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Nuclear energy

New Patent for Nuclear Reactor Component with Enhanced Oxidation Resistance

Strategic Insights

— 2 min read

A team of inventors from Commissariat a l'energie atomique et aux energies alternatives (Paris, France) has developed a novel process for manufacturing a nuclear reactor component with improved resistance to oxidation and hydriding. The patent, published online on October 7, 2025, describes a method of chemical vapor deposition of an organometallic compound by direct liquid injection (DLI-MOCVD) to create a protective layer on a substrate composed of a metal such as zirconium or titanium. This protective layer is designed to prevent or attenuate the oxidation and hydriding of the substrate, which can lead to the degradation of the nuclear reactor component.

The invention aims to improve the resistance to oxidation and hydriding at high temperatures, particularly between 700° C. and 1200° C. or even above 1200° C., which is critical under accident conditions such as reactivity insertion accidents or loss of primary coolant accidents. The patent also aims to improve the oxidation and hydriding resistance time, beyond which the integrity of the nuclear component is no longer ensured. Furthermore, the process is intended to be versatile, economical, and environmentally friendly, making it suitable for industrial-scale manufacturing.

Key Takeaways:

  • The invention proposes a process for manufacturing a nuclear reactor component with improved resistance to oxidation and hydriding.
  • The process involves the method of chemical vapor deposition of an organometallic compound by direct liquid injection (DLI-MOCVD).
  • The nuclear reactor component comprises a substrate based on a metal such as zirconium or titanium, and at least one protective layer coating the substrate composed of a partially metastable chromium.
  • The protective material comprises a stable chromium crystalline phase and a metastable chromium crystalline phase.
  • The invention aims to improve the resistance to oxidation and hydriding under accident conditions, particularly between 700° C. and 1200° C. or above 1200° C.
  • The process is intended to be versatile, economical, and environmentally friendly, making it suitable for industrial-scale manufacturing.
  • The claims of the invention cover a wide range of nuclear reactor components, including fuel claddings, spacer grids, guide tubes, plate fuels, and absorber rods.
  • The invention includes a liner, an interposed layer, and a homogeneous or heterogeneous multilayer protective coating.

Statistics:

  • Temperatures for oxidation under accident conditions: greater than 700° C., between 800° C. and 1200° C.
  • Temperature increase rate: 0.1° C./second to 300° C./second
  • Percentage of stable chromium crystalline phase in the protective material: not specified
  • Percentage of metastable chromium crystalline phase in the protective material: not specified
  • Thickness of the protective layer: not specified
  • Number of multilayer protective coatings: not specified
  • Density of the protective layer: between 90% and 100% of the density in solid form of the stable metallic chromium

Sources:

  • Boichot, Raphael. Nuclear reactor component having a coating of partially metastable chromium. U.S. Patent Number 12437885, filed July 21, 2021, and published online on October 7, 2025. Patent URL (for desktop use only): https://ppubs.uspto.gov/pubwebapp/external.html?q=(12437885)&db=USPAT&type=ids

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