Since 1965, the International Maritime Organization (IMO) has published a major international instrument known as the International Maritime Dangerous Goods Code (IMDG Code). This Code is for the carriage of dangerous goods of any kind by sea. It addresses matters such as packing and container stowage, with particular reference to the segregation of incompatible substances. The IMO provisions for radioactive material are based on the IAEA Regulations. The IMDG Code offers guidance to those involved in the handling and transport of radioactive materials during sea transport.
In 1993, the IMO also established the Code for the Safe Carriage of Irradiated Nuclear Fuel, Plutonium and High-Level Radioactive Wastes in Flasks on Board Ships (INF Code) to complement the IAEA Regulations. Although the package design remains the primary safety measure, this Code introduces recommendations for the design of vessels transporting radioactive material. These complementary provisions address such issues as stability after damage, fire protection, and structural resistance. In January 2001, the INF Code was made mandatory and renamed the International Code for the Safe Carriage of Packaged Irradiated Nuclear Fuel, Plutonium and High-Level Radioactive Waste on Board Ships.
The INF Code defines classes of vessels based on the aggregate level of radioactivity that a ship is permitted to transport.
| Class of ship | Criteria |
|
Class INF 1 ship |
Ships which are certified to carry materials with an aggregate radioactivity less than 4,000 TBq (1). |
|
Class INF 2 ship |
Ships which are certified to carry irradiated nuclear fuel or high-level radioactive wastes with an aggregate radioactivity less than 2 x 106 TBq and ships which are certified to carry plutonium with an aggregate radioactivity less than 2 x 105 TBq. |
|
Class INF 3 ship |
Ships which are certified to carry irradiated nuclear fuel or high-level radioactive wastes and ships which are certified to carry plutonium with no restriction on the aggregate radioactivity of the materials. |
Note (1) TBQ = Tera-becquerels is the S1 unit of disintegration of a radioactive nuclei per second e.g. 9 x 1012 Bq can be expressed as 9 TBq
