Retrieval, characterisation and packaging of intermediate level waste for storage

As managing contractor, Costain delivered the project which involved tunneling into reinforced concrete bunkers to retrieve solid graphite waste for characterisation and packaging into shielded boxes. Specific services provided on the project included:

• Construction
• Manufacturing
• Integrated Testing
• Installation
• Commissioning

Remote Handling

The active nature of the waste necessitated that all operations be remotely controlled. Access to the bunkers and retrieval of the waste is via remotely operated Brokk vehicles which load material into a hopper for transfer into 3m³ packages at a throughput of 8 per week.

Off Site Integrated Testing

Recognising the challenging operating environment the equipment would need to operate within, the entire plant was modularised, assembled and tested offsite prior to installation. This allowed demonstration of throughput performance and the opportunity for early operator training, as well as gains in efficiency during installation. 

Waste Monitoring

To meet the requirements of the intermediate level waste store, each package had its radiological inventory assessed and recorded. Also, the final waste packages were swabbed and analysed to ensure that the external surface of the package was free from contamination prior to transfer to the store.

Oxygen Reduced Atmosphere

Retrieval operations required an oxygen reduced atmosphere to reduce any risk of fire. This was achieved by installing a nitrogen generation package to inject nitrogen into the process area and bunkers.