Surveillance and maintenance challenge overview

Keeping our nuclear legacy safe and secure costs millions of pounds each year. There is an opportunity to deploy innovative approaches to reduce this cost and improve the strategic approach of deferred decommissioning.

The vast Sellafield site is home to many facilities that have a planned stage of surveillance and maintenance. It takes place after operations have ceased and until the plant is ready for demolition. The term surveillance and maintenance is applied to the function of monitoring and keeping safe and secure nuclear plants and their nuclear inventory in their post- operational lives. Surveillance and maintenance, therefore, is conducted as part of ensuring nuclear material is appropriately immobilised, cooled, contained and shielded.

Surveillance and maintenance is often extended, from years into decades as the Sellafield decommissioning programme develops over time.

The programme adapts to deliver an overall risk and hazard reduction mission within available funds.

The spending on surveillance and maintenance, part of the UK taxpayer’s nuclear liability, is significant; often many £millions per annum per plant.

The purpose of these Sellafield Ltd surveillance and maintenance Challenge Statements is to seek innovative ideas that will reduce the cost of the surveillance and maintenance of nuclear facilities:

  • Reducing surveillance and maintenance costs, through innovation, can save millions of pounds
  • These savings can be used to accelerate decommissioning
  • Acceleration, in turn, further reduces surveillance and maintenance periods and costs
  • The UK taxpayer receives better value for money
  • Our nuclear legacy is dealt with sooner



This Challenge Statement seeks innovative ideas to address the costs associated with the surveillance and maintenance of nuclear chemical process plants. These comprise large, shielded cells containing stainless steel vessels and pipework.


Image right: Isometric view of a chemical process cell

<50m high
<10m2 footprint
<5m thick reinforced concrete walls, multiple main process vessels, many pipes and ventilation ducts, mild steel supports
<15 minutes human- working time due to radiation and heat

The interconnected stainless steel tanks, columns and vessels can be several metres in length or diameter, weighing several tonnes. This equipment was used to undertake chemical reactions and processes on the radioactive feedstock. Fuel reprocessing plants, e.g. ThORP and Magnox, contain tens of cells, linked together to form a complete separation process.

The facilities can be up to 60 years old, with all the attendant condition and asset care issues.