Some Quantitative Aspects of Measuring Liquid Wastes in Large Collection Basins

The low level, uranium bearing liquid wastes from the ammonium diuranate (ADU) process used in some low enriched uranium fuel fabrication are typically measured in small critically safe tanks prior to discharge to waste disposal or to large storage basins. To check the cumulative accuracy of the measurements made in the small tanks, an engineering scale experiment was conducted over a several year period to determine the accuracy which could be achieved by measuring the liquid waste in a large shallow storage basin. The accuracy evaluation was performed using a large flat bottom basin of about a 600,000 gallon capacity as a batch measurement vessel. This report describes some of the quantitative aspects of this type of measurement and reports the limit of error which can be achieved if such vessels are used for accountability purposes.