molten salt reactor experiment

Molten Salt Reactor Experiment (MSRE) Description

Contact: Mauricio Tano, mauricio.tanoretamales.at.inl.gov

Model summarized and documented by Andres Fierro, Dr. Samuel Walker, and Dr. Mauricio Tano

The MSRE was a graphite moderated flowing salt type reactor with a design maximum operating power of 10 MW(th) developed by Oak Ridge National Laboratory ( Robertson, 1965 ). The reactor ran for more than 13,000 hours at full power before its final shutdown in 1969. The general layout of the experiment is shown in Figure 1 .

Figure 1: Schematic design of MSRE loops ( Fratoni et al., 2020 ).

The fuel salt was a fluoride-based ionic liquid containing lithium, beryllium, zirconium and uranium fuel. The coolant salt was a mixture of lithium fluoride and beryllium fluoride. The reactor consisted of two flow loops: a primary loop and a secondary loop. The primary loop connected the reactor vessel to a fuel salt centrifugal pump and the shell side of the shell-and-tube salt-salt heat exchanger. The secondary loop connected the tube-side of the shell-and-tube heat exchanger to a coolant salt centrifugal pump and the tube side of an air-cooled radiator. Two axial blowers supplied cooling air to the radiator. Piping, drain tanks, and “freeze valves” made up the remaining components of the heat transport circuits. The heat generated in the core was transferred to the secondary loop through the heat exchanger and ultimately rejected to the atmosphere through the radiator.

The three main features of this experiment are:

The core circulation system, where the molten salt fuel flows through rounded-rectangular channels in the vertical graphite moderator stringers

The centrifugal pump that provided continuous circulation, facilitated heat transfer and the removal of fission products

The two-loop heat exchanger system with an approximately 25-second fuel loop circulation time in the reactor.

We note that the MSRE was a thermal reactor with a highly negative reactivity temperature coefficient. The vertical graphite stringers are shown in Figure 2 .

Table 1: MSRE Reactor Specifications

Figure 2: Picture of MSRE core graphite stringers in core assembly ( Briggs, 1964 ).

• Material Properties and MSRE Setup

The fuel salt in the MSRE primary loop was LiF-BeF4-ZrF4-UF4 according to the design specifications of the MSRE ( Beall et al., 1964 ; Cantor, 1968 ), of which the thermophysical properties are listed in Table 2 .

Table 2: Thermophysical properties of the fuel salt

Table 3: Thermophysical properties of the coolant salt in heat exchanger.

Table 4: Thermophysical properties of Hastelloy® N alloy used in the heat exchanger.

• S E Beall, P N Haubenreich, R B Lindauer, and J R Tallackson. MSRE Design and Operations Report. Part V. Reactor Safety Analysis Report . Technical Report ORNL-TM-732, Oak Ridge National Laboratory, Oak Ridge, TN, 1964. [BibTeX] @techreport{Beall1964, author = "Beall, S E and Haubenreich, P N and Lindauer, R B and Tallackson, J R", address = "Oak Ridge, TN", number = "ORNL-TM-732", institution = "Oak Ridge National Laboratory", title = "{MSRE Design and Operations Report. Part V. Reactor Safety Analysis Report}", year = "1964" }
• R. Briggs. Molten-salt reactor program semiannual progress report. Technical Report ORNL-3626, Oak Ridge National Laboratory, 1964. [BibTeX] @techreport{ORNL_3626, author = "Briggs, R.", title = "Molten-salt reactor program semiannual progress report", institution = "Oak Ridge National Laboratory", number = "ORNL-3626", year = "1964" }
• S Cantor. Physical Properties of Molten-Salt Reactor Fuel, Coolant, and Flush Salts . Technical Report ORNL-TM-2316, Oak Ridge National Laboratory, Oak Ridge, TN, 1968. URL: https://www.osti.gov/biblio/4492893 https://www.osti.gov/servlets/purl/4492893 , doi:10.2172/4492893 . [BibTeX] @techreport{Cantor1968, author = "Cantor, S", address = "Oak Ridge, TN", doi = "10.2172/4492893", institution = "Oak Ridge National Laboratory", number = "ORNL-TM-2316", title = "{Physical Properties of Molten-Salt Reactor Fuel, Coolant, and Flush Salts}", url = "https://www.osti.gov/biblio/4492893 https://www.osti.gov/servlets/purl/4492893", year = "1968" }
• Massimiliano Fratoni, Dan Shen, Germina Ilas, and Jeff Powers. Molten salt reactor experiment benchmark evaluation. Technical Report Project 16-10240, University of California Berkeley, 2020. [BibTeX] @techreport{osti_1617123, author = "Fratoni, Massimiliano and Shen, Dan and Ilas, Germina and Powers, Jeff", title = "Molten Salt Reactor Experiment Benchmark Evaluation", institution = "University of California Berkeley", number = "Project 16-10240", year = "2020" }
• R H Guymon. MSRE systems and components performance . Technical Report ORNL-TM-3039, Oak Ridge National Laboratory, Oak Ridge, TN, 1973. [BibTeX] @techreport{Guymon1973, author = "Guymon, R H", address = "Oak Ridge, TN", number = "ORNL-TM-3039", institution = "Oak Ridge National Laboratory", title = "{MSRE systems and components performance}", year = "1973" }
• R C Robertson. MSRE design and operations report. Part I. Description of reactor design . Technical Report ORNL-TM-728, Oak Ridge National Laboratory, Oak Ridge, TN, 1965. [BibTeX] @techreport{Robertson1965, author = "Robertson, R C", address = "Oak Ridge, TN", number = "ORNL-TM-728", institution = "Oak Ridge National Laboratory", title = "{MSRE design and operations report. Part I. Description of reactor design}", year = "1965" }

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Initially developed in the 1950s, molten salt reactors have benefits in higher efficiencies and lower waste generation. Some designs do not require solid fuel, which eliminates the need for manufacturing and disposing of it. In recent years, growing interest in this technology has led to renewed development activities.

Molten salt reactors (MSRs) are seen in some countries as a promising advanced reactor technology because of the various benefits associated with them. They operate at higher temperatures, which lead to increased efficiencies in generating electricity. In addition, low operating pressures can reduce the risk of a large break and loss of coolant as a result of an accident, thereby enhancing the safety of the reactor.

