Nevada Test Site 2007 Waste Management Monitoring Report Area 3 and Area 5 Radioactive Waste Management Sites
Environmental monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site. These data are associated with radiation exposure, air, groundwater, meteorology, vadose zone, subsidence, and biota. This report summarizes the 2007 environmental data to provide an overall evaluation of RWMS performance and to support environmental compliance and performance assessment (PA) activities. Some of these data (e.g., radiation exposure, air, and groundwater) are presented in other reports (National Security Technologies, LLC, 2007a; 2008; Warren and Grossman, 2008). Direct radiation monitoring data indicate exposure levels at the RWMSs are at background levels. Air monitoring data at the Area 3 and Area 5 RWMSs indicate that tritium concentrations are slightly above background levels. A single gamma spectroscopy measurement for cesium was slightly above the minimum detectable concentration, and concentrations of americium and plutonium are only slightly above detection limits at the Area 3 RWMS. The measured levels of radionuclides in air particulates are below derived concentration guides for these radionuclides. Radon flux from waste covers is well below regulatory limits. Groundwater monitoring data indicate that the groundwater in the uppermost aquifer beneath the Area 5 RWMS is not impacted by facility operations. The 136.8 millimeters (mm) (5.39 inches [in.]) of precipitation at the Area 3 RWMS during 2007 is 13 percent below the average of 158.1 mm (6.22 in.), and the 123.8 mm (4.87 in.) of precipitation at the Area 5 RWMS during 2007 is 6 percent below the average of 130.7 mm (5.15 in.). Soil-gas tritium monitoring at borehole GCD-05U continues to show slow subsurface migration consistent with previous results. Water balance measurements indicate that evapotranspiration from the vegetated weighing lysimeter dries the soil and prevents downward movement percolation of precipitation more effectively than evaporation from the bare-soil weighing lysimeter. Data from the automated vadose zone monitoring system for the operational waste pit covers show that evaporation continues to slowly remove soil moisture that came from the heavy precipitation in the fall of 2004 and the spring of 2005. The vegetated final mono-layer cover on the U-3ax/bl disposal unit at the Area 3 RWMS effectively removes moisture from the cover by evapotranspiration. During 2007, there was no drainage through 2.4 meters (8 feet) of soil from the Area 3 drainage lysimeters that received only natural precipitation or were vegetated but water drained from the bare-soil Area 3 drainage lysimeter that received 3 times natural precipitation. Elevated tritium levels in plants and animals sampled from the Area 3 and Area 5 RWMSs show tritium uptake by the biota, but the low levels of other radionuclides do not suggest that there has been intrusion into the waste. All 2007 monitoring data indicate that the Area 3 and Area 5 RWMSs are performing within expectations of the model and parameter assumptions for the facility PAs.
- Research Organization:
- National Security Technologies, LLC (NSTec), Mercury, NV (United States)
- Sponsoring Organization:
- USDOE - National Nuclear Security Administration (NNSA)
- DOE Contract Number:
- DE-AC52-06NA25946
- OSTI ID:
- 934450
- Report Number(s):
- DOE/NV/25946-490; TRN: US0804137
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nevada Test Site, 2006 Waste Management Monitoring Report, Area 3 and Area 5 Radioactive Waste Management Sites
Nevada National Security Site 2010 Waste Management Monitoring Report Area 3 and Area 5 Radioactive Waste Management Sites
Related Subjects
AIR
AMERICIUM
CESIUM
DRAINAGE
GAMMA SPECTROSCOPY
GROUND WATER
LYSIMETERS
MONITORING
NEVADA TEST SITE
PARTICULATES
PLUTONIUM
PRECIPITATION
RADIATION MONITORING
RADIOACTIVE WASTE MANAGEMENT
RADIOISOTOPES
RADON
TRITIUM
WASTE MANAGEMENT
WASTES
Radioactive Waste Managment Site
Environmental Monitoring