Below is the text of the statement made by Alistair Goodlad, the then Parliamentary Under-Secretary of State for Energy, in the House of Commons on 6 February 1986.
British Nuclear Fuels plc has reported that during maintenance operations yesterday there was a small release of plutonium radioactivity within the main reprocessing building at Sellafield. The incident arose during maintenance operations on a pump, during which air was accidentally blown across a flow of liquid with plutonium in it. This caused a mist with a small amount of plutonium in suspense. Monitoring equipment in the building, which is extremely sensitive, gave an alarm. The staff quickly traced the sources of the escape, shut off the flow of air and instituted procedures for evacuating all non-essential staff.
Tests on staff contamination have so far shown no cause for concern. BNFL will carry out further tests on staff over the next few days. On present evidence, there was no risk to the public.
A member of the nuclear installations inspectorate was on site and was notified at the time. My Department and other interested Government Departments were notified shortly afterwards. The company has estimated that a very small radiation release from the building of 50 micro-curies may have occurred, but no release was, in fact, discernible from its monitoring equipment outside the building.
The nuclear installations inspectorate has already initiated an investigation in co-operation with the radio-chemicals inspectorate, and will make a statement about the incident within the next few days. The company is also conducting its own inquiries into the incident.