Baseline radionuclide concentrations in soils and vegetation around the proposed Weapons Engineering Tritium Facility and the Weapons Subsystems Laboratory at TA-16

摘要

A preoperational environmental survey is required by the Department of Energy (DOE) for all federally funded research facilities that have the potential to cause adverse impacts on the environment. An environmental survey was conducted over the proposed sites of the Weapons Engineering Tritium Facility (WETF) and the Weapons Subsystems Laboratory (WSL) at Los Alamos National Laboratory (LANL) at TA-16. Baseline concentrations of tritium (H-3), plutonium (Pu-238 and Pu-239), and total uranium were measured in soils, vegetation (pine needles and oak leaves), and ground litter. Tritium was also measured from air samples, while cesium (Cs-137) was measured in soils. The mean concentration of airborne tritiated water during 1987 was 3.9 pCi/cu m. Although the mean annual concentration of H-3 in soil moisture at the 0-5 cm (2 in) soil depth was measured at 0.6 pCi/mL, a better background level, based on long-term regional data, was considered to be 2.6 pCi/mL. Mean values for Cs-137, Pu-238, Pu-239, and total uranium in soils collected from the 0--5 cm depth were 1.08 pCi/g, 0.0014 pCi/g, 0.0325 pCi/g, and 4.01 micrograms/g, respectively. Ponderosa pine (Pinus ponderosa) needles contained higher values of Pu-238, Pu-239, and total uranium than did leaves collected from gambel's oak (Quercus gambelii). In contrast, leaves collected from gambel's oak contained higher levels of C-137s than what pine needles contained.