Long-term PTB intercomparison of passive H*(10) dosemeters used in area monitoring

Abstract

This intercomparison serves to investigate the long-term behaviour of passive (or similarly used active) H*(10) dosemeters which are dedicated to the monitoring of the surroundings of nuclear plants and accelerators and used in the radiation field of the natural ambient radiation. From autumn 2005 to spring 2007, approx. 650 photon and neutron dosemeters were exposed to environmental radiation at three dosimetric reference sites, operated by the Physikalisch-Technische Bundesanstalt (PTB). In addition to the measurements under natural conditions a number of dosemeters was also subjected to an additional irradiation in PTB photon and neutron fields. Ten measuring bodies and institutions, which are involved in ambient monitoring in Germany, Austria and Switzerland, took part in this intercomparison. The intercomparison revealed the typical precision to be expected from long-term dose measurements in the natural environment. The difference of the response of the dosemeters to terrestrial and to cosmic radiation was determined. From the results of this intercomparison some sources of uncertainty were identified and some recommendations to improve area monitoring were derived.

EURADOS intercomparison of passive H*(10) area dosemeters 2014

“…Nevertheless, this detection limit is e.g. required by a German directive (see Dombrowski and Neumaier, 2012 for further details), because 0.1 mSv is 10% of the permissible effective dose limit of 1 mSv per year for a member of the public, defined in 2013/59/Euratom.…”

“…to the terrestrial and the cosmic component of the environmental radiation, for the complete measuring period. This extended free-field site is equipped with a number of active detectors which are operated permanently around the clock, like photon detectors and particle detectors (more details can be found in Dombrowski and Neumaier, 2012). The latter are used to measure the dose (rate) produced by the secondary cosmic radiation.…”

“…After the dosemeters were sent back to their owners, the latter read out the dose values and PTB provided reference values and finally certificates. A more detailed description of the PTB reference measuring sites for environmental radiation is found in Dombrowski and Neumaier (2012). In this reference, the calcula-tion of the reference values for all measurements is explained in addition.…”

Review of the thermoluminescent dosimetry method for the environmental dose monitoring

“…If the field is known at the place of the mea sure ment, the cal i bration could be done with the qual ity that has sim i lar mean spec trum en ergy. Thus, it is rec om mended in [57,58] that cal i bra tion should be done in pho ton fields, pref er a bly in a sealed 226 Ra source.…”

“…( 2) and (3) [28]. The in flu ence of ap pro pri ate cal i bra tion qual ity is un der lined in [58]. In the most re cent study [60], a de tailed anal y sis of mea surement un cer tainty for pas sive do sim e try sys tems was performed and a few con clu sions were drawn:…”