[Right Wing Assault]

Apparently, it's very different from sub-sea geology where nukes have been successfully used before.

When were they used before to seal leaks?

[Windflier]

When were they used before to seal leaks?

I can't give you a source for the information, but I've seen it posted several times on oil spill threads, with links attached.

Apparently, the Russians closed some leaking sub-sea wells with low yield tactical nukes at one time.