Material Sample Collection with Tritium and Gamma Analyses at the University Of Illinois's TRIGA Nuclear Research Reactor
The University of Illinois in Champaign-Urbana had an Advanced TRIGA reactor facility. Scientech, LLC was tasked with fully characterizing the facility and part of this characterization involved the collection and analysis of samples by NMNTI of the various solid media including concrete, graphite, metals, and sub-slab surface soils for immediate analysis of Activation and Tritium contamination well below the easily measured surfaces.
Performing quantitative volumetric concrete or metal radioanalyses safer and faster (without lab intervention) was a key objective of this dynamic characterization approach. The concrete core bores were shipped to certified laboratories where the concrete residue was run through a battery of tests to determine the contaminants. The existing core boring operation volatilized or washed out some of the contaminants (like tritium) and often times cross-contaminated the area around the core bore site. The volatilization of the contaminants can lead to airborne problems in the immediate vicinity of the core bore. Cross-contamination can increase the contamination area and thereby increase the amount of waste generated that needs treated and stabilized before disposal. The goal was to avoid those field activities that could cause this type of release.
Therefore TruPro® in conjunction with radiometric instrumentation was utilized to produce contamination profiles through the material being studied. All samples (except metals) on-site were analyzed within 10 minutes for tritium using a calibrated portable liquid scintillation counter (LSC) and analyzed for gamma activation products using a calibrated ISOCS. Improved sample collection with near real time analysis along with more historical hazard analysis enhanced significantly over the baseline coring approach the understanding of the depth distribution of contaminants and thus by sampling & characterizing complex slab, sub-slab and reactor bioshield annulus locations helped validate, develop, and refine the site characterization and decommissioning plan. The water used in traditional coring can result in a radioactive liquid waste that needs to be dealt with. This would have been an issue at University of Illinois. Considerable time, risk reduction and money are saved using this profiling approach.