Hydrological and meteorological data for an unsaturated zone study near the radioactive waste management complex, Idaho National Engineering Laboratory, Idaho: 1985--86

The hydrologic properties of the unsaturated zone and amount of net recharge to the system must be determined to field-calibrate a mathematical model to predict the long-term migration of radionuclides in the unsaturated zone. This study is being conducted to provide that necessary data for a specific area. Radioactive waste has been buried at the RWMC (Radioactive Waste Management Complex) at the INEL (Idaho National Engineering Laboratory) since 1952. In 1985, the US Geological Survey and EG ampersand G Idaho, Inc., in cooperation with the US Department of Energy, began a study of the geohydrology of the RWMC to provide a basis for estimating the extent of and the potential for migration of radionuclides in the unsaturated zone beneath the waste burial trenches and pits. Two test trenches were installed in the surficial sediment adjacent to the RWMC burial ground to collect hydrologic data from undisturbed and disturbed soil. Hydrologic data collected during 1985 and 1986 included measurements, taken every 12 hours, of soil temperature and soil-water potential from 30 sensors placed at selected depths to about 6 meters using thermocouple psychrometers; and soil-moisture content measurements collected weekly in 9 neutron-probe access holes with a neutron moisture depth gage. Meteorological data averaged every 6 hours included wind speed, wind direction, relative humidity, air temperature; solar radiation and precipitation were totaled over the 6-hour period. 18 refs., 14 figs., 19 tabs