Assessment Of Radiation Impact Research Articles

Transfer factors of 238U, 232Th, 40K, 210Pb to crops and radiation impact assessment in semi-arid environment

AbstractResearch on the safety of staple agricultural food products has always been one of humanity’s priorities and provides input for dose assessment models. Within this important priority, activity concentrations, transfer factors, and radiological effects of 238U, 232Th, 210Pb, and 40K were studied for selected crops in a village close to the NORM area, located in Central Anatolia region of Turkey. The RESRAD-onsite code has been used to assess the total dose rate. The simulation of the risk analysis covered 80 years. The maximum total dose of 0.5 mSv y−1 was obtained at t = 30 years.

Comprehensive assessment of radiation impact from natural radioactivity and tritium around Rooppur NPP before commissioning and predicted exposures of NPP operation

The research work undertakes an in-depth evaluation of radiation impact on the population due to natural radioactivity and tritium around the Rooppur Nuclear Power Plant (RNPP) before it is put into operation in the People's Republic of Bangladesh. Expected atmospheric releases during normal operation of the RNPP following commissioning are also evaluated. The dose of tritium β-radiation that the residents of Rooppur would receive from their drinking water before the RNPP is put into operation is assessed using techniques suggested by Momot et al. (2017) and Zhuravkov et al. (2019). Risk is calculated using the linear non-threshold approach. The findings of dose and risk assessment on the general public are four orders of magnitude below the permissible limits of 1 mSv/yr. and 5.0 × 10−5, respectively. Calculated dose and risk levels are 3 orders of magnitude lower than the annual effective dose and risk due to naturally occurring radionuclides in drinking water within Bangladesh including the Rooppur area. It is also calculated how much radiation the populace will be exposed to from anticipated atmospheric releases when the RNPP is operating normally after commissioning. This has been done following models of the International Atomic Energy Agency (IAEA) using CROM software. 3.67 μSv/yr., or 0.37% of the annual dose quota of 1 mSv/yr., is the estimated annual effective dose to the local population. Consequently, it can be said that there is low radiation risk to Bangladesh's people, both before and after the RNPP's commissioning of its two VVER-1200 reactor units. Following commissioning, the radiation monitoring information can be utilized to calculate the dose of technogenic radiation exposure and, consequently, the RNPP's contribution to the overall radiation dose to the general public.

Soil-to-plant transfer of 40K, 238U and 232Th and radiological risk assessment of selected mining sites in Nigeria

One of the major route through which humans are exposed to ionizing radiation is via food chain, which is consequent of soil-to-plant transfer of radionuclides. This work reported the activity concentrations of 40K, 238U and 232Th in samples of water, soil and guinea corn grains collected from Beryllium and Gold mining sites in Kwara, Nigeria. In-situ measurements at approximately 1 m in the air was carried out using a well-calibrated portable Gamma Spectrometer (Super Spec RS-125), while the soil, water and the guinea corn samples were analyzed using a ‘3 × 3’ inch lead-shielded NaI (Tl) detector. The measured activity concentrations of the natural radionuclides in the soil from both mines are lower than the in-situ measurements. This was attributed to the contribution from other terrestrial materials on-site. The estimated mean transfer factors (TFs) for 40K, 238U and 232Th are 0.21, 0.17 and 0.31, and 0.46, 0.19 and 0.28 respectively for the Beryllium and Gold mining sites. While the TFs for 238U and 232Th exceeded the mean value of 0.0062 and 0.0021 for 238U and 232Th respectively, the TFs for 40K are well below the 0.74 for cereals grains provided by International Atomic Energy Agency (IAEA). The radiation impact assessment using the Monte Carlo simulations reveals values that were generally less than the global average values provided by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Hence, the risk of cancer inducement due to radiation exposure is within the acceptable limits for both mining sites.

Assessment of dose rate to terrestrial biota in the area around coal fired power plant applying ERICA tool and RESRAD BIOTA code

