21-25 June 2021
Clarion Congress Hotel Prague
Europe/Prague timezone
Proceedings of the ANIMMA 2021 conference are now available online in open access: https://www.epj-conferences.org/animma-2021

#08-125 Modelling the response of an in-situ CdTe detector to radionuclides in groundwater.

23 Jun 2021, 16:40
5m
LEO (Clarion Congress Hotel Prague)

LEO

Clarion Congress Hotel Prague

Poster 08 Decommissioning, Dismantling and Remote Handling 08 Decommissioning, Dismantling and Remote Handling

Speaker

TURKINGTON, Graeme (University of Glasgow)

Description

This research examines the potential deployment of a cadmium telluride strontium-90 detector in groundwater boreholes at nuclear decommissioning sites. This is represents a novel approach to monitoring strontium-90 contamination at decommissioning sites such as Sellafield, and has the potential to reduce lifetime monitoring costs while providing information on a significantly reduced timescale. A Geant4 simulation was used to model the deployment of the detector in a contaminated groundwater borehole. It was found that the detector was sensitive to strontium-90, yttrium-90, caesium-137 and potassium-40 decay, some of the significant beta emitters found at Sellafield. However, the device showed no sensitivity to carbon-14 decay, due to the inability of the weak beta emission to penetrate both the groundwater and the detector shielding. The limit of detector for such a sensor when looking at solely strontium-90 decay would be 323 BqL$^{-1}$ after a 1 hour measurement and 66 BqL$^{-1}$ after a 24 hour measurement. Existing techniques are capable of examining strontium-90 decay below the World Health Organisations safe drinking water limit of 10 BqL$^{-1}$. A GaAs sensor with twice the surface area, but 0.3 % of the thickness was modelled for comparison. Using this sensor, sensitivity was increased, such that the limit of detection for strontium-90 was 91 BqL$^{-1}$ after 1 hour and 18 BqL$^{-1}$ after 24 hours. However, this sensor sacrifices the potential to identify the present radionuclides by their end-point energy.

Primary author

TURKINGTON, Graeme (University of Glasgow)

Presentation Materials