Individual and workplace monitoring measurements made after a 240Pu incident and during the clean-up operations

On 3 August 2008, five glass vials containing around 7 GBq of 240Pu in nitric acid solution burst in a laboratory operated by the IAEA in Seibersdorf (Austria). The vials were located in a fire-proof safe in the IAEA Safeguards Analytical Laboratory, and the release of the 240Pu caused an air contamination in the room and in adjoining rooms. Immediate emergency work was carried out, which was then followed by a long period of clean-up operations. A large number of conventional individual and workplace monitoring measurements were carried out immediately after the incident and during the clean-up work. In addition, due to the fact that 240Pu has a very low background presence in the environment, and that the IAEA laboratories operate an inductively coupled plasma mass spectrometry system capable of very low levels of detection of this radionuclide, a number of non-conventional measurements were made to detect 240Pu on, for example, the photographic camera used to document the incident, on nasal swabs from the first responders, etc. Plastic beakers were left in the corridor of the controlled area to accumulate 240Pu from precipitation to see whether it was possible to detect traces of the radionuclide. This paper presents the measurements obtained, and discusses their relevance to occupational radiation protection. (authors)