MSRs also generate less high-level waste, and their design does not require solid fuel, eliminating the need for building and disposing of it. These reactors can adapt to a variety of nuclear fuel cycles (such as Uranium-Plutonium and Thorium-Uranium cycles), which allow for the extension of fuel resources. They can also be designed as nuclear waste “burners” or breeders. The high-temperature heat generated by MSRs can then be used for electricity generation and for other high-temperature process heat applications.

Development of MSR technology is on the increase in many countries.  They work on a variety of reactor concepts, which can trace their origins to the Molten Salt Reactor Experiment embarked on by the Oak Ridge National Laboratories in the 1960s. Current research and development efforts are focused on resolving materials-related issues, assessing safety features, developing core design methods and evaluating economic models.

The IAEA fosters an international exchange of information on the advances in reactor technology, including for MSRs. It provides a forum for international collaboration on R&D activities and supports Member States by providing objective and reliable information and understanding of various reactor technologies and their non-electric applications.

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Status of Molten Salt Reactor Technology

Treatment of Residual Sodium and Sodium Potassium from Fast Reactors

Challenges related to the use of liquid metal and molten salt coolants in advanced reactors.

Molten Salt Reactor Technology Development Continues as Countries Work Towards Net Zero

New CRP: R&D to Advance Decommissioning of Sodium Cooled Fast Reactors (T24009)

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Promising designs for nuclear power reactors using molten salt

Selecting the right metal can alleviate the corrosion problem..

Promising new designs for both fission and fusion nuclear power reactors rely on molten salt to play key roles, such as transferring heat out to produce electricity and to keep important metal components cool. But a major concern is corrosion: Will the radiation inside a nuclear reactor speed up the rate at which the salt corrodes and weakens those metal components? MIT researchers have demonstrated that some metal alloys will corrode not more but less when they’re exposed to radiation under some conditions. The team devised and built an experimental setup that emulates conditions inside a molten salt–based nuclear reactor. Tests with various alloys show that certain combinations of elements become more resistant to corrosion when they are also subjected to radiation. The researchers provide simple guidelines for designers and operators to follow when selecting commercial alloys for their molten salt–based nuclear reactors.

Most discussions of how to avert climate change focus on solar and wind generation as key to the transition to a future carbon-free power system. But Michael Short , the Class of ’42 Associate Professor of Nuclear Science and Engineering and associate director of the Plasma Science and Fusion Center (PSFC), is impatient with such talk. “We can say we should have only wind and solar someday. But we don’t have the luxury of ‘someday’ anymore, so we can’t ignore other helpful ways to combat climate change,” he says. “To me, it’s an ‘all-hands-on-deck’ thing. Solar and wind are clearly a big part of the solution. But I think that nuclear power also has a critical role to play.”

For decades, researchers have been working on designs for both fission and fusion nuclear reactors using molten salts as fuels or coolants. While those designs promise significant safety and performance advantages, there’s a catch: Molten salt and the impurities within them often corrode metals, ultimately causing them to crack, weaken, and fail. Inside a reactor, key metal components will be exposed not only to molten salt but also simultaneously to radiation, which generally has a detrimental effect on materials, making them more brittle and prone to failure. Will irradiation make metal components inside a molten salt–cooled nuclear reactor corrode even more quickly?

Short and Dr. Weiyue Zhou PhD ’21, a postdoc in the PSFC, have been investigating that question for eight years. Their experimental findings show that certain alloys will corrode more slowly when they’re irradiated—and identifying them among all the available commercial alloys can be straightforward.

The first challenge—building a test facility

When Short and Zhou began investigating the effect of radiation on corrosion, practically no reliable facilities existed to look at the two effects at once. The standard approach was to examine such mechanisms in sequence: first corrode, then irradiate, then examine the impact on the material. That approach greatly simplifies the task for the researchers but with a major trade-off. “In a reactor, everything is going to be happening at the same time,” says Short. “If you separate the two processes, you’re not simulating a reactor; you’re doing some other experiment that’s not as relevant.”

So, Short and Zhou took on the challenge of designing and building an experimental setup that could do both at once. Short credits a team at the University of Michigan for paving the way by designing a device that could accomplish that feat in water rather than molten salts. Even so, Zhou notes, it took them three years to come up with a device that would work with molten salts. Both researchers recall failure after failure, but the persistent Zhou ultimately tried a totally new design, and it worked. Short adds that it also took them three years to precisely replicate the salt mixture used by industry—another factor critical to getting a meaningful result. The hardest part was achieving and ensuring that the purity was correct by removing critical impurities such as moisture, oxygen, and certain other metals.

As they were developing and testing their setup, Short and Zhou obtained initial results showing that proton irradiation did not always accelerate corrosion but sometimes actually decelerated it. They and others had hypothesized that possibility, but even so, they were surprised. “We thought we must be doing something wrong,” recalls Short. “Maybe we mixed up the samples or something.” But they subsequently made similar observations for a variety of conditions, increasing their confidence that their initial observations were not outliers.

The successful setup  

Central to their approach is the use of accelerated protons to mimic the impact of the neutrons inside a nuclear reactor. Generating neutrons would be both impractical and prohibitively expensive, and the neutrons would make everything highly radioactive, posing health risks and requiring very long times for an irradiated sample to cool down enough to be examined. Using protons would enable Short and Zhou to examine radiation-altered corrosion both rapidly and safely.

The researchers’ experimental setup. This diagram shows the key features of the setup that the researchers designed and built to explore the effect of radiation on corrosion inside a molten salt nuclear reactor. The test chamber appears in yellow. A thin sample of the alloy being tested (at the center, red) is suspended between a bath of molten salt (green) and a beam of protons coming from the other side (dashed lines). With this setup, a single foil sample can be exposed to molten salt over its entire surface and—at the same time—to radiation limited to a circle at its center. Experiments show that the impact of radiation on corrosion damage varies widely from alloy to alloy.

The final design for their experimental setup is illustrated in the diagram above. The test chamber is shown in yellow. The bath of molten salt is shown in green. The thin sheet of the metal alloy being tested is at the center (in red), and the beam of protons enters from the left (dashed lines). With this setup, a thin foil sample of the alloy being tested is exposed to molten salt on one side and bombarded with proton radiation on the other side, but the proton beam is restricted to a circle in the middle of the foil sample. “No one can argue with our results then,” says Short. “In a single experiment, the whole sample is subjected to corrosion, and only a circle in the center of the sample is simultaneously irradiated by protons. We can see the curvature of the proton beam outline in our results, so we know which region is which.”

