Fabrication of Al2O3/FeAl Coating as Tritium Permeation Barrier on Tritium Operating Component on Quasi-CFETR Scale

Limited CFETR-scale experience of engineering preparation techniques of tritium permeation barrier (TPB) exists up to date. Aimed at processing some real components that are usually tubular components sealed in one end, in the tritium cycling systems of China Fusion Engineering Test Reactor (CFETR), an Al2O3/FeAl coatings as TPB was prepared on tubular components of 321 type stainless steel components with a length of 400mm and an external diameter of 150mm, by Al-electroplating followed by heat treating and selective oxidation. The ability to construct TPB coated components on quasi-CFETR scale was demonstrated, with fabricating a TPB of Al2O3/FeAl coating with a double-layered structure, consisted of an outer -Al2O3 layer with a thickness of 0.3 mu m and an inner (Fe,Cr,Ni)Al/(Fe,Cr,Ni)(3)Al layer of 40 mu m in thickness. The tritium permeation reduction factors of the Al2O3/FeAl TPB on component were 229 and 96 at 500 and 600 degrees C respectively. Finally, signatures and gaps of TPB mass process on CFETR-scale were discussed.