Sellafield Pile 1 chimney tower crane base construction

Construction of the new tower crane base in a highly congested and regulated nuclear environment.

The project scope

Installation of the first phase of demolition equipment for dismantling of the iconic 70-year-old Pile 1 chimney at Sellafield. The project involved:

• Ground investigation works and the handling/removal of contaminated spoil
• Installation and testing of temporary working platforms for the piling rig and 300 Te mobile crane
• Assisting the piling contractor with the installation of the 16m steel cased piles for the tower crane base
• Construction of the RC crane base (85m³) for the erection of the 150m high tower crane, including all associated formwork/falsework temporary works, reinforcement and concrete testing
• Construction of a new storage and handling facility for the contaminated waste concrete sections generated during demolition, which included a bespoke retractable tent system, change room facilities and perimeter security fencing
• Construction of the new RC gantry crane base used for the movement, manipulation and loading of the contaminated concrete sections
• Installation of new surface water and foul water drainage systems

Key quantities:

• Excavation: 200 m3
• RC concrete: 420 m3
• Reinforcement: 75 t

Challenges & successes

The work was carried out in a high radiation / contamination area which required additional workforce training and working procedures to be implemented. This caused some delays to the schedule, but we worked in collaboration with our client and the piling contractor to recover the schedule.

The work was carried out in a high security area of the site with access restrictions. This required us to manage labour, plant and material logistics in and out of the site in close collaboration with our client and the security department. This involved accurate forecasting and planning by providing a 3 week logistics look ahead plan – continually detailing all labour, plant and material access requirements.

We discovered a significant amount of uncharted buried cables, pipework and underground structures during excavation. To overcome this, we used Vacuum Excavation which accelerated the works, mitigated the schedule delays and reduced the safety hazard of hand digging in this area.