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Programme and Project Partners at Sellafield.

Contractors in the most demanding of Industries.

Nuclear Contracting Growth

Our growth began when construction giant Kier invited William King Construction to tender for a major masonry contract at Sellafield, which led to a commercial flooring contract.

This led to the next major masonry project on the Box Encapsulation Plant, a joint venture between Balfour Beatty and Jacobs.

William King Construction also works as a subcontractor to facility management company Mitie on the Sellafield site and in November 2022 was awarded the biggest project in the company’s history in the form of masonry and internal fire door fit-out for the SIXEP Continuity Plant project.
It is also involved in masonry work on a new building for Cumbria Nuclear Constabulary at Sellafield.

Willaim King Construction has a growing order book on the Sellafield site, most recently being awarded a £2.6m package of work within its Programme and Project Partners framework.


William King Construction's projects include the complete delivery of the masonry package on the Bepps+Diff project on the Sellafield site in Cumbria. One of Europe's most complex working environments proved to be a challenge which needed strict quality control and careful planning from the team.


Working to all the principles associated with a highly complex site like Sellafield, safety is a huge part of our daily routine. We work with local consultants and Citation, a national company who offers unrivaled HR and Health & Safety support and expertise.

We work to ISO 9001, and our staff members are trained with NEBOSH, City & Guilds and CITB, we are also proud members of the National Federation of Builders.

Proud to work in partnership with:

Programme and Project Partners at Sellafield.
M+W Group
Sellafield Ltd
PHP Architects: Home
Copeland Borough Council
Balfour Beatty

William King Construction.
Phoenix Enterprise Centre
Cleator Moor
CA25 5BD

William King Construction (Sellafield)
Industrial Park, Unit 16 Cross Lanes
Gosforth Road
CA20 1FB

William King Construction
167-169 Great Portland Street,

Telephone: 01946 448123

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LABC Regional Finialist 2020