Nuclear power plants are exposed to high-energy radiation, which degrades materials over time.
Particles and rays interact with critical components, particularly in the reactor core, leading to swelling, embrittlement, and reduced mechanical strength. Gamma rays penetrate deep into materials, weakening their structure and limiting their lifespan.
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The durability of materials used in nuclear systems remains a challenge. Researchers are developing radiation-resistant nanomaterials to address these issues.
These materials are designed to withstand radiation-induced damage, improving structural integrity and operational efficiency.
Mechanism of Radiation Resistance
Radiation exposure in nuclear systems leads to early material failure and reduces performance. High-energy particles cause structural defects, such as interstitial atoms and voids, which weaken the material over time. These microstructural flaws accumulate, eventually leading to bulk macroscopic failure.
The resistance of nanomaterials to radiation damage comes from their microstructure. Grain boundaries (GBs) in nanostructured metals act as defect sinks, absorbing radiation-induced defects and preventing structural degradation. Because nanostructured materials have a high density of grain boundaries, they are more effective at absorbing and dissipating radiation damage caused by nuclear particles and gamma rays.1
Some nanomaterials also exhibit self-healing properties. Materials such as nano-ceramics and nano-porous crystalline structures can rearrange their atomic structure after radiation exposure, improving their ability to withstand long-term operation in nuclear environments.
How Are Radiation-Resistant Nanomaterials Used in Nuclear Systems?
Reactor Core Components
Materials used in reactor cores must withstand high radiation exposure while maintaining the structural integrity of fuel rods during fission reactions. The impact of radiation on these materials is measured in displacements per atom (dpa), a metric that tracks atomic dislocations caused by high-energy particles.
As newer generations of nuclear reactors operate at temperatures exceeding 800°C, radiation damage can reach 150-200 dpa, making the selection of durable materials essential.2
One widely studied material is Ferritic-martensitic oxide-dispersion-strengthened (ODS) alloys. These alloys offer high stability and exceptional strength, making them suitable for nuclear applications.
Researchers have tested 12Cr ODS by exposing it to 3.5 MeV Fe2+ self-ions at high temperatures. After 100 cycles of exposure, the material exhibited negligible void formation and minimal defect accumulation, demonstrating its resistance to radiation-induced damage. This makes ODS alloys a strong candidate for use in reactor cores and cladding materials.3
Stainless steel is another critical material in reactor cores. Researchers have improved its radiation resistance by introducing high-density nanoparticles. Experiments on 316L stainless steel have shown that dispersing titanium carbide (TiC) nanoparticles within the steel matrix enhances its strength and durability under radiation.
Upon exposure, the modified nanomaterial formed 5 % fewer helium bubbles, and the bubbles were smaller than those in unmodified stainless steel. The material also exhibited reduced swelling, improving the structural integrity of the nuclear core.4
Fusion Reactors
Tungsten is widely used as a plasma-facing material (PFM) in fusion reactors due to its exceptional thermal properties and resistance to extreme temperatures. However, radiation exposure can weaken its structural integrity over time.
To enhance its radiation resistance, researchers have developed tungsten nanocomposites by alloying tungsten with nano-dots and nanoparticles of tantalum.
These modifications significantly improve its ability to withstand radiation-induced damage, making tungsten-based nanomaterials a strong candidate for structural applications in fusion reactors.
Copper and its alloys are also used in fusion reactors, particularly for their thermal conductivity and mechanical stability. To improve their radiation tolerance, researchers have introduced nano-voids into nano-twinned copper alloys. These engineered voids act as defect absorption sites, capturing radiation-induced damage.
The integration of nano-voids along twin boundaries allows for the efficient capture of mobile defect clusters, preventing the accumulation of radiation-induced structural damage.
In nano-twinned metals, interconnected twin boundary networks accelerate the transport of defect clusters to nano-voids, where they undergo bilateral recombination. This process minimizes radiation damage and prevents phase instability at the atomic level.5
Radiation Resistant Coatings
As nuclear technology advances, particularly in nuclear fusion, radiation-resistant coatings are becoming essential for enhanced shielding and material longevity.
Researchers are using simulation technologies, such as the Molecular Dynamics (MD) framework, to study the mechanisms behind radiation tolerance and develop more effective protective materials.
A recent study conducted simulations on bimetallic core-shell nanoparticles, specifically FeCu core-shell nanoparticles. Both the outer Cu shell and the Fe-Cu core-shell interface acted as primary defect sinks, absorbing radiation-induced damage.
