MEASURING THE ACCELERATION OF A NUCLEAR TRANSPORT CASK DURING ROUTINE AND NORMAL TRANSPORT CONDITIONS

Instrumented transport tests were performed with an empty radioactive material cask called CADM weighing 23 metric tons at the CEA Marcoule site. This cask was centred in a transport frame on a non-slip mat and transported vertically. It was secured by four lashing chains equipped with tensioning ratchets attached to shackles on the lugs of the cask and to anchor rings on the trailer platform. These tests aimed at measuring the acceleration experienced by the cask, the trailer platform and the transport frame in all three directions (longitudinal, transverse and vertical), as well as measuring the forces in the lashing chains of the cask during several transport operations under routine and normal conditions. Instrumentation included a speed sensor on the towing tractor, force sensors on the lashing chains and accelerometers on the lugs of the cask, the transport frame and the trailer platform. The force, acceleration and speed were measured under routine transport conditions along two onsite transport routes on the CEA Marcoule site. These parameters were also measured under normal (and even incident) transport conditions with configurations of sudden acceleration, emergency forward braking, backward braking and forward braking in a curve, crossing curbs, small roundabouts and speed bumps. Acceleration signals were recorded continuously and analysed by removing transients (sliding time averaging). The minimum and maximum values of each measurement were extracted for the tests and processed statistically. The results of this analysis made it possible to determine the following upper-bound accelerations under routine and normal transport conditions: - 0.5g longitudinal forward and 0.35g longitudinal backward - 0.35g transverse - 0.55g vertical.