A compact, dual-zone vertical tube furnace for the determination of tritium and carbon-14 in decommissioning wastes

A compact dual zone, two work-tube, vertical tube furnace system (Raddec Pyrolyser-Mini) has been designed for the determination of H-3 and C-14 in decommissioning wastes. An optimised methodology was developed following improvements to sample holder and bubbler trap design, sample loading and loading temperature, as well as length and style of heating programmes. A significant efficiency enhancement was obtained through ‘hot-loading’ of the sample into the furnace at 600 °C before finally ramping to 900 °C. Direct trapping of H-3 and C-14 in a scintillation vial located in a special anti-suck-back bubbler further improved operations, leading to a reduction in analysis time and measurement sensitivity. Co-trapping of the analytes and dual-label liquid scintillation counting also proved effective. Overall, the developed methodology led to a reduced analyte extraction/trapping time of 150 min whilst achieving limits of detection of <1 Bq/g. Validation of the procedure was assessed using a range of spiked matrices relevant to nuclear site decommissioning, reference materials and operationally-exposed materials. The compact size of this thermal extraction system is such that it allows for deployment in fume cupboards, gloveboxes and a mobile laboratory.

Pyrolyser-mini, H-3, C-14, Decommissioning, Rapid method, Bubbler design

10.1016/j.apradiso.2021.109995

0969-8043

Warwick, Phillip

f2675d83-eee2-40c5-b53d-fbe437f401ef

Croudace, Ian

24deb068-d096-485e-8a23-a32b7a68afaf

Burrell, Frances

17557794-ae6b-4c71-9d9b-3fed6ebdbf49

January 2022

Warwick, Phillip

f2675d83-eee2-40c5-b53d-fbe437f401ef

Croudace, Ian

24deb068-d096-485e-8a23-a32b7a68afaf

Burrell, Frances

17557794-ae6b-4c71-9d9b-3fed6ebdbf49

Warwick, Phillip, Croudace, Ian and Burrell, Frances (2022) A compact, dual-zone vertical tube furnace for the determination of tritium and carbon-14 in decommissioning wastes. Applied Radiation and Isotopes, 179, [109995]. (doi:10.1016/j.apradiso.2021.109995).

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A compact, dual-zone vertical tube furnace for the determination of tritium and carbon-14 in decommissioning wastes - Accepted Manuscript

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e-pub ahead of print date: 29 October 2021

Published date: January 2022

Additional Information: Funding Information: Funding: This work was supported by the Nuclear Decommissioning Authority under their Direct Research Portfolio [ NS4510-500-003 ]. We thank Jonathan Cox (formerly NSG Environmental ) and David Wickenden (Magnox Ltd), for their oversight of this research, Ben Russell ( National Physical Laboratory ) for a contribution relating to the mobile laboratory deployment and David Loudon and Yvonne Morris ( Nuclear Decommissioning Authority ) for their support of the study. Funding Information: Funding: This work was supported by the Nuclear Decommissioning Authority under their Direct Research Portfolio [NS4510-500-003]. We thank Jonathan Cox (formerly NSG Environmental) and David Wickenden (Magnox Ltd), for their oversight of this research, Ben Russell (National Physical Laboratory) for a contribution relating to the mobile laboratory deployment and David Loudon and Yvonne Morris (Nuclear Decommissioning Authority) for their support of the study. Publisher Copyright: © 2021 Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

Keywords: Pyrolyser-mini, H-3, C-14, Decommissioning, Rapid method, Bubbler design