Inspecting encapsulated waste

Project

CM&I technology development and selection

Benefits

Muon tomography will help understand waste evolution within stored waste containers to confirm evolution models. This gives regulators and stakeholders confidence in our ability to manage wastes for interim storage and identifies potential issues with waste containers in sufficient time to allow an appropriate and timely response.

Current Status

The work is currently scheduled to undergo decision governance in June 2023. Following this, a project will be initiated to develop the chosen technology and eventually implement it within the BEP.

Delivery Partners

Jacobs, Lynkeos Technology Ltd, NNL, Rapiscan Systems, REACT Engineering Ltd

Contact Details

Sara Higgins, Alex Allen

technical.innovation@sellafieldsites.com

The Box Encapsulation Plant (BEP) will process legacy wastes prior to interim storage until a final disposal option is available. CM&I is required to understand the waste container performance and condition that can be used to inform the finishing requirements and ultimate disposal.

CM&I within the Box Encapsulation Plant and Stores (BEPS) will either be performed in-situ, where the waste containers are not moved from the store, or ex-situ, where waste containers are returned from the store to the BEP for enhanced monitoring.

Ex-situ monitoring will be used to provide reassurance that the waste is evolving as expected and assure the internal integrity of waste containers. The only viable options that can see through such large and robust waste containers are muon tomography and high energy X-ray radiography. A decision of which technology to use was needed to allow for further development and ultimately timely implementation of a technology.

• Muon tomography is a passive detection system, using the scattering of naturally occurring muons to produce an image of a waste container and its contents. NNL and Lynkeos have developed muon technology to test the capabilities for imaging nuclear waste containers.

• High energy X-ray radiography would use an X-ray fan beam to scan the waste containers. A turntable and bogie design has been developed by Jacobs and Rapiscan Systems that would allow for waste container rotation to produce the required image.

Both technologies were developed to a roughly equal stage to enable a fair comparison. A Technology Readiness Assessment, Technology Roadmap and NDA Value Framework Assessment was conducted to assess each option, alongside a third option of developing neither technology. This identified the maturity, risks and remaining development required, as well as the safety, risks, enablers and ability to implement each technology.

The outcome from the assessment process is that muon tomography should be taken forward for further development and implementation. Muon tomography is a passive technology with fewer safety concerns and has the potential to obtain more valuable information about the waste containers than X-ray.