SELLAFIELD Ltd has been given an extension to improve the condition of a cooling tower, after a watchdog recognised the "significant progress" made so far.

The Office for Nuclear Regulation (ONR) demanded improvements in September in the firm's management and control of the legionella bacteria in the tower at its Highly Active Liquid Effluent and Storage (HALES) facility.

The original deadline was January, however the ONR has this week granted an extension until May 19.

In September, both the ONR and Sellafield Ltd said there has not been an outbreak of legionnaires’ disease, but the regulators said steps must be taken to “minimise the likelihood” of the bacteria spreading and being released. Sellafield Ltd accepted that its cleaning regime was not sufficiently “robust”. The stand-by tower is not currently in operation.

A ONR spokesperson said: "Sellafield Ltd has made demonstrable improvements and has completed a significant amount of work to date.

"As the cooling tower in question is not currently in operation, and therefore poses no risk to the public, it was our considered judgement that this extension will allow the further necessary improvements to be completed in a safe and sustainable manner to secure long-term, effective risk control."