69 research outputs found

    Establishing National diagnostic reference levels in the Russian Federation based on regional dose surveys

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    Establishing diagnostic reference levels (DRLs) in a big country is complicated due to differences in radiological practice between different regions. In 2009-2014, a dose survey was performed in six Russian regions. Based on the results of the survey, preliminary DRLs for conventional X-ray examinations were established on a national level. Additionally, the local authorities were granted the possibility to establish regional DRLs if the local dose distributions significantly differed from the proposed national DRLs

    Radiological environmental monitoring at the ESS facility – Annual report 2020

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    Results from the radiological environmental monitoring of the European Spallation Source (ESS) are presented for year 2020.Among the 63 environmental samples analysed for gamma emitting radionuclides, no elevated levels of anthropogenic radioactivity were observed. All samples (except two samples of lichen) had activity concentrations below the MDA for the natural radionuclides as well as 137Cs, and normal levels of 40K. In sewage sludge, detectable levels of 177Lu and 1311 were observed in samples that were measured within one week after sampling.Mobile gamma spectrometry surveys were carried out around ESS and MAX IV (when operating at high frequency during a test run). No deviating radiation levels were observed.The samples analysed for their 3H activity concentration (120 samples) were generally below the detection limit using the current procedure, instrumentation and analysis time (MDA typically 1.6 Bq L-1). The results show no evidence of any local contamination of 3H in Lund during 2020.The 14C data in the 26 samples of grass, fruits, berries, crops, milk, honey and meat of in the Lund area and in southern Sweden is consistent with the declining 14C specific activity in atmospheric CO2. Seasonal variations were observed in the 14C data. No evidence of anthropogenic 14C contamination in the Lund area was noted during 2020.The report presents the first base-line measurements of 129I (10 samples) in the ESS environmental monitoring programme. The 129I activity concentrations ranged between (3.18 ± 0.20)∙1011 atoms/kg d.w. for grass and (1.31 ± 0.03)∙1013 atoms/kg d.w. for moss. These values are in the expected range

    A passive neutron dosemeter for measurements in mixed neutron-photon radiation fields

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    The project combines the highly sensitive salt(NaCl) dosemeter for photon radiation with a neutronphotonconverter in the form of thin gadolinium foilsenclosing the salt. Using an identical salt dosemeter butwithout gadolinium cover determines the primaryphoton contribution. With these twin dosemeters placedin a polyethylene sphere, both photon and neutron dosecontributions can be estimated. This paper describes thedesign and optimization of the construction as well astests and a preliminary calibration of the dosemeter forestimation of neutron dose equivalent in the mixedneutron and photon beam from a Cf-252 source.Currently, the lowest neutron dose equivalent possibleto quantify is around 1 mSv. Some suggestions forfurther improvements are also discussed

    Household salt (NaCl) for optically stimulated luminescence dosimetry: an overview

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    This brief overview of the use of household salt (NaCl) in optically stimulated luminescence (OSL) dosimetry is focusing on the use of NaCl pellets. It is suggested that the most optimal use of household NaCl, in general prospective dosimetry, is to compress the salt grains to pellets and read the radiation induced signal using OSL rather than TL. A summary of the main OSL dosimetric properties is provided for two Swedish household salts, and compared to the OSL properties of 100 different salts from all over the world

    Radiological environmental monitoring at the ESS facility – Annual report 2021

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    Results from the radiological environmental monitoring of the European Spallation Source (ESS) are presented for 2021. Previous zero-point assessments (2017-2020) have mainly focussed on terrestrial samples. New sample types for 2021 include a sediment sample from a pond at the ESS and brown seaweed (Fucus) from Lomma bay and from the east coast of Scania (Skillinge). For gamma-emitting radionuclides, increased levels of anthropogenic radioactivity (177Lu and 131I) originating from hospital use, were only observed in sewage sludge samples. For tritium, the majority of the samples had activity concentrations that were below the minimum detectable activity (MDA) of 1.62 Bq l-1. Expected environmental levels, without any evidence of local contamination, were also seen in the 14C data

    Esitmation of effective doses for barium meal fluoroscopic examinations

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    The aim of the current study is to establish conversion coefficients (CCs) from dose-area product to effective dose for barium meal (BM) fluoroscopic examinations. The study is based on data collected at a major University hospital in St-Petersburg, Russia. The structure of the BM examinations was evaluated and a computational model for effective dose estimation, using PCXMC 2.0 software, was developed. Resulting values of CCs estimated in the study were comparable with previously published data for BM examinations

    Region-specific radioecological evaluation of accidental releases of radionuclides from ESS

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    Gadolinium-148 is one of the radionuclides of most concern that will be produced in the tungsten target of the European Spallation Source (ESS), as a by-product of the spallation reaction used by the facility to produce neutrons. Since 148Gd a pure alpha emitter, it is both very radiotoxic and difficult to measure. With its half-life of 75 years, it will remain in the environment for a long time if released from the facility during normal operation or after an accident. There are still uncertainties regarding the amounts that actually will be produced by spallation in the tungsten targets of the facility. As Gd-148 does not occur naturally in the environment, there is no information available about its analysis in environmental samples but a few studies provide data from irradiated target material analysed by alpha spectroscopy or inductively coupled plasma mass spectrometry (ICP-MS). This report is a continuation of the SSM project as described in the SSM report 2020:08, entitled “Identifying radiologically important ESS-specific radionuclides and relevant detection methods” that focused on the ESS-related radionuclides that will be the most relevant to study and monitor in the environment as well as the analytical techniques to detect them. The present report focuses on the rare earth elements (REEs), including their radioactive isotopes, in particular Gd-148, and is intended to highlight the knowledge gaps that exist regarding their fate in the specific environment of the ESS area. In the first part of the report, the available literature on radioecological models was reviewed, with emphasis on ESS-related radionuclides. The existing modelling programmes were surveyed as well as the most relevant environmental parameters and experimental radioecological data required to build models specific to the ESS.In the second part of the report, the area in the vicinity of the ESS was surveyed to identify the important producers of foodstuff, what plant species are grown in the area and also the local husbandry and hunting practices, in order to identify critical pathways after a radioactive dispersion into the environment in connection with a potential accident at the ESS. In the third part of this report, after a thorough literature review and preliminary assays, we propose to investigate the use of ICP-MS for assessment of Gd-148 in the event of an accidental release, knowing that this analytical technique is already used for the measurement of stable Gd and REEs in the environment. The existing methods to extract REEs from environmental samples (soil, water, plants, and animal products) and to properly assess their concentration are described in the form of a literature review. The presented examples of methods were selected to fit the type of environment found around the ESS facility and the local agricultural and horticultural practices. A pilot study was also conducted to test extraction and measurement methods on the specific type of soil around ESS. These results are presented at the end of this report
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