Operators have been given a date for the former nuclear plant at Dounreay to be demolished.
Babcock Dounreay Partnership has committed to levelling the site by September 14, 2023.
Roger Hardy, head of the Babcock management team, confirmed on Friday that the complex of redundant fuel and waste plants have to be flattened in just over 11 years.
Though it is a "big ask", Mr Hardy said he was confident the deadline could be met.
The consortium, headed up by Babcock, will face financial penalties if they fail to complete the task by the required date.
The Nuclear Decommissioning Authority is underwriting the site's clean-up with annual funding of £150m.