scholarly journals Radiological survey on radon entry path in an underground mine and implementation of an optimized mitigation system

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Amin Shahrokhi ◽  
Tibor Kovacs
Keyword(s):  
Black Shale ◽  
Radon Concentration ◽  
Ventilation System ◽  
Mining Activity ◽  
Reference Level ◽  
Active Surface Area ◽  
The European Union ◽  
Mining Operations ◽  
Radon Exhalation ◽  
European State

Abstract Background The European Union council has introduced the basic safety standards (EU-BSS) for protection against the dangers arising from exposure to ionizing radiation by laying down a new radon reference level at workplaces. In this regard, all European state members must establish a national reference level based on all pre-defined requirements. After implanting the directive 2013/59/Euratom by European state members, new challenges have been revealed to mitigate radon appropriately in underground workplaces due to the exciting limitations (e.g., ventilation system, dust dispersion, air injection, etc.). Therefore, a conceptual design of an environmental radiological survey was defined and implemented by examining the hypothesis to find practical solutions following EU-BSS. The main objectives of this study were to identify the potential radon entry paths, utilize an optimized ventilation system, and carry on long-term radon monitoring in an operational underground manganese mine. Results The mullock rocks (the geological structure of the mine walls) contained a small amount of Ra-226 (2–4 Bq kg−1). On the other hand, the mine ore (black shale, underlayer black shale, and carbonate ore) has shown the highest concentration of Ra-226 (12–16 Bq kg−1) and the highest radon exhalation (1.2–1.6 mBq s−1 m−2). The surface radon exhalation from the mine walls was in the range of 0.7 ± 0.1 and 1.5 ± 0.2 mBq m−2 s−1. It was found that shortly after mining activity was undertaken, radon concentration increased dramatically with an average of about 5900 ± 420 Bq m−3 near the freshly broken walls. The optimized mobile mitigation system reduced radon concentration to 250 ± 41 Bq m−3 on average. Conclusion Apart from the fact that aged walls were involved in the radon accumulation, considering the mine ventilation performance and the total active surface area, the exhaled radon from the aged walls could not be the primary potential source of high radon concentration when mining activity was undertaken. According to the obtained results, the ores, recently fragmented during the course of mining operations, were the primary path. Therefore, after successfully identifying the radon entry path, radon concentration could be reduced to meet the EU-BSS requirement by implementing the developed mitigation system.

scholarly journals Radon in houses of Kowary – Sudety Mountains, Poland

Nukleonika ◽  
2020 ◽  
Vol 65 (2) ◽  
pp. 149-152
Author(s):  
Jerzy Olszewski ◽  
Katarzyna Walczak
Keyword(s):  
European Union ◽  
Radon Concentration ◽  
Geometric Mean ◽  
Reference Level ◽  
The European Union ◽  
Sudety Mountains ◽  
Radon Concentrations

AbstractThe presence of uranium makes the Kowary area characterized by an increased concentration of radon in the air and the living houses. Measurements of periodic radon concentrations in dwellings of Kowary were carried out three times in the last 20 years. It can be observed that 20 years ago level of radon concentrations in houses of Kowary were lower than today. Measurements carried out in Kowary over 20 years have shown that residents are exposed to radon concentrations, which often exceed 300 Bq m−3 – a reference level recommended by the European Union. The present geometric mean of radon concentration in houses of Kowary (260 Bq m−3) exceeds the geometric mean of radon concentration of buildings in the rest of Poland (142 Bq m−3).

scholarly journals Low Radon Cleanroom for Underground Laboratories

2021 ◽  
Vol 8 ◽  
Author(s):  
Ivan Štekl ◽  
Jirí Hůlka ◽  
Fadahat Mamedov ◽  
Pavel Fojtík ◽  
Eva Čermáková ◽  
...  
Keyword(s):  
Radon Concentration ◽  
Time Course ◽  
Ventilation System ◽  
Basic Research ◽  
High Volume ◽  
Interior Space ◽  
Radon Exhalation ◽  
Decay Products ◽  
Volume Ventilation ◽  
Radon Decay

