M.S. Thesis Presentation by Dale Thomas
Monday, December 9, 2002

(Dr. Chris Wang, advisor)

"Radiochemical Methods and Results Used to Characterize Concentrations of Radioactive Materials
in Soil at the Former McClellan Air Force base (AFB) "


After approximately 40 years of operation as an Air Force Logistics Center, McClellan Air Force Base closed as a Department of Defense installation in April, 2001. Several of McClellan’s operational missions and requirements mandated the use and disposal of radioactive materials. Radium-226 was commonly used in aircraft dials and gauges. Various isotopes of neptunium, plutonium, and other fission products were used in radiochemistry laboratories that supported nuclear treaty monitoring efforts. Early radioactive material disposal practices included landfill and burial pit disposal through the early 1970s. Several studies and remedial efforts are currently ongoing at the former USAF installation to minimize environmental effects and reduce risk to the general public.

This thesis will describe the analytical methods used in the laboratory analysis of samples collected to support a reference area survey. Over 800 analyses were conducted for 172 soil samples. It will detail the handling, preparation, chemical dissolution, element extraction and measurement techniques for various target nuclides. Its fundamental objectives are to document the methods used in conducting the analysis and assess range and statistical distribution of the results as the principle mechanism for establishing derived concentration guideline levels (DCGL) for future remediation activities on the former McClellan AFB and to support risk assessments from exposure to radioactive contaminants.