Sellafield Ltd has been issued with an improvement notice following a 'significant' incident at the site last year.

Safety regulator the Office for Nuclear Regulation (ONR) said the notice requires the company, which runs the site near Seascale, to make improvements in its arrangements for construction design and management.

Dr Mina Golshan, deputy chief inspector and director of ONR's Sellafield Decommissioning Fuel and Waste Division, said: "This incident involved damage to a high voltage underground electric cable during excavation works.

"Although the incident did not result in an injury, it had the potential to impact the health and safety of workers working in the vicinity.

"The notice requires Sellafield Ltd to make improvements ensuring that risks arising from excavation work on the site are controlled and managed appropriately."

The ONR said the notice was issued in response to the incident, which occurred in September last year, during construction activities on the Fellside Steam Generating Plant.

Sellafield must comply with requirements of the notice by April.

A Sellafield spokesman told the News & Star: "During construction works for a new steam generation plant at the Sellafield site, an underground electricity cable was struck, leading to a temporary dip in power to parts of the site.

"Those plants impacted by the dip applied their loss of power procedures to maintain the safety and security of the site.

"No one was injured as a result of the cable strike and there were no environmental consequences.

"Sellafield Ltd has carried out a thorough investigation, has been liaising with the Office for Nuclear Regulation, and is in the process of implementing the findings."