A company at the centre of a radiation alert on Aberdeen beach is being ordered to stop discharging waste into the sea, BBC Scotland has learned.
Traces of radiation were found at Aberdeen beach
Scotoil, which cleans equipment for the oil industry, was named as the most likely source last year.
Environment protection agency Sepa will officially announce on Friday that the firm will have to find other means of getting rid of the material by 2008.
Scotoil said it could close their business, and it plans to appeal.
Fears have now been expressed about more than 50 jobs at Scotoil.
A stretch of the beach was closed in August 2005 when traces of radiation were found in the sand.
Sepa said it had found "slightly raised" levels of radioactivity in a very small area of sand on the high tide line at the southern end of the beach near the harbour wall.
It originally identified the recycling company Scotoil as the most likely source. Sepa later said no link had been established.
Scotoil's waste is in the form of naturally occurring radioactive material produced during oil production.
This is removed from oilfield equipment at Scotoil's premises in Aberdeen and the waste is disposed of by discharge to the sea.
A Sepa spokesman told BBC Scotland: "We believe there is a need for improvement and we believe two years to do that is a reasonable length of time."
However Scotoil said it could see no alternative, and that the 2008 deadline could force the business to close.
Offshore union Amicus expressed concern at the potential loss of more than 50 jobs at Scotoil.
Amicus regional officer Graham Tran said Amicus fully supported the move to cease radioactive waste being discharged into the North Sea.
However he said: "It is important that Scotoil is afforded a reasonable timetable to comply with Sepa's instruction.
"We have to recognise that this is not a multi-national oil company that we are dealing with.
"I will be seeking an early meeting with local politicians, who serve the constituency where Scotoil are based, in the hope that they could use their influence to have Sepa revisit this matter with a view to agreeing a more realistic timetable."