Greek Atomic Energy Commission

Agía Paraskeví, Greece

Greek Atomic Energy Commission

Agía Paraskeví, Greece
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Agency: European Commission | Branch: H2020 | Program: COFUND-EJP | Phase: NFRP-07-2015 | Award Amount: 29.25M | Year: 2015

The proposed European Concerted Programme on Radiation Protection Research (acronym: CONCERT) aims to contribute to the sustainable integration of European and national research programmes in radiation protection. It will do so by focusing resources and efforts in five key directions: Bring together the elements of the European scientific communities in the fields of radiation effects and risks, radioecology, nuclear emergency preparedness, dosimetry and medical radiation protection, whose joint expertise is essential to continue the development of radiation protection knowledge in a multidisciplinary mode to reduce further the uncertainties in radiation protection. Strengthen integrative activities between the various areas of expertise, in particular biology, biophysics, epidemiology, dosimetry and modelling as well as fostering the use of existing infrastructures and education and training activities in radiation protection. Stimulate and foster scientific excellence, by setting up and co-funding advanced research programmes with the potential to enhance current knowledge and the scientific evidence base for radiation protection. Exchange and communicate with all stakeholders, including the professional organizations concerned with radiation protection, the regulatory organizations across Europe, the public and media where necessary, and the international community of scientific, technical, legal and other professional experts in radiation protection. Foster the harmonious application of available scientific basis for radiation protection practices across Europe, by bringing together scientific and technical expertise in radiation protection issues, standard setting know how, particularly with respect to the implementation of the Euratom Basic Safety Standards (BSS) at the legal, administrative and operational level. To reach its goals, CONCERT will have seven Work Packages each of which will focus on each of the key directions.

Agency: European Commission | Branch: FP7 | Program: CP | Phase: Fission-2012-3.3.1 | Award Amount: 6.50M | Year: 2013

This proposal aims to close gaps that have been identified in nuclear and radiological preparedness following the first evaluation of the Fukushima disaster. It addresses the call Fission-2010-3.3.1: Update of emergency management and rehabilitation strategies and expertise in Europe. The consortium intends to review existing operational procedures in dealing with long lasting releases, address the cross border problematic in monitoring and safety of goods and will further develop still missing functionalities in decision support system ranging from improved source term estimation and dispersion modelling to the inclusion of hydrological pathways for European water bodies. As the management of the Fukushima event in Europe was far from being optimal, we propose to develop means on a scientific and operational basis to improve information collection, information exchange and the evaluation for such types of accidents. This will be achieved through a collaboration of industry, research and governmental organisations in Europe taking into account the networking activities carried out under the NERIS-TP project. Furthermore, the NERIS Platform member organisations (so far 43 partners) will be actively involved in the development.

Agency: European Commission | Branch: FP7 | Program: CP-CSA | Phase: Fission-2013-3.1.1 | Award Amount: 10.26M | Year: 2013

Within the OPERRA project, it is proposed that the MELODI Association, as a well-advanced network, takes the lead in establishing the necessary structures able to manage the long-term European research programmes in radiation protection, also taking advantage of the valuable experience gathered through the DoReMi network of excellence. Whilst in fields adjacent to low-dose risk research (radioecology, nuclear emergency management) scientific issues would continue to be hosted by the sister associations, Alliance and NERIS, these associations are encouraged to join MELODI to establish an umbrella structure as equal partners. OPERRA will exploit the synergies of EURATOM and other EC programmes considering the most relevant joint program areas and mechanisms for funding joint activities. The project will also strengthen the links with national funding programs as well as the European education and training structures. Also, it will take steps towards a greater involvement of those new Member States who could benefit from increased participation in the radiation research programmes. Finally, OPERRA will take steps to further integrate the joint use of infrastructures in European countries, and to develop and facilitate an easier access to research infrastructures. The final objective of this project is to build up an umbrella coordination structure that has the capacity in a legal and logistical sense to administer future calls for research in radiation protection as a whole (including low-dose risk, radioecology, nuclear emergency management, and also research activities related to the medical uses of ionizing radiation) on behalf of the European Commission. OPERRA will prepare the organisation for a first competitive call by the end of 2013 for projects in low-dose risk research and a second competitive call in 2014 for broader projects in radiation protection research, subject to the approval of EC services, with the support of Go-between administrator operator and an external advisory entity.

