pdf Rupture of a package containing iodine-131 (96 kB)
Description of the incident
The incident took place when a package containing 5 GBq of iodine-131 fell and was damaged on the internal roads of an airport. The type A package contained I-131 (used in the treatment of thyroid cancers) in the form of powder inside capsules.
For transportation, the capsules are placed in vials protected by a lead container, which is placed in a metal box with a sealed lid, all packaged in a carton. When being dispatched from the warehouse towards the aircraft, the package in question fell from the vehicle, undoubtedly because of a lack of secure stowage. The package then was crushed by vehicles using this road which ruptured the containment and lead to the dispersion of radioactivity on the road and surrounding surfaces.
The damaged package was discovered by a law enforcement patrol which, ignoring the nature of the product, moved it to the side in order to free the road. While moving the package, the officers saw the radioactive warning symbol (its initial position was not visible). Consequently, they established a security perimeter and alerted firemen specialised in radiological interventions who, after arriving at the scene of the incident, undertook the first measurements.
Radiological consequences
The first measurements undertaken detected two surface contamination spots (some distance apart) with a contact dose rate of 100 to 200 µSv/hr, and a dose rate of about 10 µSv/hr at 50 cm. Body monitoring and urine tests performed the same day showed that the four persons involved in the this monitoring received no significant intakes of iodine-131.
In terms of the officers who first arrived on the scene and moved the package, the following doses were estimated:
Internal exposure by inhalation: an activity of 250 Bq was measured by gamma body monitoring, which represents a committed effective dose of 2 µSv.
External Exposure: using realistic exposure scenarios, the dose was estimated to be 5 µSv (the worst case estimate was 65 µSv).
Lessons learned from the incident
It should be ensured that all persons responsible for the handling of packages in airports understand the meaning of the radiation warning symbol. It is important to remember that the labeling of packages must be on two opposite sides. Security and similar staff (eg the officers in this incident) should also be made aware.
Procedures relating to the handling and stowage of packages containing radioactive material should be drawn up by the operators and made available to staff. Packages containing radioactive material must be securely stowed during movement, transport and other warehousing operations, and this stowage must be checked and periodically verified.
It is necessary to periodically inform and train persons responsible for package handling about the risks of exposure and the precautions to take during normal operations and in the case of accidents.
Contingency plans for dealing with accidents should be prepared. These should include suitable PPE (e.g. gloves) for handling damaged or leaking packages.