Search

Since 2012, the European Radiation Dosimetry Group (EURADOS) has developed its Strategic Research Agenda (SRA), which contributes to the identification of future research needs in radiation dosimetry in Europe. Continued scientific developments in this field necessitate regular updates and, consequently, this paper summarises the latest revision of the SRA, with input regarding the state of the art and vision for the future contributed by EURADOS Working Groups and through a stakeholder workshop. Five visions define key issues in dosimetry research that are considered important over at least the next decade. They include scientific objectives and developments in (i) updated fundamental dose concepts and quantities, (ii) improved radiation risk estimates deduced from epidemiological cohorts, (iii) efficient dose assessment for radiological emergencies, (iv) integrated personalised dosimetry in medical applications and (v) improved radiation protection of workers and the public. This SRA will be used as a guideline for future activities of EURADOS Working Groups but can also be used as guidance for research in radiation dosimetry by the wider community. It will also be used as input for a general European research roadmap for radiation protection, following similar previous contributions to the European Joint Programme for the Integration of Radiation Protection Research, under the Horizon 2020 programme (CONCERT). The full version of the SRA is available as a EURADOS report (www.eurados.org).

The European Radiation Dosimetry Group (EURADOS) is a network of organizations and scientists promoting research and development in the dosimetry of ionizing radiation, contributing to harmonization in dosimetry practice across Europe, and offering education and training in areas relevant for dosimetry. As a registered non-profit association under German law, EURADOS is currently running eight active working groups (WGs): WG2 on “Harmonization of Individual Monitoring”, WG3 on “Environmental Dosimetry”, WG6 on “Computational Dosimetry”, WG7 on “Internal Dosimetry”, WG9 on “Dosimetry in Radiotherapy”, WG10 on “Retrospective Dosimetry”, WG11 on “Dosimetry in High-Energy Radiation Fields”, and WG12 on “Dosimetry in Medical Imaging”. This paper presents recent scientific results obtained within these working groups, and additionally highlights the role of EURADOS as an organization which contributes to the development of a systematic strategy of radiation protection research in Europe.

International audience; The European Radiation Dosimetry Group (EURADOS) has set up intercomparison exercises for personal dosemeters on a regular basis. In 2017, the second EURADOS intercomparison for neutron dosemeters (IC2017n) took place. The intercomparison concerned the performance of neutron dosemeters provided by individual monitoring services to measure neutron personal dose equivalent, Hp(10). The irradiations, which included exposures to neutrons and mixed fields of neutrons and photons as commonly encountered in workplaces, were performed in accredited irradiation facilities in terms of Hp(10). The range of energies used in the intercomparison extended from thermal to several MeV, with different dose values and angles used. The paper reports on the results of this intercomparison for whole body neutron dosemeters.

An experimental campaign was conducted to assess the neutron dose field inside the biological shield of the PETrace cyclotron at the S. Orsola-Malpighi hospital in Bologna. The results of the survey were analyzed to confirm that neutrons are emitted isotropically, thus validating the hypothesis of nuclear evaporation, as opposed to cascade, as the dominant mechanism for neutron emission.

International audience; The European Radiation Dosimetry Group (EURADOS) has been organising dosimetry intercomparisons for many years in response to an identified requirement from individual monitoring services (IMS) for independent performance tests for dosimetry systems. The participation in intercomparisons gives IMS the opportunity to show compliance with their own quality management system, compare results with other participants and develop plans for improving their dosimetry systems. In response to growing demand, EURADOS has increased the number of intercomparisons for external radiation dosimetry. Most of these fit into the programme of self-financing intercomparisons for dosemeters routinely used by IMS. This programme is being coordinated by EURADOS working group 2 (WG2). Up to now, this programme has included four intercomparisons for whole-body dosemeters in photon fields, one for extremity dosemeters in photon and beta fields, and one for whole-body dosemeters in neutron fields. Other EURADOS working groups have organised additional intercomparisons including events in 2014 for eye-lens dosemeters and passive area dosemeters for environmental monitoring. In this paper, the organisation and achievements of these intercomparisons are compared in detail focusing on the similarities and differences in their execution. © The Author 2016. Published by Oxford University Press. All rights reserved.

International audience; Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises-based on input from EURADOS Working Groups (WGs) and Voting Members-five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS website (www.eurados.org).

