Perimeter Air Sampler 6 (Northeast of Building 90 at Fence)
Thorium-230 Alpha Spectroscopy Monthly Results
Action limit for thorium-230 is 2.00E-14 µCi/ml (10 CFR 20 Appendix B Table 2).
Pre-operational average thorium-230 baseline activity concentration is 2.1E-17 µCi/ml.
Month	Hours	Lab Qualifier	Activity Concentration ± Uncertainty (µCi/mL)
Jan-09	1010	U	6.4E-18	±	9.0E-18
Feb-09	675	U	9.6E-18	±	7.6E-18
Mar-09	667	U	1.7E-17	±	2.7E-17
Apr-09	676	U	3.5E-17	±	3.2E-17
May-09	842		3.2E-17	±	1.6E-17
Jun-09	669		4.2E-17	±	2.6E-17
Jul-09	841	U	1.1E-17	±	2.4E-17
Aug-09	648	U	8.6E-18	±	2.4E-17
Sep-09	676	U	-5.2E-18	±	1.0E-17
Oct-09	837	U	2.3E-17	±	2.8E-17
Nov-09	672		3.5E-17	±	2.4E-17
Dec-09	673	U	1.7E-17	±	2.0E-17
Lab Qualifier Flags
NR	No data reported for this radionuclide due to laboratory error or data found unacceptable during review
J	Nuclide identified, the associated numerical value is approximated
U	Nuclide not detected above the reported MDC or 2 sigma counting uncertainty
0.00E+00	Not detected in spectra
NA	Data not available at this time