World War II airplanes to blame for radiation halting work on SSEN cable near Dounreay
The radioactive contamination that has suspended work on a high voltage cable between Orkney and Caithness is being linked to wartime aircraft.
Work on part of the mainland link of SSEN Transmission’s new cable was halted because of the presence of radioactive contamination.
Now, it has emerged that the pollution is being linked to operations at the World World II airfield at Dounreay.
The company has been required to have extra monitoring carried out before it resumes work on its new substation.
The Scottish Environment Protection Agency (Sepa) wants the work done as part of the planning process.
A spokesperson said: “We have identified the need for monitoring for radioactivity to be undertaken at the site where the substation will be constructed.
“The monitoring is needed due to the proximity of the site to the former RAF Dounreay base.
“Following the identification of radium contamination at the site, SSEN has stopped work while it acquires an Environmental Scotland authorisation permit.
“A permit is needed due to the presence of radium contamination at depth and the planned excavation work beyond these depths.”
The spokesperson added: “The site is secure and there is no public access to it.”
SSEN said traces of radiation were found during onshore earthworks at its Dounreay West substation.
A spokesperson for SSEN Transmission said: “In line with our robust environmental mitigation plans and following advice from our specialist contractor, the affected areas were immediately isolated, and exclusion zones established.
“As a further precaution, all works on site have been temporarily suspended whilst further tests and assessments take place.
“Sepa has been notified and we will continue to work with them, our contractors and all other relevant stakeholders.”
The spokesperson said none of its employees had suffered any harm.
NRS Dounreay, which operates the nearby nuclear plant, has offered its help in dealing with the issue.
A spokesman said: “SSEN Transmission notified us of the discovery of suspected radium-226 during preparatory groundwork for the construction of an electrical substation on undeveloped land leased by SSEN from our parent body, the Nuclear Decommissioning Authority.
“Radium-226 was used historically in the instrument panels of military aircraft and we believe this is likely to be a legacy of the wartime airfield.
“NRS Dounreay is engaged with all parties working on a resolution to this.”
SSEN plans to install a 200kV high voltage alternating current cable which will connect Orkney to the Scottish mainland for the first time.
The £900 million project is being designed to connect up to 220 megawatts of renewable energy to the national grid.
