SIXEP Continuity Plant

Published By GOV.UK [English], Fri, Feb 18, 2022 3:58 AM

The challenge

The existing Site Ion Exchange Effluent Plant (SIXEP) which has been operational since 1985 removes radioactivity from various site effluent streams on the Sellafield site.

The Site Ion Exchange Effluent Plant (SIXEP) on the Sellafield site

It acts as the ‘kidneys’ of the site filtering out radioactive material before discharging to sea.

SIXEP is one of our key effluent treatment plants because of the role it plays in treating effluents from high hazard and risk reduction programmes from the First Generation Magnox Storage Pond and the Magnox Swarf Storage Silo.

The effluent treatment capability currently provided by the plant is needed until around 2060 and is fundamental to the delivery of the Magnox Operational Programme, Advanced Gas-cooled Reactor Programme and high hazard and risk reduction activities.

Due to the age of the original SIXEP, which was only designed to operate for 25 years, we need a facility that will take over the role of effluent treatment for the Sellafield site.

The solution

The solution is to build a new treatment plant to replace the existing facility.

That new facility is the (SCP), which will be an essential replacement for SIXEP. It’s 30+ years old with currently no backup and some single point failure mechanisms.

An external image of the proposed

A cut away of the proposed

SIXEP has an excellent track record, operating 24/7 and reducing the site’s environmental impact for the past 35 years.

The new plant will make sure that we have continued availability of effluent treatment for the future work of reducing high hazard and risk reduction activities.

The new facility is under construction north of the existing SIXEP facility. It will replace the current effluent treatment function of SIXEP itself, with modifications to the existing plant to allow effluent to be diverted to the new facility as soon as it’s been through active commissioning.

Benefits:

The replacement SCP project is fundamental to high hazard risk reduction activities.

Status:

Currently under construction with an active commissioning date currently set at April 2029

Collaboration:

The is being delivered by the Programme and Project Partners, which is made up of lot partners:

- KBR (integration partner)

- Jacobs (design and engineering partner)

- Morgan Sindall Infrastructure (civils construction management partner)

- Doosan Babcock Ltd (process construction management partner)

- Sellafield Ltd as the 5th partner

Progress so far

Major milestones that have already been achieved are:

project baseline has been set and agreed

detailed design gate passed with the described as best in class amongst other major projects on the Sellafield site

final business case approved by the HM Treasury in December 2021, 3 months ahead of schedule

completion of the foundation for Process and Services Building in February 2022 completed ahead of schedule.

12 new contracts awarded in 2021, including several key contracts to supply unique, highly complex plant and equipment

main concrete slab constructed

3 tower cranes installed and supporting construction of concrete walls and structural steel frame installation

approximately 5,000m3 of concrete installed in 2021 and first-phase steel work erected.

final concrete slab pour completed in February 2022, ahead of schedule

Next steps

The first project wide milestone is due in July 2022. This will be the completion of 2 large stainless steel process vessels, which will be ready for performance testing.

Design for manufacturing is also coming to completion in the next few months , the remaining 14 procurement packages are to be placed in 2022.