The results with that arrangement were unchanged from the initial results. They confirmed the researchers’ preliminary findings, supporting their controversial hypothesis that rather than accelerating corrosion, radiation would actually decelerate corrosion in some materials under some conditions. Fortunately, they just happen to be the same conditions that will be experienced by metals in molten salt–cooled reactors.

Why is that outcome controversial? A closeup look at the corrosion process will explain. When salt corrodes metal, the salt finds atomic-level openings in the solid, seeps in, and dissolves salt-soluble atoms, pulling them out and leaving a gap in the material—a spot where the material is now weak. “Radiation adds energy to atoms, causing them to be ballistically knocked out of their positions and move very fast,” explains Short. So, it makes sense that irradiating a material would cause atoms to move into the salt more quickly, increasing the rate of corrosion. Yet in some of their tests, the researchers found the opposite to be true.

Experiments with “model” alloys

The researchers’ first experiments in their novel setup involved “model” alloys consisting of nickel and chromium, a simple combination that would give them a first look at the corrosion process in action. In addition, they added europium fluoride to the salt, a compound known to speed up corrosion. In our world, we often think of corrosion as taking years or decades, but in the more extreme conditions of a molten salt reactor it can noticeably occur in just hours. The researchers used the europium fluoride to speed up corrosion even more without changing the corrosion process. This allowed for more rapid determination of which materials, under which conditions, experienced more or less corrosion with simultaneous proton irradiation.

The use of protons to emulate neutron damage to materials meant that the experimental setup had to be carefully designed and the operating conditions carefully selected and controlled. Protons are hydrogen atoms with an electrical charge; and under some conditions, the hydrogen could chemically react with atoms in the sample foil, altering the corrosion response, or with ions in the salt, making the salt more corrosive. Therefore, the proton beam had to penetrate the foil sample but then stop in the salt as soon as possible. Under these conditions, the researchers found they could deliver a relatively uniform dose of radiation inside the foil layer while also minimizing chemical reactions in both the foil and the salt.

Tests showed that a proton beam accelerated to 3 million electron-volts combined with a foil sample between 25 and 30 microns thick would work well for their nickel-chromium alloys. The temperature and duration of the exposure could be adjusted based on the corrosion susceptibility of the specific materials being tested.

Experimental results with model compounds. This figure shows results from tests on a simple alloy consisting of just nickel and chromium. The blue image shows the side of the foil sample facing the proton beam. The whole sample was exposed to molten salt, while only the circle at the center was also subjected to the beam of protons. The boundary between the two areas is clear. The electron microscope image to the right focuses on the region inside the red rectangle. The area at the right in the image shows dark patches where the salt penetrated all the way through the foil, while the area on the left shows almost no such dark patches. The curvature marking the boundary between the damaged and less-damaged regions in the two images is the same, confirming that damage is less extreme where the sample was both corroded and irradiated.

The top figure above shows sample results. The blue image shows the side of the foil sample facing the proton beam. During the experiment, the entire sample was exposed to molten salt on the opposite side, and the circular region at the center was simultaneously bombarded with protons from this side. The difference in appearance is striking in this optical image. The electron microscope image at the right focuses on the region inside the red rectangle. The area at the right in the image shows dark patches where the salt penetrated all the way through the foil, while the area on the left shows almost no such dark patches. The curvature marking the outside of the radiation beam in the blue image matches the curvature between the damaged and less-damaged regions in the electron microscope image, validating the researchers’ experimental approach.

To confirm that the dark patches were due to corrosion, the researchers cut through the foil sample to create cross sections. In them, they could see tunnels that the salt had dug into the sample. “For regions not under radiation, we see that the salt tunnels link the one side of the sample to the other side,” says Zhou. “For regions under radiation, we see that the salt tunnels stop more or less halfway and rarely reach the other side. So we verified that they didn’t penetrate the whole way.”

The results “exceeded our wildest expectations,” says Short. “In every test we ran, the application of radiation slowed corrosion by a factor of 2 to 3 times.”

More experiments, more insights  

Subsequent tests with the model alloys provided further insights. To more closely replicate commercially available molten salt, the researchers omitted the additive (europium fluoride) that they had used to speed up corrosion, and they tweaked the temperature for even more realistic conditions. “In carefully monitored tests, we found that by raising the temperature by 100 degrees Celsius, we could get corrosion to happen about 1,000 times faster than it would in a reactor,” says Short.

Images showing damage on the salt-facing side of a foil sample. These electron microscope images show the side of the foil of the nickel-chromium alloy sample facing the molten salt. The one on the left shows a section that was only exposed to the molten salt. The corrosion is clearly focused on the weakest part of the structure—the boundaries between the grains in the metal. The image on the right shows a section that was exposed to both the molten salt and the proton beam. Here the corrosion isn’t limited to the grain boundaries but is more spread out over the surface. Experimental results show that these cracks are shallower and less likely to cause a key component to break.

Sample results with the molten salt (without the corrosive additive) plus the nickel-chromium alloy appear in the figure above. These images show the salt-facing side of the sample, so the directly corroded side. The image on the left is from the corrosion-only region, while the one on the right is from the region that was also irradiated. The corrosion damage seen in the two regions is distinctly different.

Short explains the observations. Metals are made up of individual grains inside which atoms are lined up in an orderly fashion. Where the grains come together there are areas—called grain boundaries—where the atoms don’t line up as well. In the corrosion-only image on the left, dark lines track the grain boundaries. Molten salt has seeped into the grain boundaries and pulled out salt-soluble atoms. In the corrosion-plus-irradiation image on the right, the damage is more general. It’s not only the grain boundaries that get attacked but also regions within the grains.

So, when the material is irradiated, the molten salt also removes material from within the grains. Over time, more material comes out of the grains themselves than from the spaces between them. The removal isn’t focused on the grain boundaries; it’s spread out over the whole surface. As a result, any cracks that form are shallower and more spread out, and the material is less likely to fail.

Testing commercial alloys

The experiments described thus far involved model alloys—simple combinations of elements that are good for studying science but would never be used in a reactor. In the next series of experiments, the researchers focused on three commercially available alloys that are composed of nickel, chromium, iron, molybdenum, and other elements in various combinations.

Results from the experiments with the commercial alloys showed a consistent pattern—one that confirmed an idea that the researchers had going in: The higher the concentration of salt-soluble elements in the alloy, the worse the radiation-induced corrosion damage. Radiation will increase the rate at which salt-soluble atoms such as chromium leave the grain boundaries, hastening the corrosion process. However, if there are more not-soluble elements such as nickel present, those atoms will go into the salt more slowly. Over time, they’ll accumulate at the grain boundary and form a protective coating that blocks the grain boundary—a “self-healing mechanism that decelerates the rate of corrosion,” say the researchers.

