Modelling and detection of cosmic ray muons: the development of a muon imagingsystem for large shielded storage vessels

摘要

The nature of material found within active 'legacy waste' storage vessels and otherradiation shielded vessels coupled with the distinct lack of access makes representativesampling or visual inspection of the vessel extremely problematic and in some casesimpossible. In recent years the use of non-intrusive and non-invasive imaging techniques tosafely interrogate non-nuclear (industrial) storage vessel or process units has seen asignificant increase. However, until recently the radiation shielding which is commonplaceon all nuclear sites has rendered existing remote non-intrusive imaging techniques useless.This is due to the limiting penetrative power of X-rays and gamma-rays as well as lack ofaccess for other semi-invasive techniques such as electrical and acoustic imaging. Here,the use of naturally occurring ubiquitous galactic and solar cosmic rays for imaging theinventories of shielded vessels are considered. More specifically, high energy secondarycosmic ray muons have been modelled, detected and attenuated (absorbed) which hasprovided a suitable platform for the design of a prototype muon imaging system. Such asystem will enable the internal imaging of otherwise opaque shielded storage vessels byharnessing the muons superior penetrative power, thus providing valuable inventorymeasurements which will enable a safer and more economic legacy waste recoverystrategy.