In-ground environmental radioactivity monitoring in the Culpeper Basin, Virginia, using LiF thermoluminescence dosimeters
A new environmental in-ground radioactivity monitoring technique using LiF thermoluminescence dosimeters was tested in the Culpeper Basin, Northern Virginia. The dosimeters were buried at a depth of 0.45 m (∼ 18 in.) for approximately four months. There was a significant positive correlation (at the 99.9% confidence level) between the total accumulated radioactivity signal from the dosimeters and the on-site 100 second gamma-ray spectrometer measurements. The minimum-maximum dose rate from the buried thermoluminescence dosimeter measurements was 0.06 to 1.08 mR per day (or 2.5 to 44.5µR per hour).
There are two factors which permit better background levels of radioactivity to be established by thermoluminescence dosimeters compared with other methods for environmental monitoring programs. First is the great sensitivity of thermoluminescence dosimeters in terms of minimum dose rate that can be registered (mR per month orµR per hour). Second is the fact that accumulation of radioactivity signal over a long period of time tends to eliminate short-term environmental changes that affect measurements with gamma-ray spectrometers and scintillation counters.
KeywordsDose Rate Significant Positive Correlation Monitoring Program Environmental Monitoring Scintillation Counter
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- Johnson, S. S., 1979, Radioactivity surveys: Virginia Minerals, v. 25, p. 9–14.Google Scholar
- Johnson, S. S., T. M. Gathright, W. S. Henika, 1979, Gammaray spectrometry and geologic mapping: Virginia Minerals, v. 25, p. 17–23.Google Scholar
- Lindholm, R. C., 1979, Geologic history and stratigraphy of the Triassic-Jurassic Culpeper Basin, Virginia: Geol. Soc. America Bull., Part II, v. 90, p. 1702–1736Google Scholar
- McDougall, D. J., 1968, Thermoluminescence of Geological Materials: Academic Press, London, 678 p.Google Scholar
- Nielsen, B. L., and V. Mejdahl, 1970, Gamma-ray logging by means of thermoluminescence dosimeters: Danish Atomic Energy Commission, Riso Rept. no. 219, 17 p.Google Scholar
- Nielsen, B. L., and L. Botter-Jensen, 1973, Natural background radiation levels from areas of major geological units in Greenland, determined by means of thermoluminescence dosimetry: Modern Geology, 4, 119–129.Google Scholar
- Siegel, F. R., 1974, Applied Geochemistry: Wiley Interscience, New York, 353 p.Google Scholar
- Smith, R. C., 1979, Radon detection using thermoluminescence dosimeters in uranium exploration: In Uranium exploration techniques, G. R. Parslow, ed., Saskatchewan Geol. Soc. Spec. Publ. no. 4, p. 85–108.Google Scholar
- Vaz, J. E., and R. S. Sifontes, 1978, Radiometric survey using thermoluminescence dosimetry in the Cerro Impacto (Venezuela) thorium deposit: Modern Geol., v. 6, p. 147–152.Google Scholar
- Zimmerman, D. W., C. R. Rhyner, and J. R. Cameron, 1967, Thermal annealing effects on the thermoluminescence of lithium fluoride, F. H. Attix, ed., Proceedings of the Int'l Conf. on Luminescence Dosimetry, Stanford University, Stanford, CA, U.S.A.E.C., p. 86–100.Google Scholar