Thus, if an alloy consists mostly of atoms that don’t dissolve in molten salt, irradiation will cause them to form a protective coating that slows the corrosion process. But if an alloy consists mostly of atoms that dissolve in molten salt, irradiation will make them dissolve faster, speeding up corrosion. As Short summarizes, “In terms of corrosion, irradiation makes a good alloy better and a bad alloy worse.”

Steps involved in setting up the test chamber for an experiment with the proton accelerator. A. Working inside a glove box, postdoc Weiyue Zhou first drops in a pellet of salt—the key to emulating the corrosive environment inside a molten salt–based nuclear reactor. B, C. Next, he places a sample of the metal being tested on the top of the test chamber, where it will be exposed to the salt pellet beneath it. The metal sample is a foil disc about 21 millimeters in diameter and just 25 to 30 microns thick. D. Here, Zhou prepares to put the top on the test chamber. E. And here he screws on the top, sealing it shut. The test chamber is now ready to be mounted on the proton accelerator. With this setup, the researchers expose the whole foil sample to the corrosive salt, and—by shielding part of it from the incoming protons—they also subject a limited but well-defined section of it to the proton beam at the same time. Credit: Gretchen Ertl

Real-world relevance plus practical guidelines

Short and Zhou find their results encouraging. In a nuclear reactor made of “good” alloys, the slowdown in corrosion will probably be even more pronounced than what they observed in their proton-based experiments because the neutrons that inflict the damage won’t chemically react with the salt to make it more corrosive. As a result, reactor designers could push the envelope more in their operating conditions, allowing them to get more power out of the same nuclear plant without compromising on safety.

However, the researchers stress that there’s much work to be done. Many more projects are needed to explore and understand the exact corrosion mechanism in specific alloys under different irradiation conditions. In addition, their findings need to be replicated by groups at other institutions using their own facilities. “What needs to happen now is for other labs to build their own facilities and start verifying whether they get the same results as we did,” says Short. To that end, Short and Zhou have made the details of their experimental setup and all of their data freely available online. “We’ve also been actively communicating with researchers at other institutions who have contacted us,” adds Zhou. “When they’re planning to visit, we offer to show them demonstration experiments while they’re here.”

But already their findings provide practical guidance for other researchers and equipment designers. For example, the standard way to quantify corrosion damage is by “mass loss,” a measure of how much weight the material has lost. But Short and Zhou consider mass loss a flawed measure of corrosion in molten salts. “If you’re a nuclear plant operator, you usually care whether your structural components are going to break,” says Short.  “Our experiments show that radiation can change how deep the cracks are, when all other things are held constant. The deeper the cracks, the more likely a structural component is to break, leading to a reactor failure.”

In addition, the researchers offer a simple rule for identifying good metal alloys for structural components in molten salt reactors. Manufacturers provide extensive lists of available alloys with different compositions, microstructures, and additives. Faced with a list of options for critical structures, the designer of a new nuclear fission or fusion reactor can simply examine the composition of each alloy being offered. The one with the highest content of corrosion-resistant elements such as nickel will be the best choice. Inside a nuclear reactor, that alloy should respond to a bombardment of radiation not by corroding more rapidly but by forming a protective layer that helps block the corrosion process. “That may seem like a trivial result, but the exact threshold where radiation decelerates corrosion depends on the salt chemistry, the density of neutrons in the reactor, their energies, and a few other factors,” says Short. “Therefore, the complete guidelines are a bit more complicated. But they’re presented in a straightforward way that users can understand and utilize to make a good choice for the molten salt–based reactor they’re designing.”

This research was funded by Eni S.p.A. through the MIT Plasma Science and Fusion Center’s Laboratory for Innovative Fusion Technologies. Earlier work was funded by the Transatomic Power Corporation and by the U.S. Department of Energy Nuclear Energy University Program. Equipment development and testing was supported by the Transatomic Power Corporation. For other funding sources and additional information about the research, please see the following:

AlMousa, W. Zhou, K.B. Woller, and M.P. Short. “Effects of simultaneous proton irradiation on the corrosion of commercial alloys in molten fluoride salt.” Corrosion Science , June 2023. Online: doi.org/10.1016/j.corsci.2023.111154 .

Zhou, K.B. Woller, G. (T.) Zheng, P.W. Stahle, and M.P. Short. “A simultaneous corrosion/irradiation facility for testing molten salt-facing materials.” Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms , December 4, 2018. Online: doi.org/10.1016/j.nimb.2018.11.024 .

Zhou, Y. Yang, G. Zheng, K.B. Woller, P.W. Stahle, A.M. Minor, and M.P. Short. “Proton irradiation-decelerated intergranular corrosion of Ni-Cr alloys in molten salt.” Nature Communications , July 2020. Online: doi.org/10.1038/s41467-020-17244-y .

This article appears in the Winter 2024 issue of Energy Futures .

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The evolution of molten salt reactors

Although there are many new designs for molten salt reactors today, the history of the development of molten salt-based reactor systems dates back to the 1950s.

The nuclear industry was the first to recognise the potential of molten-salt-based energy-generation systems in the 1950s during the U.S. Aircraft Nuclear Propulsion Program.

This program, which was later abandoned, led to the Molten Salt Reactor Experiment at Oak Ridge National Laboratory, which demonstrated the viability of energy-generating using molten salt reactor (MSR) technology.

Advantages of new molten salt-based reactor systems

The main advantages of MSRs stem from the thermo-physical properties of molten salts: high boiling point, low viscosity, low vapour pressure, high thermal conductivity, and high volumetric heat capacity.

The high boiling point and low vapour pressure are of interest because of the operational safety of a molten-salt-based system at atmospheric pressure, and favourable heat transfer characteristics that enable efficient and economic energy transfer and storage.

The ISMR R molten salt reactor system under development

These systems are inherently safe because any breach of the reactor containment vessel leads to the solidification of the salt, which would prevent an uncontrolled release of radioactive material.

MSRs offer unmatched design flexibility, as they can vary in size and power output, utilise a variety of fuels including plutonium-239, uranium-235, and uranium-233 bred from thorium, and they operate with both thermal and fast neutron spectrums.

