Decommissioning will be phased in over 60 years
An application to build a new plant to clean up radioactive effluent at the Dounreay nuclear site has been lodged.
The UK Atomic Energy Authority (UKAEA) said the plant would form part of decommissioning work at the site in Caithness.
The £2.4m project will remove radioactivity from the effluent before it is discharged into the sea.
It will deal with waste from the prototype fast reactor.
The reactor, one of three built and operated at Dounreay, was closed in 1994.
The fuel has been removed and a £17m plant built to destroy the 1,500 tonnes of sodium liquid metal used as coolant.
The next stages in decommissioning include the steam cleaning of components and facilities coated with traces of sodium.
The cleaning will generate liquors containing radioactive material caesium-137 and cobalt-60, which will need to be cleaned up before being discharged to sea.
The UKAEA wants planning consent to build the new plant which will contain an
ion exchange column to clean up the liquors.
It will have a special resin in the column which will trap radioactivity as the effluent flows through it.
Experts at Prague University are to design the column and will make sure it reaches the standards of environmental protection.
Meanwhile, the radioactivity trapped in the resin will be stored on-site.
UKAEA project manager Mick Moore said: "Subject to planning and regulatory consent, the new plant will be good news for the environment because it means we will be able to clean up the effluent before it is discharged."
It is expected to create 15 jobs, and is one of around 20 new plants expected to be required as part of the decommissioning process.