The Clermont radiometric reference rocks: a convenient tool for dosimetric purposes

Boreholes drilled in 8 different rocks situated in the vicinity of the Clermont TL laboratory have been used for testing and calibrating methods devoted to measurement of natural radioactivity. The present paper gives updated data for the nuclide contents and internal dose rates for those reference media. Two examples of applicat ion are presented. The first example shows dose rate calibration of a scintillator gamma probe using a threshold method. The second example shows a routine technique for TL dosimetry, based on the rocks for dose rate reference.