The Health Protection Agency's Radiation Protection Division has today published a report on accidents and incidents involving the transport of radioactive materials in the UK , from 1958 to 2004 1. The report finds that the most serious of these events involved the transport of poorly shielded industrial radiography sources, which occurred mainly in the 1970s. Some of these incidents led to radiation exposures to workers and members of the public. Better training has ensured that no similar events have occurred for 20 years 2. The report also details trends in other types of events; for example, a rise in incidents of excess radioactive contamination on nuclear fuel flasks in the late 1990s was reduced by better procedures at nuclear power stations. Radiological consequences from these incidents, both to workers handling the flasks and to members of the public, were negligible. The report concludes that good training of the workers involved in the transport of radioactive materials should always be a priority.

Radioactive materials are widely used in hospitals, general industry and research. It is necessary for these materials to be transported from suppliers to customers, and for some radioactive wastes to be returned from customers to suppliers or to waste facilities. All these materials are normally transported by road. Radioactive materials associated with the nuclear industry are mainly moved by road and rail. Also, exports and imports of radioactive materials are made by sea and air. Up to half a million packages are transported in the UK annually, and during these shipments events can occur. Packages that are damaged or poorly prepared can have the potential for radiological consequences for workers and members of the public in the vicinity. Damaged or poorly prepared packages can result in increased dose rates around the package or releases of radioactive material.

The analysis of the information on reported accidents and incidents provides an overview of the types of events that have featured throughout the period covered. For example, there was an increase in occurrences of excess contamination on flasks and rail wagons used to transport irradiated nuclear fuel (INF) from the late 1990s to the early 2000s. The occurrence of these events was reduced by improved conditions in power station storage ponds and more thorough cleaning and monitoring of INF flasks. During the 1970s there were many events involving packages being damaged at airport cargo centres, but their occurrence was greatly reduced by improvements in handling procedures. In the later years of the period, events involving contaminated items and lost sources being discovered in scrap metal were increasingly being reported.

Most of the recorded events have resulted in negligible radiological consequences to the workers involved or to members of the public. Only in 19 out of 806 cases reported, radiological exposures were not negligible; almost all of those events occurred in the earlier years of the reported period, only two having occurred since the mid 1980s. The most serious radiological consequences occurred as a result of transporting improperly packaged industrial radiography sources, mainly in the 1970s.

Accidents and incidents that happen during the transport of radioactive materials, as in the transport of other types of materials, inevitably occur from time to time. However, the frequency of occurrence of such events, and their effects, can be reduced by the establishment of comprehensive radiation protection programmes and emergency procedures. Appropriate training of workers involved in these transport operations should always be a priority.

The study was funded by the Department for Transport and the Health and Safety Executive.

1 J S Hughes, D Roberts and S J Watson. Review of events involving the transport of radioactive materials in the UK , from 1958 to 2004, and their radiological consequences.

RPD-014. ISBN: 0-85951-577-X.
Available to download from the HPA website

2 There was a potentially serious incident in 2002 involving a radiotherapy source which, however, did not lead to any significant radiological exposure.

Health Protection Agency, UK