Provision of a Steelwork Clad, Portal Framed Building

Dounreay Site Restoration Limited (DSRL) is awarding a Contract for the manufacture and erection of a steel portal frame building and ancillary steelwork structures. The building is required to provide suitable support and protection for a shielded ADU Floc immobilisation process line which is to be built on the Dounreay site. The supporting ancillary steelwork structures include a pipe bridge, external fire escape and covered walkway.

The portal frame structure will fix directly to a 1m thick reinforced concrete foundation slab which will be constructed by others as part of the Civil Works associated with the new facility. The pipe bridge plinths and foundations required for the ancillary structures will also be constructed by others.

The main building structure is approximately 12m x 18m on plan with an eaves height of 10m and a roof pitch of 15°. The structure incorporates a 5 tonne runway beam along the full length of the building.

A 5m x 10m lean-to structure is also attached to the main building for storage and export facilities. This secondary structure is approximately 10m x 5m on plan with an eaves height of 4m and a roof pitch of 15°.

The structures are to be clad with insulated profiled metal cladding with a core thickness of 100mm and a fire rating of 30mins. The building includes 4 No. roller shutter doors and 4 No. fire escape doors.

The pipe bridge is of lattice beam construction, 45m in length and supported on 5 column frames all circa 6.5m in height. The spans between column supports vary between 19.5m and 4.0m. The external fire escape is a braced steel structure with dunbar flooring and the covered walkway comprises of a series of transverse steel portal frames clad in proprietary insulated profiled metal cladding.