Sellafield B6

Overview

Sellafield’s 110-metre chimney, infamous as the site of Britain’s worst nuclear accident in 1957, required a carefully managed first-phase demolition. More than 50 years on, radioactive levels had decayed sufficiently to allow the removal of the filter gallery and 500 tonnes of contaminated structural steel, concrete, and masonry. We were engaged to support a £15 million decommissioning programme at this highly sensitive nuclear site.

The Challenge

The demolition posed complex technical and contractual risks. Contaminated materials had to be safely dismantled, bagged, and recorded for disposal, while maintaining rigorous safety and environmental standards. The project had been let under an NEC3 Option C Target Cost contract, but with disputes over scope variations and performance, stakeholder confidence in the contractor had eroded. Without intervention, the contract was at risk of protracted dispute and delay.

Our Approach

We implemented decisive commercial and programme leadership by:

• Re-negotiating and re-baselining the contract to agree a revised target cost, programme, and performance indicators.

• Establishing a collaborative, integrated project team with clear governance and regular daily, weekly, and monthly progress meetings.

• Driving a recovery programme to restore confidence in both delivery and contractual compliance.

The Outcome

The project was completed ahead of schedule and under budget, with stakeholder confidence fully restored. Our intervention not only safeguarded delivery of this critical phase of decommissioning, but also protected the reputation of both client and contractor.