International audience; In 2012, the European Radiation Dosimetry Group (EURADOS) performed an intercomparison for neutron dosemeters that are intended to measure personal dose equivalent, Hp(10). A total of 31 participants registered with 34 dosimetry systems. The irradiation tests were chosen to provide the participants with useful information on their dosimetry systems, i.e. linearity, reproducibility, responses for different energies and angles and to simulated workplace fields. This paper gives details of the extensive information derived from the exercise. © The Author 2015. Published by Oxford University Press. All rights reserved.

International audience; In the framework of the ORAMED project (Optimization of RAdiation protection for MEDical staff ), funded by theEuropean Union Seventh Framework Programme, different studies were aimed at improving the quality of radiation protectionin interventional radiology and nuclear medicine. The main results of the project were presented during a final workshop heldin Barcelona in January 2011, the proceedings of which are available in the open literature. One of the ORAMED tasks wasfocused on the problem of eye-lens photon exposure of the medical staff, a topic that gained more importance especially afterthe ICRP decision to lower the limiting equivalent dose to 20 mSv per year. The present technical note has the scope, besidesbriefly summarising the physical reasons of the proposal and the practical implications, to provide, in tabular form, a set ofair kerma to $Hp$(3) conversion coefficients based on the adoption of a theoretical cylindrical model that is well suited for reproduction of the mass and the shape of a human head.

In recent years an increased interest in assessment of eye lens doses in interventional radiology has been observed, due to the fact that it seems that cataracts may be induced by radiation doses at levels lower than so far expected. One of the tasks of the EU FP7 ORAMED project was to develop the first dosemeter specially dedicated to measurements of HP(3). This goal was achieved by designing and testing of the EYE-D™ dosemeter. This dosemeter, comprising an MCP-N (LiF:Mg,Cu,P) thermoluminescent detector and an optimized polyamide capsule, was developed by the RADCARD company. The dosemeter is designed for an indefinite use and enables cold sterilization. The test measurements and Monte Carlo calculations of the photon energy response and angular response produced very satisfactory results: all obtained values are within about 20% around unity (with respect to Cs-137). The dosemeter fulfills all requirements for its application in dosimetry in interventional radiology.

Due to the recent new interest of the dosimetric community generated by evidence of larger number of induced cataracts for the same absorbed dose, in the frame work of the ORAMED project ( Oramed, 2008 ) a task was devoted to the critical revision of the eye lens dose assessment procedures. The present paper summarizes the Monte Carlo analyses carried out to optimize the H p (3,Ω) calculations in order to produce a set of conversion coefficients H p (3,Ω)/ K a as close as possible to those of the limiting quantity H T (eye lens)/ K a. Comparison were carried out with already published values calculated for a previous theoretical phantom, mainly suited for the calculations of H p (10,Ω)/ K a .

The European Union is funding the ORAMED Contract (Optimization of RAdiation protection for MEDical staff) project that aims at developing methodologies for better assessing and reducing exposures to medical staff for procedures resulting in potentially large doses or complex radiation fields, such as interventional radiology, nuclear medicine and new developments. One of the ORAMED Working Tasks is addressed to the discussion and implementation in the radiation protection practice of the eye lens equivalent dose. The aim of this task group is to develop a personal dosemeter characterized in term of H p (3). Until now H p (3) conversion coefficients were not reported in the official recommendations and the available data were calculated for a 30 × 30 × 15 cm 3 slab phantom that is far away to represent the head. A reduced slab phantom, for both calculating the quantities and type testing personal dosemeter in terms of the operational quantity, was previously proposed by ENEA Bologna team. The study demonstrated that a reduced slab phantom is better representative of a real situation, but the angular dependence of H p (3,α) due to the edges of the slab reduces its applicability. Therefore a better-suited phantom is proposed here. The dosimetric assessment in terms of this quantity is seldom performed in the various workplaces (e.g. hospitals) and therefore a question rises about its usefulness and practical implementation. The present work tries to introduce new elements in the discussion on the quantity H p (3) and to propose a more suitable theoretical cylindrical phantom (and a corresponding experimental one for the calibration procedures) to better approximate the head in which the eyes are placed.