While thermal MSRs maximise the utilisation of fuel, fast MSRs minimise nuclear waste –bringing  significant advantages for proliferation-resistance and waste minimisation.

And, owing to their inherent load-following capabilities, the proposed MSR systems provide unmatched operational flexibility given they can operate in remote areas as well as in existing complex electricity networks.

MSRs can complement the intermittency of renewable energy generation, in turn, promoting a low-emissions hybrid renewable-nuclear energy network.

Today MSRs hold the promise of being one of the most efficient energy-generation systems, even when compared to the current Light Water Reactor (LWR) systems, which are part of Generation III+ reactors.

This is demonstrated by the Energy Return on Investment (EROI) coefficient, which is simply a ratio of the energy output (E out ) and energy input (E in ).

At the level of Government, the current research and development of MSR systems is overseen by the Generation IV International Forum (GIF). Australia joined this international effort in 2017 by signing the GIF Framework Agreement. ANSTO is the implementing agency for Australia. 

Government agencies were joined by a number of start-up companies, including Terra Power, Terrestrial Energy and Moltex, among others. Some of these companies pursue the development and near-future deployment of commercially-available MSR systems independently.

With a rapidly evolving space industry, there is a renewed interest in MSR systems for nuclear electric propulsion , as well as extra-terrestrial surface power .

The nuclear industry and other relevant government organisations are pursuing molten-salt-based energy-generation systems  focused predominantly on electricity and industrial heat production and, potentially, propulsion.

The renewable energy-generation industry has built on a decades-long effort by developing molten-salt-based Thermal Energy Storage systems  to combat the intermittency of renewable energy generation.

Challenges today 

The widespread deployment of molten-salt-based energy-generation and energy-storage systems has been hindered predominantly by the development and standardisation of suitable structural materials.

These materials are required to withstand a combination of challenging environmental conditions, including highly corrosive molten salts, high operating temperatures, and damage from high energy particles created by the ongoing fission process.

In addition, a number of challenges exist with respect to the supply chain, remote operation, tritium production, and the complex chemical processes required for fission product separation.

These challenges are technical rather than conceptual in nature.

They are presently being addressed at ANSTO and elsewhere with the application of various novel numerical analysis techniques backed by experimental validation, as well as the development of intricate robotics, specifically relating to remote operation and advanced manufacturing.

Advanced reactors

Advanced nuclear reactors, such as molten salt-based reactors and very high-temperature reactors provide a viable option within a future mix of energy systems.

ANSTO's contribution to the advancement of molten salt based reactor systems

ANSTO, as the Australian centre for nuclear-related research and as the custodian of large research infrastructure is well-positioned to undertake research on molten sale based reactor systems using its capabilities and expertise.

Generation IV Nuclear Reactors

Australia is as a member of the Generation IV International Forum (GIF), a cooperative international endeavour, involving the participation of 12 other nations and the European Union to work together on long term research on advanced nuclear technologies.

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Copenhagen Atomics enlists PSI to validate reactor technology

01 July 2024

Denmark's Copenhagen Atomics has signed a large-scale experimental collaboration agreement with Switzerland's Paul Scherrer Institute (PSI) to conduct the first critical experiment on thorium molten salt reactors in Europe.

Molten salt reactors (MSRs) use molten fluoride salts as primary coolant, at low pressure. They may operate with epithermal or fast neutron spectrums, and with a variety of fuels. Much of the interest today in reviving the MSR concept relates to using thorium (to breed fissile uranium-233), where an initial source of fissile material such as plutonium-239 needs to be provided. There are a number of different MSR design concepts, and a number of interesting challenges in the commercialisation of many, especially with thorium.

Copenhagen Atomics is developing a containerised molten salt reactor. Moderated with unpressurised heavy water, the reactor consumes nuclear waste while breeding new fuel from thorium. Small enough to allow for mass manufacturing and assembly line production, the reactor has an output of 100 MWt.

Through its collaboration with PSI, a critical experiment will be carried out using Copenhagen's thorium-fed 'Onion Core' reactor design at PSI's facilities. The experiment is scheduled for 2026-27.

The purpose of this experiment is to validate the technology and provide valuable experience for the collaboration partners in the design, construction, licensing, operation and decommissioning of the new molten salt reactor technology, as well as to collect data for commercial deployment, and with open source data for validation of reactor modelling tools.

The collaboration agreement runs initially for four years.

"We're very excited to work on advancing molten salt reactor technology together with PSI, who come with world-class expertise, experience, and facilities to conduct large-scale nuclear experimental work," said Aslak Stubsgaard, CTO of Copenhagen Atomics.

Marco Streit, Head of PSI Hot Laboratory, added: "Personally, I am very glad that Copenhagen Atomics has decided to work with PSI as a collaboration partner to prove the feasibility of their vision here at our institute."

Copenhagen Atomics said it is already producing and testing full-scale test reactor prototypes at its headquarters in Copenhagen along with dozens of smaller-scale loop tests and salt production. The company's molten salt reactors use lithium, thorium and low-enriched uranium fluoride salt as the reactor fuel and can be factory manufactured in modules the size of a 40ft shipping container, with the long-term goal of making commercial thorium molten salt breeder reactors, with a levelised cost of electricity price of USD20 per MWh.

In May last year, a collaboration between Danish and Indonesian companies announced thet were to study the operational and regulatory conditions for constructing an ammonia production facility in Indonesia powered by Copenhagen Atomics' small and modular thorium molten salt reactors. The nuclear power plant part of the project will comprise of 25 SMR modules providing a total of 1 GW.

A few months earlier, UK Atomics - a subsidiary of Copenhagen Atomics - submitted a Generic Design Assessment (GDA) entry application for its containerised molten salt reactor to the UK Department for Business, Energy and Industrial Strategy. GDA is a process carried out by the Office for Nuclear Regulation and the Environment Agency to assess the safety, security, and environmental protection aspects of a nuclear power plant design that is intended to be deployed in Great Britain.

According to Copenhagen Atomics, the reactors will be deployed by UK Atomics, who will build, own and operate a fleet of autonomous reactors, "eventually numbering in thousands". This business model, selling energy-as-a-service, will enable a cost-effective and low-risk deployment, it said.

The first commercial reactor is scheduled to begin operating in 2028.

