Fission Track Analysis (FTA) at our facility is a refined, non-invasive method to quantify the levels of Pu-239 in an individual. Urine samples are collected and chemically processed to reduce the volume and contaminants. The samples are placed on Lexan© slides or electrodeposited onto stainless steel planchets prior to irradiation in our reactor facility. Neutrons from our reactor induce fission and the fission fragments then create small tracks in the Lexan detectors that can be optically viewed and quantified. The FTA process has been modified and tested on other sample types and can be used to measure levels of activity for other fissionable isotopes. The current procedure has a Pu detection limit of 2.8 microBq/L (76 aCi/L), much lower than typical alpha spectroscopy equipment.

Typical Fission Tracks Shown at 200x Magnification

• Determination of plutonium-239, thorium-232, and natural uranium isotopic concentrations in biological samples using photofission track analysis, J. Parry, Ph.D. Dissertation, University of Utah, August 2005.
• Using Fission Track Analysis Techniques to Measure Plutonium Isotopic Ratios, J.L. Wilde, Ph.D. Dissertation, University of Utah, August 2004.
• Lexan Lucidity Due to Neutron Fluence, J.D. Bess, B.S. Thesis, University of Utah, April 2003.
• Using Plutonium Excretion Data to Predict Dose from Chronic and Acute Exposures, M.P. Krahenbuhl, J.L. Wilde, and D.M. Slaughter, Radiat. Prot. Dosimetry, 87: 179-186, 2000.
• Utilizing Distinct Neutron Spectra and a System of Equations to Differentiate Competing Reactions in Activation Analysis,Dong-Ok Choe, Kevan D. Weaver, and David M. Slaughter, J. Radioanal. Nucl. Chem., Vol. 244, No. 3, 2000.
• Decreasing the Fission Track Analysis Detection Limit of Plutonium Concentrations in Human Excreta by Utilizing Two Distinct Neutron Energy Spectra, Dong-Ok Choe, Ph.D. Dissertation, University of Utah, August 2000.
• Plutonium excretion in urine of residents living near the Rocky Flats Environmental Technology Site, Ibrahim SA, Whicker FW, Reuss SK, Whicker RD, Chapman PL, Krahenbuhl MP., Health Phys. Apr;76(4):368-79, 1999.
• Improving process methology for measuring plutonium burden in human urine using fission track analysis, M.P. Krahenbul, D.M. Slaughter.,J. Radioanal. Nucl. Chem., 230(1-2) 153, 1998.
• Ultra Sensitive Detection and Dose Reconstruction for Plutonium-239 through Fission Track Analysis of Urine, M.P. Krahenbul, Ph.D. Dissertation, University of Utah, December 1998.