Value of Information Analysis Project Gnome Site, New Mexico

The Project Gnome site in southeastern New Mexico was the location of an underground nuclear detonation in 1961 and a hydrologic tracer test using radionuclides in 1963. The tracer test is recognized as having greater radionuclide migration potential than the nuclear test because the tracer test radionuclides (tritium, 90Sr, 131I, and 137Cs) are in direct contact with the Culebra Dolomite aquifer, whereas the nuclear test is within a bedded salt formation. The tracer test is the topic here. Recognizing previous analyses of the fate of the Gnome tracer test contaminants (Pohll and Pohlmann, 1996; Pohlmann and Andricevic, 1994), and the existence of a large body of relevant investigations and analyses associated with the nearby Waste Isolation Pilot Plant (WIPP) site (summarized in US DOE, 2009), the Gnome Site Characterization Work Plan (U.S. DOE, 2002) called for a Data Decision Analysis to determine whether or not additional characterization data are needed prior to evaluating existing subsurface intrusion restrictions and determining long-term monitoring for the tracer test. Specifically, the Work Plan called for the analysis to weigh the potential reduction in uncertainty from additional data collection against the cost of such field efforts