Researched and written by World Nuclear News

Related topics

Partnership to advance nuscale smr design, doe agrees partnerships for smr deployment, small is beautiful for federal funds, terrapower breaks ground for natrium plant, construction of finnish pilot smr plant to start in 2025, verdict on edf and khnp bids being considered by czech government , iter's proposed new timeline - initial phase of operations in 2035, usa announces new cooperation to support ghana smr plans, uk smr contest deadline pushed back two weeks.

WNN is a public information service of World Nuclear Association

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Advanced reactors / copenhagen atomics signs collaboration agreement with switzerland’s psi.

By David Dalton 1 July 2024

Danish company plans experiments to validate TMSR nuclear technology

Danish thorium molten salt reactor (TMSR) developer Copenhagen Atomics has signed an experimental collaboration agreement with Switzerland’s Paul Scherrer Institute (PSI), to validate the TMSR technology.

The partnership between Copenhagen Atomics and PSI aims to conduct a thorium molten salt critical experiment in 2026, a statement said.

Copenhagen Atomics said the experiment will provide valuable experience for the design, construction, licensing, operation and decommissioning of the new MSR technology and collect data for commercial deployment.

The collaboration agreement runs initially for four years and will position Europe at the forefront of advanced reactors, Copenhagen Atomics said.

It said TMSR technology has huge potential to become one of the world’s most abundant energy sources. To date, the bulk of TMSR experiments have taken place in China, so this represents “a major step forward for the tech in Europe”, Copenhagen Atomics said.

The company said the use of thorium over uranium has several advantages. Thorium, a naturally occurring radioactive metal that is found in soil, rock and water, is much more abundant than uranium and there is enough thorium in the Earth’s crust to “cover the entire lifetime of the human race”.

According to Copenhagen Atomics, thorium offers a lower price per kWh of energy generated and produces less long-lived nuclear waste than uranium.

In 2023 Copenhagen Atomics said it had raised €20m ($21.4m) to accelerate the development of its TMSR technology.

Co-founder Thomas Jam Pedersen said the funding would support plans to have the first commercial reactors online in 2028.

A rendering of a power plant based on Copenhagen Atomics thorium molten salt modular reactors. Courtesy Copenhagen Atomics.

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Naarea and CNRS establish molten salt research laboratory

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France-based nuclear start-up Naarea (Nuclear Abundant Affordable Resourceful Energy for All) is partnering with the French National Centre for Scientific Research (CNRS – Centre national de la recherche scientifique) and Université Paris-Saclay (UPS) to establish a laboratory dedicated to molten salt chemistry.

Naarea, founded in 2020 by Jean-Luc Alexandre and Ivan Gavriloff, is developing the XAMR molten salt fast neutron micro-generator (40MWe or 80MWt). The company has received support from the French Alternative Energies & Atomic Energy Commission (CEA) and CNRS, as well as industry players such as Assystem, Dassault Systèmes, Orano and Framatome.

The new Innovation Molten Salt Lab (IMS Lab) will benefit from 20-years of expertise in molten salt chemistry from the Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (ICJLab), a joint research unit of CNRS and UPS with a team of nearly 730 people. Naareasays it will contribute “technological knowledge in the fields of materials, neutronics, safety analysis and materials and fuel data”.

IMS Lab’s roadmap “will aim to foster collaborative work and capitalise on the concepts and innovations developed at Naarea to the benefit of the European molten salt reactor sector … the goal … is to become the European leader in the field of molten salts research and development, for both molten salt nuclear reactors and other non-nuclear applications such as metallurgy and concentrated solar power”.

The roadmap will aim to foster collaborative work and capitalise on the concepts and innovations developed at Naarea to the benefit of the European molten salt reactor sector, in particular in the context of the strategic partnerships it recently formed. This collaboration also aims to create synergies with other public and private entities with an interest in research on the properties of molten salts.

Naarea CEO Jean-Luc Alexandre said IMS Lab “allows us to pool our skills and demonstrates our ability to step up our efforts to develop our XAMR project”. It also “marks a significant milestone for NAAREA, which is positioned to make a vital contribution to establishing and achieving recognition for true French leadership and expertise in the field of molten salt research at European level.”

Jean-Luc Moullet, Deputy CEO for Innovation at CNRS described IMS Lab as “an ambitious joint laboratory that symbolises the contribution of French research to the revival of the nuclear sector. The CNRS encourages the development of joint laboratories, which offer a flexible and long-term framework conducive to the development of fruitful public-private partnerships.”

Camille Galap, President of Université Paris-Saclay said the university is committed to contributing to finding solutions to scientific and technological challenges. “We are therefore delighted to join this partnership with Naarea and the CNRS to create the joint laboratory, IMS Lab, whose research work will help respond to the critical challenges of decarbonising energy, in particular for industry.”

Naarea and CNRS teams have been working together for a year and common patents are already being filed. They relate in particular to the technology for carrying out the synthesis of salts. Another concerns “the right element to mix with metal in the right proportion to avoid corrosion regardless of the reaction”, said Alexandre.

The laboratory will also be able to conduct experiments for other nuclear start-ups that relying on molten salts such as Stellaria or Thorizon, with which Naarea has a partnership. “The idea is to work for the sector, but also to open research on molten salts to non-nuclear applications, such as metallurgy or concentrated solar,” Alexandre added.

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ACU and Natura expect molten salt research reactor construction permit this fall

Natura Resources, which is supporting the construction of a molten salt research reactor on the campus of Texas’s Abilene Christian University, announced in mid-June that it expects the Nuclear Regulatory Commission to complete its safety assessment and issue a permit for the nonpower test reactor in September.

The reactor, dubbed the Natura MSR-1, will be built with support from Natura, the Department of Energy, and a consortium of universities known as the Natura Resources Research Alliance. The consortium includes ACU, Georgia Institute of Technology, Texas A&M University, and University of Texas–Austin. Operating at up to 1 MWt, the reactor would use HALEU dissolved in FLiBe salt (a mix of lithium fluoride and beryllium fluoride).

“The environmental assessment and upcoming completion of the safety evaluation for a construction permit are significant steps forward in the first deployment of the Natura MSR-1 system,” said Natura Resources founder and president Doug Robison. “This deployment at ACU will not only demonstrate successful licensure of a liquid-fueled molten salt reactor but will provide critical operational data that will help us meet the world's growing energy needs.”

