Headspace Gas Analysis and Venting for TRU Waste Drums

Transuranic (TRU) wastes generated in U.S. Department of Energy (DOE) operations have, since the early 1970's, been packaged to a large extent in unvented 55-gallon steel drums and have been stored with the intention of future retrieval. These wastes are intended to be disposed of permanently in the DOE Waste Isolation Pilot Plant (WIPP) facility. Today, there are safety concerns regarding these stored drums because of the potential presence of combustible headspace gases. Such gases can include hydrogen and methane resulting from the radiolytic decomposition of hydrogenous waste materials (e.g., paper, plastics, moisture) and/or from the presence of generally small amounts of combustible Volatile Organic Compounds (VOCs) that are cocontaminants of the TRU wastes. Any future handling and transportation of these waste packages must address this concern. Additionally, the WIPP Waste Acceptance Criteria require all packages to be vented, and all such packages to be shipped in the DOE TRUPACT-II Type B container must be both vented and shown to meet combustible gas concentration limitations. To provide a safe method for penetrating the drum lid and, if present, inner plastic liner lid, sampling and analyzing the headspace gases, and installing an approved filter vent, NFT Incorporated (NFT), working with the Westinghouse Savannah River Company (WSRC), has developed a Drum Venting System (DVS) for the remote performance of these venting and analysis functions. This paper discusses the design features and planned operations of the