Abstract Sandia National Laboratories (SNL) has conducted an extensive study of emergency response planning applicable to sea transport of plutonium for the Japan Nuclear Cycle Development Institute (JNC). This work covered four separate areas to better define the accident environment for long range sea transport of nuclear materials. A probabilistic safety analysis evaluated technical issues for the transport of plutonium between Europe and Japan. An engine room fire aboard a purpose built ship was used to analyse the vulnerability of plutonium packaging designed to International Atomic Energy Agency (IAEA) standards. A comprehensive corrosion study estimated the time required for sea water to breach a containment boundary in submerged generic plutonium packaging. A survey of worldwide commercial recovery capabilities provided a compilation of information on the capabilities of salvaging high value cargo from sunken ships. This paper addresses salvage modes from harbour depths to the deepest ocean trenches. Previous studies (J. L. Sprung et al., SNL reports SAND98-1171/1 and SAND98-1171/2, May 1998) included a probabilistic risk assessment of the overall safety, source term evaluations and finite element structural dynamics calculations to determine the effects of ship to ship collisions on nuclear material containers and the effects of ship fires on transport packaging as determined by actual fire experiments conducted on board a test ship. The previous studies, together with this work, form a comprehensive technical basis that encompasses the overall safety of sea transport of plutonium between Europe and Japan. Based on these technical analyses, transport of nuclear materials by sea in Type B packaging, approved in accordance with US Nuclear Regulatory Commission (NRC) and IAEA regulations, and carried in purpose built ships with adequate surveillance, has a very high degree of safety for the failure modes studied. Non-purpose built ships do not have the redundancy in safety features provided by the newer purpose built ships. However, SNL studies on non-purpose built ships have shown accident environments to be within NRC and IAEA regulatory assumptions for Type B packaging. These studies were carried out for both structural ship to ship collisions and engine room fires by analysis (for the collisions) and direct experimentation and analysis (for the fires). Thus, land transport mode regulations are applicable for sea transport accident conditions.