Why Aren't Molten Salt Nuclear Reactors Everywhere?

Molten salt nuclear reactors are green, and can be developed at relatively low cost. But there is one big reason they are not currently commercialized. And this is beyond the issue of gaining local zoning and government approvals. But this problem is being addressed successfully at the current time by research and manufacturing outfits like Copenhagen Atomics.

[Voltechs]

Couldn’t you also electrically energize the metal parts to give back free electrons when needed? This is how ship hulls prevent rusting at sea

[HammerOn-bugx]

Finally! Someone who knows the major issue. Keeping oxygen/water out of salt is an almost insurmountable problem as they have an affinity for both.

[jimgraham]

Thanks, I don't think corrosion is really the problem. Molten salt has been used in industry for years for heat capture, storage and transmission. A good example are solar thermal generators.

The main issue in MSRs is the presence of the fuel compounds entrained in the salt and the neutron flux around the reactive part of the core that could alter the chemistry.

Weinberg investigated these issues with the 1960s MSR experiment at Oakridge and found solutions to most of them.

Reportedly the current Chinese development MSRs designed to follow on the Oakridge experiment, have found no real problems with corrosion but are tweaking the Hastalloy n steel by adding a slightly higher proportion of nickel.

The main issue why MSRs didn't progress was the arguments between Weinberg and Rickover.

Weinberg was into high temperature gas cooled Brayton cycle (think small light gas turbines). His activities had been championed by the USAF.

Rickover was a live steam Rankine cycle man (think large heavy steam turbines). He was sponsored by the USN.

The USAF lost interest and Weinberg his funding. Rickover gained control over the funding pot, had his rival, Weinberg, fired and the MSR program closed.

Thirty years on, Oakridge was reportedly on the verge of dumping all their MSR documentation (blue prints design notes etc, ) when during a period of rapprochement, visiting Chinese engineers asked for and were given copies of the MSR documentation.

The rest is history, China currently has two experimental MSRs operational and is planning to move on to an engineering prototype shortly. Their vision is pretty much that of Weinberg, small high temperature gas cooled reactors for use in remote regions without access to cooling water. Think abundant power for the third world.

Belatedly the US is trying to catch up and funding has recently been provided for an developmental MSR in Texas.

[GaryMarriott]

Apart from the purely technical, one reason these are not everywhere is LFTR reactors are proliferation resistant & cannot be used to make nulclear weapons. Thus governments cannot get their cut of that sweet sweet clean plutonium.

[phillbradshaw]

We've had Hastelloy N, a nickel alloy since the '50's. Real reason tech hasn't been embraced is MSR's don't make fissile material 4 bombs

[grogyan]

Corrosion is not just a reaction with oxygen.
It is just an undesirable chemical reaction for a container/vessel/tube

[SamMulder-gb]

In college I built the gas blanket for a molten salt test system. Very fun stuff!

[Mr_nah]

Why don't just use a ceramic coating to avoid this issue?

[flamesofhellstudio]

Rust only occurs with iron because rust is specifically iron oxide. Corrusion doesn't mean rust. Rust is just how iron corrodes from reacting to oxygen. The green stuff on copper is corrosion too but it actually forms a protective layer. We also have a ton of non corrosive metals that are cheap and used already everyday.

[rooknado]

This is highly valuable information, yet extremely niche to my interests! I have an amateur passion for nuclear science, specifically the workings of a reactor; more specifically Soviet nuclear reaction systems.

[stephenbrickwood]

5 times more electricity is needed to replace fossil fuels.
40, 000 km of grid is needed for every 1gW of electricity, the generation plant is dirt cheap compared to the grid it needs.

$1million per km. Big open country or crowded population centre streets.

Nobody talks about the grid constraints to more electricity generation.

[JegaSingam]

Might sound simplistic, but would a glass or ceramic lined pipes or reactor container be suitable to prevent corrosion.

[jackiechan]

Guy on YouTube years ago was claiming they were a viable alternative to regular nuclear power. Well done for educating us.

[kwest]

What's the cost though to make thee salt ultra pure?..

[roadsideprophet]

Only iron rusts. Others it would be called oxidation

[edainari]

Brilliant! These are some hardworking personnel to figure this out!

[luker.]

What is the issue with non-metal refractory? Like silica? It's not that expensive is it?

[liledw]

Neutron flux is another huge issue.

And recycling the expensive refined chemicals that are used to moderate the reaction is another huge issue.



That being said, there was a button of issues with fast breeder uranium reactors too.. but we needed them for the war effort and money was no object so we figured it out.

[shagrat]

They ran the MSRE in Oak Ridge National Laboratory from 1965 to 1969 and they found the corrosion to be negligible. Now that was over 50 years ago and metallurgy and industrial processes have seen quite some enhancements. In the end the question as with all nuclear plants is financial viability over the complete runtime.

[akeelahmed]

Use fusion tech to keep the salt way

But either just use elec directly form the background