This paper discusses the possible release mechanisms for radionuclides on board the sunken nuclear submarine Komsomolets. With an aim to determine whether or not the sunken submarine presents any significant hazards to man, a worst-case approach is taken in estimating the environmental effects of the released radionuclides. It is found that neither the submarine hull nor the reactor vessel will be destroyed by corrosion for at least 1000 years. While the total radionuclide inventory presently is estimated to be approx. 8 PBq, only approx. 1 TBq is released annually into the surrounding environment. The distribution of the released radionuclides in the ocean has been modeled, and it was found that not even in the most heavily affected waters will the present contamination levels change significantly due to the Komsomolets. In short, this study, which does not pretend to completely answer all environmental questions related to the sunken submarine, clearly indicates that the Komsomolets represents no significant hazard to man, today or in the future.