The purpose of the European Commission technical recommendations (TR) for monitoring individuals occupationally exposed to external radiation is to provide guidance on those aspects of the implementation of the European Union Parliament and Council Directives directly related to individual monitoring of external radiation, and to encourage harmonisation thereof. They are mainly aimed at the management and staff of IM services but also at manufacturers, laboratories supplying type-testing services, national authorities trying to harmonise approval procedures, and government bodies to harmonise regulations and guidance. The TR main topics are: objectives and aims of IM for external radiation; dosimetry concepts; accuracy requirements; calibration, type testing and performance testing; approval procedures; quality assurance and quality control; and dose record keeping. Attention is paid to particular aspects, such as wide energy ranges for the use of personal dosemeters, pulsed fields and non-charged particle equilibrium; and use of active personal dosemeters. The TR give proposals towards achieving harmonisation in IM and the eventual mutual recognition of services and of dose results.

The European Radiation Dosimetry Group (EURADOS) carried out a co-ordinated action, supported within the 6th Framework Programme of the European Commission entitled 'A Co-ordinated Network for Radiation Dosimetry (CONRAD)'. The project, executed from January 2005 to March 2008, yielded a large number of scientific results in different areas of dosimetry. This paper describes the objectives and general aspects of the project while the results are given in several contributions in this volume. Special consideration is given to the results and implications of the feasibility study for a sustainable network in radiation dosimetry, which was also carried out within the CONRAD project.

The ENEA photon dosemeter, introduced in 1995, consisting of two differently filtrated LiF(Mg,Cu,P) detectors, has been modified recently. The ABS (acrylonitrile butadiene styrene) plastic support has been replaced by a new aluminium card supporting the same two detectors (LiF(Mg,Cu,P) GR200). The new card, fully developed at the ENEA-Radiation Protection Institute (which is going to be patented), can now be processed through a Harshaw Model 6600 Automated TLD Reader, a hot gas reader. This paper reports the results of the individual calibration of approximately 60,000 LiF(Mg,Cu,P) GR200 detectors inserted on the new aluminium cards. Before the implementation in routine of the new cards, the reader has been characterised. Steps and tests to be made to use the card in routine (i.e. reader stability, linearity, reproducibility, etc.) are reported. The whole dosimetric system now combines the very good performances of the Harshaw Model 6600 reader and that of LiF(Mg,Cu,P) thermoluminescent material.

With the aim of improving neutron sensors for monitoring external neutron exposure, we have analysed the workings of a converter plus silicon PIN diode detector arrangement. A phenomenological analysis of the conversion and signal generation of different converter materials and their effectiveness is given. The results are compared with experimental measurements. Because of the fundamentally different interactions of thermal neutrons versus high energy neutrons, we study the two species separately. For thermal neutrons, two types of neutron converters were examined, 6LiF (crystalline) and Kodak 10B films. For fast neutrons in the energy range from 1 to 20 MeV hydrogen rich Lucite—PMMA (H8C5O2) and Polyethylene—PE (CH2) converters were studied. For thermal neutrons and a pure 10B-converter the theoretical response in counts/neutron reaches a value of B S TOT =0.0684 and for a pure 6LiF-converter LiF S TOT =0.0543 . The corresponding experimental responses are 0.0062 for KODAK 10B film and 0.0223 for 6LiF converters. The difference between theory and experiment is understood by the necessity to use a lower level discriminator to eliminate unwanted counts coming from electrons and gammas. In the case of the 10B converter impurities in the converter material reduce the signal. Our analysis for fast neutrons allows us to calculate the ratio of sensitivity for Polyethylene to Lucite, for which we predict a value of 1.6. For the measured sensitivities for PE and PMMA, using an 241Am–Be neutron source, we obtain the values of 0.00225 and 0.0015 respectively, the ratio being 1.5.

The ENEA fast neutron dosemeter is based on a planar poly allyl diglicol carbonate (PADC) placed in a polyethylene holder. The present paper reports the results of an experimental study of a CR-39 ® material with the addition of 0.1% of dioctylphthalate (DOP) produced by the Italian company Intercast Europe S.p.A. The etching procedure is: pre-etching with 40% KOH water solution 6.25 N and 60% ethyl alcohol at 70°C followed by 12 h of etching in 6.25 N KOH water solution. For the energy dependence of response, dosemeters have been irradiated with neutron sources ( 241 Am –Be, 252 Cf , Pu–Li) and 14.9 MeV monoenergetic neutrons. The dosimetric performance of the material for fast neutrons is expressed in terms of sensitivity, background value, lowest detectable dose and energy dependence of response. Moreover, the results of a quality acceptance test of the material, performed on 11 sheets ( 980×980 mm 2 , 1.4 mm thick) of the same production batch, are given. Therefore, the homogeneity of the neutron sensitivity and of the background signal within a sheet and the whole batch is considered. The results are compared with the acceptance test outcome for a CR39 standard material batch.

