Sellafield LTD yesterday lost its appeal against a £700,000 fine for sending bags of radioactive waste to a landfill site.

The owner of the Sellafield nuclear reprocessing site in Cumbria sent bags containing plastic, tissue and clothing to Lillyhall landfill site in Workington when it should have sent them to a specialist facility.

Sellafield Ltd argued that the fine was "manifestly excessive," claiming that there was a negligible risk of any harm.

In a separate case Network Rail (NR) challenged a £500,000 fine after a boy was seriously injured in an accident on an unmanned level crossing near Beccles, Suffolk, in July 2010.

It too moaned that the fine was excessive given its guilty plea and the remedying of safety failures at the crossing.

But Lord Chief Justice Lord Thomas, sitting in the Court of Appeal with Mr Justice Mitting and Mrs Justice Thirlwall, said there were no grounds for criticising the level of either fine.

In the case of Sellafield, Lord Thomas indicated that the fine was "little more than a week's profit" with the company's annual turnover at £29 million - or £560,000 a week.

He said: "It must be viewed against the requirement that those engaged either as directors or shareholders of companies engaged in the nuclear industry must give the highest priority to safety as Parliament has directed."

In NR's case the harm was serious and even greater harm was foreseeable, he added.