A mobile simulation and ARIMA modeling for prediction of air radiation dose rates

Author(s):  
Hemn Salh ◽  
Fatih Külahcı ◽  
Serpil Aközcan

Abstract A spatial simulation method in .mp4 format was proposed to determine Fukushima radioactive fallout transport and the Absorbed Dose Rate, Annual Effective Dose Equivalent, and Excess Lifetime Cancer Risk were determined for 10 months after the accident (March 11 2011). The findings of this study demonstrate that an appropriate ARIMA model can be applied for radiation dose time-series in the case of nuclear reactor accidents like Chernobyl and Fukushima to predict the future air dose rates, which can provide valuable information in determining the evacuation zones, decontamination processes, and radiation protection progresses. The model forecasted results and the actual observation data in the same period shows a gradual decrease in the air dose rates during the prediction period. Moreover, there is a good agreement between them as the prediction and observation scatter plot follows each other with small variations. These results provide important insights into the predictability of ARIMA models; thus, the models were utilized to forecast the air dose rates for the period (January 2020 - October 2020).

2020 ◽  
Vol 65 (1) ◽  
pp. 1-18
Author(s):  
Branislava Mitrovic ◽  
Dragana Todorovic ◽  
Jelena Ajtic ◽  
Borjana Vranjes

This review paper discusses the content of natural (40K, 238U, 226Ra, and 232Th) and artificial (137Cs) radionuclides in the soil of the mountains of Maljen, Tara and Kopaonik in the Republic of Serbia over 2002-2015. In addition, the paper gives radiation hazard parameters, i.e., radium equivalent activity, absorbed dose rate, annual effective dose equivalent, external hazard index, annual gonadal dose equivalent, and excess lifetime cancer risk outdoors that we calculated from the obtained content of the natural radionuclides in the soil samples. We compared the parameters to previously published results for different parts of the country and looked into the radioecological status of the investigated areas.


2020 ◽  
Vol 24 (3) ◽  
pp. 435-442 ◽  
Author(s):  
M. Atipo ◽  
O. Olarinoye ◽  
B. Awojoyogbe ◽  
M. Kolo

Mineral mining and milling can be a source of national economic and technological development. However, mining of minerals has been confirmed to disturb the natural distribution of radioisotopes in the soil, air and water bodies in the biota. In an attempt to evaluate the radiological burden resulting from tin mining activities at Rayfield-Du area of Jos, the background gamma-radiation level in the mine was measured via a well calibratedhand-held dosimeter placed at 1 m above ground level. The mean absorbed dose rate, annual effective dose rate and excess lifetime cancer risk for the mine was 0.83 μSvh-1; 1.44 mSv-1 and 0.005 respectively. Generally, dose rates were higher in the mine pits and processing areas as compared to administrative areas of the mine. The mean measured dose rate and calculated dose parameters for the mine were all high when compared to the regulatory limit for public exposure. The potential of developing radiation-induced health defects as a result of high radiation absorbed dose rate by the miners and dwellers around the mine is highly probable.  Keywords: Gamma-radiation; mine; absorbed dose rate; radiation exposure.


Author(s):  
Amir Hamzah ◽  
Hery Adrial ◽  
Subiharto Subiharto

EVALUATION OF RADIATION DOSE RATE OF RSG-GAS REACTOR. The RSG-GAS reactor has been operated for 30 years. Since the nuclear reactor has been operated for a long time, aging process on its components may occur. One important parameter for maintaining the safety level of the RSG-GAS reactor is to maintain radiation exposure as low as possible, especially in the working area. The evaluation results should be able to demonstrate that the radiation exposure of the RSG-GAS is still safe for workers, communities and the surrounding environments. The purpose of this study is to evaluate radiation exposure in the working area to ensure that the operation of RSG-GAS is still safe for the next 10 years. The scope of this work is confirming the calculation results with the measured radiation dose in the RSG-GAS reactor working area. Measurement of radiation exposure is done by using the installed equipments at some points in the RSG-GAS working area and a portable radiation exposure measurement equipment. The calculations include performance of a modeling and analysis of dose rate distribution based on the composition and geometry data of RSG-GAS by using MCNP.  The analysis results show that the maximum dose rate at Level 0 m working area of RSG-GAS reactor is 3.0 mSv/h with a deviation of 6%, which is relatively close to the measurement value. The evaluation results show that the dose rate in RSG-GAS working area is below the limit value established by the Nuclear Energy Regulatory Agency of Indonesia (BAPETEN) of 10 mSv/h (for the average effective dose of 20 mSv/year). Therefore, it is concluded that the dose rate in RSG-GAS working area is safe for personnel..Kata kunci: dose rates, RSG-GAS, radiation safety, MCNP.


