Northern Irish firm Graham Construction will build vaults on a former military airfield in the Scottish Highlands

Graham Construction will begin work next month on a £100m store for low-level radioactive waste from a former nuclear power station.

The Northern Irish firm will construct up to six shallow vaults on a former military airfield near Dounreay in the Scottish Highlands for client Dounreay Site Restoration Limited (DSRL).

When complete in 2014, they will be used to hold items like paper, rags, tools, glass, concrete and clothing which contain small quantities of mostly short-lived radioactivity.

Dounreay’s nuclear reactor was shut down in 1994 and work to decommission the site has been underway since then as part of a £2.6bn project.

The cost of the project is being met by the Nuclear Decommissioning Authority (NDA), which is investing £100m for the safe disposal of low-level radioactive waste (LLW) from the site.

Clearing and dismantling Dounreay in expected to produce up to 240,000 tonnes of LLW, which will be placed in steel drums and crushed by a compactor. Once in the vaults, it will be covered with concrete.

Phillip Colville, finance director with site closure contractor Dounreay Site Restoration Ltd, said: “The disposal site provides a safe long-term home for the legacy of low-active radioactive waste at Dounreay and provides the community with a cash flow that can help to sustain it beyond the closure of the site.”