Multi-functional surface coatings resistant to chloride-induced stress corrosion cracking, nuclear radiation, wear and thermal cycling

Chloride induced stress corrosion cracking in dry storage canister welds for spent nuclear fuel is identified as a potential safety concern. These materials are also subjected to radiation and wear. Multi-functional surface coatings could be a solution to mitigate these problems. The surface coatings on dry storage canister weld substrates resistant concurrently to pitting, CISCC, nuclear radiation, wear and thermal cycling are yet to be developed. The overall objective of Phase-I is to apply novel metal matrix nanocomposite coatings and prove its efficacy in resisting pitting and chloride induced stress corrosion cracking. During Phase-II, we will prove its usefulness in resisting nuclear radiation, wear and thermally stability. During Phase-I, we will design the metal matrix nanocomposites based on metallurgical principles. These metal matrix nanocomposites will consist of nano-particle reinforcements, and Ni predominant metal matrix. The coatings will be deposited applying a solid- state high pressure cold spray method with mechanically alloyed ball milled powder feedstock. The coated samples will be tested for their pitting and chloride induced stress corrosion cracking resistance and related to their metallurgical behavior. Several groups including commercial sector and the Federal Government will be benefited by the outcome of the technology, if the project is carried over into Phase II or Phase III and beyond. There is a huge market for anti-corrosion coatings and radioactive waste management worldwide and therefore the proposed technology is highly marketable. Successful completion of this research will help develop coated structural materials with superior resistance to combined chloride induced stress corrosion and radiation. The outcome of the proposed research will help building long lasting dry storage canisters for spent nuclear fuel. Development of efficient dry storage canisters for spent nuclear fuel will safeguard human health and minimize the impact on the environment and will benefit the public at large.