Dounreay Site Restoration Ltd wants to restore an area of land designated as a rubble dump during the construction and operation phases of the site.
An estimated 70,000m3 of material from the construction and demolition of buildings was deposited in the area beyond the eastern perimeter of the site from 1960 or so.
The site, known as Landfill 42, was taken out of use in 2005 and needs to be restored under environmental and planning regulations.
This will involve repositioning approximately 16,000m3 of material and the construction of a new sea defence. A substantial impermeable membrane and an estimated 25,000 tonnes of rock will be used in the closure works.
The work is expected to cost £1-2 million and, subject to regulatory controls, is due for completion by the end of 2011.
Gas and groundwater monitoring will continue for a number of years after restoration until the licence can be surrendered to the Scottish Environment Protection Agency.
The landfill is known to contain hazardous materials, including metals, asbestos and minor radioactive pollution from ground excavation and building demolition work dating back to the 1960s and 1970s.
Phil Cartwright, contaminated land manager at DSRL, said extensive work had been carried out in recent years to characterise the facility.
“We studied several options for closure of the landfill and carefully considered the environmental impact of each,” he said.
“We believe the facility can be left in a safe condition with the engineering measures identified in our closure application to the Scottish Environment Protection Agency.”
The landfill is adjacent to ground now being developed as a site for the disposal of low-level radioactive waste from decommissioning the site.