Flagship Sellafield project seals major milestone
Source: gov.uk (2025-05-15)

Plutonium treatment plant moves a step closer to completion

The Sellafield Product and Residue Store Retreatment Plant (SRP) is one of our largest and most complex construction projects.

When finished it will play an essential role in managing the UK’s plutonium stockpile.

The project celebrated an important milestone this week as its roof was sealed with a final concrete pour, making the main building watertight and ready for internal fit-out.

The Sellafield Product and Residue Store Retreatment Plant - first and last concrete pour - YouTube (https://www.youtube.com/watch?v=WCC_fRdlMYM)

Once operational, the plant will retreat and repackage existing material into more durable, long-term storage packages, ensuring they can be safely stored into the next century and beyond.

The project is being delivered under Sellafield’s Programme and Project Partners (PPP) infrastructure delivery model which brings together KBR, Amentum, Morgan Sindall Infrastructure, Altrad Babcock, and a wider supply chain, to deliver a 20-year pipeline of major infrastructure projects.

Completing the vast roof slab required 12 weeks of work and over 2,700 cubic metres of concrete to be poured and pumped to heights up to 30 metres.

The achievement moves the project closer to active commissioning and operations in support of the government’s plutonium disposition strategy (https://www.gov.uk/government/news/nda-group-welcomes-government-decision-on-plutonium-disposition) announced earlier this year.

Sellafield Ltd projects director, Andy Sharples, said:

I’m immensely proud of the progress being made on SRP. It’s a project of national significance and is crucial to the delivery of our special nuclear materials strategy and managing one of the site’s highest hazards.

Milestones like this show how we’re transforming major project delivery at Sellafield while progressing our mission to create a clean and safe environment for future generations. Congratulations to everyone who has played a part in this latest achievement.

SRP project director, John Leslie, added:

I’m delighted we’ve reached another pivotal moment in the delivery of SRP, and I want to congratulate the team on their latest achievement.

This is an extremely complex major project to deliver, and through our PPP delivery model we have collaborated with our supply chain partners Kier, Severfield and Mammoet to achieve another significant step forward.

Delivering projects of this scale and keeping them on track, while keeping everyone safe, is no mean feat and is thanks to the collaboration and professionalism demonstrated everyday by hundreds of people across our supply chain all striving for excellence.

Louis Twentyman, a graduate of PPP’s internship scheme and now a site engineering apprentice on the project, said:

It’s amazing to be part of a project the scale of SRP, and one with such an important role in the site’s decommissioning.

Not everyone gets to work on projects of this stature and where there’s something interesting and exciting happening every day. It’s amazing seeing it progress and to be part of it all – I can’t wait to say I helped to build that.

Further information on Sellafield Ltd’s priorities and progress (https://www.gov.uk/guidance/sellafield-ltd-priorities-and-progress)