The challenge

NTS was developing a design for a reusable Type B radioactive materials transport container to be used to transport low heat generating radioactive wastes.

The size, number and grade of bolts to be identified within the design were required to be finalized and in support of this, NTS required a material testing programme to assist in that process.

The performance of nuclear transport packages is stringently assessed against design criteria prescribed in the International Atomic Energy Agency (IAEA) transport regulations and various tests are required to be carried out to determine package performance, including tests designed to represent accident conditions of transport. A 9m drop onto an unyielding target is considered the bounding accident case for this transport container design.

This NTS requirement was based on smaller, scaled bolts which would enable them to determine failure limits in terms of plastic strain and energy for the lid bolts in the transport container. All specified tests were destructive, i.e. the bolts were tested to failure.

What we delivered

Lucideon delivered a destructive testing programme of various bolt grades and sizes, loaded in double shear, single shear, dynamic single shear and tension. Testing was undertaken at temperatures to minus 40°C, with all Jigs required for the testing programme designed and built by Lucideon.

Due to the complexity of bolted joints, the size of the actual bolts, the intended purpose of the results and the large number of variables involved in both test and Finite Element Analysis (FEA) model development, a delivery approach was adopted to gradually introduce additional variables (and complexity) by a series of phased tests.

Value to the client

From the validated FEA models, Lucideon's client could infer failure criteria of the bolts and bars which can be used as acceptance criteria during development of nuclear transport packages.