A British SSBN (nuclear powered ballistic missile submarine) was recently discovered to have a fist sized hole in its hull. The hole, caused by corrosion, was patched, but questions were raised about why such a thing could happen. Well, it's complicated.

The sub in question, HMS Revenge, was decommissioned in the 1980s. It's nuclear fuel, weapons and all noxious chemicals were removed. But the nuclear reactor is still radioactive, and will remain so for thousands of years. When the sub was built, in 1969, the plan was to simply sink the sub, in very deep water, when it was decommissioned. But that practice has since been outlawed by international treaty. Plan B was to cut up the decommissioned nuclear subs, and then bury the radioactive bits in a national repository for radioactive waste. But there has never been any agreement on where to locate said national repository.

The current plan is to do nothing and wait. Plan B for that plan is to eventually (just before the old nuclear boats rot so much that they no longer stay afloat) cut them up and store the radioactive section (the reactor compartment) near the naval base (Rosyth, in Scotland) where these retired subs are tied up. The government does not want to discuss this, as the Scots would not be pleased. But possession is 9/10ths and all that. Besides, the English have been screwing the Scots for centuries, and you know how the Brits are about tradition.