Operation and routine maintenance of the automatic monitor for hexavalent chromium in Columbia River water

摘要

A Technicon Autoanalyzer for hexavalent chromium has been installed at the Automatic Columbia River Monitoring Station located along the west bank of the Columbia River. The sample water is delivered to the building by a deep well jet pump for continuous monitoring for gross gamma, (sup 131)I, hexavalent chromium, and for emergency water samples. An alarm system indicates unusually high activity levels. The unit was installed to detect hexavalent chromium which reaches the river as a result of cooling water treatment for the production reactors upstream, and via groundwater as a result of waste disposal practices at the 300 Area. The detection of the Cr(sup +6) ion is based upon its reaction with diphenylcarbazide to produce a reddish-violet color in slightly acid solutions. The degree of color is indicated by light absorption in the calorimeter which is plotted on the recorder and is directly related to the concentration of hexavalent chromium in the river water. Although designed to operate continuously and automatically, routine inspection is required to assure proper functioning of all components and to perform the required maintenance and pick up of recorded data. The following data is to provide general information relevant to the operation and maintenance of the system. (ERA citation 19:029923)