Notice is hereby given by the University of Ottawa of the intent to enter into a contract with Picarro Inc. to purchase a cavity ring-down spectroscopy system designed specifically for the measurement of oxygen and hydrogen isotopes in water. The research program that will be supported by this purchase is a collaboration with the Nuclear Waste Management Organization (NWMO). The overall goal is to identify a geological environment that is suitable for the long-term isolation of spent nuclear fuel, and the uOttawa contribution focuses on the use of pore water geochemistry and isotopes to understand the mobility of deep groundwater with the understanding that stagnant groundwater systems provide the best isolation capability. The ideal geological environment is one where the rocks have extremely low permeability (e.g. shale), but low permeability poses great challenges for sampling pore water to measure its geochemical and isotopic characteristics. A very important aspect of the research program involves developing new and innovative methods for sampling and analyzing the pore water characteristics in these rocks.
The instruments being purchased include a high-precision cavity ring-down spectrometer for 18O and 2H isotopic analysis in water, an induction module (IM) for extracting water from solid materials such as plant leaves, stems and tissues, a micro-combustion module (MCM) for elimination of organics and a high-precision vaporizer designed for liquid water analysis. The IM and the MCM are critical components that are absolutely necessary to the success of the research. These components will generate data as an integrated system to study the porewater isotopic composition of low permeability rocks. This system will support cutting-edge research being conducted in one of the University of Ottawa’s labs to further understand solute transport in ancient hydrological systems and support international programs in search of suitable geological sites for management of radioactive waste.
The project aims to measure the stable oxygen and hydrogen isotope composition of water in the pores of low-permeability rocks, such as shale. The water is first extracted from the rocks by absorption into a cellulosic paper, and then the water must be released from the paper into a cavity ring-down spectrometric measurement device. The measurement system must be capable of extracting the water from the paper and passing it through to the spectrometer. In addition, naturally occurring soluble organic compounds may be present in the rock pore water and are absorbed by the paper along with the water. When the water is released from the paper (by the IM), the organic compounds will tend to travel with the water toward the spectrometer. In the spectrometer, the organic compounds interfere with the measurements of oxygen and hydrogen stable isotopes in the water so these must be removed by the MCM before the gases enter the spectrometer.
The system consists of four (4) main equipment components:
- L2130-i High Precision Cavity Ring-Down Spectrometer (CRDS)
- A0213 Induction Module (IM)
- This component allows for the extraction and high-precision isotope analysis of matrix-bound water from solid samples such as papers, leaves and soils.
- It must be fully integrated with the CRDS analyzer.
- It merges the sample extraction and analysis steps.
- A0214 Micro-Combustion Module™ (MCM)
- This component removes organic interference from water samples to improve the accuracy of water isotopes analysis.
- It is fully integrated and compatible with Picarro’s IM and the high-precision vaporizer.
- A0211 High Precision Vaporizer
