Engineering consultancy Frazer-Nash has completed a study for the Nuclear Decommissioning Authority (NDA) into the safety of canisters containing nuclear waste under impact conditions. 

Steel canisters are currently used to contain vitrified high-level waste from reprocessing operations.  The NDA is reviewing a number of options for the long term storage of such canisters and appointed Frazer-Nash in 2008 to assess the strength of a number of potential canister storage containers in the highly unlikely event one is dropped during transport or emplacement.

Frazer-Nash’s work involved using finite element analysis to create computer models representing each potential container design falling from heights of up to eight metres in a number of orientations.  The results from the analyses provided the stresses in both the containers and canisters, and allowed an assessment of the energy absorbed by the waste itself to be estimated.  This assessment enabled the team to evaluate the container options and assess the performance of each under impact conditions.

Project manager Graeme Anderson commented:
“There are many factors which affect the protection offered by the waste canister containment package, including the height it is dropped from, the angle at which it hits the ground and the weight of the container and its contents.  We examined a range of impact scenarios to each of the containers being assessed in order to identify which provided the best overall protection from impact loads.

“The results from our work will support the NDA in their decision to select an appropriate solution.  This may involve selecting the option that currently offers the best protection or altering the design of the others to improve their strength.”