Sellafield reveals £25m Windscale reactor decommissioning plans

Contractors are being sought for up to £25 million of decommissioning and demolition work at the former Windscale nuclear reactor complex at Sellafield.

Two procurement notices published within five days outline the next stages of work at the Windscale Advanced Gas-cooled Reactor (WAGR), which helped pioneer Britain's second generation of nuclear power stations.

The larger contract, worth between £10 million and £20 million, involves stripping out buildings, managing radioactive waste, removing asbestos and preparing the complex for further demolition.

A notice published on October 21 states: "The facility is now progressing towards its final phase of decommissioning and demolition."

It reveals that records confirm the presence of both low-level and intermediate-level radioactive waste, resulting in continuing radiological and contamination hazards.

Buildings within the complex remain under active surveillance and maintenance and are classified as 'Beta Gamma contamination facilities'.

The contract includes the removal of equipment and other internal structures, radioactive waste management, decontamination, scaffolding and safety-related work.

It is scheduled to run from April 2027 until April 2031.

A separate tender, published on Monday, October 26, seeks a contractor for the demolition of the B55 Office Complex and B55.2 Turbine Hall, at an estimated cost of between £2.5 million and £5 million.

The buildings will be dismantled down to their existing ground-floor slabs using high-reach demolition machinery.

However, contractors face a particular challenge because an electrical substation located within the structures must remain operational throughout the work.

The notice states: "A key constraint is Substation 65, which is located within the B55/B55.2 structure and must remain operational and be protected from demolition impacts, dust and water ingress throughout the works."

It also highlights uncertainties involving 'ageing structures, buried services, below-ground voids and incomplete historical information'.

Detailed surveys and demolition engineering will be required to manage the risks.

The WAGR reactor was commissioned in 1962 and operated until 1981, serving as a prototype for advanced gas-cooled reactors subsequently developed for commercial electricity generation.

Its distinctive spherical containment building became a familiar feature of the Sellafield skyline.

Following the dismantling and removal of its reactor core, completed by 2012, the complex entered a period of care and maintenance.

The latest contracts represent further steps towards decommissioning the remaining facilities, although neither notice confirms a date for demolition of the spherical reactor building itself.

Both contracts are being procured by A2R, a joint venture between Altrad and AtkinsRéalis, under Sellafield's Decommissioning and Nuclear Waste Partnership framework.

The contracts are advertised as suitable for small and medium-sized businesses.

Bids for the larger contract close on November 3, while companies have until November 10 to bid for the B55 demolition work, which is scheduled for April to December 2027.

Sellafield reveals £25m Windscale reactor decommissioning plans | News and Star