Nuclear submarines, usefull as a dirty WMD?

[TteFAboB]

Hi,

What are the possible uses of a [modern] Nuclear Submarine as a dirty weapon?

From what I know, the reactors are usually strongly sealed, but can a sub reactor explode strong enough to breach the seal and cause enough damage within a considerable area?

I suppose you can drill the thing or however else use it to spread radioactivity, but can it spread enough radioactivity?

Could the torpedo arsenal help in any way? Besides from having a nuclear warhead, could they be used as "dirty" weapons too? Like carrying radioactive material?

Is there a historical record of accidents? If so, what was the level of damage caused? And could they be deliberately reproduced with modern nuclear subs?

Please, do share your knowledge, Navy sources refuse to cooperate, every information is "confidential"...