MODEL CALIBRATION OF AN AIRBORNE GAMMA SPECTROMETER FOR SEARCHING OF RADIONUCLIDE SOURCES USING UAV.

A study of a small airborne gamma spectrometer usability, carried by unmanned aerial vehicle (UAV), during a search for radionuclide sources and estimating their activity was performed. Model calculations of calibration coefficients for Georadis D230A spectrometer (with two NaI (Tl) 2″ x 2″ detectors), 241Am, 57Co, 137Cs, 192Ir, 60Co and 152Eu radionuclides and set of flight altitudes from 1 up to 25 m were done. The results were compared with the results of experimental measurements for 137Cs and 60Co sources using vertical heights up to 10 m above the source on the ground.

STUDY OF 222RN CONTINUOUS MONITORING TIME SERIES AND DOSE ASSESSMENT IN SIX EUROPEAN CAVES.

The present work aims to assess the effective doses from long-term continual radon monitoring in six European caves (Slovenia, Slovakia and the Czech Republic), including influencing environmental factors. Caves are important radiation protection subjects because of elevated radon activity concentration (~kBq/m3), mostly due to the low natural ventilation. The sources of radon gas are most often underground rock layers and clastic sediments.

Analysis of geophysical and meteorological parameters influencing Rn activity concentration in Mladeč caves (Czech Republic) and in soils of Phlegrean Fields caldera (Italy).

The present work concerns a detailed analysis of Radon time series to differentiate endogenous from exogenous phenomena which provide anomalous signals. Two-year data from two sites in Czech Republic and in Italy are analyzed in order to contribute to the prevention of natural hazards. A new hybrid forecasting method is implemented and tuned for the identification of Radon anomalies in the time series.

ANALYSIS OF RADON TIME SERIES RECORDED IN SLOVAK AND CZECH CAVES FOR THE DETECTION OF ANOMALIES DUE TO SEISMIC PHENOMENA.

Anomalies in the radon (222Rn) releases in underground environments are one of the phenomena that can be observed before earthquake occurrence. Continuous measurements of radon activity concentration, and of meteorological parameters that influence the gas emission, were performed in three Slovak and Czech caves during 1-y period (1 July 2016-30 June 2017). The radon activity concentration in caves shows seasonal variations, with maxima reached during summer months.

THE USE OF DECONVOLUTION TECHNIQUE FOR THE ANALYSIS OF GAMMA SPECTROMETRY DATA FROM FIELD MONITORING USING UNMANNED AERIAL VEHICLES.

Airborne gamma spectrometry is an effective tool for prompt monitoring and mapping of large areas contaminated after NPP accident, radionuclides leakage cases, an impact of uranium ore mining and processing, etc. Airborne spectrometry data analysis using deconvolution technique enables to calculate air kerma rates and/or radionuclides concentrations as well as identification of radionuclides. Application of this technique on the airborne data (from manned as well as an unmanned survey using drones) is rather specific due to the requirements for short time of one scan data acquisition, a relatively long distance from the source and small detector size, due to the limited payload of the usually used drones.

RADON CONCENTRATION TIME SERIES MODELING AND APPLICATION DISCUSSION.

In the year 2010 a continual radon measurement was established at Mladeč Caves in the Czech Republic using a continual radon monitor RADIM3A. In order to model radon time series in the years 2010-15, the Box-Jenkins Methodology, often used in econometrics, was applied. Because of the behavior of radon concentrations (RCs), a seasonal integrated, autoregressive moving averages model with exogenous variables (SARIMAX) has been chosen to model the measured time series.

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.

Evaluation of human body irradiation caused by radionuclides deposited in the filtration unit of gas mask.

Radioactive aerosol particles represent a serious risk for people facing the consequences of nuclear accident of any kind. The first responders to emergency situation need to be protected by personal protective equipment which includes radiation protection suit supplemented with gas mask. The purpose of this work is to estimate the dose to the organs of responder's body as a result of radionuclide deposition in the filtration unit of the gas mask.

The overview of the radon and environmental characteristics measurements in the Czech show caves.

This paper focuses on the measurement and assessment of absorbed doses of radiation in caves of the Czech Republic, some of which exhibit high activity concentration of radon in air. Presented is an analysis and recommendations based on measurement results obtained in the underground caves over the past 12 y. The most important results for cave environments were as follows: integral radon monitoring using RAMARN detectors can provide more consistent results for calculating the effective dose; no major differences were shown in the average radon activity concentration during working time as opposed to non-working time; the unattached fraction of radioactive particles in air ranged from 0.

Remedial activities effectiveness verification in tailing areas.

The complex radiological study of the basin of sludge from the uranium ore mining and preprocessing was done. Air kerma rates (including its spectral analysis) at the reference height of 1 m above ground over the whole area were measured and radiation fields mapped during two measuring campaigns (years 2009 and 2014). K, U and Th concentrations in sludge and concentrations in depth profiles (including radon concentration and radon exhalation rates) in selected points were determined using gamma spectrometry for in situ as well as laboratory samples measurement.

MCNPX evaluation of gamma spectrometry results in high radon concentration areas.

