Nuclear power has tried to reinvent itself for two decades with the so-called Fourth Generation and Small Modular reactors. Both have failed.
The Nuclear Fourth Generation Forum celebrated its 20th anniversary1 on 28 April 2021.
The Fourth Generation set out to solve an age-old and existential problem for nuclear power, that there is not enough cheap uranium for a sustained growth of nuclear.
Theoretically there is a lot of uranium, but most of it is in low-grade ores. Mining is not cheap, clean, quick or popular.
Long-term nuclear needs uranium to be used more efficiently. That requires fast-neutron reactors, as was recognised already during the Manhattan project back in 1944.
A standard “slow neutron” reactor uses only a small part of the energy in uranium. Fast neutrons can split all the uranium, plutonium and thorium nuclei.
The drawback is that a fast-neutron chain reaction is much like an atomic bomb. It is hard to control and hard to cool. Coolants are liquid metal, sodium, lead or mercury.
Efforts to build fast-neutron reactors have been ongoing for 75 years, and have resulted in a number of serious accidents, from the Clementine reactor in the US (1946–52) onwards. They were a series of financial disasters, with the French Superphenix as probably the worst case. Some did not even start operation (Clinch River, Monju, Kalkar). The French/EU Astrid project spent 800 million euros on R&D, after which it was ditched in 2019.
But the die-hard fast reactor proponents have persisted and got a new chance when George W. Bush became president in 2001, and the Generation IV Forum was formed. It identified six reactor technologies for the next generation of nuclear. Here is a summary of what happened so far:
- The gas-cooled fast reactor: one smallish reactor under construction in China, since 2012. At least four years late.
- The lead-cooled fast reactor: formerly used for Russian submarines, construction of one reactor started in Russia 2021.
- The molten salt reactor: another idea from the 1950s. Has generated much hype, but no construction.
- The sodium-cooled fast reactor: formerly called fast breeder reactor. Abandoned in Europe, America, and Japan, but developed in Russia and China (by Russia). Since 2001 Japan and France have abandoned development of this reactor type, as the US, Germany and the UK did earlier.
- The supercritical water-cooled reactor: nothing.
Over the last 20 years, Generation IV has delivered at best 5 TWh of electricity per year since 2016, all of it from Beloyarsk 4 in Russia.
For comparison, solar power grew from 1 TWh globally in 2000 to about a 1000 TWh in 2020.
Most of the Generation IV tech requires reprocessing of spent fuel from today’s reactors. Reprocessing means sawing the intensively radioactive fuel and dissolving it in boiling nitric acid, so the uranium and plutonium can be reused.
It is dangerous and expensive. It also means that plutonium will be much more readily available for terrorists and governments that want nuclear weapons. For these reasons, and others, reprocessing was abandoned in the US in the 1970s, after which Germany and the UK followed suit. The last UK plant is being shut down in 2021. Japan has a reprocessing plant under construction – since 1993 –but despite a price tag of 28 billion dollars so far, its future is uncertain.
Capital costs are much higher for Generation IV, because the reactors themselves are more expensive than a standard reactor. On top of that, they have to support reprocessing plants, plutonium fuel plants, and waste vitrification plants.
“Small modular reactors” have been hyped for several years, just like Generation IV, but nothing happens. There are reasons for this, as there are reasons why most reactors became so big in the first place.
The small reactors could in priciple be manufactured in a factory, like cars. But their construction is dependent on location. The safety case must make it reasonably sure that the reactor will get enough water and power in every conceivable situation, and that it is not subject to flooding, tsunamis, earthquakes, idiots, crashing planes and terrorist attacks.
Much of the costs are the same whether it is a 1600 MW reactor (Olkiluoto 3), a 160 MW reactor or a 16 MW reactor.
Security and safety also carry about the same cost for a small or a large reactor. All reactors contain huge amounts of radioactivity. There has to be physical intrusion protection and armed guards twenty-four seven. Staff must also be present in the control room twenty-four seven.
With enough political will it is possible to build a few small modular reactors in the world, if money is no object. The question is why.
Billionaires Bill Gates and Warren Buffet and the TerraPower company claimed in early June 2020 that they are building a small modular reactor in Wyoming, a “multibillion dollar project to be split evenly between government” and themselves.
“This is our fastest and clearest course to becoming carbon negative”, said Wyoming’s governor, Mark Gordon, to the Guardian.
How fast? It “hopes to apply” for a licence by 20262.
Another way to reduce carbon would be to catch up with other states on wind and solar. But that is not the Wyoming way. The state has threatened to sue other states because their climate goals have led to less demand for Wyoming coal and coal power.
Wyoming is by far the top coal producer in the US, and also has the highest CO2 output per kilowatt hour generated. TerraPower claim that their reactor is the solution for the 2030s.
This may be an attractive time perspective for fossil interests.
Fredrik Lundberg
1 www.world-nuclear-news.org/Articles/Generation-IV-Forum-marks-anniversary
2 www.world-nuclear-news.org/Articles/TerraPower-eyes-Natrium-construction...
