Evaluation of dose rate data provided by non-governmental networks

Broj civilnih mreža koje pružaju kvazi-trenutne podatke o jačini doze je poslednjih godina u porastu. Ovi podaci su javno dostupni preko internet platfomi sa slobodnim pristupom. Istraživanja na temu civilnih mreža su retka, a merenja čiji su rezultati u njima predstavljeni su uglavnom izvršena široko dostupnim jednostavnim ručnim dozimetrima. Bez detaljnog testiranja ovih uređaja u metrološkim laboratorijama, postoji velika verovatnoša javljanja značajnih razlika između zvaničnih podataka i podataka iz civilnih mreža, što može imati značajne posledice. U okviru projekta 16ENV04 Preparedness je sprovedeno sistematskoispitivanje civilnih mreža. Tako je identifikovano 16 tipova uređaja koji se često koriste. Učesnici projekta su nabavili po 4 dozimetra od svakog tipa, čije je ispitivanje trenutno u toku. Procedura koriššena za ispitivanje je ukratko opisana u ovom radui prikazani su preliminarni rezultati za 2 tipa dozimetara.In recent years, the number of non-governmental networks providing quasi real time dose rates is growing. This data is available to the general public via open access based platforms on the internet. The research on the non-governmental networks is scarce and the measurements represented there are mostly carried out using broadly available commercial simple hand-held devices. Without proper testing of these devices in metrological laboratories, there is a significant possibility for discrepancies between the official and non-governmental data, which may have wider implications. Within project 16ENV04 Preparedness, a systematic study of non-governmental networks produced a list of 16 types of dosimeters that are commonly used. Four dosimeters of each type were sourced and commissioned by project partners and are currently undergoing the testing. Test procedures are shortly described in this paper and preliminary results for 2 types of dosimeters are presented.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Testing of low-cost dosimeters used in non-governmental networks within 16ENV04 Preparedness project

Recent advances in microelectronics and information technologies, along with the expansion of citizen science, have changed the way measurements are done in many scientific fields, including ionising radiation dosimetry. Many low cost user-friendly instruments are now available for purchase over the internet. Most of the instruments can be connected with applications for real time measurements, and some of them provide possibilities for real time upload to the specialized public websites. Low cost and low requirements for technical knowledge allow many laymen to perform measurements, and results can be easily disseminated via social networks and media outlets. These results are often not verified and low-cost instruments are usually not type tested, so there is a significant possibility for such results to cause misinformation of public or even unwarranted panic. Research on non-governmental dosimetry networks has been conducted within the Work Package 3 of 16ENV04 Preparedness, scientific project within the European Metrology Programme for Innovation and Research (EMPIR). The research has identified non-governmental networks with the densest networks and most active websites, because such networks have the largest potential impact on the public. Measuring instruments used in non-governmental networks (MINN) have been identified, and a total of 16 types of MINNs have been sourced, commissioned and tested in dosimetry laboratories of Vinca Institute of Nuclear Sciences (VINS), Serbia, PhysikalischTechnische Bundesanstalt (PTB), Germany, National Physics Laboratory (NPL), United Kingdom and Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). The tests included linearity and energy dependence of the response in photon fields generated at each institute, determination of inherent background, response to cosmic radiation, response to small changes of background radiation and tests of dependence of the response on climatic conditions – humidity and temperature, at PTB facilities. The research has shown that most of the MINNs are based on non-compensated Geiger Mueller tubes, with the consequence that the energy dependence does not conform to the requirements of relevant standards. Dead time correction is not performed in most low-cost instruments, but the linearity is within ±15 % in the dose rate range of interest for environmental monitoring. Response to small changes in background dose rate is dependent not only on the radiation detector, but also on the software and the mode of operation selected by user. In field tests, most dosimeters were sensitive to small changes in background radiation.VIII International Conference on Radiation in Various Fields of Research : RAD 2020 : book of abstracts; Virtual Conferenc

Testing of the measuring instruments in non-governmental networks for the purpose of environmental monitoring of ionising radiation

Non-governmental networks for environmental monitoring employ a wide range of radiation protection instruments from different manufacturers, which provide the public with often unreliable dosimetric data. These Measuring Instruments in Non-governmental Networks (MINN) are mostly based on Geiger-Muller tube gas detectors, which represent low-cost easily operated instruments. An extensive testing of these devices was performed in order to validate the data acquired with MINN within the 16ENV04 Preparedness EMPIR project. In total, 16 different dosemter types were selected, with a sample size of four dosemeters per dosemeter type. Performance testing included the energy dependence and the linearity tests of the dosemeter response. Additionally, during the Researcher Mobility Grant associated with the 16ENV04 project, two Geiger-Muller based dosemeter types, with a sample size of two dosemeters per type were included in the testing. These instruments were subjected to the angular dependence testing in both horizontal and vertical planes, besides the energy dependence and linearity tests in the reference Cs-137 field at Physikalisch-Technische Bundesanstalt (PTB). For all the dosemeter types, inherent background, response to secondary cosmic radiation and the response to small changes of dose rate were determined at the metrological facilities of PTB. The sensitivity of the measuring instruments used in non-governmental networks to small variations of the ambient dose equivalent rate was examined by exposing the dosemeters to low dose rate Cs-137, Co-60 and Ra-226 radiation sources, in order to estimate the effect of environmental radioactive contamination with artificially produced radionuclides. For the comparison purposes, besides the measuring instruments used in non-governmental networks, a previously characterized CdZnTe-based spectrodosemeter was irradiated with the aforementioned radiation fields. The measured values were compared with a reference Reuter-Stokes ionisation chamber used for low-dose rate level measurements.RAP 2020 : International conference on radiation applications; Book of abstracts; Virtual conference, 202

