Nuclear reactor breakthrough: New material can replace costly nickel alloys

The US has set a target to produce 100 percent of its electricity using renewable energy sources by 2035, and nuclear power will play a major role in its clean energy transition.

About 20 percent of all the electricity produced in the US already comes from nuclear power plants. However, this isn’t enough. If the country wants to become a leader in the clean energy space, it needs to boost its nuclear energy program and make its nuclear plants more efficient than ever.

A big issue with nuclear reactors is their dependency on nickel-based alloys, which are expensive and are abundantly found in countries (like Russia, Indonesia, Philippines) that are not always on good terms with the US. Moreover, the high moisture content of nickel ore poses transport challenges as well.

Addressing these issues, a team of researchers from Department of Energy ‘s (DOE) Argonne National Laboratory (AGL) have developed a framework to find material that could replace these nickel-based alloys. Using their framework, the AGL team identified and tested some promising materials.

In fact, the researchers have identified a new material that can successfully endure intense radiation testing and withstand extreme reactor conditions for extended periods.

The use of nickel-based alloys in nuclear reactors

For context, nickel-based alloys play a crucial role in nuclear reactors. These materials have exceptional properties, such as high corrosion resistance , mechanical strength at extreme temperatures, and resistance to radiation damage.

This is why nickel-based alloys are used as a protective coating for different components of a nuclear reactor.

For instance, these are used for cladding the fuel rods used in a reactor. The cladding serves as a barrier to contain radioactive materials and shield the fuel from coolant.

These alloys are also used for various other purposes, such as enhancing the strength and durability of diverse structural components in reactors.

Testing the new framework and a new material

According to the researchers, an ideal coating material must have high corrosion resistance as it has to withstand extreme temperatures and radiation during the operations of a nuclear power plant.

A poor coating material can adversely affect a reactor’s performance and even pose safety issues ranging from overheating to radiation leakage . The new framework considers all these factors while identifying and proposing an alternative to nickel-based alloys.

“With this new framework, we have more input from multi-physics simulations to make sure each iteration gives enough improvement. We make sure each change would be beneficial and that helps us speed up the optimization procedure,” said Yinbin Miao, a researcher at AGL.

It basically involves performing repeated experiments and testing until an optimized solution is found. For instance, using the framework, the researchers identified a material that could work as an alternative to nickel-based alloys.

Testing of the new material

The research team tested the new material by exposing it to high radiation conditions using the Argonne Tandem Linac Accelerator System (ATLAS), a large device used to study atomic nuclei.

The material was bombarded with heavy ions to simulate the intense radiation conditions within a reactor.

Interestingly, the new material demonstrated a high level of resistance to corrosion, which is essential for withstanding the harsh environment inside a nuclear reactor . Notably, this resistance was a primary focus for the researchers.

Besides, the testing allowed the researchers to simulate a year’s worth of reactor exposure in just one day.

Promising implications

“The new ATLAS Materials Irradiation Station degraded the material’s properties as much in a day as a nuclear reactor does in a year, minus the long-lasting radioactivity. They demonstrated that the new material could indeed withstand reactor conditions and resist corrosion,” the researchers note .

Now that the tested material has shown immense significance for nuclear applications, the AGL team will soon patent it.

These results successfully show that the framework can lead to the identification of promising nickel alloy alternatives. It can lower the overall expenses of nuclear reactor construction and maintenance. Additionally, these alternative materials can be easily and safely transported, mitigating potential hazards.

However, this is just an initial step, and further research is required to refine the framework and evaluate its efficacy in a real nuclear reactor.

You can read the AGL news release here.