Sellafield sludge plant reaches milestone
19 March 2009
A project to build a facility to deal with sludge that accumulated over more than two decades of Magnox fuel processing at Sellafield is making progress, with the first phase of the project reaching a major landmark. The Sludge Packaging Plant, or SPP1, will receive legacy sludge from a storage pond dating back to the earliest days of the UK's nuclear power program, and process it into a product suitable for long term storage or disposal. The first stage of the two-phase project is the construction of a buffer storage facility to receive and store the waste in storage vessels, which will be installed in a hardened concrete shielded cell. This has now reached the halfway stage with the completion of first concrete pouring. Concrete pouring started in May 2008, and by February a total of 2360 cubic metres of concrete had been poured with 500 tonnes of reinforcing steel fixed.
The buffer storage facility is being supplied by an alliance of Balfour Beatty, Doosan Babcock and Sellafield Ltd, and this stage of the project also includes the design and construction of a short pipebridge to transport the sludge from the pond to the facility.
Module contract
Meanwhile, Mech-Tool Engineering Ltd has been awarded a £1.5 million ($2.2 million) contract to design and build a multi-services processing module that will house a range of equipment for SPP1, including an electrical substation and switchgear, compressor units, HVAC equipment (heating, ventilation and air conditioning) and a manned control room. It will be fire-rated to protect personnel and equipment for up to 30 minutes as well as being able to withstand earthquakes.
The project is the first nuclear industry contract won by Mech-Tool, which specialises in blast and fire protection in the offshore industry. According to Phil Bullock, Mech-Tool modular products division director, the company's bespoke packaged solutions, primarily developed for the offshore sector, are attracting more and more onshore customers. "The environmental conditions may be different, but the challenges in terms of protecting personnel and equipment are just as real," he said.
The company says it will design the module using 3D-modelling 'walk-through' software. The eight split units making up the entire module will be built at Mech-Tool's facility in north-east England and transported to Sellafield by road before being assembled on site by March 2010.
Built and commissioned between 1948 and 1952, the Magnox storage pond was used to store, cool and prepare Magnox fuel prior to reprocessing. Throughout its operational phase the plant stored and processed approximately 27,000 tonnes of fuel, or approximately 2.5 million fuel rods. The plant ceased decanning operations in 1986, becoming a fuel handling plant, but sludge and waste that accumulated throughout the building over the 1970s, as well as in the pond itself, have added to the clean-up challenge. De-sludging activities, with the assistance of a remote controlled vehicle dubbed 'Metal Mickey', are already under way in the pond, which has been described as one of the highest hazard facilities at Sellafield.