A trial inter-comparison has been performed among four fast neutron dosimetric services: PSI(CH), ENEA (I), DRPS (UK), LANL (US). The PADC used for the tests has been produced by Intercast Europe S.p.A. Three sets of detectors have been employed: two of PADC standard material from two different batches, and one of PADC with the addition of 0.1% dioctylphthalate. Each set consisted of 50 detectors. For each set of detectors, 20 have been irradiated free-in-air at 1 mSv of H ∗ (10) with an 241 Am–Be source at ENEA-IRP, whilst the other detectors have been used as background samples. For each batch the value of the average background signal, B, the average neutron sensitivity, S, and minimum detectable dose equivalent, MDDE, have been determined. Two identical tests have been completed and separated with a time of 4 months in order to evaluate the ageing effect on the material stored in different conditions. Each dosimetric service processed the detectors according to local routine procedures. Three laboratories used an Autoscan60 reader, whilst one laboratory has an in-house reading system. Therefore, the results of the tests allowed a comparison of either the performance PADC materials, of different batches and of different compositions, or to evaluate how different etching, reading and storage conditions affect the results.

The ENEA fast neutron dosemeter is based on a planar PADC (poly allyl diglycol carbonate) placed in a polyethylene holder. The CR-39 (registered trademark of PPG Industries Inc.) material, produced by Intercast Europe S.p.A., has been used in the routine of the Individual Monitoring Service (IMS) since 1998. Since then, acceptance tests on average sheet background track density and sheet neutron sensitivity have been made on new batches as a quality control within a quality assurance programme of the IMS of ENEA-Institute for Radiation Protection (IRP). Dosemeters were irradiated with a 241Am-Be source at ENEA-IRP and processed through a chemical etching procedure (pre-etching with 40% KOH water solution 6.25 N and 60% ethyl alcohol at 70 degrees C followed by 12 h of etching in 6.25 N KOH water solution). In this paper we present the analysis of acceptance testing data for more than 30 sheets of CR-39 plastic produced in 1998, 1999 and 2000. Moreover, we compare the performance of sheets of CR-39 of standard composition with that of sheets of CR-39 with the addition of DOP (dioctylphthalate), in different concentrations, on the hasis of average background density, neutron sensitivity and background fluctuation that limit the lower detectable dose. This study demonstrates the need for acceptance tests to assure the quality of the dosimetric performance of these dosemeters, which is considerably dependent on the quality of the CR-39 plastic.

The energy dependence of the response function S(E), of CaF 2 :Tm (TLD-300) thermoluminescent material (3.2 × 3.2 × 0.90 mm 3 ribbons) was measured from 6 keV up to 1250 keV ( 60 Co) using 55 Fe, 137 Cs and 60 Co γ ray sources as well as X ray ISO reference beams. To the best knowledge of the authors the data for energies below 45 keV are reported for the first time. The S(E) function was also calculated in the energy range from 1 keV up to 20 MeV and compared with the experimental data relative to the total glow curve. The comparison shows good agreement from 1250 keV down to 40 keV. At lower energy the discrepancy increases. This is interpreted in terms of the X ray attenuation within the thickness of TLD-300. Finally, measurements point out the effects of different reading and annealing treatments on the measured function S(E).

Radiation Protection Dosimetry, 161 (1-4), ISSN:0144-8420, ISSN:1742-3406

The current situation amongst Member States is that there are widely differing national requirements for dosimetric services and for dosemeter performance. It is clear that with the free movement of workers within the European Union (EU) and the requirements for individual dosimetry given in Council Directive 96/29 EURATOM, a degree of harmonisation of requirements and procedures of EU Member States would be desirable. A EURADOS action group, made up of members from each of the EU Member States plus Switzerland, was set up with the overall objectives of consolidating within the EU the quality of individual monitoring using personal dosemeters and assisting movement towards harmonised procedures. An outline of the work of the action group is given and the term 'harmonisation' is discussed.