Aim of a low radon cleanroom technology is to minimize at the same time radon, radon decay products concentration and aerosol concentration and to minimize deposition of radon decay products on the surfaces. The technology placed in a deep underground laboratory such as LSM Modane with suppressed muon flux and shielded against external gamma radiation and neutrons provides “Zero dose” space for basic research in radiobiology (validity of the LNT hypothesis for very low doses) and for the fabrication of nanoelectronic circuits to avoid undesirable “single event effects.” Two prototypes of a low radon cleanroom were built with the aim to achieve radon concentration lower than 100 mBq·m3 in an interior space where only radon-free air is delivered into the cleanroom technology from a radon trapping facility. The first prototype, built in the laboratory of SÚRO Prague, is equipped with a standard filter-ventilation system on the top of the cleanroom with improved leakproofness. In an experiment, radon concentration of some 50 mBq·m−3 was achieved with the filter-ventilation system switched out. However, it was not possible to seal the system of pipes and fans against negative-pressure air leakage into the cleanroom during a high volume ventilation with the rate of 3,500 m3·h−1. From that reason more sophisticated second prototype of the cleanroom designed in the LSM Modane uses the filter-ventilation system which is completely covered in a further improved leakproof sealed metal box placed on the top of the cleanroom. Preliminary experiments carried out in the SÚRO cleanroom with a high radon activity injection and intensive filter-ventilation (corresponding to room filtration rate every 13 s) showed extremely low radon decay products equilibrium factor of 0.002, the majority of activity being in the form of an “unattached fraction” (nanoparticles) of 218Po and a surface deposition rate of some 0.05 mBq·m−2·s−1 per Bq·m−3. Radon exhalation from persons may affect the radon concentration in a low radon interior space. Balance and time course of the radon exhalation from the human body is therefore discussed for persons that are about to enter the cleanroom.

scholarly journals Indoor radon activity concentration and effective dose rates at schools and thermal spas of Ilgin

2020 ◽  
Vol 35 (4) ◽  
pp. 339-346
Author(s):  
Mehmet Erdogan ◽  
Murat Abaka ◽  
Kaan Manisa ◽  
Hasan Bircan ◽  
Coskun Kus ◽  
...  
Keyword(s):  
Radon Concentration ◽  
Primary Schools ◽  
Indoor Radon ◽  
Reference Level ◽  
Distribution Analysis ◽  
Indoor Radon Concentration ◽  
Radon Activity ◽  
Dose Rates ◽  
Basement Floor ◽  
Effective Doses

Indoor radon activity concentrations and radon doses on the ground floor and basement floor of 19 schools (kindergardens, primary schools, secondary schools, and high schools) and thermal spas of Ilgin district in Konya, have been measured using the AlphaGUARD PQ 2000PRO radon detector, for three days in the first half of 2016. According to the results, while the indoor radon concentration for only one location, in total, is above the Turkish action level of 400 Bqm?3, the values for 10 locations are above the reference level of 100 Bqm?3, recommended by WHO. The calculated annual effective doses for inhalation of the radon in indoor air were also found to be 0.26 ?Sv for the minimum and 4.36 ?Sv for the maximum. The parametric distribution analysis is also performed with 3-parameter Weibull distribution and some remarks are provided on radon concentration activity.

Radiological Parameters Due to Radon-222 in Soil Samples at Baghdad Governorate (Karakh), Iraq

2017 ◽  
Vol 60 (2) ◽  
pp. 72-78
Author(s):  
Ali Abid Abojassim ◽  
Ahmed Rahim Shltake ◽  
Laith Ahmed Najam
Keyword(s):  
Radon Concentration ◽  
Annual Effective Dose ◽  
Track Detector ◽  
Soil Samples ◽  
Reference Level ◽  
Nuclear Track Detector ◽  
Radium Content ◽  
Can Technique ◽  
Level 3 ◽  
Radon Concentrations

Measurements of radon concentration, effective radium content, potential alpha energyconcentration (PAEC) and annual effective dose (AED) were estimated for soil samples in fifteen locationsof the Baghdad governorate (Karakh) in the central part of Iraq. In this survey we used the can technique,containing nuclear track detector (CR-39). The obtained values of radon concentration measurements weregenerally low, ranging from 38.12±13.46 to 94.51±16.5 Bq/m3, with an average 66.07 Bq/m3, while theeffective radium content varied from 5.80±0.21 Bq/kg to 14.39±0.33 Bq/kg with an average 10.09 Bq/kg. The average of the PAEC and AED were assessed to be 7.14 mWL 1.66 mSv/y, respectively. The resultsof the present study shows that the radium content are lower than the allowed limit reported by Organizationfor Economic Cooperation and Development (OECD) that is equal to 370 Bq/kg. In general, it is seen thatthe AED limit was within the recommended reference level (3 mSv/y to 10 mSv/y) of the World HealthOrganization. Also, it is found that there is a strong correlation (R2= 1) between radon concentrations andeffective radium content. The results obtained from this study indicate that the locations of Karakh hasbackground radioactivity(radon concentrations) levels within the natural limits.

