Open Call for Innovation – Post Operational Clean Out at Sellafield.

For most of its existence, the main business focus of the Sellafield site in west Cumbria has been nuclear reprocessing. Reprocessing activities at Sellafield are due to come to an end over the next two years, and preparations will begin to transition into a Post Operational Clean Out (POCO) phase.

POCO (Post Operational Clean Out) is the process that takes place when a nuclear plant has reached the end of its operating life and is the final phase in a plant’s operating life before decommissioning begins.

The aim of POCO at Sellafield is to reduce the risk and hazard in a facility by safely removing the nuclear and chemotoxic inventory and, ultimately, reducing the lifetime costs of the redundant plants.

In simple terms, POCO gets the plant as radiologically and chemically clean as can be to reduce the risk and hazard and, in turn, makes the plant cheaper to care for in advance of being dismantled.

It is estimated that the cost benefit of POCO could be a potential saving of £1.8bn across the life span of three key reprocessing facilities at Sellafield. 

At least 87 facilities are due to undergo POCO over the next 40 years. 

Current POCO practice is focused on carefully sequenced washout of the plants using water or simple acids, employing existing process equipment and techniques. Successful POCO requires the mobilisation of materials which:

  • Are highly radioactive and chemotoxic;
  • May be either solids and deposits, or a combination of both;
  • Have become adhered or attached to vessel walls, process equipment and pipes;
  • Have become engrained within metal cell walls;
  • Are remaining solvents within process systems.

The recovery and transfer of waste during current baseline POCO methods involves ejection (steam) pumping and systems under vacuum.

For clarity, a ‘cell’ in this instance is an enclosed space within a facility at Sellafield, separated from the external environment, in which active material is processed. They are often inaccessible by man, but are often serviced by pipe-works feeding into, and out of, the cell.

Characterisation is critical to understanding if POCO targets have been met but this is challenging at Sellafield as many plants were not intentionally designed to support post-operational sampling or characterisation. It is essential that containment is maintained.

______________________________________________________

Sellafield would like to explore:

ACCESS

  • Alternative cell and vessel access.
  • Remote handling and navigation techniques.
  • Reduced human intervention.

CHARACTERISING

  • Deployment of innovative technologies for visual, physical and radiological characterisation.
  • Material identification – solids (which may be loose or adhered), solvents and engrained activity.
  • The location and assessment of radiation dose i.e. ‘hot spots’

CLEANING

  • The use of new reagents to aid dissolution of insoluble materials and deposits contained in tanks.
  • Alternative techniques to mobilise solids, solvents, adhered and engrained material.

TRANSFERRING

  • The use of retrieval and disposal tools, and techniques.
  • In-situ storage and grouting applications.
  • Shielding and containment technologies.

______________________________________________________


The opportunity for innovative solutions

This information is published as an open call for innovation, with Sellafield looking for technologies, processes and characterisation techniques which could deliver game-changing improvements over the current baseline POCO methodology.

This would entail the development of alternative approaches to effectively remove and reduce hazardous material within the process equipment and associated cells.

To support our principles, we need to consider;

  • the potential for cost savings gained by eliminating over-engineered packages;
  • improved efficiencies through reduced complexity of deployment.

______________________________________________________


What are the next steps?

Game Changers invite any persons, SMEs, large organisations or academics to apply to the programme and help overcome the challenges faced by Sellafield in this specific area of decommissioning.

Funding is available through the Game Changers Innovation Programme for new innovations, technologies and approaches which may aid Sellafield in their decommissioning mission, and which demonstrate commercial potential for the innovator.

______________________________________________________