Incident at Irradiation Facility
Co-60 sources are used at the Sterigenics irradiation facility in Fleurus in various irradiation installations for the purpose of sterilising foodstuffs and medical equipment.
The Co-60 sources (3600 TBq (Terabequerel) for the cell that was concerned by the incident) are contained in a cell composed of thick concrete outer walls. This serves as a protective shield against radiation when the irradiation installation is operating.
When the irradiation installation is not operating, the sources are stored in a water pool. A secured hydraulic system allows to transfer the sources to the cell to irradiate the items placed in the cell. Specific procedures as well as safety interlocks are available to ensure that the irradiation start-up sequence can be performed in a safe way.
On May 7th, during loading/unloading operations of a batch, a technician informed the operator that he would enter the irradiation cell to perform some measurements. When the operator had finished loading, he initiated the irradiation start-up sequence without checking that no human beings were present in the cell. The technician immediately triggered one of the emergency stop systems inside the cell. This emergency stop interrupts the start-up sequence and shuts down the whole installation.
The incident was notified to Sterigenics’ General Manager on May 11th and the latter reported the incident to Bel V, the subsidiary of the Federal Agency for Nuclear Control (FANC). A FANC inspector was sent to the site immediately, accompanied by an expert from the subsidiary to investigate all the causes of the incident.
In the meantime, immediate actions have been taken, in particular a ban on interfering in any way with the routine product irradiation process.
The incident had no radiological consequences, neither for Sterigenics employees nor for the environment.
The public was informed of the incident by a communication on the website of the FANC.
Event date: Thu, 07-05-2009