Although, at present, neither Italian legislation nor technical protocols require that personal dosimetry is performed to assess H p (d), the ENEA Individual Monitoring Service (IMS) is able to supply thermoluminescence (TL) whole-body and extremity dosemeters for photon and beta fields, based on LiF(Mg,Cu,P) detectors and these have been fully developed at the ENEA Institute for Radiation Protection (IRP). All irradiation tests have been performed with ISO phantoms and ISO recommended reference radiations at the ENEA-IRP Secondary Standard Dosimetry Laboratory. The whole-body dosemeter contains two LiF(Mg,Cu.P) (GR200) detectors that are filtered differently. One is filtered on both sides by 290 mg.cm -2 mass per area (270 mg.cm -2 Al + 20 mg.cm -2 plastic protective layer); the other is filtered on both sides by a plastic layer of 20 mg.cm -2 mass per area. In photon radiation fields, the maximum uncertainty due to the energy dependence of the response, is ±4% for H p (0.07) in the energy range 13 keV to 202 keV, and ±15% for H p (10) in the range 13 keV to 1.25 MeV. The dosemeter response in terms of H p (d,α) in beta fields has been investigated recently. The results of a EURADOS trial performance test for photon and beta fields are reported and discussed in this paper. The extremity dosemeter currently used at ENEA IMS consists of a GR200 detector glued on a kapton strip identified by a bar code. Its response in terms of H p (0.07,α) has been measured recently and the results are given. Moreover, different dosemeter assemblies have been tested to compare the performances in photon and beta fields. Therefore, the following three constructions have been prepared: (1) an MCP-Ns (8.5 mg.cm - mass per area) detector with a Mylar filter of 0.5 mg.cm -2 mass per area; (2) a polyethylene filter of 12 mg.cm - 2 mass per area; and (3) a GR200 (210 mg.cm -2 mass per area) detector with a Mylar filter of 0.5 mg.cm 2 . Finally, a brief discussion on international and Italian requirements for personal monitoring is given.

This paper examines the current status within EU Member States and Switzerland of requirements for approved dosimetric services. The present situation amongst Member States is that there are widely differing national requirements for the performance of dosimetric services and dosemeters. It is clear that with the free movement of workers within the EU and the multinational ownership of companies, a degree of harmonisation of requirements and procedures would be desirable. The paper aims to assist harmonisation, by giving the current status of procedures and requirements in Member States and Switzerland thereby allowing comparisons to be made. 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 also appear in this issue of Radiation Protection Dosimetry.

The ENEA fast neutron dosemeter is based on a planar PADC (Poly Allyl Diglicol Carbonate) placed in a polyethylene holder. The present paper reports the results of a preliminary experimental comparison of a CR-39 ® material with the addition of 0.1% of DOP (Dioctylphthalate), produced by the Italian company Intercast Europe S.p.A., and TASTRAK material produced by the British company TASL (UK). The etching procedure is for both materials: pre-etching with 40% KOH water solution 6.25 N and 60% ethyl alcohol at 70 °C followed by 12 h of etching in 6.25 N KOH water solution. Dosemeters have been irradiated with neutron sources ( 241 Am-Be) at the ENEA Calibration Service for Ionizing Radiations. For each kind of set of detectors, 10 have been irradiated free-in-air at 1 mSv of H*(10) with an 241 Am–Be source at ENEA Calibration Service for Ionizing Radiations, whilst the other 40 detectors have been used as background samples. The dosimetric performance of the material for fast neutrons is expressed in terms of sensitivity, background value and lowest detectable dose. For each batch the value of the average background signal, the average neutron sensitivity and minimum detectable dose equivalent have been determined. Two identical tests have been completed and separated with a time of 6 months in order to evaluate the aging effect on the material stored in the same conditions. The results are compared with our acceptance test. A comparison of criteria the performance of the two CR-39 ® materials is reported.

A study was undertaken to evaluate the response of the ENEA Photon Personal Dosemeter, slightly modified in design, in terms of H p (0.07, a) and H p (10, α). A filtration of 20 and 270 mg.cm -2 respectively for the two LiF(Mg,Cu,P) detectors employed was adopted according to a preliminary analytical simulation. The new dosemeter can measure both H p (0.07, α) with a maximum uncertainty of ±4% in the range from 10 to 200 keV and H p (10, α) with a maximum uncertainty of ±15% in the range from 10 keV to 1.25 MeV, using the detector responses together with a correction function with respect to their ratio. Moreover, tests were performed to evaluate the dosemeter angular response (0°, 20°, 40° and 60°) obtaining good results according to international recommendations. All irradiation tests were performed at SSL of ENEA Institute for Radiation Protection in Bologna using the ISO water phantom (30 × 30 × 15 cm 3 ) and standard ISO filtered X ray beams as well as 137 Cs and 60 Co sources. This work represents a preliminary type test of the ENEA photon personal dosemeter and allows its introduction in routine dosimetry practice in accordance with the ICRU reference quantities.

A new ENEA dosemeter based on two TL detectors, LiF(Mg,Cu,P) (GR-200) and 7 LiF(Mg,Cu,P) (GR-207), was investigated. The different thermal neutron and gamma sensitivities of the two detectors allow a good dose equivalent estimation in mixed n-γ fields. The higher sensitivity of both detectors as compared with LiF(Mg,Ti) and 7 LiF(Mg,Ti) detectors, currently used at ENEA for routine personal dosimetry, allows a lower dose equivalent threshold to be achieved as well as a better discrimination of the neutron and gamma components of the radiation field. A dose calculation algorithm was developed and assessed by experimental tests performed both at ENEA Institute for Radiation Protection thermal neutron irradiation facility as well as at the IPSN SIGMA facility in Cadarache (France). The intercalibration test supplied the necessary guidelines for future routine dosemeter calibrations. Our results demonstrated that the new dosemeter can easily replace the currently employed dosemeter for mixed thermal neutron and gamma fields in routine personal dosimetry.

The Institute for Radiation Protection of ENEA has employed for many years a solid state nuclear track detector CR-39 as a fast neutron personal dosemeter with good results. The 1990 recommendations of ICRP 60 has introduced new parameters to neutron dosimetry that require harmonisation of the dosemeters' response within international recommendations. This paper reports the results of an experimental study performed at ENEA in order to investigate the dosimetric performance of two kinds of CR-39 produced in UK and Italy. Sensitivity, lowest detectable dose, background, linearity, energy and angular responses are compared between the two CR-39 materials. Irradiation tests have been performed with monoenergetic neutron beams in the range from 100 keV to 20 MeV, as well as with 252 Cf and 241 Am-Be sources. The Italian CR-39 material, used elsewhere for heavy ions detection in scientific applications, has here been comprehensively tested for neutron dosimetry purposes. Results were very satisfactory and it has therefore been introduced in the ENEA Personal Dosimetry Service.

We present the results of an experimental work aimed at improving the performances of the CR-39® (Registered Trademark of PPG Industries Inc.) nuclear track detector for neutron dosimetry applications. The work was done in collaboration with the Intercast Europe S.p.A., producer of CR-39 for commercial and scientific applications. We compare the CR-39 made with different additives concentrations and different polymerization processes. We evaluate the response of the CR-39 to fast neutrons from three sources: 241AmBe, 252Cf and 238PuLi. Particular attention was paid to background fluctuations that limit the lower detectable dose.

The new recommendation issued by the International Commission on Radiological Protection (ICRP) introducing a 20-mSv annual dose limit for the eye lens stimulated an interesting debate among the radiation protection community. In the present work the problem of estimating Hp(3) for neutron realistic workplace spectra is treated, employing the recently published Hp(3)/F conversion coefficients with the aim of establishing a workplace-dependent relationship between Hp(10) and Hp(3). The results demonstrate that, whilst the two quantities can differ by less than 10 %, in general, Hp(10) cannot be considered a conservative estimate of Hp(3).

This paper reviews the revised Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation as issued by the European Commission as Radiation Protection 160. These recommendations are aimed at all stakeholders in radiation protection dosimetry with an emphasis in the responsible technical staff of approved dosimetry services. This paper briefly touches each Chapter and ends with a more in depth section on the uncertainty evaluation of dose measurements. © 2012 Elsevier Ltd. All rights reserved.

The ORAMED (Optimization of RAdiation protection for MEDical staff) project is funded by EU-EURATOM within the 7° Framework Programme. Task 2 of the project is devoted to study the dose to the eye lens. The study was subdivided into various topics, starting from a critical revision of the operational quantity H(p)(3), with the corresponding proposal of a cylindrical phantom simulating as best as possible the head in which the eyes are located, the production of a complete set of air kerma to dose equivalent conversion coefficients for photons from 10 keV to 10 MeV, and finally, the optimisation of the design of a personal dosemeter well suited to respond in terms of H(p)(3). The paper presents some preliminary results.

