in the future. No one would expect Bill Gates and Warren Buffett — two of the richest white men in history — to foot the bill for their boondoggles all by themselves, would they?
All Of The Above
The key to understanding this story is found in Governor Gordon’s use of the words “all of the above.” That’s free market speak for “We’re happy to have a piddly little 350 MW facility of over here, just so long as we can continue supporting coal- and gas-powered generating plants that churn out hundreds of gigawatts over there.” In other words, it’s a smokescreen designed to allow fossil fuel interests to kick the can down the road a little further and add some greenwashing to their corporate portfolios at the same time.
Being rich does not necessarily make a person all that smart. America needs more nuclear power like a fish needs a bicycle. People in Wyoming may be fooled by this blather, but CleanTechnica readers aren’t taking the bait. Natrium was probably selected as the name of thus new nuclear technology because it sounds a little like “nature” or “natural.” That’s a great marketing ploy, but we’re not buying it. Frankly, the Bill and Warren show is more than a little disappointing.