Cost benefit and risk assessment for selected tank waste process testing alternatives

The US Department of Energy has established the Tank Waste Remediation System (TWRS) program to safely manage wastes currently stored in underground tank at the Hanford Site. A TWRS testing and development strategy was recently developed to define long-range TWRS testing plans. The testing and development strategy considered four alternatives. The primary variable in the alternatives is the level of pilot-scale testing involving actual waste. This study evaluates the cost benefit and risks associated with the four alternatives. Four types of risk were evaluated: programmatic schedule risk, process mishap risk, worker risk, and public health risk. The structure of this report is as follows: Section 1 introduces the report subject; Section 2 describes the test strategy alternative evaluation; Section 3 describes the approach used in this study to assess risk and cost benefit; Section 4 describes the assessment methodologies for costs and risks; Section 5 describes the bases and assumptions used to estimate the costs and risks; Section 6 presents the detailed costs and risks; and Section 7 describes the results of the cost benefit analysis and presents conclusions.