The interface between different materials accelerates chemical breakdown. //

In the case of the crevice between the stainless steel and the glass, a lot happens when some of the metals present dissolve. They can drop the local pH, which will then increase the rate at which the stainless steel corrodes. Meanwhile, some of the dissolved metal ions will include some of the radioactive material. To balance the chemistry, the environment outside the crevice will become more basic, which could trigger additional chemical reactions.

Real-world data
That's what can happen. What actually does? To find out, the researchers used a standard (non-radioactive) glass material and stainless steel.