INES-event
INES 3

PLUTONIUM NITRATE LEAK IN CELL

Plutonium nitrate leaked from a corroded pipe to the containment cell and accumulated as a crystalline solid mass. There was no release to the Operations Areas nor to the Environment. The spillage was removed, the plant repaired and restarted.
The evaporator cell incident at Sellafield which involved the recovery of radioactive liquor and was safely and successfully dealt with, has now been reclassified from Level 1 to Level 3 on the International Nuclear Event Scale. The incident on September 8 involved an escape of plutonium nitrate from defective pipework into a contained cell, but did not result in any release of radioactivity to the environment or plant operating areas and no one was exposed to any abnormal radiation exposure. However, it has now been reclassified to Level 3 on the scale following a thorough examination which concluded that the installed safety devices were not monitoring adequately under the existing circumstances. As it was, the plutonium nitrate which escaped into the cell was safety contained and a comprehensive programme of work has since been undertaken not only in carrying out repairs but also in the installation of various equipment and monitoring instrumentation designed to give earlier warning of any similar failure in future and ease recovery operations.

Location: BNFL, Sellafield
Event date: Tue, 08-09-1992
Nuclear event report
Legenda & explanation