Analysis of soil samples from OMRE decommissioning project

In order to establish that the present Organic Moderated Reactor Experiment (OMRE) site does not exceed the criteria for radioactive contamination, samples obtained from the remainder of the facility that was not removed such as soil, concrete pads, various structural materials, and the leach pond area were analyzed to determine their radioactive content. The results of the analyses performed on soil samples are presented. Results of this study indicate that the activity at the OMRE decommissioned area is confined to localized areas (i.e., the leach pond area and reactor area). Comparisons of radionuclide concentrations measured in soil taken from the lip of the leach pond with concentrations in soil obtained outside the Idaho National Engineering Laboratory (INEL) site boundaries indicate that the concentration in the soil at the edge of the leach pond is at background levels. The vertical augering technique was determined to be the best approach for obtaining shallow soil samples at the INEL. Selection of this technique was based on ease of operation and analytical results. Less area is disturbed per sample than with the horizontal trenching and coring techniques. The radionuclide analysis of the samples shows the existence of a few regions in the reactor and leach pond areas that were still above INEL release criteria. These regions have been or are being further decontaminated