The DVS safely vents drums of hazardous and radioactive wastes, prevents buildup of explosive gases inside the drum, and characterizes the drum gases to ensure compliance to shipping, handling, and disposal requirements. The DVS uses Nucfil's® patented carbon-bonded-carbon, HEPA-grade filter element encased in a hardened filter housing that punctures the liner of the TRU waste drum, where a sample of the headspace gas is taken. The head-space gas sample is directed through a noncarbon, HEPA-grade filter into a dual-column, dual-detector gas chromatograph to be analyzed for hydrogen and volatile organics. An additional gas sample can be collected for laboratory analysis.
After successful analysis of the headspace gas, the filter assembly is permanently attached to the drum lid by means of self-tapping threads. The device allows continued safe release of gases from inside the containment vessel. The mechanical assembly is enclosed in an explosion-resistant cabinet during the entire operation. Both the glovebox and the cabinet are supplied with a constant flow of HEPA-filtered air to maintain the desired flow and pressure differential conditions. The exhaust air is then filtered by a roughing filter in series with single or dual HEPA filters.