Pro-nuclear advocates should stop bashing advanced nuclear
I wish I knew why some nuclear advocates feel that it’s worth their time to spread as much negative information as they can find about the potential utility and value of advanced nuclear power technologies.
IMO, modern water cooled reactors qualify as advanced in the same way as a modern BMW engine qualifies as advanced even if it is still using the same Otto Cycle (4-stroke spark plug internal combustion) that was first patented in 1861.
There are very innovative water-cooled reactor designs. Reactors that don’t use any coolant pumps or nuclear power plants that can be assembled almost as easily as Lego sculptures offer new, valuable capabilities.
I like large, water-cooled reactors when they can fit customer needs as long as they can be properly managed and completed. (Large grids do not necessarily have room for large reactors because they likely have sufficient generators to supply their current loads.)
Even though experiments have been conducted with other coolants over the years, there were a number of reasons, some having to do with the state of material science or controls technology at the time, those systems were not deployed commercially. (Does anyone remember the “success” of the Lisa or the Next? Did those experiences mean that the Macintosh wasn’t advanced and shouldn’t be developed? Did the failure of the Newton prevent the development of the iPad?)
It’s not often talked about, but the adoption of water cooled reactors had a purposeful geopolitical aspect. The US built excess enrichment capacity for a large scale weapons buildout during the Truman and Eisenhower administrations.
When we finally chose to allow selected private companies to participate in developing power reactors, we had strong political and economic motives to ensure that our standard became the world’s standard. We thus offered low enriched uranium at prices below cost to better compete against natural uranium reactors. US vendors also built large order books by over promising and under delivering on price and schedule. By the time the customers realized they were paying more and getting less, it was too late for customers to change their technology selection.
The fact that alternative nuclear concepts were not deployed and water cooled reactors (both heavy and light) WERE deployed does not mean that the water cooled reactors have inherent superiority.
The fact that we have built and operated a substantial number of water cooled reactors gives that technology a leg up. But it’s incorrect to say that we know how to build them well or affordably. Our parents might have done a reasonably good job, but their skills are not inheritable. There are some teams that have done pretty well, but they are mostly inaccessible to us.
Smaller reactors offer the opportunity for smaller capital expenditures, less complex financial arrangements, smaller partnerships and less overall risk. They also offer the opportunity for significantly shorter construction periods and faster learning.
By definition, we need to build more units of smaller reactors to produce the same amount of power as fewer units of large reactors, but building more units enables us to move further down a Wright’s Law learning curve.
Some design alternatives address some of the characteristics of water cooled reactors that are inherent to the technology.
Example: Helium and nitrogen are inert gases that do not corrode tanks, pipes and heat exchangers. They do not change phase within the potential operating temperature and pressure conditions of a reactor. They can be heated to very high temperatures. (There is a currently operating helium cooled reactor [Japan’s HTTR] that has been operating with a coolant outlet temperature of 950 ℃ for years using 1990s material technologies. With modern materials, higher temperatures are possible.)
The best reason for higher operating temperatures is the dramatically improved efficiency those temperatures enable. Moving from 30% to 40% is a 33% increase. That doesn’t just affect fuel costs; it means that the same equipment might be able to produce 33% more units of output that can be sold into the market.
Higher temperatures might also allow designers to use Brayton cycle machines or even combined cycle machines borrowed from the highly successful natural gas power plant industry.
Molten salts will contain and isolate radioactive materials if the salt leaks. There is no driving force that would distribute materials outside of the plant boundaries.
Reactors cooled by sodium or lead can enable fertile material to be converted to fissile material at a rate that exceeds the consumption of fissile material. Breeding economics change when uranium prices increase. (The current price of uranium is about 3 times as high as it was a year ago.)
These POTENTIAL advantages of advanced reactors are not a given, but they can be powerful if achieved.
I don’t understand why some advocates think that we have an either-or choice to make. The nuclear sector is a tiny fraction of the size that it needs to be in order to make the kind of contributions it is capable of. Having a wide variety of projects to work on and technologies to refine helps attract some of the best and brightest engineers, technicians, financiers and marketers to the sector.
Start up ventures often attract talent that big, established companies would stifle. Some of that talent comes in the form of mid to late career professionals with refined skills in similar or contributing industries. It would seem nearly impossible for an establishment nuclear company to attract a SpaceEx engineer or the founder of a successful drone company.
Building more of what we already know might offer more immediate returns, but it isn’t necessarily the best recipe for long term success.
I’m a fission fan. I invite others to join me and to stop investing time in bashing new nuclear.
I should also disclose that I’m a venture capitalist with a significant focus on the advanced nuclear sector, so I am professionally biased towards that sector.
