Cooper Specialised Handling, the UK’s sole national distributor of Konecranes lift trucks and reachstackers, will be contributing to the safe decommissioning of a well-known nuclear power station by supplying a custom-built reachstacker.
The Konecranes reachstacker supplied by Cooper SH will handle 45 tonne concrete overpacks containing Intermediate Level Nuclear Waste (ILW) for Magnox North at its Trawsfynydd Site. The truck will move the ILW into a purpose-built store which will contain the waste until a national repository has become available.
Cooper SH designed a unique attachment to handle the specially built 2.5 metre square concrete overpacks encasing a heavy duty stainless steel box in which the waste is transported. Critical factors to the safe application include the control of the vertical lift the distance of the driver from the box of ILW and a number of bespoke recovery procedures.
Doug Barber, ILW Store Project Lead at Trawsfynydd Site, commented, "This is an unusual handling application in that the number of lifts is small, but the operation needs to meet the highest levels of environmental, security and safety standards.
"The UK nuclear industry is one of the toughest industrial regimes in the world. And 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."
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 pre-requisite of the supply contract to adhere to the strict quality demands of the nuclear industry.
The specially designed attachment has unique elongated twist locks which produce a synchronised arc and extension as the boom moves in, ensuring a permanent vertical lift. The Konecranes machine has also been programmed with different logic and load curve characteristics to handle the waste load versus the lighter stillage utilised for handling drums, thereby ensuring each load is handled with the same care and attention.
David Cooper, managing director of Cooper SH, explained, "This has represented one of our most unique challenges. It is certainly the first time we have been asked how slow our reachstacker 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. In addition, we were asked to provide an override system to manually raise the boom in the eventuality 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 twistlocks.
Trawsfynydd Site has a purpose built ILW store located on 15.4 hectares in the heart of Snowdonia National Park. It is a twin reactor station now defuelled and being decommissioned. 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 for a total of 25 hours. Cooper’s contract includes full contract hire and all-inclusive service and maintenance and the total contract equates to a cost in excess of £16,000 per hour.