THE AUG 2008 INCIDENT AT THE IAEA SAFEGUARDS ANALYTICAL LABORATORY INVOLVING A SMALL QUANTITY OF PU-240

A broad range of radioanalytical measurements are carried out in support of nonproliferation treaty verification, nuclear waste processing, environmental monitoring, and national and global security applications at the Safeguards Analytical Laboratory (SAL). A broad range of Certified Reference Materials are utilized to ensure the quality of analyses performed. Some of these reference materials are extremely rare and seldom produced, which may result in considerable storage time before use. On August 3 rd , 2008, an incident later described as INES level 1occurred in a storage safe of SAL. An investigation of this incident strongly suggests that it was triggered by the fracture of a glass vial containing a nitrate solution of plutonium 240. The most likely cause of the breakage is excessive internal pressure arising from the generation of radiolytic gases (primarily hydrogen and oxygen). The rupture of a single vial would not be expected to be a sufficiently energetic event to break adjacent vials, as occurred, or to account for the damage to the tray within the safe on which the vials were stored. It appears likely that the breakage of subsequent vials (a further four) and damage to the tray occurred as a result of a deflagration involving the radiolytic gases released from the first, and perhaps subsequent, vials. This paper describes the root cause leading to the incident as well as its consequences and the clean-up effort.