Sellafield has been hit with a formal warning after failing to alert the traffic regulator of a £700,000 fine it received for sending radioactive waste to landfill.

The incident which resulted in the substantial fine took place seven years ago when four bags of low-level radioactive waste were sent to the Lillyhall landfill site.

As the company did not inform the traffic commissioner when it was issued with the fine in 2013, a public inquiry was held this week.

Traffic commissioner for the north west of England, Simon Evans, recorded formal warnings on Sellafield's goods vehicle and public service operator licences.

A Sellafield spokesman said: "We accept the judgement and we apologise for our failure to declare the relevant information, due to an administrative oversight.

"We alerted the commissioner as soon as the oversight was discovered. "We have a long track record of successful operations and we will continue to uphold the highest standards of safety and security."

Mr Evans said he was "satisfied" from what he had heard and read, that the convictions did not "adversely impact upon the operator's repute."

He added that while the convictions represented "serious administrative failures" these were "not reflected" in the management of the operator licences, except in one regard.

Sellafield's compliance record, with respect to the operation of HGVs and Public Service Vehicles (PSVs), demonstrated operator licence undertakings were consistently met over an extended period, Mr Evans said.