The radon concentration in underground workplaces may reach tens of thousands of Bq m(-3). A simple MCNPXTM Monte Carlo (MC) model of a cave was developed to estimate the influence of radon on the in situ gamma spectrometry results in various geometries and radon concentrations. The detector total count rate was obtained as the sum of the individual count rates due to 214Bi in the air, radon in the walls and deposition of radon daughters on surfaces.

Revealing the hidden faults in the SE flank of Mt. Etna using radon in-soil gas measurement.

Although there are many methods for investigating tectonic structures, many faults remain hidden, and they can endanger the life and property of people living along them. The slopes of volcanoes are covered with such hidden faults, near which strong earthquakes and gas releases can appear. Revealing hidden faults can therefore contribute significantly to the protection of people living in volcanic areas.

Radon, carbon dioxide and fault displacements in central Europe related to the Tōhoku Earthquake.

Tectonic instability may be measured directly using extensometers installed across active faults or it may be indicated by anomalous natural gas concentrations in the vicinity of active faults. This paper presents the results of fault displacement monitoring at two sites in the Bohemian Massif and Western Carpathians. These data have been supplemented by radon monitoring in the Mladeč Caves and by carbon dioxide monitoring in the Zbrašov Aragonite Caves.

A pilot study of the dependence of radon concentration on the tectonic structures, using simple geophysical methods.

It is well known that there are great variations in radon concentrations in the soil gas on building sites. The concentration may sometimes vary by more than two orders of magnitude. The tectonic structure of the bedrock is one of the factors that influence the intensity of the radon outflow.

The use of caves as observatories for recent geodynamic activity and radon gas concentrations in the Western Carpathians and Bohemian Massif.

In recent years, many underground spaces such as caves and deep mines have been used to monitor geodynamic activity in the Western Carpathians and Bohemian Massif. In addition, long-term radon gas monitoring has also being undertaken in three of the caves. The observed radon concentrations have shown diurnal, seasonal and yearly variations.

Radon dose calculation methodology for underground workers in the Czech Republic.

The project focused on classifying the level of irradiation from natural ionising radiation sources for workers in publicly accessible caves and in caves used for speleotherapy, with applicability to other underground workplace. A correct and accurate procedure (and calculation) is defined for determining the effective dose that workers are exposed to in caves, based on the results of integral measurements of radon volume activity and on the length of time spent by workers in the caves. A review was made of various approaches for evaluating lung irradiation found in the literature.

Contribution of atmospherical radon to in-situ scintillation gamma spectrometry data.

In-situ gamma spectrometry can be used for monitoring and determining natural and man-made radionuclide concentrations in the environment. The low detection limit of potential contaminants depends on the natural background variations, including variations in the atmospheric concentrations of radon and its decay products. The scintillation spectrometer response for atmospheric radon was simulated by the Monte Carlo method, and the results were compared with the experimental measurements over large water surfaces.

Gamma spectrometric measurements of depth-related radionuclide distribution in walls.

The method for depth-related radionuclide distribution was evolved for approximate determination of the spatial lay-out of radionuclides in materials. The method is based on different attenuation coefficients for various energies of gamma radiation. For each material, the attenuation coefficient decreases with rising energy of radiation.

Radiation sources in the environment near NPP Temelin.

A widely discussed question is how much a nuclear power plant really contributes to irradiation of the people living in its vicinity. A number of laboratory and in situ measurements were performed in the area surrounding NPP Temelin, on the basis of which we can specify the irradiation of this area from various sources. The evaluation includes the contributions from natural sources, such as radon, terrestrial radiation and cosmic radiation, together with the contribution from inhalation and ingestion of radionuclides.

Data analysis from monitoring of radionuclides in the nuclear power plant Temelin ecosystem area.

Changes in the ecosystem occur naturally, however, can also be due to man's activity. The unique ecosystem monitoring based on studying contamination of the bioindicators by man-made radionuclides has been providing data from the area of nuclear power plant (NPP) Temelin (CR) using laboratory gamma spectrometry for past 8 years. The increase in radioactivity in the NPP ecosystem area resulting from its operation is evaluated through comparison with a zero level of (137)Cs mass activities and by obtained data trend analysis.

Investigation and remediation of houses affected by radon phenomena connected with earlier exploration of silver and uranium ore.

The sources of gamma radiation inside buildings affected by earlier silver and uranium mining activities are discussed. Possibilities how to reduce gamma dose rates from building materials were studied on several houses located in the old mining town Jáchymov. Results of the efficiency analysis are presented.

Effective dose assessment for workers in caves in the Czech Republic: experiments with passive radon detectors.

The new RAMARN system for radon volume activity measurement was developed in 2003 and has been in use since then. RAMARN system consists of a plastic chamber that is conically cylindrical in shape and about 0.5 l in volume; a bare Kodak LR 115 is located on the bottom of this diffusion chamber.

Assessment of the dose from radon and its decay products in the Bozkov dolomite cave.

The dose from radon and its progeny remains a frequently discussed problem. ICRP 65 provides a commonly used methodology to calculate the dose from radon. Our work focuses on a cave environment and on assessing the doses in public open caves.