I was reading about the nuclear accidents in early Soviet submarines and got a couple of questions, hope this is the appropiate forum to ask them. Let's assume that a submarine suffers both a hull and reactor vessel rupture (for example, as a result of an attack in wartime) while at periscope depth (to ignore high water pressure conditions). I was wondering: -What substances would bubble into the air and which ones would stay in water? And now let's imagine that the submarine is able to emerge and somehow the reactor is still working (maybe moderated by seawater and because they use HEU, sometimes around 97% enrichment) but out of control. What substances would we see then? (Or, in other words: what substances would a reactor emit if just opened?) AFAIK, these reactors are usually light water moderated PWRs with HEU for fuel. Thanks in advance!