2020 ◽  
Vol 15 (1) ◽  
pp. 107-118
Author(s):  
Daniel Hatungimana ◽  
Caner Taşköprü ◽  
Mutlu İçhedef ◽  
Müslim Murat Saç ◽  
Şemsi Yazıcı ◽  
...  

ABSTRACT The aim of this study is to determine the radon and natural radioactivity concentrations of some building materials and to assess the radiation hazard associated with those mortar materials when they are used in the construction of dwellings. Radon measurements were realized by using LR-115 Type 2 solid state nuclear track detectors. Radon activity concentrations of these materials were found to vary between 130.00 ± 11.40 and 1604.06 ± 40.5 Bq m−3. The natural radioactivity in selected mortar materials was analyzed by using scintillation gamma spectroscopy. The activity concentrations for 226Ra, 232Th and 40K for the studied mortar materials ranged from ND to 48.5 ± 7.0 Bq kg−1, ND to 41.0 ± 6.4 Bq kg−1 and ND to 720.4 ± 26.8 Bq kg−1, respectively. Radium equivalent activities, external and internal hazard indexes, gamma and alpha indexes and absorbed gamma dose rates were calculated to assess the radiation hazard of the natural radioactivity in studied samples. The calculated Raeq values of all samples were found to be lower than the limit of 370 Bq kg−1 set for building materials. The estimated hazard index values were found to be under the unity and the absorbed dose rate values were also below the worldwide average of 84 nGy h−1.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3012
Author(s):  
Se Kye Park ◽  
Dong Yun Choi ◽  
Duyoung Choi ◽  
Dong Yun Lee ◽  
Seung Hwa Yoo

In this study, a high-density polyethylene (HDPE)-based carbon fiber-reinforced thermoplastic (CFRTP) was irradiated by an electron-beam. To assess the absorbed dose rate influence on its mechanical properties, the beam energy and absorbed dose were fixed, while the absorbed dose rates were varied. The tensile strength (TS) and Young’s modulus (YM) were evaluated. The irradiated CFRTP TS increased at absorbed dose rates of up to 6.8 kGy/s and decreased at higher rates. YM showed no meaningful differences. For CFRTPs constituents, the carbon fiber (CF) TS gradually increased, while the HDPE TS decreased slightly as the absorbed dose rates increased. The OH intermolecular bond was strongly developed in irradiated CFRTP at low absorbed dose rates and gradually declined when increasing those rates. X-ray photoelectron spectroscopy analysis revealed that the oxygen content of irradiated CFRTPs decreased with increasing absorbed dose rate due to the shorter irradiation time at higher dose rates. In conclusion, from the TS viewpoint, opposite effects occurred when increasing the absorbed dose rate: a favorable increase in CF TS and adverse decline of attractive hydrogen bonding interactions between HDPE and CF for CFRTPs TS. Therefore, the irradiated CFRTP TS was maximized at an optimum absorbed dose rate of 6.8 kGy/s.


2010 ◽  
Vol 58 (spe4) ◽  
pp. 25-32 ◽  
Author(s):  
Wagner de S. Pereira ◽  
Alphonse Kelecom ◽  
Delcy de A. Py Júnior

A methodology was developed for converting the activity concentration of radionuclides (Bq kg-1) into absorbed dose rate (Gy y-1), aiming an approach to environmental radioprotection based on the concept of standard dose limit. The model considers only the internal absorbed dose rate. This methodology was applied to the cubera snapper fish (Lutjanus cyanopterus, Cuvier, 1828) caught off the coast of Ceará. The natural radionuclides considered were uranium-238, radium-226, lead-210, thorium-232 and radium-228. The absorbed dose rates were calculated for individual radionuclides and the type of emitted radiation. The average dose rate due to these radionuclides was 5.36 µGy y-1, a value six orders of magnitude smaller than the threshold value of absorbed dose rate used in this study (3.65 10³ mGy y-1), and similar to that found in the literature for benthic fish. Ra-226 and U-238 contributed 67% and 22% of the absorbed dose rate, followed by Th-232 with 10%. Ra-228 and Pb-210, in turn, accounted for less than 1% of the absorbed dose rate. This distribution is somewhat different from that reported in the literature, where the Ra-226 accounts for 86% of the absorbed dose rate.


2019 ◽  
Vol 184 (3-4) ◽  
pp. 527-530 ◽  
Author(s):  
Y Shiroma ◽  
M Hosoda ◽  
K Iwaoka ◽  
M Hegedűs ◽  
H Kudo ◽  
...  

