Power and Utilities | Hoisting & Lifting Equipment | by STAHL CraneSystems | Nov 28, 2018
When the 13th amendment of the Atomic Energy Act was put in place in 2011, it was decided that Germany would move away from use of nuclear power as a source of energy. As a result, all nuclear power stations in Germany were set to be decommissioned by the end of 2022. The shutdown and subsequent dismantling of these stations presented a logistical challenge to the operators, with tons and tons of material having to be dismantled, relocated and moved. Durable and reliable technology from STAHL CraneSystems proved to be the perfect technology for the job.
The Philippsburg nuclear power plant (NPP), operated by EnBW was one of the locations affected by this. The boiling water reactor in Unit 1 of the nuclear power plant (NPP 1) was, after 32 years of operation, one of the first eight reactors to be taken from the grid. In May 2017, after completion of the approval process, dismantling of this plant began. At this time, the pressurized water reactor in Unit 2 (NPP 2) was also approaching the end of its operating life and scheduled for shut down.
The highly radioactive spent fuel elements of the two reactors had been stored in suitable containers in an interim storage facility of the NPP since 2007 and were not affected by the dismantlement. Of the total mass of an EnBW nuclear power plant, up to 98% were conventional reusable and raw materials and 1-3 % were low to medium-level radioactive residues. The total mass of the nuclear power plant NPP 1 was approximately 398,000 tons and that of NPP 2 approximately 783,000 tons.
To enable efficient handling of these masses, EnBW put a special dismantling infrastructure in place. This consisted of a residue processing center for the treatment of residues and a waste storage facility in which the radioactive waste would be stored until the permanent disposal site “Schacht Konrad” near Salzgitter was commissioned and built on the premises of the nuclear power station.
In January 2017, EnBW contracted Innokran GmbH, a certified partner of STAHL CraneSystems, to install three crane systems in the Philippsburg residual waste processing center and waste storage facility. In the processing center, a frequency-controlled SHWF 8 winch from STAHL CraneSystems with a lifting capacity of 32 tons was used on a double girder overhead travelling crane with a span of 20 meters.
The SHW 8 winch from STAHL CraneSystems is based on the tried-and-tested SH wire rope hoist program and is designed for a high-load bracket up to 160,000 kg. Thanks to its robust and low-maintenance design, it is ideally suited to everyday work. The modular assembly of the winch enables various designs and trolley variants ideal for a wide range of applications and solutions tailored to specific requirements. The SHWF 8 winch in Philippsburg has a lifting speed range of 0 to 4 m/min. and is continuously variable.
In addition, an auxiliary SHF 50 hoist with a lifting capacity of 5 tons was installed. The power supply lines for the hoists each run protected in an energy chain. When the load moves downwards, the generator-generated energy is converted into heat by the braking resistance and can be released into the environment by convection. In addition, the special safety standards applicable in nuclear technology require redundant implementation of brakes and measuring systems. Some components, such as the switch cabinet, are made of corrosion-free stainless steel for easier cleaning; a paint coating is not required.
The biggest challenge with such a plant is the complete documentation of all work processes, including those of supplier companies. EnBW attached great importance to this. After the preliminary test has been carried out, the components are joined according to a welding plan. Before painting, all material stamps are compared and the execution of the welds, dimensional accuracy and completeness are inspected by external inspectors.
Working together, STAHL CraneSystems and Innokran GmbH once again provided a best-in-class solution to meet a customer’s unique application needs.
The power supply lines for the 32 t SHWF 8 winch and the auxiliary 5 t winch each run protected in an energy chain.