Internal contamination of a worker in a fuel pellets fabrication workshop
The event occurred in the pelleting workshop, where mixtures of plutonium and uranium oxide powders are compacted into cylindrical pellets. These operations are carried out in glove boxes. While cleaning a glove box containing a compacting press, one of the gloves was punctured, causing atmospheric contamination of the working area. This contamination was detected by the room’s radiation monitors and the area was evacuated in accordance with the procedures in force.
One of the three people present in this room was contaminated. The CEA Marcoule medical service then took charge of this person.
Orano Cycle informed ASN of this event on 12 February, indicating that radio-toxicological analyses had been run to estimate the committed dose for this person.
These analyses, which lasted several months, show that the committed dose could exceed the annual dose limit set at 20 mSv. Therefore, on 24 June 2020, Orano Cycle reported this event as a “significant event” in accordance with ASN’s requirements. The CEA Marcoule medical service and Orano Cycle are continuing their investigations in order to determine the committed dose value, since the estimated committed dose for this event is far higher than expected on the basis of the atmospheric contamination level measured by the workplace monitors when the event occurred.
This event had no consequences on either the installations or the environment. Orano Cycle cleaned the room and assessed the equipment used. The licensee started to work on improving the mechanical strength of the gloves and the configuration of the workstations. ASN will also assess the results of investigations concerning the relationship between the level of contamination measured by the monitors and the estimated committed dose.
Event date: Tue, 11-02-2020