History of the plutonium bioassay program at the Los Alamos National Laboratory, 1944-2006

In 1944 Los Alamos National Laboratory (LANL) instituted a program for the collection and analyses of urine samples from individuals working with plutonium. This program has operated continuously for over 60 years. During that time the plutonium bioassay program incorporated advances in urine sample collection, radiochemical separation techniques, alpha-spectroscopy and thermal ionization mass spectrometry measurement techniques as well as cleanroom technology. All of these advances have produced incremental improvements in plutonium detection limits. A chronological description is given of the methodologies used in the plutonium bioassay program at Los Alamos.