> Their fuel is enriched far higher than terrestrial nuclear plants Which is surely one of the reasons why they generate less waste -- less non-fissile fuel to

> Their fuel is enriched far higher than terrestrial nuclear plants Which is surely one of the reasons why they generate less waste -- less non-fissile fuel to be irradiated, smaller reactor vessels to be activated, etc. Plus the average power generated is way lower for a nuclear submarine. A single commercial ~1 GW nuclear reactor quite likely produces as much power as the whole US submarine fleet on average, and there's hundreds of such ~1 GW units in the world. And less power means fewer fission events, which means less activation and less waste. So even a sunk sub is nowhere near the levels of a sunk commercial waste fuel shipment when it comes to what either of the two could release into the environment should the bad stuff leak out.