10.12768/DYYJ-EH49
McWhan, A. F.
A. F.
McWhan
Dobrzynska, W.
W.
Dobrzynska
Grimbergen, T. W. M.
T. W. M.
Grimbergen
Nuclear Research and Consultancy Group
Figel, M.
M.
Figel
Helmholtz Zentrum München
Romero, A. M.
A. M.
Romero
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
Stadtmann, H.
H.
Stadtmann
Seibersdorf Laboratories (Austria)
EURADOS Intercomparison 2012 for Whole Body Dosemeters in Photon Fields
European Radiation Dosimetry Group e.V. (EURADOS)
2015
EURADOS Report
FOS: Physical sciences
Hürkamp, Kerstin
Kerstin
Hürkamp
Helmholtz Zentrum München
2015-04
en
2226-8057
978-3-943701-09-8
5.2 MB
pdf
EURADOS Report 2015-02
Abstract: EURADOS Working Group 2 (WG2) has developed a system for a self-sustained programme of regular intercomparisons. Four intercomparisonsfor whole body dosemeters (IC2008, IC 2010, IC2012and IC2012n) and one for extremity dosemeters (IC2009) have now been carried out. The number of participating systems has increased significantly from 62 in 2008 to 88 in 2012.
IC2012was carried out by an organization group (OG) composed of Andrew McWhan and Wioletta Dobrzynska (Cavendish Nuclear Limited, co-ordinator and co-ordinating laboratory), Tom Grimbergen (NRG), Ana Maria Romero (CIEMAT), Hannes Stadtmann (Seibersdorf Laboratories) and Markus Figel (Helmholtz Zentrum München).
There were 74 participating institutes from 30 countries (8 from outside of the EU) with 88 dosimetry systems. However, one participant decided to withdrawafter hearing about the problems with some of the irradiations (see below). Participants’ systems included 59 TLD, 12 Film, 11 OSL and 5 dosemeter systems based on other techniques (Other), i.e.radiophotoluminescence(RPL), direction storage (DIS) or active personal dosemeters (APD). As with IC2010, there were a sufficient number of OSL systems for them to be included as a separate category in the analysis. A total of 2288 dosemeters were received and re-labelled, 1760 of which were then irradiated and processed. All irradiations were carried out by GAEC (Greek Atomic Energy Commission, Greece). Their irradiation laboratory is accredited to EN ISO/IEC 17025 as required by the protocol developed by the OG.
Unfortunately, two significant technical problems were experienced with IC2012:
i) All dosemeters were x-rayed in transit (by air freight) between Berkeley and the irradiation laboratory. To avoid the possibility of further transit x-ray,the dosemeters were returned from the irradiation laboratoryto Berkeley overland in a vanhired exclusively for this consignment.
ii) An intermittent technical malfunction of the x-ray system resulted in errors with some of the x-ray and mixed field irradiations.
During routine maintenance of the laboratory equipment at the end of the intercomparison (carried out after all the dosemeters had been returned to the participants) the irradiation laboratory identified a problem with the shutter mechanism of their x-ray set. It was concluded that this would have impaired the reliability of the N-40 and the mixed field Cs137+N150 45° irradiations. The problem, which was intermittent, produced non-uniform fields for some of the irradiations. The problem was not detected during the routine daily laboratory QA checks because the test chamber was located in a zone of the field which was not affected by the fault. After detailed analysis by OG, all of these suspect irradiations were excluded from IC2012 and they were not included in any of the participants’ certificates. All participants were offered substitute irradiations, outside of IC2012, completely free of charge.
Out of the total of 87 systems, 69 reported both Hp(10) and Hp(0.07 ) with 18 IMS reporting Hp(10) results only. The results show that 90% of all the systems fulfil the general performance criteria fromISO14146, where 10% outliers per system are permitted. In total,79% of all single results are within the trumpet curve used as acceptance criteria. The median of all response values was very close to unity.
These results were presented at the participants’ meeting held at AM2013 in Barcelona.
The high number of participants confirms that there continues to be a substantial demand for international intercomparison exercises, particularly in Europe, and that these are of significant operational value for Individual Monitoring Services (IMS).
Following the success of the previous intercomparisons, a further intercomparison for whole body dosemeters for photon fields was scheduled for 2014.