“SCABBLING” SET FOR WIDER INDUSTRIAL APPLICATION

Scabbling utilises Ultra High Pressure (UHP) water jetting techniques together with a rotating epicyclic cleaning head to remove waste build up on submerged surfaces, which can then be removed using vacuum techniques.

A system developed for decontaminating submerged surfaces in radioactive waste containers is set for wider industrial application, according to a specialist Midlands engineering company, Nuclear Engineering Services Limited (NESL).

Through its work for the British Nuclear Group in the design, manufacture, assembly and test of waste retrieval machines for use in the Silo Emptying Plant at Sellafield, NESL has considerable experience of the factors to be considered when handling wet or solid radioactive waste. Together with its associate company, Power Jet Systems Ltd., it is now developing a bespoke range of water jet cleaning equipment for these particularly hazardous duties.

The latest generation of equipment utilises Ultra High Pressure (UHP) water jetting techniques together with a rotating epicyclic cleaning head to continuously remove active surfaces to a given depth. These wastes are then removed using vacuum techniques. This complete process is commonly known as ‘scabbling’. These scabbling techniques can be used underwater or in dry environments as required by the specific application.

Scabbling techniques have already been successfully deployed in the nuclear industry for the decommissioning of active silos or ponds containing nuclear waste materials submerged in water. In both cases, the water in the silo or pond acts as a radiation barrier for not only the active contents but also the concrete wall structure.

Following the removal of active waste from the pond or silo a further decommissioning operation removes the water barrier. This provides significant challenges with respect to contaminated airborne particulate and the use of sophisticated remote access. The use of UHP Scabbling techniques either by underwater deployment or the use of a floating pontoon can reduce the activity level of the concrete structure as the water barrier is removed. Through this method the pond or silo can then be accessed by manual means providing a significantly cheaper solution for the overall process.

Commenting on the development programme in the company’s water jet decontamination activity, NESL’s Sales Director John Cooper said, “Whilst developed principally for use in industrial environments, these techniques have far-reaching applications throughout the nuclear industry. Our work in the hazardous and active environments with NESL, combined with our specialist UHP knowledge within PJS, provides an ideal team to exploit the full potential of this equipment”.

Employing 145 staff at their facility at Ettingshall in Wolverhampton, NESL has recently been named as the Black Country Chamber of Commerce Champion Business of the Year, in recognition of its innovative use of technology in its products and services to the nuclear, defence and industrial sectors.

www.powerjet.co.uk