Progress update: Natura’s announcement followed a June 12 letter from the NRC to Rusty Towell, director of the Nuclear Energy Experimental Testing Laboratory (NEXT Lab) at ACU, detailing the agency’s progress on the application review. ACU submitted its application in August 2022 . That December, the NRC estimated that it could issue a construction permit in May 2024. According to the NRC’s June 12 letter, “ACU needed additional time to further consider and refine certain design aspects of its MSRR,” and the NRC issued requests for additional information in December 2023. Based on ACU’s response, the NRC now estimates completion of a final safety evaluation and construction permit issuance in September 2024.

Groundbreaking on the Science & Engineering Research Center (SERC) at ACU, which will house the NEXT Lab and reactor, took place in March 2022, and in August 2023 that construction was completed.

A commercial future: Once the research reactor is operational, Natura anticipates gaining “real-time operational data to support commercial reactor development.” That commercial product would be a “small modular MSR system that will be fabricated on an assembly line and shipped to site via truck or rail.” Natura reports that “the regulatory engagement plan for this system has been submitted to the NRC and we will soon begin raising capital to support the next steps of engineering and design for this system.”

Natura wants to meet future electricity demand in Texas and beyond, and cites recent testimony delivered by ERCOT chief executive officer Pablo Vegas and others in the Texas Senate Committee on Business & Commerce that grid demand in Texas will grow from about 85 gigawatts to 150 gigawatts within six years—a 75 percent increase.

Abilene-based Natura Resources was established by Robison, a third-generation oilman and member of the ACU Board of Trustees, according to ACU, which also reports that “Natura has agreed to funding of $30.5 million over the next three years in support of NEXTRA’s mission.”

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Natura Resources pushes forward with plans for ACU’s Molten Salt Research Reactor

ABILENE, Texas ( KTAB/KRBC ) – In mid-June, Natura Resources announced that it anticipates the Nuclear Regulatory Commission to finish its safety assessment and issue a permit for the non-power test reactor in September.

Natura Resources is backing the construction of a molten salt research reactor at Abilene Christian University. The reactor, named the Natura MSR-1, is expected to be the first Nuclear Regulatory Commission (NRC) approved construction permit for a liquid-fueled molten salt reactor. It will also be the second NRC-approved construction permit for an advanced reactor of any kind.

ACU submits application to be approved for nuclear research reactor

“This deployment at ACU will not only demonstrate successful licensure of a liquid-fueled molten salt reactor but will provide critical operational data that will help us meet the world’s growing energy needs,” said Natura Resources founder and president Doug Robison .

The goals for the Natura MSR-1 are to reduce regulatory uncertainty and collect operational data. While some other developers mine data from the 1950s and 60s to develop their systems, Natura Resources will have real-time data to support commercial reactor development.

Sen Cornyn tours ACU’s NEXT lab, praising ‘groundbreaking’ scientific developments

Natura was founded in Abilene in 2020 in response to the DOE’s charge to design and deploy a liquid-fueled molten salt reactor. Later that year, the Natura Resources Research Alliance, comprised of Abilene Christian University (ACU), the Georgia Institute of Technology, Texas A&M University, and the University of Texas at Austin, was formed.

As for the next steps in bringing the reactor to Abilene, Natura shared that they are “already pushing forward with the development of our small modular MSR system that will be fabricated on an assembly line and shipped to site via truck or rail.  The regulatory engagement plan for this system has been submitted to the NRC and we will soon begin raising capital to support the next steps of engineering and design for this system.”

Copyright 2024 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

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Kairos Power just completed testing on the largest FLiBe molten salt system ever built.   

The company's first Engineering Test Unit (ETU 1.0) is now undergoing decommissioning at its manufacturing facility in Albuquerque, N.M., after more than 2,000 hours of pumped salt operations.   

ETU 1.0 is the first of three systems that are being built to inform the design, construction, and operation of Hermes — a low-power reactor that the company is using to advance the development of its fluoride salt-cooled high-temperature reactor (KP-FHR) technology.

More than a Pinch of Salt

ETU 1.0 started operations last December and used 12 metric tons of FLiBe, a fluoride-lithium-beryllium salt coolant produced at its Molten Salt Purification Plant in Elmore, Ohio.  

The system was filled with 30,000 surrogate fuel pebbles and more than 300 graphite reflector blocks to replicate conditions inside the Hermes reactor core.  

Over the course of six months, Kairos Power put ETU 1.0 through its paces with thousands of hours of regular operation, as well as successful tests designed to simulate failure scenarios — including a primary pipe break and freezing of the salt coolant. 

At its peak, the system reached 675 degrees Celsius and a salt flow rate of 3,000 gallons per minute.  

Control room staff monitored ETU 1.0 around the clock and collected more than 10 terabytes of performance data in addition to analyzing salt samples and inspecting 1,673 surrogate fuel pebbles.  

“With our iterative approach, Kairos Power aims to learn by building, and we’ve learned a tremendous amount from building and operating ETU,” said Edward Blandford, Kairos Power co-founder and Chief Technology Officer . “With this milestone, we now have the team, the knowledge, and the capabilities needed to successfully deploy Hermes and the iterations that will follow.”

One Step at a Time

Kairos Power is following a “rapid iterative development” approach to bring its KP-FHR advanced nuclear reactor to market.   

That means designing, building, and testing multiple prototypes, learning lessons, and improving processes along the way.   

ETU 1.0 — a full-scale, electrically heated prototype of Hermes — was the first step on that path. Kairos Power has already gained invaluable insights and experience from the ETU program, both on the technical and logistical sides.  

Crucially, ETU 1.0 served as a vehicle for Kairos Power to exercise the supply chain and establish new capabilities in-house, including the production of high-purity fluoride salt coolant and specialized reactor components.

What's Next?

The next iteration of the project, ETU 2.0, is already underway in Albuquerque and will focus on demonstrating the modular design of the reactor.   

After that, ETU 3.0 will be built in Oak Ridge, Tenn., adjacent to the eventual site of the Hermes reactor. 

Hermes is supported by the U.S. Department of Energy’s Advanced Reactor Demonstration Program. It will use a TRISO fuel pebble bed design with a molten fluoride salt coolant to achieve a thermal power level of 35 megawatts.    

In December 2023, the Nuclear Regulatory Commission approved the construction permit application for Hermes. Kairos Power plans to have the reactor operational as early as 2026.  

Through repetition and refinement of the design and construction process, Kairos Power aims to reduce development risk and lay the groundwork for commercializing its 140-megawatt-electric KP-FHR high-temperature molten salt reactor.   

The KP-FHR commercial reactor could be operational in the early 2030s.