Abstract The latest car-borne survey was carried out by Hirosaki University in order to grasp the local distribution of the absorbed dose rate in air after the evacuation order was lifted on Namie Town in 2017. The car-borne survey of absorbed dose rate in air was carried out on most of the roads which were accessible by car in Namie Town using a 3-in × 3-in NaI(Tl) scintillation spectrometer. The range of the absorbed dose rate in air was calculated to be 0.041–11 μGy h−1. The distribution maps of the absorbed dose rate in air were drawn based on the data obtained during the surveys in 2011, 2015 and 2017. The comparison of these absorbed dose rates in air suggests that the elevated absorbed dose rate in air in Namie Town caused by the FDNPP accident may be decreasing faster than natural decline which includes weathering effect and physical decay due to the artificial decontamination.


2020 ◽  
Vol 190 (4) ◽  
pp. 355-363
Author(s):  
Jahan Zeb ◽  
Mohammad Wasim ◽  
Muhammad Awais ◽  
Asad Ullah ◽  
Talat Iqbal ◽  
...  

Abstract This study presents a detailed measurement of indoor and outdoor terrestrial gamma radiation levels in different cities of Pakistan. The measurements covered dwellings in 27 cities, covering all provinces and region of Azad Kashmir. Most of the houses were of attached type, made of brick walls and concrete roofs. The measurements were made by a handheld radiation survey meter containing Geiger–Muller tube. The average absorbed dose rate in air was 100 ± 32 nGy h−1 for indoor and 74 ± 30 nGy h−1 for outdoor. The population-weighted mean terrestrial dose rates were 90 nGy h−1 for indoor and 78 nGyh−1 for outdoor. The ratio of indoor to outdoor absorbed dose rate was 1.5 as compared to 1.3 for the world average. The estimated average annual effective dose rate was 0.58 ± 0.18 mSv a−1 and the mean excess life time cancer risk was 2.0 × 10−3.


2019 ◽  
Vol 184 (3-4) ◽  
pp. 500-503
Author(s):  
K Inoue ◽  
M Arai ◽  
H Tsuruoka ◽  
K Saito ◽  
M Fujisawa ◽  
...  

Abstract Absorbed dose rates in air were measured for the whole area of the Kanto region in 2015, 2016 and 2017 (n = 31 147). The mean absorbed dose rates in air for each prefecture measured by car-borne surveys were from 44 to 67 nGy h−1 (13–289 nGy h−1). The absorbed dose rate in air from artificial radionuclides (134Cs + 137Cs) measured by fixed-point observation (n = 507) was from 1 to 14 nGy h−1 (0–105 nGy h−1), and meaning that the contribution ratios of 134Cs and 137Cs were 3–22%. The deposited location of artificial radionuclides was less than 1000 m from ground level and depended on the topography, wind direction and precipitation field.


2020 ◽  
Vol 35 (2) ◽  
pp. 154-164
Author(s):  
Sreten Ilic ◽  
Tatjana Golubovic ◽  
Natasa Pajic ◽  
Mirjana Djurasevic ◽  
Aleksandar Kandic

This paper presents the results of analyses of radionuclide content in the samples of the surrounding soil and clayey material of ?Zbegovi? open-pit mine in Donje Crniljevo, Serbia. Samples from 78 sites were collected and prepared. The activity concentrations were determined for radionuclides: 238U, 232Th, 40K, 226Ra, and 137Cs. The mean values obtained are as follows: 23 Bqkg?1, 89 Bqkg?1, 372 Bqkg?1, 56 Bqkg?1, and 11 Bqkg?1, respectively. Concentrations of 238U, 40K, and 226Ra in the studied area do not deviate from the values obtained for the soil in Serbia. The concentration of 232Th in the studied area is slightly higher relative to average values for soil, and slightly lower compared to similar deposits of clayey material in the world. Measurements performed showed that the open-pit mine of clayey material is completely uncontaminated surface as far as 137Cs is concerned, while there are sites where measured 137Cs concentrations are significantly higher, which is due to topographic differences and inhomogeneous surface contamination of land after the Chernobyl accident. To assess the radiological risks in the observed area, the following indices were determined: absorbed dose rate, annual outdoor effective dose, absorbed dose for biota, excess lifetime cancer risk outdoors as well as external radiation hazard index. The mean value of the estimated absorbed dose rate in the given area amounts to 80.1 nGyh?1, and the annual outdoor effective dose ranges from 46.9 to 134 Sv. Absorbed dose rate for biota in the studied area is 1.31 10?4 Gyd?1. The mean excess lifetime cancer risk outdoors for the population is 3.8 10?4, and t he mean value of the external radiation hazard index obtained in this study is 0.48, which is consistent with the world average. A low dose of radiation will not pose a risk to the population and biota in the studied area.


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