Kantemiris I.,National and Kapodistrian University of Athens | Kantemiris I.,Greek Atomic Energy Commission | Karaiskos P.,National and Kapodistrian University of Athens | Papagiannis P.,National and Kapodistrian University of Athens | Angelopoulos A.,National and Kapodistrian University of Athens
Medical Physics | Year: 2011

Purpose: Modern clinical accelerators are capable of producing ion beams from protons up to neon. This work compares the depth dose distribution and corresponding dose averaged linear energy transfer (LET) distribution, which is related to the biological effectiveness, for different ion beams ( 1H, 4He, 6Li, 8Be, 10B, 12C, 14N, and 16O) using multi-energetic spectra in order to configure spread-out Bragg peaks (SOBP). Methods: Monte Carlo simulations were performed in order to configure a 5 cm SOBP at 8 cm depth in water for all the different ion beams. Physical dose and dose averaged LET distributions as a function of depth were then calculated and compared. The superposition of dose distribution of all ions is also presented for a two opposing fields configuration. Additional simulations were performed for 12C beams to investigate the dependence of dose and dose averaged LET distributions on target depth and size, as well as beam configuration. These included simulations for a 3 cm SOBP at 7, 10, and 13 cm depth in water, a 6 cm SOBP at 7 depth in water, and two opposing fields of 6 cm SOBP. Results: Alpha particles and protons present superior physical depth dose distributions relative to the rest of the beams studied. Dose averaged LET distributions results suggest higher biological effectiveness in the target volume for carbon, nitrogen and oxygen ions. This is coupled, however, with relatively high LET values-especially for the last two ion species-outside the SOBP where healthy tissue would be located. Dose averaged LET distributions for 8Be and 10B beams show that they could be attractive alternatives to 12C for the treatment of small, not deeply seated lesions. The potential therapeutic effect of different ion beams studied in this work depends on target volume and position, as well as the number of beams used. Conclusions: The optimization of beam modality for specific tumor cites remains an open question that warrants further investigation and clinically relevant results. © 2011 American Association of Physicists in Medicine.

Agency: European Commission | Branch: FP7 | Program: CP | Phase: Fission-2007-3.2-01 | Award Amount: 2.45M | Year: 2008

The state-of-the-art analysis performed in the FP6 CONRAD project highlighted high extremity doses and a lack of systematic data analysis on exposures to the staff in interventional radiology (IR) and nuclear medicine (NM). To optimize the working procedures in the medical field with respect to radiation protection, a project focussed on improving the knowledge on extremity and eye lens exposures is proposed, combined with an optimization in the use of active personal dosemeters. The first objective is to obtain extensive extremity dose data for staff in IR, with special attention to eye lens doses and the analysis of the radiation protection measures. At the present time there is no suitable dosimeter for eye lens dosimetry. Hp(3) is mentioned as the operational quantity to control the dose limits, but there are no conversion coefficients nor a calibration procedure available. The second objective of the project is to develop a formalism to measure eye lens doses and to design a prototype eye lens dosemeter. IR staff belongs to a specific working group which could benefit from a real time accurate dose assessment. Therefore, the third objective is to study the behaviour of commercial active personal dosemeters under real conditions and to design a prototype that could solve the present problems. In NM the doses to the different parts of the hands will be systematically mapped, with special attention to unsealed therapy sources, aiming to estimate the real dose load of NM workers and to describe appropriate protection measures. The different objectives of this project will be achieved through well coordinated measurement campaigns in European hospitals. Simulations will be performed to determine the main parameters that influence the extremity and eye lens doses and the effectiveness of different radiation protection measures. The final objective is to develop a program to disseminate all conclusions and recommendations to the interested parties.

Agency: European Commission | Branch: FP7 | Program: CP | Phase: SEC-2007-1.3-01;SEC-2007-4.3-03 | Award Amount: 2.64M | Year: 2008

The proposal concerns the technology development for instruments with the following capabilities: (a) To make spectroscopic measurements with efficiency equivalent to that of NaI detectors and energy resolution close to that of HPGe devices but without using cryogenic systems. (b) To find the direction and the distance of the radioactive source. (c) To localize the source into a cargo and estimate the radioactive source activity taking information about the source environment (shielding, absorption in the surrounding materials) (d) To work at a wide range of absorbed dose rates by adjusting the effective volume of the detector. The above capabilities will improve the quality of the data gathered by the customs officers during the routine inspections at the boarders and will assist the first responders in case of a radiological or nuclear emergency to estimate the exact situation. Basic tasks of the project will be: (a) The growth of high purity, detector grade Cd(Zn)Te crystals. Their performance will be optimized by material purification, selection of right dopants and post-growth processing to obtain high resistivity, high transport properties and homogeneous distribution of these material properties in the grown crystals. The growth of crystals with a diameter up to 75 mm will be performed. (b) The fabrication of pixel detectors having structure of p-n and Schottky diodes. This will permit the application of bias voltage high enough to collect all the induced charge by both electrons and holes. (c) The design of pixel electronics capable for simultaneous imaging and spectroscopy. The electronics will be bump bonded to the pixel detectors. This is essential for the localization and the identification of the radioactive source. (d) The construction of a portable instrument having a stack of detecting elements. This will allow to exploit the Compton Effect for the localization of the radioactive source and also to have variable detection efficiency.

