Real-Time Gamma Imaging of Technetium Transport through Natural and Engineered Porous Materials for Radioactive Waste Disposal

• Published in: Environmental science & technology 2013-12, Vol.47 (23), p.13857-13864
• Main Authors: Corkhill, Claire L, Bridge, Jonathan W, Chen, Xiaohui C, Hillel, Phil, Thornton, Steve F, Romero-Gonzalez, Maria E, Banwart, Steven A, Hyatt, Neil C
• Format: Article
• Language: English
• Subjects: Adsorption; Applied sciences; Calibration; cameras; cement; Chemical elements; Computer Systems; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; equations; Exact sciences and technology; Gamma Cameras; image analysis; isomers; Isotopes; Numerical Analysis, Computer-Assisted; Pollution; Pollution, environment geology; Porosity; Porous materials; porous media; Quartz; Quartz - chemistry; Radioactive materials; radioactive waste; Radioactive Waste - analysis; Radioactive wastes; Real time; Refuse Disposal; sand; technetium; Technetium - analysis; United Kingdom; Waste disposal; Wastes
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/es402718j

We present a novel methodology for determining the transport of technetium-99m, a γ-emitting metastable isomer of 99Tc, through quartz sand and porous media relevant to the disposal of nuclear waste in a geological disposal facility (GDF). Quartz sand is utilized as a model medium, and the applicability of the methodology to determine radionuclide transport in engineered backfill cement is explored using the UK GDF candidate backfill cement, Nirex Reference Vault Backfill (NRVB), in a model system. Two-dimensional distributions in 99mTc activity were collected at millimeter-resolution using decay-corrected gamma camera images. Pulse-inputs of ∼20 MBq 99mTc were introduced into short (