Thu, 04 June, 2020
A collaborative project, between TWI Ltd, Ionix Advanced Technologies (Ionix), Precision Acoustics Limited (PAL) and University of Sheffield (UoS), towards developing and manufacturing radiation resilient ultrasonic sensors (reDRESS) has been completed with high praise from the project’s funding body, InnovateUK.
The goal of the reDRESS project was to construct a reliable ultrasonic testing (UT) sensor, capable of operating at 350°C for defined periods, whilst exposed to high levels of gamma and neutron radiation. This would allow engineers to undertake a UT inspection close to the core of a nuclear reactor, which is an extremely hot (> 350°C) environment, with high radiation levels.
TWI’s role centred on identifying radiation facilities to expose sensors to gamma and gamma + neutron radiation, as well as investigating cabling solutions for connecting the sensors to the UT equipment during testing. TWI identified two suitable facilities to test the samples, the Dalton Nuclear Facility (DCF) in Cumbria, England, and the Joseph Stefan Institute (JSI), Ljubljana, Slovenia, exposing them to a total of 10 MGy and 10 MGy of mixed gamma + neutron radiation respectively.
TWI successfully identified suitable cabling solutions to connect the sensors to the UT equipment and investigated the link between the reduction in the piezoelectric effect and microstructural damage caused by radiation exposure. The piezo-ceramic UT sensors, developed by Ionix, withstood the gamma + neutron and gamma exposure with no observable change in performance. The piezo-polymer and fibre optic sensors, developed by PAL, survived longer than predicted, however, the polymer sensors were found to be unsuitable for use under neutron radiation but could be utilised for the long term monitoring under gamma radiation. With further development the fibre-optic sensors could be implemented in a neutron + gamma environment radiation. The University of Sheffield (UoS) successfully modelled the radiation exposure of the components so that selective radiation hardening could be applied to their electronics where necessary.
Click here for more information on the ReDress project.
Water resistance testing at TWI North East’s 7m dive tank facility
Testing the sensors in at the Joseph Stefan Institute (JSI), Ljubljana, Slovenia nuclear reactor
