Molten salt nuclear reactors still not ready for prime time

If the world is to decarbonize energy without a major economic collapse, nuclear power must be part of the picture. Solar and wind energy generation are growing world-wide, but both will always have to deal with the intermittency problem. Batteries and hydroelectric storage can address some of this, but alternative energy sources must be available for back-up on cloudy days and during still air. The only realistic alternative is nuclear.

Despite the storied failures of Three Mile Island, Chernobyl and Fukushima, light water reactors have had a remarkable history of safe operation. What about other forms of nuclear power generation?

I mentioned molten salt reactors (MSRs) in a previous post. Their virtues include more efficient use of fissile materials, use of thorium, which is more abundant in the earth’s crust, and fuels that are difficult or impossible to weaponize. Considerable research into MSR technology took place in the ‘50s and ‘60s, nearly all of it in my hometown of Oak Ridge, Tennessee. And there is renewed interest in developing and building commercial MSRs in the US, Canada, the UK, France, China and India. 

It turns out the MSRs have some drawbacks. Chief among them is the long-term operation of power generation using radioactive materials in corrosive salt solutions at high temperature. Despite decades of well-funded research, MSRs have failed to live up to their potential.

“The Molten Salt Reactor Experiment’s history is riddled with extensive problems, both during its operational lifetime and the half century thereafter. These problems were not accidental but a result of the many material challenges faced by the reactor itself.

 

“Any other molten salt reactor will encounter these problems too. France’s Institut de Radioprotection et de Sûreté Nucléaire, the Nuclear Innovation and Research Office in the United Kingdom, and other research laboratories have all drawn this conclusion. According to the Institut de Radioprotection et de Sûreté Nucléaire, “numerous technological challenges remain to be overcome before the construction of an MSR can be considered.”

“Should molten salt reactors ever be constructed, they are unlikely to operate reliably. And if they are deployed, they would likely result in various safety and security risks. And they would produce several different waste streams, all of which would require extensive processing and would face disposal related challenges.”

With molten salt fission reactors off the table and commercial fusion energy perennially 10 years in the future, light water nuclear reactors will have to be part of the global decarbonization plan.

https://thebulletin.org/2022/06/molten-salt-reactors-were-trouble-in-the-1960s-and-they-remain-trouble-today/