First Fuel Produced for the Idaho National Lab's Experimental Molten Salt Reactor.

[NNadir]

First fuel produced for molten salt reactor experiment

Idaho National Laboratory has launched full-scale production of enriched fuel salt for the world's first test of a molten chloride salt fast reactor - technology that could be deployed as soon as the 2030s for both terrestrial and maritime applications.

The Molten Chloride Reactor Experiment (MCRE) project - a public-private collaboration between Southern Company, TerraPower, CORE POWER, and the US Department of Energy (DOE) - is planned to be the first reactor experiment hosted at the Laboratory for Operation and Testing in the United States (LOTUS) test bed being built at the lab by the DOE's National Reactor Innovation Center. It uses liquid salt as the fuel and the coolant, allowing for high operating temperatures to efficiently produce heat or electricity.

The Molten Chloride Reactor Experiment will need 72 to 75 batches of fuel salt to enable it to go critical - giving Idaho National Laboratory (INL) its largest fuel production challenge in 30 years, according to the DOE Office of Nuclear Energy. The fuel salt production process began in 2020, but early attempts yielded far below the goal of 90% conversion of uranium metal into uranium chloride and production of 18 kg of fuel salt per batch. But a breakthrough in 2024 - when the team developed a new step to improve uranium utilisation - eventually led to the achievement of 95% conversion and full-batch production. They have since demonstrated they can produce a batch in as little as one day, according to INL.

The first fuel salt production batch was delivered at the end of September, with four further batches to be produced by March 2026...

The orange pedophile apparently supports this effort, which has no bearing on whether or not it is a good idea. If the orange pedophile supports the statement that water is wet - although it's possible, being senile, he might not - that does not make water dry.

For molten salts, I am personally a fluoride kind of guy because of the nuclear reaction ³⁵Cl[n, gamma]³⁶Cl will take place in chloride salts. Removing ³⁵Cl to prevent this reaction, and using a pure ³⁷Cl salt requires expensive isotopic separations. (I doubt the INL fuel is isotopically separated pure ³⁷Cl) This said, it is unlikely that given its mobility and the solubility of most of its salts, it is doubtful that released ³⁶Cl could ever be present in concentrations that would engender significant health risks, even at a point where secular equilibrium was reached even with it's long half-life, 301,000 years.

(BNL does not give capture cross sections for ³⁶Cl; I'm sure it's somewhere in the literature, but I'm too lazy to look.)

I have, for the record, proposed to my son a control salt, an iodide salt made from fissiogenic iodine, a mixture of ¹²⁷I and ¹²⁹I for a special type of reactor, however this type of salt that I proposed will shut a reactor down, not operate it. (It's a very, very, very esoteric system.)

Bromine has the same problems as chlorine, only worse. A bromide molten salt will not support fission.

I fully understand some rationale for chloride, inasmuch as chlorine is earth abundant and there is a risk of fluorine depletion. It may not affect nuclear salts all that much because of the high energy density of nuclear fuels, which makes them environmentally superior to all other fuels and all other systems for producing energy.

Very few of the concerns raised by antinukes about radioactive materials hold much water against the alternatives, one of which is the destruction of the planetary ecosystem from fossil fuel waste, but that said, in concert with an ignorant media, selective attention, and a poorly educated public with respect to nuclear issues, the war on nuclear energy has been highly successful, something I regard as a reason behind the collapse of the planetary atmosphere. To my mind, as often stated, nuclear energy is the only workable tool we have to ameliorate - as much as is possible at this late date - the aforementioned collapse. I regard it as impossible to accumulate enough ³⁶Cl to represent a real risk under any circumstances. This also said, one only has to look at the carrying on about Fukushima tritium to recognize how these silly objections result in paroxysms of stupidity. The number of people harmed, the number of fish, harmed by Fukushima tritium is effectively zero.

This INL molten chloride reactor will, in any case, be the third molten salt reactor to operate to my knowledge, the first being the original MSRE at Oak Ridge which operated with a FLIBE salt, a version of the same reactor built and now operating in China without much difference apparently from the Oak Ridge original.

These reactors, if the materials science holds up, offer the prospect of doing a hell of a lot more than simply and merely generating electricity, to which the article alludes.

Have a nice day.

[yourout]

1. Interesting.... Will they use thorium?

Are they breeding U233?
Will they use a brayton cycle gas turbine?

[NNadir]

2. I confess I do not have a detailed understanding of this particular reactor. There are so many interesting ideas...

...floating around that we are seeing what Weinberg described, referring to the 1950's and 1960's as "the first nuclear era."