Investigation into the performance of dose rate measurement instruments used in non-governmental networks

In the aftermath of a nuclear or radiological accident, an extended mapping of reliable dose rate values is of key importance for any governmental decision and countermeasures. Presently, numerous dosimetry network stations, operated by the national governments of the member states in Europe, provide such dose rate data on an hourly basis. Nevertheless, there are large areas in Europe that are not covered at all by these early warning networks and other areas that show only a low density of governmental network stations. Hence, there may be a significant lack of information in case of a nuclear or radiological emergency. As a consequence of the Fukushima Daiichi nuclear power plant accidents in 2011, a number of non-governmental radiation monitoring networks (NRMN) appeared on the internet, providing dose rate data based on stationary as well as on mobile measurements of ionizing radiation by laypersons. Especially the mobile detectors are able to cover large areas in short time. Therefore, it is of considerable importance to investigate the feasibility of using dose rate data from non-governmental networks as a complementary input to the European Radiological Data Exchange Platform (EURDEP). Within the European Metrology Program for Innovation and Research (EMPIR), the project 16ENV04 “Preparedness” has studied the metrological relevance of such non-governmental dose rate data (also called crowd-sourced radiological monitoring) in the most comprehensive way so far. Sixteen different dose rate detector systems (in general 4 of each type, plus 2 types with 2 detectors, i.e. 68 detectors in total) used in NRMN have been investigated for the reliability of their data and the corresponding networks, and their data provision to the public were analyzed. The most relevant performance parameters of dosimetry systems (detector's inherent background, energy dependence and linearity of the response as well as the response to secondary cosmic radiation, the sensitivity to small increases of the dose rate and finally the stability of the detector's indication at various climatic conditions - temperature and humidity) have been investigated for fourteen representative types of non-governmental dose rate measuring instruments. Results of this comprehensive performance study of the simple, light-weighted and cheap dose rate meters used in NRMN, and conclusions on the feasibility of using their data for governmental monitoring in case of a nuclear or radiological emergency are presented. © 2021 The Author

New metrology for radon at the environmental level

International audienc

Cadmium zinc telluride solid-state detector characterization for its use as a spectro-dosemeter

Concerning ionising radiation monitoring in the environment in areas which, by normal means, are inaccessible, e.g. in contaminated areas after a nuclear or radiological incident, the use of highly mobile systems, comprising of unmanned airborne vehicles equipped with ionising radiation detector, is advised in order to protect the health and the life of first responders. As a promising candidate, the compact solid-state spectrometer based on CdZnTe is characterised by performing irradiations in the reference radionuclide radiation fields of PTB. The energydependent conversion coefficients are derived from recorded pulse-height spectra, and they enable calculation of the operational radiation protection quantity, ambient dose equivalent rate, directly from the spectrum without deconvolution. The validity of the conversion coefficients was evaluated by determining the deviation of the calculated dose rate from the reference ambient dose equivalent rate for the 226Ra radionuclide, available at the Underground Dosimetry Laboratory (UDO II) of PTB. By employing the derived conversion coefficients, the detector “linearity” (dose rate dependence of the response) was checked in the 137Cs reference fields of different ambient dose equivalent rates ranging from 25 nSv/h up to 1 µSv/h. The deviation of the calculated 226Ra dose rate from the achieved reference value was +2%Peer ReviewedPostprint (published version

Evaluation of dose rate data provided by non-governmental networks

Broj civilnih mreža koje pružaju kvazi-trenutne podatke o jačini doze je poslednjih godina u porastu. Ovi podaci su javno dostupni preko internet platfomi sa slobodnim pristupom. Istraživanja na temu civilnih mreža su retka, a merenja čiji su rezultati u njima predstavljeni su uglavnom izvršena široko dostupnim jednostavnim ručnim dozimetrima. Bez detaljnog testiranja ovih uređaja u metrološkim laboratorijama, postoji velika verovatnoša javljanja značajnih razlika između zvaničnih podataka i podataka iz civilnih mreža, što može imati značajne posledice. U okviru projekta 16ENV04 Preparedness je sprovedeno sistematskoispitivanje civilnih mreža. Tako je identifikovano 16 tipova uređaja koji se često koriste. Učesnici projekta su nabavili po 4 dozimetra od svakog tipa, čije je ispitivanje trenutno u toku. Procedura koriššena za ispitivanje je ukratko opisana u ovom radui prikazani su preliminarni rezultati za 2 tipa dozimetara.In recent years, the number of non-governmental networks providing quasi real time dose rates is growing. This data is available to the general public via open access based platforms on the internet. The research on the non-governmental networks is scarce and the measurements represented there are mostly carried out using broadly available commercial simple hand-held devices. Without proper testing of these devices in metrological laboratories, there is a significant possibility for discrepancies between the official and non-governmental data, which may have wider implications. Within project 16ENV04 Preparedness, a systematic study of non-governmental networks produced a list of 16 types of dosimeters that are commonly used. Four dosimeters of each type were sourced and commissioned by project partners and are currently undergoing the testing. Test procedures are shortly described in this paper and preliminary results for 2 types of dosimeters are presented.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј