Uncertainty estimation in 60Co gamma-ray dosimetry at JAERI involving a two-way dose intercomparison study with NPL in the dose range 1-50 kGy

The uncertainties in Co-60 gamma-ray dosimetry at JAERI have been estimated by reviewing irradiation and calibration procedures. The uncertainty in dose delivered by the JAERI calibration system has been estimated to be 2.2% (2 sigma) and the uncertainty in dose measurement using JAERI alanine/ESR transfer dosimeters has been estimated to be 3.4% (2 sigma), A two-way dose intercomparison study between NPL and JAERI employing alanine-PS, alanine-paraffin, and dichromate dosimeters as transfer dosimeters was performed to confirm the estimated uncertainty over the dose range 1-50 kGy. Dose intercomparison results using both alanine and dichromate dosimeters show agreement within about 2%, which gives confidence in the estimated uncertainty in Co-60 gamma-ray dosimetry at JAERI. (C) 1999 Elsevier Science Ltd. All rights reserved.