Two photon TL dosemeters based on LiF:Mg,Cu,P fixed onto cards are tested in order to compare their dosimetric performance. ENEA cards have been used as a routine since 1995 and they contain chips of GR200A (Solid Dosimetric Detector and Method Laboratory—SSDML, China), whilst cards by RADCARD have been commercially available only recently and they contain chips of MCP-N (made in Poland). The cards, which have the same dimensions, were both read out with a Harshaw 6600 Automated TLD reader, according to the reading cycle recommended by the manufacturer. A sample of 10 cards of the two types were compared on their performance relating to gamma-sensitivity, detection threshold, linearity, dose range, coefficient of variation, repeatability, and residual signal. Moreover, tests have been performed to evaluate their plastic resistance when heated at a temperature higher than 240 ∘ C . Results are reported and discussed.

Individual monitoring services (IMS) in Europe do not comply with the same legal or approval requirements. Anyway, a degree of harmonisation existing in individual monitoring practices in Europe has been achieved mainly thanks to documents as standards or international recommendations, which with different weight represent invaluable vehicles of condensed information transfer. However, implementation of standards is not straightforward and harmonisation is not directly a consequence. Somehow, ‘harmony’ is needed also in standards: IEC and ISO standards, on performance requirements for dosemeters sometimes have different approaches (i.e. performance criteria). Moreover, standards do not all refer to reliability, and therefore being in compliance with standards does not by itself assure that dose results are reliable. Standards are not the only reference documents for an IMS. EURADOS working group on ‘Harmonisation of Individual Monitoring in Europe’, who has been active in the years 2001-2004, suggested a classification of publication on individual monitoring, distinguishing between standards and documents of relevance, which can be both national and international. None of the two categories are mandatory unless specified in legislation. The Council Directive 96/29/EURATOM and its implementation in each EU Member States has fostered harmonisation of the approach (i.e. approval of dosimetric services) and of the reference quantities for individual monitoring within EU, but national legislation still allow substantial differences in individual monitoring from country to country.

H p (3) has been defined as the operational quantity for eye lens dosimetry. H p (3)/ka conversion coefficients were evaluated at the GSF (Germany) in a 30×30×15 cm 3 4-elements ICRU slab phantom for various energies and incident angles through Monte Carlo. The ISO report 12,794 suggests to employ a PMMA water filled phantom, of the same dimensions, for dosemeter calibration in terms of H p (3). The present paper briefly summarises the main aspects of a study carried out at ENEA-Radiation Protection Institute (Bologna, Italy) to provide practical procedures for the calibration of dosemeters in terms of H p (3). Tabulations of a new set conversion coefficients and air kerma backscatter factors are provided as a function of energy and incident angle. The paper demonstrates that a more accurate approach to the dosimetric assessment in terms of H p (3) could be rather simply introduced employing a reduced phantom.

The results of a study of two commercially available LiF(Mg,Cu,P) TL materials, a GR200 detector and a MCP-Ns thin detector, are described in order to use these phosphors for individual monitoring for the extremities. After a dosimetry system has been type tested, the implementation routine is not straightforward. Additional tests and software modification are needed to make the routine system work comply with the type test results. Not often can literature be found on the steps required to implement the results in a routine study. This paper reports the results of the individual calibration of about 15 000 extremity dosemeters, 12 000 containing a GR200 detector and 3000 an MCP-Ns thin detector. It describes the experimental procedure followed in order to assure reproducibility and stability of the results with proper accuracy and reliability. In particular, this is the first time that results on homogeneity of such a large batch of MCP-Ns detectors are reported.

