Assessment of the Risk of Radioactive Contamination Release from Accidents in Nuclear Ships and Submarines at Sea

The operation of marine nuclear reactors mirrors that of all nuclear reactors. However, unlike other reactors, much of the information regarding marine reactors is classified, making it challenging to assess their safety levels. While the likelihood of an accident resulting in the release of radioactivity from the core of a nuclear reactor on a ship or submarine into the environment is minimal, the potential for such incidents cannot be disregarded. Numerous studies have explored the risks associated with accidents in nuclear reactors. This article provides a descriptive examination of various aspects of accidents in nuclear ships and submarines, delving into the extent of risks posed by these incidents. The article highlights the rigorous safety measures incorporated into the design and construction of nuclear vessels and submarines to prevent the release of radioactive materials in case of accidents. Each nuclear system, including the fuel casing, cooling system, and safety chamber, presents potential risks of radioactive material leakage into the environment. By categorizing nuclear accidents based on these subsystems, safety protocols aimed at preventing contamination spread and ensuring nuclear safety are reviewed. Furthermore, the emission characteristics of radioactive materials released into the marine environment during a nuclear accident are explored in terms of half-life, emission range, and decay types. The study also investigates the crucial role of seawater in attenuating and modifying the radiation properties of radioactive materials. It is demonstrated that fast neutrons and gamma rays are rapidly attenuated by surrounding seawater, typically traveling less than 1 meter. Additionally, most radioactive materials resulting from a nuclear accident emit alpha (α) and beta (β) radiation, both of which have limited ranges of less than 10 cm in water, with seawater serving as an effective shield against this type of radiation pollution.