Improved Ex-Tank Leak Detection and Monitoring Technology Demonstrations in Support of Single-Shell Tank Waste Retrieval at the Hanford Site in Richland, Washington

摘要

Led by the United States Department of EnergyrnOffice of River Protection (DOE-ORP) and CH2M HILLrnHanford Group, Inc. (CHG), a team of experts fromrnPacific Northwest National Laboratory (PNNL),rnLawrence Livermore National Laboratory (LLNL),rnLawrence Berkley National Laboratory (LBNL),rnUniversity of Texas at Austin, Duke Engineering Services,rnVista Engineering Technologies, L.L.C., andrnHydroGEOPHYSICS, Inc. have been working together tornnarrow the field of new external tank leak detectionrntechnologies. The ability to detect and assess potentialrnleaks more quickly will help reduce potential risks tornpublic health and the environment during efforts tornretrieve millions of gallons of waste from Hanford’s olderrnsingle-shell tanks (SST’s). A method for early andrnreliable detection of leaks around and below the entirern75-foot diameter bottom of a SST is needed.rn“Proof-of-concept” testing of six ex-tank leak detectionrnand monitoring technologies was conducted at Hanford’srn105-A Mock Tank Site in August 2001. A workshop wasrnconducted in January, 2002 to review the results andrnselect the best of the methods tested for further testing andrndemonstration in support of an SST retrieval. Threernmethods were selected: High Resolution Resistivity;rnElectrical Resistance Tomography – Long Electrodes;rnand Electrical Resistance Tomography – Point ElectrodernArrays.rnPlanned development activity includes performancernevaluation tests to determine probability of detection andrnthe probability of false alarm for each technology andrndeployability tests in an actual Hanford tank farmrnenvironment.