not one of those incidents were due to reactor failure. running a reactor is complicated. operating a submarine at depths is also complicated. combining them doesn't mean either one gets less complicated. a failure of some complicated part of the submarine does not mean the power source failed. assuming they do with flippant "but subs have sunk" comments is just disingenuous at best.
Tangentially related: it's public knowledge that in the late 60s the US Army basically dropped a bunch of chemical weapons off of a pier on the Jersey Shore [1]. OK, so maybe that's an attempt at humor by hyperbole on my part, but it isn't far from the truth - they apparently determined that scuttling a ship filled with VX in the Atlantic is the optimal way to dispose of it.
Also, let’s not forget about Hanford site, which was part of the US nuclear program