In the UK, low level radioactive waste (LLW) is sent to the national Low Level Waste Repository (LLWR) at Drigg in Cumbria. Strict rules limit the specific activity of waste that is sent to the LLW Repository and waste producers and consignors have to demonstrate that the waste they send to the repository meets its conditions for acceptance. However, the limited capacity of the Low Level Waste Repository means that it is just as important for waste consigners to ensure that inactive ‘free release’ or ‘exempt’ waste is not inadvertently sent to the repository. Incorrect segregation of waste in a decommissioning activity can mean that large amounts of the waste produced is below the exemption limit and could therefore be disposed of in conventional landfill. Sellafield Ltd. is using a pair of Canberra WM2750 Clearance Monitors to assay 100 litre packages of soft waste produced in some of their decommissioning activities at Sellafield. The WM2750 uses low resolution gamma spectrometry (LRGS) to determine the radionuclide content of packages or drums of LLW up to a maximum of 140 litre capacity. It uses a lead shielded measurement chamber to reduce the local radiation background along with high efficiency sodium iodide (NaI) detectors in order to obtain the measurement sensitivity required to be able to distinguish between LLW and exempt waste in a measurement time of less than 1 minute per package. This paper describes the waste monitoring process and the design of the clearance monitor — in particular how it was calibrated and the performance testing that was carried out to ensure that waste items identified by the monitors as being exempt waste are suitable for disposal to a conventional landfill site.
Skip Nav Destination
The 11th International Conference on Environmental Remediation and Radioactive Waste Management
September 2–6, 2007
Bruges, Belgium
Conference Sponsors:
- Nuclear Division and Environmental Engineering Division
ISBN:
978-0-7918-4339-0
PROCEEDINGS PAPER
Use of a Shielded Low Resolution Gamma Spectrometer for Segregation of Free Release and Low Level Waste
C. G. Wilkins,
C. G. Wilkins
Canberra UK, Ltd., Didcot, Oxfordshire, England, UK
Search for other works by this author on:
E. Alvarez,
E. Alvarez
Canberra UK, Ltd., Didcot, Oxfordshire, England, UK
Search for other works by this author on:
J. Cocks,
J. Cocks
Canberra UK, Ltd., Didcot, Oxfordshire, England, UK
Search for other works by this author on:
L. Davison,
L. Davison
Sellafield, Ltd., Sellafield, Cumbria, England, UK
Search for other works by this author on:
A. Mattinson
A. Mattinson
Sellafield, Ltd., Sellafield, Cumbria, England, UK
Search for other works by this author on:
C. G. Wilkins
Canberra UK, Ltd., Didcot, Oxfordshire, England, UK
E. Alvarez
Canberra UK, Ltd., Didcot, Oxfordshire, England, UK
J. Cocks
Canberra UK, Ltd., Didcot, Oxfordshire, England, UK
L. Davison
Sellafield, Ltd., Sellafield, Cumbria, England, UK
A. Mattinson
Sellafield, Ltd., Sellafield, Cumbria, England, UK
Paper No:
ICEM2007-7163, pp. 643-648; 6 pages
Published Online:
May 29, 2009
Citation
Wilkins, CG, Alvarez, E, Cocks, J, Davison, L, & Mattinson, A. "Use of a Shielded Low Resolution Gamma Spectrometer for Segregation of Free Release and Low Level Waste." Proceedings of the The 11th International Conference on Environmental Remediation and Radioactive Waste Management. 11th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B. Bruges, Belgium. September 2–6, 2007. pp. 643-648. ASME. https://doi.org/10.1115/ICEM2007-7163
Download citation file:
13
Views
Related Proceedings Papers
Related Articles
Development and Calibration of an Indigenous Spectroscopic System for Radiation Portal Monitor Application
ASME J of Nuclear Rad Sci (July,2023)
Noncontact Displacement Measurement of Nuclear Waste Canisters in a Geological Disposal by Using an Electromagnetic-Wave Approach
ASME J of Nuclear Rad Sci (October,2020)
NED Chair's Message
ASME J of Nuclear Rad Sci (January,2024)
Related Chapters
Environmental and Related Requirements
Decommissioning Handbook
Sealed Radioactive Sources
Non-Proliferation Nuclear Forensics: Canadian Perspective
Characterization
Decommissioning Handbook