Independent Sampling Study 2012
Field investigation and laboratory report for:
LeRoy Moore, Ph.D.
Rocky Mountain Peace & Justice Center P. O. Box 1156
Marco Kaltofen, MS, PE, (Civil, Mass.) Boston Chemical Data Corp.
January 20, 2012
All 50 samples from the 2010 and 2011 sampling campaigns were tested for total activity and by gamma isotopic analysis. A subset of the samples was tested commercially for plutonium, radioactively-hot particles, along with confirmation testing for uranium and thorium.
Plutonium exceeded reported background levels by two orders of magnitude at locations that match those noted in the Krey Hardy report. (P. W. Krey and E. P. Hardy, 1970, “Plutonium in Soil Around the Rocky Flats Plant”)
Naturally-occurring total activity, uranium, and thorium levels are elevated in this area, and were not used as indicators of contamination.
There was no statistically significant difference between this data set and the 1970 data set. Plutonium losses appear to be approximately equal in magnitude to plutonium inputs in the Indiana St. area.
The portion of the study area surrounding Indiana St. was contaminated with plutonium isotopes, traces of americium. This zone also contained uranium and thorium bearing monazite particles. Although monazites are naturally occurring, these particles nevertheless represent an inhalation hazard, as they were in the respirable size range of 0.5 to 5.0 microns. Particles of silicates containing uranium and thorium were also detected.