Cooper Specialised Handling has supplied a custom-built Konecranes reach stacker for the decomissioning of Magnox North's nuclear power station at Trawsfynydd site.

Cooper Specialised Handling, the UK's sole national distributor of Konecranes forklifts and reach stackers, has supplied a custom-built reach stacker for the decommissioning of a well-known nuclear power station.

The Konecranes reach stacker will handle 45 tonne concrete overpacks containing Intermediate Level Nuclear Waste (ILW) for Magnox North's Trawsfynydd site. The reach stacker will move the ILW into a purpose-built store, which will contain the waste until a national repository becomes available.

Doug Barber from the Trawsfynydd site says the handling application is "unusual". "The number of lifts is small, but the operator needs to meet the highest levels of environmental, security and safety standards."

"The UK nuclear industry is one of the toughest regimes in the world. We needed absolute control of the vertical lift, a machine that could perform accurately under extremely slow conditions as well as a facility for total manual override," he adds.

Magnox North personnel were involved throughout the design, manufacturing and testing process that saw numerous visits to the Konecranes production facility in Markaryd, Sweden.

This was an essential prerequisite of the contract, to adhere to the strict quality demands of the nuclear industry.

Cooper SH designed a unique attachment to handle the specially built 2.5 sqm (26.9 sqft) concrete overpacks encasing a heavy duty stainless steel box in which the waste is transported. The control of the vertical lift, the distance of the driver from the box of ILW and a number of bespoke recovery procedures were critical to the safe operation of the reach stacker.

The attachment has elongated twist locks which produce a synchronised arc and extension as the boom moves in, ensuring a permanent vertical lift. The reach stacker has also been programmed with different logic and load curve characteristics to handle the waste load to ensure loads are handled with the same care.

David Cooper, managing director of Cooper SH, says this has been one of the company's most unique challenges. "It is certainly the first time we have been asked how slow our reach stacker could lift and lower, or how much air space there is between the driver and the load. Both parameters were critical in safe operation at Magnox," he says.

Cooper adds that the company was also asked to provide an override system to manually raise the boom in the event of truck power failure.

"A second electronic override system was also specified to ensure the machine could only travel empty when the boom was at a pre-determined height to eliminate accidental damage to the extended twist locks."

The 45 tonne Konecranes truck will move a total of 250 boxes of ILW into storage over the five years of its operational life, working a total of 25 hours. Cooper's contract includes full contract hire and all-inclusive service and maintenance, and is valued in excess of GBP16,000 (USD26,212) per hour.

The Trawsfynydd site has a purpose-built ILW store located on 15.4 hectares (38 acres) in the heart of Snowdonia National Park. It is a twin reactor station, now de-fuelled and being decommissioned.