Accelerating the decommissioning of Sellafield’s Medium Active Salt Evaporator

Key Skills & Competencies

• Problem Definition
• Methodology Development
• Rapid Problem Solving
• ‘Fit for Purpose’ Engineering Decision making
• Collaborative Team Building

Our Partners

• React Engineering – as part of Cumbria Nuclear Solutions Limited
• Sellafield Limited

The concentrate ejectors are critical to the operation of the Medium Active Salt Evaporator Plant (MASE), as they are needed for transferring radioactive liquor from the evaporators, for export from the plant. The ejectors had blocked in 2022 as the plant approached the end of its operational life, several unsuccessful attempts to unblock the ejectors had been previously undertaken.

Key Benefits

• Enabling a cost and time effective solution, accelerating decommissioning (cost savings estimated to be £5m)
• Close collaboration delivering a solution which avoided unnecessary risks and costs
• Risk reduction and early programme benefits

Project Overview

A series of options had been developed to clear the blockages, with the preferred option involving significant engineering modifications to the plant, estimated to cost in the region of £5M to implement and taken several years to complete. This approach would also have significantly impacted the cost and timescales for undertaking Post Operational Clean out and decommissioning work.

Our Approach

React Engineering had been commissioned to undertake a separate, broader study into the final decommissioning of the facility. As part of the study, we devised an innovative method to unblock the ejectors that required no plant modifications. The solution centred around utilising the original plant recovery features in a novel configuration, de-risking future decommissioning work, by removing as much of the radioactive inventory from the plant during its operational phase, for treatment by existing down-stream facilities. Our team worked collaboratively with their Sellafield Engineering and Plant Operations counterparts, to define and safely implement the methodology; the plant operations team successfully deployed the methodology within a short timeframe and unblocked the evaporator.

Benefits

• From defining the method, to implementing the work on plant, took less than one month.
• The successful unblocking of the ejector has enabled emptying of the remaining concentrate from the evaporator, allowing final evaporation operations to resume.
• This will enable the transition of the plant into POCO and decommissioning with a significantly reduced radiological inventory, reducing lifecycle costs.
• The direct cost savings associated with the innovative approach and not having to proceed with the intrusive process modifications for unblocking the ejector are estimated at £5M.