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MSRE's 50th

The short-lived Molten Salt Reactor Experiment is far from forgotten

October 15, 2015 – The Molten Salt Reactor Experiment (MSRE), which ran a brief four years in the 1960s but earned an enduring legacy as an innovative reactor technology concept, this year marks a half century since its June 1965 startup.

A workshop on molten salt reactor technologies, "From the MSRE to a New Emerging Class of Reactors 50 Years Later," is being held October 15-16 at the Department of Energy's Oak Ridge National Laboratory, which developed the reactor.

Located a valley over from the laboratory's main campus, the MSRE was inspired by the campaign to build a nuclear-powered aircraft in the 1950s. Engineers saw promising results from a design that used molten fluoride salt as a fuel carrier and coolant for an onboard reactor.

By the early 1960s, after the nuclear airplane project's cancellation, molten salt reactor efforts had transitioned to electricity generation.

Molten salt technology enables the development of high-temperature, low-pressure, passively safe reactors. While the alkali halide salts can be corrosive, ORNL's development of molten salt-compatible nickel-based alloys in the 1950s to 1970s largely addressed the corrosion issues.

The potential for molten salt reactors to work as breeder reactors attracted early proponents:  Worries about the supply of uranium at the time appeared to disqualify nuclear as a large-scale energy source. A molten-salt breeder reactor could make fuel as it operated, and the circulating fuel eliminated the need for solid-fuel changeouts and fuel- and control-rod mechanisms.

The concept also had the allure of intrinsic safety.  Molten salts expand as they heat up.  The expansion causes some of the fuel to leave the core, shutting down the reactor, so operator response is not required to turn the reactor off.

Former ORNL Director Alvin Weinberg was a staunch proponent of liquid-fuel breeder reactors, and the MSRE was his crowning glory, successfully operating from January 1965 to December 1969 with a variety of fuel configurations.

"Here we had a high-temperature fluid-fuel reactor that operated reliably and, even in the primitive embodiment represented by MSRE, had remarkably low fuel costs," Weinberg wrote in The First Nuclear Era.

The "salt" that carried the MSRE's fuel was a mixture of the fluorides of lithium-7, beryllium and zirconium with a melting point of 840º F. The fuel-laden salt flowed from the reactor's graphite-moderated core to a heat exchanger that transferred heat to another molten fluoride salt system, which carried the heat to an air-cooled radiator.

The reactor and the parts of the system that came in contact with the fiery-hot loops of circulating molten salt were made of nickel-based INOR-8, which ORNL helped develop. It's now called Alloy N and has been available commercially for 50 years in industry, representing an early example of the Lab's materials research and commercialization prowess.

Construction on the MSRE began in 1962. Test runs began in 1965 using uranium-235 as a fuel. The reactor reached full power in 1966, and operators enjoyed progressively longer runs following some initial hiccups.

In 1968, an amount of uranium-233 was added to the fuel salt to demonstrate the design's flexibility. Renowned physicist and Atomic Energy Chairman Glenn Seaborg, who led the team that created the first amounts of U-233, came to ORNL to start the reactor. The MSRE group also experimented with plutonium in the fuel salt.

Some problems arose, such as surface cracking in the Alloy N caused by fission products, but they were manageable and for the most part eventually solved.

Weinberg described the MSRE's design as "primitive," but to a layman it is complex, with its intricately engineered pump systems and complicated chemistry. It was far different from other reactors, which proved to be a disadvantage because the MSRE also had competition: The AEC was committed to sodium-cooled, "fast breeder" designs while light-water, solid-fuel reactors eventually were adopted by the nuclear power industry. The MSRE lost funding and the entire program was shut down in 1973.

The reactor has been dormant ever since. In the early 1990s, reactions from the stored fuel triggered alarms in the facility, putting the MSRE briefly in the news. The facility has remained in stable repose under the purview of DOE’s Office of Environmental Management.

At this month’s ORNL workshop, researchers and guest speakers will describe the status of molten salt reactor designs and honor veterans of the original MSRE, which was designated by the American Nuclear Society as a Nuclear Historic Landmark in 1994. Scheduled speakers include John Kotek, DOE Office of Nuclear Energy Acting Assistant Secretary, and energy company representatives including Steve Kuczynski, president and CEO of Southern Nuclear; Andrew Shaw of Hatch; Jeff Latkowski of Terrapower; and David LeBlanc of Terrestrial Energy.

More information on the MSRE and ORNL's other nuclear reactors through the years is available in retired ORNL Deputy Director Murray Rosenthal's report, "An Account of Oak Ridge National Laboratory's Thirteen Nuclear Reactors," ORNL/TM-2009/181 .

UT-Battelle manages ORNL for the Department of Energy’s Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://energy.gov/science/

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Electroplating of Refractory Metals in Molten Salts: A Review

• Advanced Functional and Structural Thin Films and Coatings
• Published: 21 June 2024

Cite this article

• Zijian Wang 1 , 2 ,
• Yuewei Cheng 3 ,
• Fuli He 3 ,
• Zepeng Lv 2 ,
• Shaolong Li 1 , 2 ,
• Bin Yang 4 ,
• Jilin He 1 , 2 &
• Jianxun Song 1 , 2  

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Molten salt has a wide electrochemical window and excellent ion conductivity, which makes it possible to electrodeposit refractory metals in molten salt to obtain coatings. Meanwhile, the electroplating rate will be faster as a result of the high temperature in the molten salt. However, due to the complex chemical/electrochemical reaction of refractory metal ions with multiple valence states in molten salt, the precise control of electroplating is difficult. In this paper, the electrode reaction process, grain nucleation and growth model, and regulation mechanism of coatings are discussed. Subsequently, the research progress of various refractory metal coatings is reviewed, and the effects of technical parameters on the morphology and properties of the coatings are discussed. The challenges faced by refractory metal molten salt electroplating are summarized and potential future research directions are also proposed.

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Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (No. 52274356) and the National Natural Science Foundation of Henan (No. 222300420545), Youth Science and technology innovation of Henan Province (No. 23HASTIT009), State Key Laboratory of Special Rare Metal Materials, China (No. SKL2023K007), and the Northwest Rare Metal Materials Research Institute, China.

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Wang, Z., Cheng, Y., He, F. et al. Electroplating of Refractory Metals in Molten Salts: A Review. JOM (2024). https://doi.org/10.1007/s11837-024-06695-z

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Received : 02 November 2023

Accepted : 23 May 2024

Published : 21 June 2024

DOI : https://doi.org/10.1007/s11837-024-06695-z

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