When exposed to primary knock-on atom (PKA) energies of up to 7 keV, the simulations revealed the formation of point defects and small defect clusters. The Fe core showed no twin defects, while the Cu shell exhibited preexisting stacking faults influenced by radiation exposure. Despite this, no significant changes in nanoparticle roughness or volume were observed.
Simulations showed that the Cu shell reduced the number of surviving interstitials in the Fe core, lowered Fe sputtering yield, and promoted defect recombination. The low number of interstitials in the Fe core suggests that the Fe-Cu interface and Cu shell function as effective defect sinks, improving radiation stability.
These findings highlight the potential of core-shell nanoparticles for use in protective coatings and radiation-resistant films in nuclear systems.6
Industry Story: Self-Healing Radiation Resistant AISI-316 Steel Nanoparticles
Nano-porous self-healing materials exhibit inherent resistance to radiation damage, making them valuable for next-generation nuclear reactors. Among these, nano-porous AISI 300 series austenitic stainless steel (SS) has demonstrated superior resistance to creep, making it a preferred material for fast nuclear reactors.
As future nuclear reactors operate at higher power levels, materials with radiation tolerance exceeding several hundred dpa are becoming essential.
A study by Aradi et al. investigated the radiation damage tolerance of AISI-316 SS nanoparticles under heavy ion collisions. The nanoparticle-incorporated stainless steel was compared with an unaltered specimen to assess the effectiveness of the nanostructured framework in mitigating radiation-induced damage.
In pure stainless steel, researchers observed accumulated displacement damage caused by radiation. However, in the AISI-316 SS nanoparticles, self-healing properties were observed during interaction with high-energy nuclear particles.
Small defect clusters formed initially, but over time, dislocation loops were reduced as interstitial pairs formed due to atomic collisions. Defect clusters migrated toward the free surface, significantly reducing overall displacement damage.
The study also found that smaller nanoparticles exhibited higher sink efficiency, meaning radiation-induced defects were absorbed more effectively. STEM-EDX imaging confirmed the absence of voids or helium bubbles, indicating improved radiation resistance.
This self-healing mechanism, driven by radiation-induced segregation, not only minimizes radiation damage but also enhances corrosion resistance and fatigue strength in nuclear environments.7
A Nuclear Renaissance! Nanomaterials and Nuclear Energy
Advancing Radiation-Resistant Materials Through Data-Driven Research
Advancements in data-driven materials development and machine learning frameworks are accelerating the discovery of radiation-resistant nanomaterials. These technologies enable researchers to predict material behavior, optimize compositions, and design structures that enhance durability in extreme environments.
However, the recyclability of these advanced materials remains an open question, requiring further investigation to ensure long-term sustainability.
To learn more about how nanomaterials are enhancing advanced technologies, explore:
References and Further Reading
- Zhang, L. et. al. (2021). Understanding the Radiation Resistance Mechanisms of Nanocrystalline Metals from Atomistic Simulation. Metals. Available at: https://doi.org/10.3390/met11111875
- International Atomic Energy Agency (IAEA). Development of Radiation Resistant Reactor Core Structural Materials. [Online] IAEA. Available at: https://www.iaea.org/sites/default/files/gc/gc51inf-3-att7_en.pdf [Accessed on: February 21, 2025].
- Kim, H. et. al. (2021). Oxide dispersoid coherency of a ferritic-martensitic 12Cr oxide-dispersion-strengthened alloy under self-ion irradiation. Journal of Nuclear Materials. Available at: https://doi.org/10.1016/j.jnucmat.2020.152671
- Sun, Z. et. al. (2021). Effects of ion irradiation on microstructure of 316L stainless steel strengthened by disperse nano TiC through selective laser melting. Materials Characterization. https://doi.org/10.1016/j.matchar.2021.111420
- Su, Z. et. al. (2023). Recent progress on interfaces in nanomaterials for nuclear radiation resistance. ChemNanoMat. Available at: https://doi.org/10.1002/cnma.202200477
- Tramontina, D. et. al. (2022). Radiation resistance in simulated metallic core-shell nanoparticles. arXiv preprint arXiv:2206.09063. Available at: https://doi.org/10.48550/arXiv.2206.09063
- Aradi, E. et. al. (2020). Radiation damage suppression in AISI-316 steel nanoparticles: Implications for the design of future nuclear materials. ACS Applied Nano Materials. Available at: https://doi.org/10.1021/acsanm.0c01611
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