Latest news
Decommissioning of Primary Separation Plant continues
Comprising over 100 tonnes of steelwork, brick and concrete, six instrument bulges historically used to extract process liquor for analysis in Sellafield’s primary separation plant have been removed from the facility and the waste treated accordingly, ahead of the planned schedule.
Instrument bulges at key locations enabled the samples to be extracted from the process lines. The bulges consist of a 2.5m long trough contained within a stainless steel liner which in turn sits within a mass concrete containment and is further shielded with lead brick and sheet.
As each instrument bulge weighs an average of 17 tonnes, the key driver behind this project was to reduce the overall loading on the building’s core.
Early characterisation work confirmed that each of the bulges varied in radioactivity levels and ranged from low level waste (LLW), through to PCM up to Highly Active (HA).
The initial scope of the project was to remove the six bulges that had been categorised as LLW and gain the knowledge and experience required to undertake the more challenging ones that had been characterised as PCM and HA.
The process for retrieving the bulges involved filling the liners with lightweight grout to prevent the spread of contamination. The connections were then severed and the liners lifted out in one piece from the concrete bulge. Once removed, the main source of radiation and contamination had been negated and the concrete bulge itself could then be demolished using coring and bursting methodology.
While six bulges have now been removed, each representing a business milestone, 18 in total were decommissioned.
The troughs and associated steelwork were disposed of as LLW while extensive sampling and characterisation work meant that the brick and concrete waste (14 tonnes per bulge) could be sentenced as very LLW and dispatched to CLESA for final disposal – making significant cost savings in disposal costs.
Sellafield Ltd Project Manager Mark Nealy said: “This has been a valuable piece of work. Whilst the remaining bulges present a greater radiological challenge, we now have a proven methodology for decommissioning that can be directly applied to the remaining bulges.”
“I would like to thank everyone involved - in particular the Clearance and Characterisation Team in the early delivery of these important executive milestones and in generating tangible cost savings.”
Acknowledging the difficulties encountered during the project, Jeremy Hunt, Programme Manager for Beta-Gamma Decommissioning projects added: “Mark and his team have worked hard to overcome some difficult issues and ultimately deliver ahead of schedule. I would also like to thank the decommissioning and demolition operations teams who have provided invaluable support over the past few months in delivering the latter stages of the work.”