Happily we are seeing a third nuclear era; it couldn't come at a better time other than say 20 years ago. (The 2nd nuclear era was the commercial era of light water reactors, with a few wonderful heavy water reactors thrown into the mix. Fast reactors in that era were not spectacular successes with the exception of the Russian reactor.)

Let me speculate on the case described in the OP:

This is deemed an "experiment." It is unlikely therefore that it will be equipped with devices for exergy recovery, Brayton or otherwise. The only experimental reactor ever hooked up to exergy recovery to my knowledge was when Enrico Fermi lit up a light bulb using power from one of his early reactors. (It was a kind of pointed joke, I think.)

I'm a big fan of Brayton cycles as a first step in process intensification to achieve high thermodynamic efficiency, but that is not, I think, the goal of this effort. The goal will be to understand issues in fuel performance - and as my son and I often discuss, what falls by the wayside too often - materials science.

I note that a Brayton cycle is generally limited to merely generating electricity. If we are to eliminate all fossil fuels, particularly petroleum, we need a broader mission for the heat.

We are entering a golden age of materials science and hopefully this will play a role in the experiment. It should; it must.

The original Weinberg MSR relied on nickel based alloys, either Inconel or Hastelloy; it slips my mind which is the case. Through my son I learned about a big neutronic issue with these alloys that may have been missed because the reactor did not operate that long.

There was no mention of thorium in the news item cited in the OP. I personally believe thorium is a key to eliminating the need for enrichment, but I'm not, or no longer am, a LTMSR kind of guy. For various reasons I don't like FLIBE although I'm very fond of other fluoride salts. (I also don't like beryllium.)

I believe that the ideal use for thorium is in ceramic or metal fuels in the presence of depleted or, better, once through, uranium obtained from used nuclear fuels. I'm not sanguine about pure ²³³U. Because of the geochemistry I believe that uranium is inexhaustible, even if there is more thorium in terrestrial ores. A lot of the "thorium is better than uranium" claims don't hold up to inspection to my mind.

To be perfectly honest, these days I'm rather fond recently of liquid metals - not necessarily sodium - which is a change for me that came only in recent years.

But look, this is a time for nuclear creativity. We know a hell of a lot more than we did in the 1960s, but we can build upon what they did then by applying this new information. We also have much advanced computational power. A computer you can buy at Best Buy or Walmart or wherever, is way more powerful than the best computers of those times. In a way, this is a measure of how brilliant the people of that era were, on the other hand, they were less constrained by radiophobia. I recently read an account of the first fast reactor ever built, the mercury cooled "Clementine" reactor. The author of the article remarked it would cost billions of dollars to build today, not because it would be difficult to build, but because of all the bureaucracy involved. They built and operated the reactor in the late 1940's. It took a few months to build, and they operated it for a few years, before dismantling it when it started to look tired.

Interestingly many of the reactor pioneers, certainly not all, lived relatively long lives. Weinberg himself, despite standing next to the isolated ²³³U in the famous picture, lived to 91. (Fermi died young; but he was something of a cowboy; the world's most brilliant cowboy, but a cowboy all the same. The control rods on the Chicago Pile were held by ropes by people standing on the core. In Italy he was playing with neutrons well before anyone else was other than, say, Chadwick. Chadwick lived into his 80s.)

[yourout]

3. I only have a superficial knowledge but a fair amount of experience in..

Other manufacturing and processes.
My limited knowledge was very interested in what I read about the old MSRE. The possibility of being able to burn up some of our spent fuel is a huge bonus.

I'm adamant that the primary coolant not be pressurized water for safety reasons.

The Chinese are rapidly pulling away from us in implementing next Gen Nukes

[NNadir]

4. The Pressurized Water Reactor is the most successful and safest energy device ever placed in commercial use...

...on a large scale.

The best existing device for burning used fuel is the CANDU, particularly alloyed with thorium, since it can function as a breeder, albeit with a much longer doubling time than a fast reactor.

This said, all of the reactor designs I discuss with my son are designed to burn used fuel, in particular, reactor grade plutonium (or, for that matter, weapons grade with the goal of denaturing it.)

Once through uranium has properties that make it superior to natural uranium, in particular an isotopic vector including ²³⁶U, not found in natural uranium.

The biggest drawback to the PWR is that it is only useful for generating electricity. (In rare cases, waste heat has been used for district heating.) Other reactors can expand the function well beyond that.