Stored waste tank sampling of radioactive high-level nuclear waste is reilu ired for continued operations, waste characterization, and site safety. The Hanford site tank farms consist of 28 double- shell and 1.49 single-shell underground storage tanks. The 'full' capacity of each of these tanks is approximately 1 million gallons. The waste stored in these tanks was generated as a result of defense materials production over the course of 4 decades. The single shell tanks are out-of-service and no longer receive liquid waste. Core samples of salt cake, liquid and sludge are remotely obtained using truck- mounted core drill platforms. Samples are recovered from the tanks through a 2.25-inch diameter drill pipe, in segments contained in specially designed stainless steel samplers approximately 1.5-inch in outside diameter and 26- inches long. The sampled material in a given segment can include crystalline salt-cake, liquid, sludge and entrained gas. Drilling parameters will necessarily vary with different waste types, e.g., crystalline salt-cake versus sludge. At times, the core sample recovery has been marginal and inadequate for laboratory analysis needs. This necessitated a system to provide the drill- truck operators with 'real-time' feedback about the physical condition of the sampled 'formation' and the percent recovery, prior to receiving visual characterization information and nuclear assay measurements from the Hanford site 222-S Analytical laboratories, a process often requiring two week turn- around of data. This real- time information allows the drill-truck engineers to immediately vary the drilling parameters to maintain sample recovery.
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