随着时间增加，芯块-包壳间隙处氚浓度不断升高。1μm Al₂O₃涂层同5μm相比，寿期末芯块-包壳间隙处氚浓度较为接近，差别较小。这主要是因为即使是1μm Al₂O₃涂层，其阻止氚渗透的作用也非常显著，将绝大部分的氚都被包容在芯块-包壳间隙处，而5μm Al₂O₃涂层也将绝大部分的氚都被包容在芯块-包壳间隙处，两者效果类似。

Over time, the concentration of tritium at the mantle-shell gap increases. The tritium concentration at the end of the mantle-cladding gap is relatively close to that of the 1μm Al₂O₃ coating compared with 5μm, and the difference is small. This is mainly because even the 1μm Al₂O₃ coating has a significant effect on preventing tritium penetration, containing most of the tritium in the mantle-envelope gap, while the 5μm Al₂O₃ coating also contains the vast majority of tritium in the mantle-envelope gap, with similar effects.