This tank characterization report presents an overview of Double-Shell Tank 241-SY-102 (hereafter, Tank 241-SY-102) and its waste contents. It provides estimated concentrations and inventories for the waste components based on the latest sampling and analysis activities and background tank information. This report describes the results of three sampling events. The first core sample was taken in October 1988. The tank supernate and sludge were next core sampled in February and March of 1990 (Tingey and Sasaki 1995). A grab sample of the supernate was taken in March of 1994. Tank 241-SY-102 is in active service and can be expected to have additional transfers to and from the tank that will alter the composition of the waste. The concentratio...