Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017.

In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (Ru). The range of concentrations varied from some tenths of µBq·m to more than 150 mBq·m The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location.

Development of an autonomous station for measurements of artificial gamma activity in surface water bodies.

This paper reports on the structure of the autonomous station for monitoring artificial gamma activity in surface water bodies for the purposes of emergency preparedness of the Czech Republic. A simple design based on the NaI(Tl) submersible detector powered by a combined solar and wind source has been employed. Data transfer is provided by a satellite connection.

Low radon exposures and lung cancer risk: joint analysis of the Czech, French, and Beaverlodge cohorts of uranium miners.

It is well established that high radon exposures increase the risk of lung cancer mortality. The effects of low occupational exposures and the factors that confound and modify this risk are not clear and are needed to inform current radiation protection of miners. The risk of lung cancer mortality at low radon exposures (< 100 working-level months) was assessed in the joint cohort analysis of Czech, French, and Canadian uranium miners, employed in 1953 or later.

Potential Source Apportionment and Meteorological Conditions Involved in Airborne I Detections in January/February 2017 in Europe.

Traces of particulate radioactive iodine (I) were detected in the European atmosphere in January/February 2017. Concentrations of this nuclear fission product were very low, ranging 0.1 to 10 μBq m except at one location in western Russia where they reached up to several mBq m.

A multinational audit of small field output factors calculated by treatment planning systems used in radiotherapy.

Background And Purpose: An audit methodology for verifying the implementation of output factors (OFs) of small fields in treatment planning systems (TPSs) used in radiotherapy was developed and tested through a multinational research group and performed on a national level in five different countries.

Materials And Methods: Centres participating in this study were asked to provide OFs calculated by their TPSs for 10 × 10 cm, 6 × 6 cm, 4 × 4 cm, 3 × 3 cm and 2 × 2 cm field sizes using an SSD of 100 cm. The ratio of these calculated OFs to reference OFs was analysed.

Determination of small field synthetic single-crystal diamond detector correction factors for CyberKnife, Leksell Gamma Knife Perfexion and linear accelerator.

Purpose: The aim of this study was to determine small field correction factors for a synthetic single-crystal diamond detector (PTW microDiamond) for routine use in clinical dosimetric measurements.

Materials And Methods: Correction factors following small field Alfonso formalism were calculated by comparison of PTW microDiamond measured ratio M/M with Monte Carlo (MC) based field output factors Ω determined using Dosimetry Diode E or with MC simulation itself. Diode measurements were used for the CyberKnife and Varian Clinac 2100C/D linear accelerator.

Mapping of radiation anomalies using UAV mini-airborne gamma-ray spectrometry.

Localization of size-limited gamma-ray anomalies plays a fundamental role in uranium prospecting and environmental studies. Possibilities of a newly developed mini-airborne gamma-ray spectrometric equipment were tested on a uranium anomaly near the village of Třebsko, Czech Republic. The measurement equipment was based on a scintillation gamma-ray spectrometer specially developed for unmanned aerial vehicles (UAV) mounted on powerful hexacopter.

THE NRPI MULTI-PURPOSE ON-LINE MONITORING STATION FOR MEASUREMENT OF NATURAL RADIOACTIVITY IN THE AMBIENT ATMOSPHERE AND IN THE SOIL.

During years 2010-12 an automated, on-line and wireless outdoor measurement station of atmospheric radon, gamma dose rate and meteorological parameters was realised at the National Radiation Protection Institute (NRPI) in Prague. At the turn of the year 2013 an expansion of the existing station was completed. Under the project funded by the Czech Technological Agency a new updated station was established, additionally equipped with modules for measurement of atmospheric radon/thoron short-lived decay products, radon in water and soil and radon exhalation rate from soil.

RADON IN WORKPLACES-CZECH APPROACH TO EU BSS IMPLEMENTATION.

The European Council Directive 2013/59/Euratom of December 2013 established inter alia the uniform basic safety standards for the health protection of individuals being subject to occupational exposure. In Article 54, a new obligation is introduced-to regulate radon exposure in workplaces. The EU Member States are obliged to set national reference value for radon in workplaces, delineate the areas where the regulation will be applied and determine the concerned types of workplaces.

SUMMARY OF THE EIGHTH CONFERENCE ON PROTECTION AGAINST RADON AT HOME AND AT WORK AND THE 13TH WORKSHOP ON THE GEOLOGICAL ASPECTS OF RADON RISK MAPPING.

This paper provides summary of the 8th Conference on Protection against Radon at Home and at Work and 13th Workshop on the Geological Aspects of Radon Risk Mapping held in September 2016 in Prague, Czech Republic.

RADON CONCENTRATION IN THE AREA OF WASTE ROCK DUMPS, BROD, CR-CASE STUDY.

There are ~7000 mining waste storage facilities including waste rock dumps in the Czech Republic. One of the radiation protection present subjects is a health impact estimation of the huge mass of material in waste rock dumps left after uranium mining. In this document are presented selected results of waste rock dump long-term monitoring in the area of shaft No.

DOSIMETRY WITH SALT IN MIXED RADIATION FIELDS OF PHOTONS AND NEUTRONS.

Salt (NaCl) represents a radiation sensitive material with a considerable potential for dosimetry in mixed radiation fields of photons and neutrons. In consequence of a gamma radiation exposure, it exhibits a strong luminescence signal following stimulation with blue light. Optically stimulated luminescence (OSL) technique can be used for measurement.

