Cr Electroplating Technology to prevent Interdiffusion between Metallic Fuel and Clad Material

摘要

Studies have been carried out in order to reduce fuel-cladding chemical interaction (FCCI) behavior of metallic fuel in sodium-cooled fast reactors (SFR) using an electroplating technique. A 20μm thick Cr layer has been plated by the electrochemical method in the Sargent bath over the HT9 (12Cr-lMo) clad material and diffusion couple tests of the U-10Zr metallic fuel as well as the rare earth alloy (70Ce-29La) have been conducted. The results show that the Cr plating can prevent FCCI behavior along the fuel-clad interface. However, cracks developed through the thickness during plating, which resulted in the migration of some fuel constituents. Variation of bath temperature, application of pulse current, and post heat treatment have been conducted to control such cracks. We found out that some conditions like the pulse current and the post heat treatment enhanced the layer property by reducing the internal cracks and improving the diffusion couple test.