Potiriadis C.,Greek Atomic Energy Commission | Kolovou M.,Greek Atomic Energy Commission | Clouvas A.,Aristotle University of Thessaloniki | Xanthos S.,Aristotle University of Thessaloniki
Radiation Protection Dosimetry | Year: 2012

Since the double disaster of the 9.0 magnitude earthquake and tsunami that affected hundreds of thousands of people and seriously damaged the Fukushima Daichi power plant in Japan on 11 March 2011, traces of radioactive emissions from Fukushima have spread across the entire northern hemisphere. The radioactive isotope of iodine 131I that was generated by the nuclear accident in Fukushima arrived in Greece on 24 March 2011. Radioactive iodine is present in the air either as gas or bound to particles (aerosols). The maximum 131I concentrations were measured between 3 and 5 April 2011. In aerosols the maximum 131I values measured in Southern Greece (Athens) and Northern Greece (Thessaloniki) were 585±70 and 408±61 μBq m -3, respectively 131I concentrations in gas were about 3.5 times higher than in aerosols. Since 29 April 2011, the 131I concentration has been below detection limits. Traces of 137Cs and 134Cs were also measured in the air filters with an activity ratio of 137Cs/134Cs equal to 1 and 131I/137Cs activity ratio of about 3. Since 16 May 2011, the 137Cs concentration in air has been determined to be about the same as before the Fukushima accident. Traces of 131I were also measured in grass and milk. The maximum measured activity of 131I in sheep milk was about 2 Bq l-1 which is 5000 times less than that measured in Greece immediately after the Chernobyl accident. The measured activity concentrations of artificial radionuclides in Greece due to the Fukushima release, have been very low, with no impact on human health. © The Author 2011. Published by Oxford University Press. All rights reserved.

Hourdakis C.J.,Greek Atomic Energy Commission
Physics in Medicine and Biology | Year: 2011

The practical peak voltage (PPV) has been adopted as the reference measuring quantity for the x-ray tube voltage. However, the majority of commercial kV-meter models measure the average peak, P, the average, , the effective, Ueff or the maximum peak, UP tube voltage. This work proposed a method for determination of the PPV from measurements with a kV-meter that measures the average or the average peak, p voltage. The kV-meter reading can be converted to the PPV by applying appropriate calibration coefficients and conversion factors. The average peak kPPV,kVp and the average kPPV,Uav conversion factors were calculated from virtual voltage waveforms for conventional diagnostic radiology (50-150 kV) and mammography (22-35 kV) tube voltages and for voltage ripples from 0% to 100%. Regression equation and coefficients provide the appropriate conversion factors at any given tube voltage and ripple. The influence of voltage waveform irregularities, like 'spikes' and pulse amplitude variations, on the conversion factors was investigated and discussed. The proposed method and the conversion factors were tested using six commercial kV-meters at several x-ray units. The deviations between the reference and the calculated - according to the proposed method - PPV values were less than 2%. Practical aspects on the voltage ripple measurement were addressed and discussed. The proposed method provides a rigorous base to determine the PPV with kV-meters from p and measurement. Users can benefit, since all kV-meters, irrespective of their measuring quantity, can be used to determine the PPV, complying with the IEC standard requirements. © 2011 Institute of Physics and Engineering in Medicine.

Petri A.,Greek Atomic Energy Commission | Karabetsos E.,Greek Atomic Energy Commission
Radiation Protection Dosimetry | Year: 2015

Artificial tanning remains very popular worldwide, despite the International Agency for Research on Cancer classification of ultraviolet (UV) radiation from sunbeds as 'carcinogenic to humans'. Greek Atomic Energy Commission has initiated a surveillance action of the artificial tanning devices in Greece in order to record the effective irradiance levels from the sunbeds and to inform and synchronise the domestic artificial tanning business sector with the requirements of the European Standard EN 60335-2-27:2010. In this direction, in situ measurements of UVemissions from sunbeds in solaria businesses all over Greece were performed from October 2013 until July 2014, with a radiometer and a portable single-monochromator spectrophotometer. Analysis of the measurements' results revealed that effective irradiance in ~60% of the measured sunbeds exceeded the 0.3 Wm22 limit value set by EN 60335-2-27:2010 and only 20%of the devices could be categorised as UV type 3. © The Author 2014.

Vogiatzi S.,Greek Atomic Energy Commission | Kipouros P.,Greek Atomic Energy Commission | Chobis M.,Greek Atomic Energy Commission
Radiation Protection Dosimetry | Year: 2011

Greek Atomic Energy Commission's Department of Licensing and Inspections conducted a national survey for the establishment of nuclear medicine (NM) dose reference levels (DRLs) for adult patients, in Greece. The administered activities (AAs) (MBq) were collected from 120 NM departments (88 % of total), during on-site inspections for licensing purposes. Factors influencing the image quality were also investigated. The established national DRLs represent the AA value corresponding to the 75th percentile of the AA frequency distributions. In their majority, national DRLs and average AAs are comparable with the ones published in the international literature. In the light of new technologies, there might be potential for reducing the higher values of AAs, in co-operation with the nuclear medicine experts. © The Author 2011. Published by Oxford University Press. All rights reserved.

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