High priority tank sampling and analysis report

In July 1993, the Defense Nuclear Facilities Safety Board (DNFSB) transmitted Recommendation 93-5 (Conway 1993) to the US Department of Energy (DOE). Recommendation 93-5 noted that there was insufficient tank waste technical information and the pace to obtain it was too slow to ensure that Hanford Site wastes could be safely stored, that associated operations could be conducted safely, and that future disposal data requirements could be met. In May 1996, the DOE issued Revision 1 of the Recommendation 93-5 Implementation Plan (DOE-RL 1996). The Implementation Plan revision presented a modified approach to achieve the original plan`s objectives. The approach concentrated on actions necessary to ensure that wastes can be safely stored, that operations can be safely conducted, and that timely characterization information for the tank waste Disposal Program could be obtained. The Implementation Plan proposed 28 High Priority tanks, which, if sampled and analyzed, were expected to provide information to answer questions regarding safety and disposal issues. The High Priority tank list was originally developed in Section 9.0 of the Tank Waste Characterization Basis (Brown et al. 1995) by integrating the needs of the various safety and disposal programs. The High Priority tank list represents a set of tanks that were expected to provide the highest information return for characterization resources expended. The High Priority tanks were selected for near-term core sampling and were not expected to be the only tanks that would provide meaningful information. Sampling and analysis of non-High Priority tanks also could be used to provide scientific and technical data to confirm assumptions, calibrate models, and measure safety related phenomenological characteristics of the waste. When the sampling and analysis results of the High Priority and other tanks were reviewed, it was expected that a series of questions should be answered allowing key decisions to be made. The first nine questions related to safety issues and the last three questions related to planning for the disposal process (retrieval, treatment, and immobilization). The 12 questions are listed