Characterization of the MVST Waste Tanks Located at ORNL


J. M. Keller
J. M. Giaquinto
A. M. Meeks

December 1996

During the fall of 1996 there was a major effort to sample and analyze the Active Liquid Low-Level Waste (LLLW) tanks at ORNL which include the Melton Valley Storage Tanks (MVST) and the Bethel Valley Evaporator Service Tanks (BVEST). The characterization data summarized in this report was needed to address waste processing options, address concerns of the performance assessment (PA) data for the Waste Isolation Pilot Plant (WIPP), evaluate the waste characteristics with respect to the waste acceptance criteria (WAC) for WIPP and Nevada Test Site (NTS), address criticality concerns, and meet DOT requirements for transporting the waste. This report only discusses the analytical characterization data for the MVST waste tanks (except for W-29 and W-30). There will be a companion report on the BVEST waste tanks that will include the analytical data and the results from rheometry experiments on the BVEST sludge.

The isotopic data presented in this report supports the position that fissile isotopes of uranium (233U and 235U) and plutonium (239Pu and 241Pu) were "denatured" as required by the administrative controls stated in the ORNL LLLW waste acceptance criteria (WAC). In general, the MVST sludge was found to be both hazardous by RCRA characteristics and the transuranic alpha activity was well above the 100 nCi/g limit for TRU waste. The characteristics of the MVST sludge relative to the WIPP WAC limits for fissile gram equivalent, plutonium equivalent activity, and thermal power from decay heat, were estimated from the data in this report and found to be far below the upper boundary for any of the remote-handled transuranic waste (RH-TRU) requirements for disposal of the waste in WIPP.

ORNL/TM-13357 in PDF Format