The ENEA Radiation Protection Institute has been operating the only neutron personal dosimetry service in Italy since the 1970s. Since the 1980s the service has been based on PADC (poly allyl diglycol carbonate) for fast neutron dosimetry, while thermal neutron dosimetry has been performed using thermoluminescence (TL) dosemeters. Since the service was started, a number of aspects have undergone evolution. The latest and most important changes are as follows: in 1998 a new PADC material was introduced in routine, since 2001 TL thermal dosimetry has been based on LiF(Mg,Cu,P) [GR-200] and 7 LiF(Mg,Cu,P) [GR-207] detectors and since 2003 a new image analysis reading system for the fast neutron dosemeters has been used. Herein an updated summary of how the service operates and performs today is presented. The approaches to calibration and traceability to estimate the quantity of H p (10) are mentioned. Results obtained at the performance test of dosimetric services in the EU member states and Switzerland sponsored by the European Commission and organised by Eurados in 1999 are reported. Last but not least, quality assurance (QA) procedures introduced in the routine operation to track the whole process of dose evaluation (i.e. plastic QA, acceptance test, test etching bath reproducibility and 'dummy customer' (blind test) for each issuing monitoring period) are presented and discussed.

Following the publication of the EU Council Directive 96/29, EURADOS coordinated two working groups (WGs) for promoting the process of harmonisation on individual monitoring of occupationally exposed persons in Europe. An overview of the major findings of the second WG is presented. Information on the technical and quality standards and on the accreditation and approval procedures has been compiled. The catalogue of dosimetric services has been updated and extended. An overview of national regulations and standards for protection from radon and other natural sources in workplaces has been made, attempting to combine the results from individual monitoring for external, internal and workplace monitoring. A first status description of the active personal dosemeters, including legislative and technical information, and their implementation has been made. The importance of practical factors on the uncertainty in the dose measurement has been estimated. Even if a big progress has been made towards harmonisation, there is still work to be done. © 2006 Oxford University Press.

The present paper summarises the activity carried out at the ENEA Radiation Protection Institute for updating the methodologies employed for the evaluation of the neutron and photon dose to the exposed workers in case of a criticality accident, in the framework of the 'International Intercomparison of Criticality Accident Dosimetry Systems' (SileÃne reactor, IRSN-CEA-Valduc June 2002). The evaluation of the neutron spectra and the neutron dosimetric quantities relies on activation detectors and on unfolding algorithms. Thermoluminescenct detectors are employed for the gamma dose measurement. The work is aimed at accurately characterising the measurement system and, at the same time, testing the algorithms. Useful spectral information were included, based on Monte Carlo simulations, to take into account the potential accident scenarios of practical interest. All along this exercise intercomparison a particular attention was devoted to the 'traceability' of all the experimental and computational parameters and therefore, aimed at an easy treatment by the user.

Preliminary results of an inter-laboratory collaborative work on the application of computerised glow curve analysis to TL personal dosimetry are presented. Very simple analysis methods have proved to be useful for the evaluation of glow curves similar to those encountered in the dosimetric control of radiation workers. A first result obtained in the study has been the possibility of simplifying the TL working procedures by eliminating pre-annealing or pre-heating steps employed in conventional systems to avoid low temperature peaks. The presence of these unwanted peaks can be detected by the computerised evaluation methods, discriminating their contribution to the dosimetric TL data.

At the Individual Monitoring Service (IMS) of the ENEA Institute for Radiation Protection (IRP), the Hp(10) fast neutron dosemeter consists of a CR-39 (PADC, poly allyl diglycol carbonate) recoil protons track detector. The tracks across the detector surface are magnified through a chemical etching procedure and counted by a semi-automated system which consists of a microscope, a camera and a PC. A new analysis system, based on the National Instruments vision tools, was developed. The track area distribution for each reading field is recorded and numerical algorithms were developed in order to correct the energy dependence of the response and to recognise the tracks due to the background. This improves the dose evaluation system in terms of accuracy and discrimination or the background.

The European Union Council Directive 96/29/EURATOM requires that 'individual monitoring shall be ... based on individual measurements which are established by an approved dosimetric service' and that 'Each Member State shall make arrangements to recognise, as appropriate, the capacity of ... approved dosimetric services'. At present, approval of dosimetric services does not have the same meaning within EU Member States and Switzerland. In some countries, service and dosemeter approval is clearly separated, in some others only one of the two is supposed to be tested, and in others no approval is required. Dosimetric requirements and criteria are based on different international documents (e.g. IEC, ISO, ANSI, CEC report) or national specific rules. Approval frequency can be once, every 2 or more years. Approval can be based on either evaluation of technical and management reports, irradiation tests, inspection on-site or the three steps together. In most cases, approval involves photon dosimetry while beta and neutron dosimetry test procedures are not as well established. However, comparisons may lead to some convergent evolution of procedures and to a greater degree of harmonisation and quality consolidation.