Low-Impact Sampling Under an Active Solid Low-Level Radioactive Waste Disposal Unit Using Horizontal Drilling Technology

Abstract

AbstractThe purpose of this project was to determine the performance of a 5.5 year old active solid low-level radioactive waste disposal unit (Pit 37) located on a mesa top at Los Alamos National Laboratory (LANL), Los Alamos, NM, and to provide in-situ (vadose zone) site characterization information to Technical Area 54, Material Disposal Area (MDA) G's Performance Assessment. The vadose zone beneath Pit 37 was accessed by utilizing low-impact, air-rotary horizontal drilling technology. Core was sampled at approximately 5-foot intervals via wire-line core method in 3 horizontal holes fanning out below Pit 37. Samples were screened and prepared in-field following LANL Environmental Restoration Project guidelines. Samples were transferred from the field to the Mobile Radiation Analysis Laboratory for initial radiological screening. Following screening, samples were delivered to an analytical lab for analyses including moisture content, 23 inorganic compounds, 60 volatile organic compounds, 68 semivolatile organic compounds, tritium, lead 210, radium 226 's Pit 37 is performing well and no significant liquid phase migration of contaminants has occurred.