Study of coverage of confidence intervals for the standardized mortality ratio in studies with missing death certificates.

This paper assesses the coverage probability of commonly used confidence intervals for the standardized mortality ratio (SMR) when death certificates are missing. It also proposes alternative confidence interval approaches with coverage probabilities close to .95.

Determination of chemical forms of C in liquid discharges from nuclear power plants.

Developments of radioanalytical methods for determination of radiocarbon in wastewaters from nuclear power plants (NPP) with pressurized light water reactors, which would distinguish between the dissolved organic and inorganic forms have been carried out. After preliminary tests, the method was used to process pilot samples from wastewater outlets from the Temelín and Dukovany NPPs (Czech Republic). The results of analysis of pilot water samples collected in 2015 indicate that the instantaneous C releases into the water streams would be about 7.

Systematic influences on the areas of peaks in gamma-ray spectra that have a large statistical uncertainty.

A method is presented for calculating the expected number of counts in peaks that have a large relative peak-area uncertainty and appear in measured gamma-ray spectra. The method was applied to calculations of the correction factors for peaks occurring in the spectra of radon daughters. It was shown that the factors used for correcting the calculated peak areas to their expected values decrease with an increasing relative peak-area uncertainty.

238U CONTENT IN URINE OF URANIUM MINERS AND ITS MODELED VALUES.

The aim of the study is to make a comparison of daily 238U excretion in urine among 115 active uranium miners and its modeled values obtained from inhalation intake of long-lived alpha emitters as measured by personal dosemeters and assessed by biokinetic models for different absorption parameters settings for inhaled uranium. A total of 144 spot samples of urine were collected. The 238U content was measured using high-resolution inductively coupled plasma mass spectrometry method.

Behaviour of Cs in forest humus detected across the territory of the Czech Republic.

The activity concentration of Cs in samples of coniferous forest humus collected across the territory of the Czech Republic in 1995 and 2005 was analysed, and it was found significantly correlated with the surface deposition caused by the Chernobyl accident. The effective (12.8 y) and environmental (22.

Ingestion intakes of Cs by the Czech population: Comparison of different approaches.

Ingestion intakes of Cs of the Czech population were calculated in two different ways - either from the measured activity of Cs in components of food in combination with statistical data about consumption rates or from retention of Cs in the human body obtained by whole body counting or calculated from daily urinary excretion of Cs. Data from the time period since 1986 to 2015 are used. The daily ingestion intake was about 25 Bq d in 1986 and is around 0.

Biomarkers for Uranium Risk Assessment for the Development of the CURE (Concerted Uranium Research in Europe) Molecular Epidemiological Protocol.

Despite substantial experimental and epidemiological research, there is limited knowledge of the uranium-induce health effects after chronic low-dose exposures in humans. Biological markers can objectively characterize pathological processes or environmental responses to uranium and confounding agents. The integration of such biological markers into a molecular epidemiological study would be a useful approach to improve and refine estimations of uranium-induced health risks.

INTERNATIONAL STANDARDS ON FOOD AND ENVIRONMENTAL RADIOACTIVITY MEASUREMENT FOR RADIOLOGICAL PROTECTION: STATUS AND PERSPECTIVES.

Radiological protection is a matter of concern for members of the public and thus national authorities are more likely to trust the quality of radioactivity data provided by accredited laboratories using common standards. Normative approach based on international standards aims to ensure the accuracy or validity of the test result through calibrations and measurements traceable to the International System of Units. This approach guarantees that radioactivity test results on the same types of samples are comparable over time and space as well as between different testing laboratories.

MONTE CARLO CALIBRATION OF THE WHOLE-BODY COUNTING DETECTION SYSTEM FOR IN VIVO MEASUREMENT OF PEOPLE INTERNALLY CONTAMINATED WITH 90SR.

This work is focused on numerical calibrations of the body counter for in vivo measurement of pure beta emitters through the produced bremsstrahlung radiation. Calibrations were performed using the UPh-02T block whole-body phantom and the Lawrence Livermore National Laboratory (LLNL) realistic torso phantom. Neither of these physical phantoms is appropriate for such calibrations; therefore, specific 90Sr sources have been manufactured to be used with the UPh-02T phantom for experimental measurement followed with Monte Carlo (MC) simulations.

Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays.

This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level.

Plutonium isotopes in the atmosphere of Central Europe: Isotopic composition and time evolution vs. circulation factors.

This paper reports evidence of Pu isotopes in the lower part of the troposphere of Central Europe. The data were obtained based on atmospheric aerosol fraction samples collected from four places in three countries (participating in the informal European network known as the Ring of Five (Ro5)) forming a cell with a surface area of about 200,000km(2). We compared our original data sets from Krakow (Poland, 1990-2007) and Bialystok (Poland, 1991-2007) with the results from two other locations, Prague (Czech Republic; 1997-2004) and Braunschweig (Germany; 1990-2003) to find time evolution of the Pu isotopes.

Bagged neural network model for prediction of the mean indoor radon concentration in the municipalities in Czech Republic.

The purpose of the study is to determine radon-prone areas in the Czech Republic based on the measurements of indoor radon concentration and independent predictors (rock type and permeability of the bedrock, gamma dose rate, GPS coordinates and the average age of family houses). The relationship between the mean observed indoor radon concentrations in monitored areas (∼22% municipalities) and the independent predictors was modelled using a bagged neural network. Levels of mean indoor radon concentration in the unmonitored areas were predicted using the bagged neural network model fitted for the monitored areas.