I often wonder if the alternative designs that get government funding and do a lot of public relations outreach/marketing are a planned opposition to building a nuclear fleet that provides 80% baseload in the USA… We kick this nuclear grid option down the road with the excuse that we’re waiting for better technology, while most of that “better tech” is 100MWe pebble beds and SMRs that can’t fill that baseload demand unless built in the thousands… The microreactors take this to comical conclusions arguing that more people and industry will relocate to the arctic tundra once $300/Mwe (at the crank) power is locally available. I also look for the interchange of executive level employees between government agencies and the startups; collusion, favoritism, and academic elitism is universally present. I’ve come to believe the DOE is funding these things to look busy, to give the appearance of moving the technology forward, while appeasing the interests that want nuclear energy suppressed. I’m a mechanical engineer with a master’s degree in Nuclear Engineering. I’ve spent 20 years in fuel design and reactor engineering mostly for operating, but also conceptual nuclear plants. I’ve done a deep enough dive to satisfy my curiosity about literally every power reactor concept ever put forth from ‘GEN4’ to MHD space reactors. There aren’t that many ways to skin this cat (fission); there are 98 elements in the periodic table, only a handful of them have any use in the reaction zone. Any fluid that enters the reaction zone needs to be simple, and relatively inert across a wide range of temperatures; there are similarly few candidates (water, helium, CO2, sodium, arguably Pb) – some of these are only inert in a carefully controlled system (sodium, fluorides) – while others present no real hazard in any context (water, helium, CO2) and are thus much preferred operationally. Let’s not forget that reactors are intended to spend most of their time in operation (decades) and very little time in design (years), so while a fluoride salt or lead might look good in a conceptual design they usually present crippling challenges in operation over years where the reactors are operated and repaired by meat bags. In the context of my experience at operating plants, I find it illogical to assume that the 38 year-old reactor that was shutdown 10 times in the last 3 years for various mechanical problems would be more reliable if the RCS were full of lead – it truly is a non sequitur.
I have other theories where a side-objective of funding ‘next-generation’ technology is a knowledge retention and transfer effort. For instance, one benefit of the various microreactor funding efforts is training the new graduates in nuclear engineering. Maybe training is THE GOAL, since it should be clear that a 5 MWe reactor that costs $20M and achieves 10% of LWR burnup with HALEU, while requiring 24-hour staffing and security in the desert or tundra or on the moon, has no valid commercial argument. Rod, we saw about $500M go up in smoke at BWXT from 2010-2015 – there was no accountability – the spending was wildly out of control – I will never forget that! mPower gave me the perspective of a lifetime. I still follow Christofer Mowry’s career… after the golden parachute received after BWXT, he left the General Fusion CEO in 07/2022, and is now at his second fusion startup. There is a lot to unpack there.
The trajectory of one company with a certain dominating leader isn’t indicative of the entire advanced nuclear sector.
I have plenty of personal stories from that experience that I could, but won’t, share.
Well, there a saying out there: “Lead, follow, or get the hell out of the way.”
Michael – It seems that you envision the third option for the United States. These designs (not all of them, but certainly some of them) will be built, but by other countries. As an example, let’s take your own words:
“… while most of that ‘better tech’ is 100MWe pebble beds and SMRs that can’t fill that baseload demand unless built in the thousands.”
China now has its HTR-PM (pebble bed design) in commercial operation, which produces 210 MWe, not 100. This is a country that has been bringing online a new coal plant EVERY WEEK. They definitely have the capability and the will to build these things in the thousands.
Meanwhile, there are plenty of people in the US who think like IBM’s Thomas J. Watson, who supposedly said (probably apocryphal): “I think there is a world market for about five computers.”
To me, defenders of Generation II LWR technology are like defenders of “core memory,” which was the standard technology for “mini-computers” 50 years ago. It worked, it was dependable (even kept state if the power was shut down), but it was expensive as hell due to specialists needing to “weave” the wires through tiny annular pieces of metal (thank goodness for women with first-class knitting skills). As a result, it was nearly gone by the 1980s.
At the same time, semiconductor manufacturing relocated from California to outside of the US. Coincidence?
I agree that microreactors and 100 MWe SMR’s are not going to get us to nuclear providing 80% of our baseload. However, SFR’s and GFR’s can be built in sizes equal to the largest LWR’s and are far more efficient both in terms of electricity generation and fuel usage. They also enable the fuel cycle to be closed. The idea that we’re stuck with LWR’s for large-scale baseload is a self-fulfilling prophecy of the worst kind. LWR’s are completely and utterly unsustainable and unjustifiable as a long-term energy/climate solution. There are no significant technological obstacles to designs like GA’s Energy Multiplier Module or the European GFR-1200. Those are the designs that we should be investing in if we’re talking about nuclear providing 80% baseload.
A good writeup Michael. A couple of poimts though.
Actually water without precise chemistry control is very corrosive. All reactors require good chemistry control (there’s no such thing as pure helium). Davis Besse shows that borated water isn’t too nice either. And 155 bar borated water at 320C doesn’t qualify as “no hazard”.
Fluoride salts are stable, don’t generate hydrogen, and corrosion control rests on having the salt reducing toward the structural alloy rather than the passivation layer required with water. Fluoride salts also do not cause stress corrosion. So it ends up a simple matter of allowance thicknesses.
I like LWRs. Much better than coal plants. But they are basically glass cannons. The power goes out, the core melts down, generating explosive hydrogen in the process that detonates the containment and spreads radionuclides all over the country. Or someone thinks there is water in the core when there isn’t and the core melts down. A glass cannon like that just begs for military grade bureacracy not unlike a nuclear missile silo. Said bureaucracy is very expensive and results in all manner of bloat that inflated prices and build times. With advanced reactors focussing on inherent safety you at least have a case for a more rational regulatory approach.
A 3000 MWt LWR gets you 1000 MWe. An advanced reactor of 3000 MWt gets you 1500 MWe. That’s a quarter billion bucks a year more revenue.
By the way, 3 outages in 10 years is very good. Solar power stations have 365 outages a year.