This paper presents the environmental radiation risk assessment based on two software program approaches ERICA Tool (version 1.2) and RESRAD BIOTA (version 1.5) to estimate dose rates to terrestrial biota in the area around the largest coal fired power plant in Serbia. For dose rate assessment software's default reference animals and plants and the best estimated values of activity concentrations of 238U, 234U, 234Th, 232Th, 230Th, 226Ra, 210Pb, 210Po, 137Cs in soil were used. Both approaches revealed the highest contribution to the internal dose rate due to 226Ra and 210Po, while 137Cs contributed the most to the external dose rate. In the investigated area total dose rate to biota derived using ERICA Tool ranged from 0.3 to 14.4 μGy h−1. The natural radionuclides exhibited significantly higher contribution to the total dose rate than the artificial one. In the investigated area, only dose rate for lichens and bryophytes exceeded ERICA Tool screening value of total dose rate of 10 μGy h−1 suggested as confident that environmental risks are negligible. The assessed total dose rates for reference animals and plants using RESRAD BIOTA were found to be 7 and 3 μGy h−1, respectively. In RESRAD BIOTA - Level 3, 10 species (Lumbricus terrestris, Rana lessonae, Sciurus vulgaris, Anas platyrhynchos, Lepus europaeus, Vulpes vulpes, Capreolus capreolus, Suss crofa, Quercu srobur, Tilia spp.) representative for the study area were modeled. Among them the highest total dose rate (4.5 μGy h−1) was obtained for large mammals. Differences in the predicted dose rates to biota using the two software programs are the consequence of the difference in the values of transfer parameters used to calculate activity concentrations in biota. Doses of ionizing radiation estimated in this study will not exhibit deterministic effects at the population level. Thus, the obtained results indicate no significant radiation impact of coal fired power plant operation on terrestrial biota. This paper confirms the use ERICA Tool and RESRAD BIOTA softwares as flexible and effective means of radiation impact assessment.

Comparative Analysis of Calculation Possibilities of MACCS and RODOS Computer Codes for Emergency Response and Analysis of Radiation Consequences of Severe Accidents at NPPs

The paper presents a brief description of the Real-time On-line Decision Support System (RODOS) and MELCOR Accident Consequence Code System (MACCS) and evaluates the application of these codes for assessment of radiation impact on the public and environment in case of a severe accident at NPP in real time mode. The experts performed comparative analysis of results obtained from calculations using RODOS, WinMACCS and HotSpot codes. In the framework of the research, the chosen comparative criteria were assessed: total effective dose, thyroid equivalent dose, skin equivalent dose, I-131 and Cs-137 ground concentration at different distances up to 50 kilometers from the source of release.

Оцінка радіаційних впливів на компоненти навколишнього середовища під час підготовки майданчика для будівництва централізованого сховища відпрацьованого ядерного палива (ЦСВЯП)

Оцінка радіаційних впливів на компоненти навколишнього середовища під час підготовки майданчика для будівництва централізованого сховища відпрацьованого ядерного палива (ЦСВЯП)

Radiation Consequences of Fire in Chornobyl NPP Exclusion Zone

In April and June 2015, the population of the Kyiv region in Ukraine was alarmed by information on possible negative radiation consequences of the serious forest fires that broke out in the 30-kilometer zone of Chornobyl NPP Exclusion Zone. The paper describes analytical research related to the assessment of radiation impact of fire in contaminated territories of Chornobylska Pushcha on the public in Kyiv applying the model assessment using JRODOS and HotSpot computer systems. The paper presents direct radiation research carried out at the same time.

The transfer of 137Cs, Pu isotopes and 90Sr to bird, bat and ground-dwelling small mammal species within the Chernobyl exclusion zone

Protected species are the focus of many radiological environmental assessments. However, the lack of radioecological data for many protected species presents a significant international challenge. Furthermore, there are legislative restrictions on destructive sampling of protected species to obtain such data. Where data are not available, extrapolations are often made from ‘similar’ species but there has been little attempt to validate this approach.In this paper we present what, to our knowledge, is the first study purposefully designed to test the hypothesis that radioecological data for unprotected species can be used to estimate conservative radioecolgical parameters for protected species; conservatism being necessary to ensure that there is no significant impact.The study was conducted in the Chernobyl Exclusion Zone. Consequently, we are able to present data for Pu isotopes in terrestrial wildlife. There has been limited research on Pu transfer to terrestrial wildlife which contrasts with the need to assess radiation exposure of wildlife to Pu isotopes around many nuclear facilities internationally.Our results provide overall support for the hypothesis that data for unprotected species can be used to adequately assess the impacts for ionising radiation on protected species. This is demonstrated for a range of mammalian and avian species. However, we identify one case, the shrew, for which data from other ground-dwelling small mammals would not lead to an appropriately conservative assessment of radiation impact. This indicates the need to further test our hypothesis across a range of species and ecosystems, and/or ensure adequate conservatism within assessments.The data presented are of value to those trying to more accurately estimate the radiation dose to wildlife in the Chernobyl Exclusion Zone, helping to reduce the considerable uncertainty in studies reporting dose-effect relationships for wildlife.A video abstract for this paper is available from: http://bit.ly/1JesKPc.

