Seismic Analysis of a High Integrity Nuclear Crane

SCX, a specialist crane supplier, were responsible for the design and supply of a high integrity nuclear crane. Working with their client, they had developed a number of different options for the crane’s layout. Eadon Consulting were initially asked to assist with the optioneering phase of the project. Our role was to carry out simple hand calculations looking at the seismic performance of the different options.

Following this initial work Eadon Consulting were then contracted to carry out a response spectrum analysis of the finalised crane structure as well as checking the mechanical components. A full beam element model of the crane was first created using Ansys V12. This was subjected to a modal analysis and subsequently a seismic response spectrum analysis. The crane had to comply with the requirements of BS2573: Rules for the design of cranes, as well as JSP 467. The various beam moments and stresses were extracted to ensure that none of the elements would fail under seismic loading.

One of the main challenges on the project was the long span of the main beams. The design of these had to be developed to ensure that they did not buckle during a seismic event. However it had to be possible to fully inspect all welding of the beams to ensure that it was acceptable for a nuclear environment. This resulted in special beam section being developed that had good buckling strength but with minimal welding.

The hoisting mechanism was also checked under various fault load cases to ensure that it was satisfactory. These included snagged loads as well as ledge loads and rope failure.

The project was successful with the feasibility of the crane structure having been proven and the whole project is now awaiting HAXOP 2 review.

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