Nuclear Decommissioning Gantry Cranes

Working for local company SCX, a specialist crane supplier, Eadon Consulting were asked to provide structural and mechanical verification calculations for a crane that is going to be used for decommissioning at Sellafield.

The crane consists of a typical gantry structure, with two long travel units running on it. The first is similar to a conventional gantry crane hoist, although with a number of modifications to make it suitable for a nuclear application. The second unit however is unusual as it contains a telescopic mast unit that can be extended down into a pond area to enable decommissioning work to be carried out. Mounted on the end of the mast is a Brokk hydraulic arm, onto which various tools can be attached.

Eadon Consulting were asked to independently verify the overall structure of the crane as well as the hoisting and mast mechanisms. In order to provide a cost effective solution, a combination of hand calculations and simple beam element models were used as seismic analysis was not required at this stage.

The biggest challenge of the project was dealing with the large number of different load cases that was possible owing to having two crane units that could move independently on a gantry structure, as well as the various fault loads that could occur. A simple method was developed that enabled all of these load cases to be analysed concurrently, cutting down on analysis time whilst ensuring every case was considered.

For more information regarding our nuclear analysis and verification services or to discuss your nuclear design requirements, please telephone 0114 309 4450 or email us.