Oldbury power station has found a new way to deal with waste sludge removal. The direct pour method, which involves encapsulating the waste in concrete, reduces waste volumes, saving time and money.
Oldbury has stored the sludge products, which have arisen through activities such as oil separation and the site laundry and shower systems, on site since it was commissioned in 1967. The traditional route for disposal used by other nuclear sites has been to transfer the waste into drums which were then packaged into an ISO container for transport to the Low Level Waste Repository (LLWR) in Cumbria.
This method, however, inevitably resulted in an inefficient use of space as cylindrical drums were packaged into rectangular ‘half height’ ISO containers.
Project teams at Oldbury decided to innovate a method that encapsulates the sludge in concrete and then pours it directly into a ‘third height’ ISO container, reducing the total volume of waste by 59%
The outcome is a reduction in the number of containers required from 10 half height ISO’s to six third height ISO’s, minimizing processing time from 12 to five weeks, shortening the overall project duration by four months and saving £800,000 for the UK taxpayer.
The first container has now been successfully mixed and dispatched off site.
“When we looked at the process we thought there must be a more efficient way of packaging the waste sludge,” said Paul Thacker, Project Lead at Oldbury.
“A similar process is already used in the oil and petrochemical industry which we felt could be successfully transferred to a nuclear site.”
One other important method adopted by the project was the technique for stiring the sludge to make the contents consistent. This was achieved by using a ‘Stem Drive’ device which is pneumatically driven and therefore does not introduce any additional waste stream to the product.
The equipment for processing has been designed and built on site by contractor Waste Management Technology. The plant is mobile and will be able to be fully removed from site when the work is complete, leaving no additional legacy for clean-up.