Radiological Characterization Issues and Success Stories for the Melton Valley Scrap Yard and Homogeneous Reactor Experiment Evaporator Response Actions

Proper characterization is essential for assuring that wastes meet any treatment or disposal site waste acceptance criteria (WAC). In addition characterization is vital for proper preparation of shipping papers for transporting the waste for treatment or disposal. Process knowledge was inadequate for characterization of legacy waste items from two sites involved in the Melton Valley Decontamination and Decommissioning (MVD&D) project at the Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL): a scrap yard containing miscellaneous contaminated items, and a liquid waste evaporator used by an experimental nuclear reactor. Waste items at both sites were contaminated with Cs-137/Ba-137m. Through the use of scaling factors, the gamma radiation associated with this radionuclide pair was used to characterize these items for proper disposal. Application of scaling factors permitted successful remediation of these sites on an accelerated schedule and avoided radiation exposure concerns associated with traditional sampling and analysis.