Development of Cold Spray Coatings for Accident-Tolerant Fuel Cladding in Light Water Reactors

Abstract

The cold spray coating process has been developed at the University of Wisconsin-Madison for the deposition of oxidation-resistant coatings on zirconium alloy light water reactor fuel cladding with the goal of improving accident tolerance during loss of coolant scenarios. Coatings of metallic (Cr), alloy (FeCrAl), and ceramic (Ti 2 AlC) materials were successfully deposited on zirconium alloy flats and cladding tube sections by optimizing the powder size, gas preheat temperature, pressure and composition, and other process parameters. The coatings were dense and exhibited excellent adhesion to the substrate. Evaluation of the samples after high-temperature oxidation tests at temperatures up to 1300°C showed that the cold spray coatings significantly mitigate oxidation kinetics because of the formation of thin passive oxide layers on the surface. The results of the study indicate that the cold spray coating process is a viable nearterm option for developing accident-tolerant zirconium alloy fuel cladding.

High-temperature oxidation resistance of chromium-based coatings deposited by DLI-MOCVD for enhanced protection of the inner surface of long tubes

“…A single layer of metallic chromium is one of the most investigated solutions. They are deposited by thermal spray [9][10][11], laser cladding [12] or PVD (Physical Vapor Deposition) [13][14][15][16]. Other coating materials and architectures are developed like non-metallic coatings, pure metals, intermetallics, metallic alloys coatings, oxides, carbides including ternary carbides as MAX phases [17,18], nitrides, composites and multilayers [19].…”

Application and Development Progress of Cr-Based Surface Coatings in Nuclear Fuel Element: I. Selection, Preparation, and Characteristics of Coating Materials

“…[51,56,[66][67][68], which can completely replace zirconium alloys. The other route is to prepare coatings on the surface of the existing zirconium alloy claddings [13,33,34,[69][70][71][72][73][74]. According to the ATF R&D plans of various countries in the world [75][76][77][78], different research institutes have focused on the R&D directions of ATF claddings.…”

“…The similar behavior of an FeCrAl coating on a Zr alloy prepared via the cold spraying method was found by Park et al [95] after exposure to high-temperature steam oxidation at 1200 • C for 3000 s. It can be seen that the diffusion of metals and eutectic reactions substantially limit the inherently excellent high-temperature oxidation resistance of FeCrAl. An Mo layer of a certain thickness deposited between FeCrAl coating and Zr matrix acts as a diffusion barrier that mitigates or prevents the above-mentioned problems [73,95]. However, further experimental research is still needed to verify the performance and reliability of Zr alloys coated with Mo and FeCrAl.…”

“…In terms of accident resistance, Cr coatings have been found to demonstrate outstanding resistance to high-temperature steam oxidation. The oxidation rate of a coated Zr alloy cladding is lower by at least one order of magnitude compared to an uncoated cladding [21,22,73,104,108,109]. Furthermore, Cr coatings greatly reduce the hydrogen absorption of claddings, alleviating the risk of hydrogen-induced embrittlement.…”

“…At present, the most extensively used preparation methods of the Cr-based coatings on Zr alloys are physical vapor deposition (PVD) [14,[18][19][20]22,23,55,[104][105][106]108,109,115,116], cold spraying (CS) [15,24,73,95,107,[117][118][119], and 3D laser melting and coating (3D-LMC) [6,17,25,33,34,69,120]; each are currently used by CEA (French Alternative Energies and Atomic Energy Commission) in France, Westinghouse Electric Corporation in the US, and KAERI in South Korea, respectively. These preparation methods and the characteristics of the prepared coatings are described in the next section.…”