Sellafield Ltd., the operator of a nuclear reprocessing site in northern England, faces prosecution over claims it sent four bags of radioactive waste to landfill, according to the U.K.’s nuclear and environmental regulators.

The company must answer charges it sent the bags from its Sellafield site to the Lillyhall landfill facility in nearby Workington in 2010, according to an e-mailed statement from the Office for Nuclear Regulation and the Environment Agency today.

The prosecution of the company, which is responsible for nuclear waste management on behalf of the U.K.’s Nuclear Decommissioning Authority, follows a 2 1/2-year investigation by regulators. It faces nine charges to be heard at Workington Magistrates Court on Dec. 12, according to the statement.

As well as waste disposal at Lillyhall, the charges relate to transporting dangerous goods, lacking adequate management and resources to meet environmental obligations, and failing to use the best tests and measurements to comply with its environmental permit, the statement shows.

Sellafield will “take the time to consider the information provided to us” by the Environment Agency and the Health and Safety Executive, Karl Connor, a spokesman for the company, said today in an e-mailed statement, declining to comment further since the matter is subject to court proceedings.

The Sellafield site is home to the world’s first commercial nuclear power station, Calder Hall, which generated electricity from 1956 to 2003.