Performance test of dosimetric services in the EU member states and Switzerland for the routine assessment of individual doses (photon, beta and neutron)

The results are given of a consolidated performance test for whole-body, and extremity personal dosemeters broadly representative of those in use in the EU member states and Switzerland. Beta, photon and neutron personal dosemeters were used to assess the routine services ability to determine and report personal dose equivalents.

In total, 69 sets of dosemeters were entered in the test by 34 services. About 1000 dosemeters were irradiated. One purpose of the consolidated performance test and the analysis of the results was to enable the assessment of criteria for the acceptability of the dosimetry of routine services. It was assumed that each service would have already done a type test before performing routine dosimetry: the radiation fields were chosen to simulate, as far as possible, workplace radiation fields by mixing combining energies and incident angles.

The results of photon dosemeters were good for all fields except for R-F. Beta test results showed that many types of dosemeter were not able accurately to determine personal dose equivalent when large incident angles and low energies were encountered. Neutron dosimetry, results were very dependent on the dosemeter type and the dose calculation algorithm.

Fast neutron fields were generally well measured, but particular problems were noted in the determination of intermediate energy fields. This illustrates the importance of such a field for calibration purposes. Of particular concern from a radiological protection point of view was the large number of results for beta and neutron dosemeters underestimating personal dose equivalent.

A considerable over-response was noted in few cases. This is one of three papers produced by the EURADOS action group. Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation. The other two papers are included in this issue of Radiation Protection Dosimetry.