A fire caused by staff error at a Scottish nuclear reactor site in October 2014 led to an "unauthorised release" of radioactivity admits Dounreay Site Restoration Limited (DSRL), the company licensed and responsible for the clean-up and demolition of the site.
DSRL said the fire at the sodium tank farm in Dounreay on 7 October was caused by "unacceptable behaviours and practices" from staff that "fell well short of our values and standards."
The fire was immediately extinguished and the site was confirmed safe within 30 minutes. No one was harmed in the incident and action has been taken to stabilise the situation and stop work in the tank farm until the Office for Nuclear Regulation (ONR) was satisfied with the DSRL's improvements.
In a statement on Dounreay.com the company said that its investigation "identified procedural non-compliances and behavioural practices that were factors in the incident, and fell short of the values and standards expected of our people. It also confirmed the release of radioactivity via an unauthorised route."
On November 11, the ONR served DSRL with an 'Improvement Notice' relating directly to the tank farm incident.
Mark Rouse, managing director of DSRL, said he accepted the improvement notice and will co-operate fully with the regulators.
"Our investigation identified unacceptable behaviours and practices that fell well short of our values and standards. It is important to take the time to ensure as many lessons are learned from this incident as possible," said Rouse.
"We are determined to improve our behaviours and compliance to ensure that we always meet the high standards expected on a nuclear site."
Dounreay is on the north coast of the Scottish Highland region of Caithness. The site was established in the 1950's and used for two nuclear power prototype testing facilities, which having ceased operation in 1994, are now being decommissioned.