VARIATIONS OF INDOOR RADON CONCENTRATION IN TRADITIONAL RUSSIAN RURAL WOODEN HOUSES

2020 ◽  
Vol 191 (2) ◽  
pp. 219-222
Author(s):  
Tatiana Petrova ◽  
Petr Miklyaev
Keyword(s):  
Radon Concentration ◽  
Indoor Radon ◽  
Ground Surface ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Indoor Radon Concentration ◽  
Radon Exhalation ◽  
Soil Gas Radon ◽  
Radon Measurements ◽  
Indoor And Outdoor

Abstract Continuous indoor radon measurements were carried out in two traditional Russian rural houses located in different villages of the Moscow region in summer of 2017 and 2018. In additional, in the summer of 2017, continuous measurements of soil gas radon activity concentration at depth 0.8 m and radon exhalation rate from the ground surface near the house were performed simultaneously. It was found that the indoor radon concentration in rural houses is subject to strong daily variations, which are characterized by highs at night and lows during the day. Indoor radon concentration is directly proportional to indoor and outdoor temperature difference and inversely proportional to wind speed. While the radon exhalation rate from the ground surface, as well as the ventilation of premises (opening doors and windows) practically do not affect the concentration of radon in Russian rural wooden houses.

Noise Reduction Treatment and Analysis of Accumulated Radon Concentration in Uranium-Like Rock Based on Wavelet Theory

2018 ◽  
Author(s):  
Fuliang Jiang ◽  
Wenchao Yang ◽  
Ming Li ◽  
Xiangyang Li ◽  
Changshou Hong
Keyword(s):  
Radon Concentration ◽  
Raw Materials ◽  
Uranium Mine ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Wavelet Theory ◽  
Actual Measurement ◽  
Radon Exhalation ◽  
Single Side ◽  
Uranium Tailings

Based on the principle of similarity, uranium ore samples were prepared from raw materials such as uranium tailings, quartz sand and refined iron powder, and then the samples were treated with different packages for measuring the sample accumulated radon concentration. In the actual measurement process, due to the characteristics of radionuclide decay, instrument reasons and human factors, the data will be a certain deviation. Therefore, the method of wavelet analysis is used to denoise the accumulated radon concentration and obtain radon exhalation rate. The results of the study show: the correlation coefficient of cumulative radon concentration fitted by wavelet denoising is improved greatly, and all of them are above 0.99, the recalculated radon exhalation rate of the single side of the sample is decreased by 0.06Bq · m−2 · s−1, and double-edged is decreased by 0.02Bq · m−2 · s−1. The experiment proved that wavelet theory can be used to correct calculated value of radon exhalation rate of uranium-like rock. At the same time, it provides a new method for further study of uranium mine radiation protection parameters.

scholarly journals SPATIAL VARIABILITY OF INDOOR RADON CONCENTRATION IN SCHOOLS: IMPLICATIONS ON RADON MEASUREMENT PROTOCOLS

2020 ◽  
Vol 191 (2) ◽  
pp. 133-137
Author(s):  
Z Curguz ◽  
G Venoso ◽  
Z S Zunic ◽  
D Mirjanic ◽  
M Ampollini ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Radon Concentration ◽  
Indoor Radon ◽  
Reference Level ◽  
Indoor Radon Concentration ◽  
Radon Measurement ◽  
Ground Floor ◽  
Preliminary Study ◽  
The Republic ◽  
Radon Measurements

Abstract The requirements about radon measurements in schools and public buildings included in most of the national and international legislations are generally restricted to all the rooms located at the ground floor and basement, assuming the soil beneath the building as the main source of indoor radon. In order to verify such an assumption for small buildings having at maximum two floors, a preliminary study was performed in 50 schools located in 15 municipalities of the Republic of Srpska. Results of this study suggest that a protocol requiring measurements at the ground floor only may be considered adequate. Due to the high radon spatial variability for rooms at the ground floor, it is preferable to require measurements in a high number of rooms (preferably in all of them) in order to assess the compliance with the reference level established by the legislation.

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