At the request of the IMO, the IAEA conducted a Coordinated Research Program from 1995-1999 to determine whether the IAEA regulations on packages take adequate account of accidents at sea. This study, “Severity, probability and risk of accidents during maritime transport of radioactive material (PDF)”, evaluated accident scenarios and concluded:

“Since the probabilities of severe ship collisions and severe ship fires are small and the individual radiation doses that might result should such a collision or fire occur are smaller than background doses, the risk of maritime transport in Type B packages of highly radioactive material such as irradiated [used] nuclear fuel, vitrified high level waste and plutonium are very small.”

This “Safety in Depth” transportation system explains why PNTL shipments are regarded by experts as some of the safest on the seas today.