The question was about spent fuel storage, not what happens in a scram.

I wouldn't worry much about the spent fuel. It's not going to melt and cause a huge radioactivity release. Even if it does heat and melt it probably won't cause a big problem. It's at least in a building and wouldn't be creating a lot of windborne radioactivity.

Now the running reactor on the site..... I hope that decay heat management doesn't require that all control systems work.
Decay heat after scram is VERY significant (5% of the power just before the scram for about an hour or something like that) and must be actively managed by the plant operators.