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- Author or Editor: A. Meek x
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Abstract
Disposal of Department of Energy (DOE) radioactive waste into repositories such as the Waste Isolation Pilot Plant (WIPP) and the Nevada Test Site (NTS) requires characterization to ensure regulatory and transportation requirements are met and to collect information regarding chemistry of the waste for processing concerns. Recent addition of an inductively coupled plasma quadrupole mass spectrometer in a radioactive contaminated laboratory at the Oak Ridge National Laboratory (ORNL) has allowed the evaluation of advantages of using ICP-MS over traditional techniques for some of these characterization needs. The measurement of long-lived beta nuclides (i.e.99Tc) by ICP-MS has resulted in improved detection limits and accuracy than the traditional counting techniques as well as reducing the need for separation/purification techniques which increase personnel exposure to radiation. Using ICP-MS for the measurement of U isotopes versus the traditional Thermal Ionization Mass Spectrometer (TIMS) technique has reduced cost and time by more than half while still maintaining the needed accuracy to determine risk assessment of the waste tanks. In addition, the application of ICP-MS to ORNL waste tank characterization has provided the opportunity to estimate non-routine radionuclides (i.e.135Cs and151Sm) and non-routine metals (i.e. Li, Ti, rare earths, etc.) using a rapid low cost screening method. These application methodologies and proficiencies on ORNL waste samples are summarized throughout the paper.
Abstract
The operation and maintenance of a complex analytical instrument such as an inductively coupled plasma mass spectrometer in a radioactive contaminated environment presents unique problems and challenges that have to be considered in the purchasing and installation process. Considerations such as vendor experience, typical radiation levels, sample matrices encountered during sample analysis, instrument accessability for maintenance, and upkeep must be incorporated into the decision process. The Radioactive Materials Analytical Laboratory (RMAL) at Oak Ridge National Laboratory (ORNL) recently purchased and installed an inductively coupled plasma mass spectrometer for the analysis of Department of Energy (DOE) radioactive waste streams. This presentation will outline the purchasing decision, installation of the instrument, and how the modifications needed to operate in a radioactive contaminated laboratory do not significantly impact the daily operation and maintenance requirements of the instrument. Also, a contamination survey of the system will be presented which demonstrates the contamination levels in the instrument from the sample introduction system to the detector.
Abstract
High energy gamma-radiation (8 to 30 MeV) is gaining acceptance for radiation therapy of patients with deep cancers. This radiation is of sufficient energy to induce photonuclear activation of the elements in the human body. Our results of measurements of nitrogen and phosphorus in an anthropomorphic phantom, a cadaver, and a cancer patient with bremsstrahlung radiation from 15 MeV electrons demonstrate the feasibility of a method to monitor these two elements in the human body in vivo by measuring the radioactivity induced in these targets by photonuclear reactions.