PWR 사용후핵연료 중간저장시설의 몬테칼로 차폐해석 방법에 대한 계산효율성 개선방안 연구

For the purpose of improving the efficiency of the radiation impact assessment of dry interim storage facilities for the spent nuclear fuel of pressurized water reactors (PWRs), radiation impact assessment was performed after the application of sensitivity assessment according to the radiation source term designation method, development of a 2-step calculation technique, and cooling time credit. The present study successively designated radiation source terms in accordance with the cask arrangement order in the shielding building, assessed sensitivity, which affects direct dose, and confirmed that the radiation dosage of the external walls of the shielding building was dominantly affected by the two columns closest to the internal walls. In addition, in the case in which shielding buildings were introduced into storage facilities, the present study established and assessed the 2-step calculation technique, which can reduce the immense computational analysis time. Consequently, results similar to those from existing calculations were derived in approximately half the analysis time. Finally, when radiation source terms were established by adding the storage period of the storage casks successively stored in the storage facilities and the cooling period of the spent nuclear fuel, the radiation dose of the external walls of the buildings was confirmed to be approximately 40% lower than the calculated values; the cooling period was established as being identical. The present study was conducted to improve the efficiency of the Monte Carlo shielding analysis method for radiation impact assessment of interim storage facilities. If reliability is improved through the assessment of more diverse cases, the results of the present study can be used for the design of storage facilities and the establishment of site boundary standards.

Assessment of radiation impact on biota as a result of hypothetical accidents at small NPP

Assessment of radiation impact on biota as a result of hypothetical accidents at small NPP

Radiation impact assessment of naturally occurring radionuclides and magnetic mineral studies of Bharathapuzha river sediments, South India

The natural radioactivity levels and magnetic measurements in sediment samples of Bharathapuzha river for the first time have been determined. Bottom sediments from 33 locations were collected to determine 226Ra, 232Th and 40K using a HPGe detector based on the high-resolution gamma spectrometry system, and magnetic susceptibility by using Bartington MS2 magnetic susceptibility meter. The calculated activity concentrations of 226Ra, 232Th and 40K have been found to vary from 21.21 to 66.03 Bq kg−1, 33.49 to 93.10 Bq kg−1 and 232.25 to 899.66 Bq kg−1, respectively. The results have been compared with worldwide recommended values and also with radioactivity measurements in river sediments of India and other parts of the world. The air-absorbed dose rate, indoor and outdoor annual effective dose rates and radium equivalent activity are calculated with an aim to access the radiation hazards arising due to the use of these materials in the construction of buildings and their mean values obtained are 74.83 nGy h−1, 367.08 μSv y−1, 91.77 μSv y−1 and 157.09 Bq kg−1, respectively. The mass-specific magnetic susceptibility values ranged widely from 35.4 to 2,160.5 × 10−8 m3 kg−1 and compared with other rivers in South India. Multivariate statistical analyses were performed to describe the magnetic and radioactivity relevance of the different groups of samples. The data obtained in the present study may be useful for radiological and magnetic mapping of the study area in the future.

Radiation impact assessment on wildlife from an uranium mine area

Abstract Uranium mining and milling activities are one of the major causes of radioactive contamination of the environment. Radionuclides, especially uranium decay-chain products, are released from plant wastes into the soil and water and consequently into vegetation where they may accumulate. Transfer of radionuclides thus represents a radiological risk to humans and non-human organisms due to accumulation of radionuclides in target tissues and the consequent ionising radiation. The uranium mine at Žirovski vrh in Slovenia, which operated from 1985 to 1990, processed about 600,000 t of U-ore. Operational wastes were deposited at the Borst and Jazbec sites. According to several studies, an environmental radiological risk to biota could be observed at sites exposed to radioactive contamination. A modelling approach can be used to estimate the risk in such areas. The ERICA tool is one of the more widely used models, developed to assess the environmental risk from ionising radiation to wildlife. In the present study, the ERICA Tool was applied for the assessment of the radiation impact on wildlife in the Žirovski vrh influential area. ERICA reference organisms, native plants and aquatic organisms were included in the assessment to screen the risk to different organisms. Total dose rate to organisms were up to 3.49, 33.0 and 2.58 μGy h −1 for Juncus effusus , lichens and Austropotamobius torrentium , respectively. Dose rates to other organisms are also presented and discussed.

Study on the Reference Plants for the Assessment of Radiation Impact on Non-Human Species in Southwest of China

This paper introduces the researches on terrestrial reference plants in a area of southwest of China, including selection of candidate reference plantsH the description of geometric characteristics, and the transfer factors of 90 Sr, 137 Cs, and Pu in plants. The plant species involved are 2 trees (Firmiana simplex, Cryptomeria fourtunei), 2 shrubs (Nerium indicum Mill, Vitex negundo Linn)�H and 1 herb (Artemisia umbrosa). Expected values of the soil-to-plant transfer factors are provided. Further researches on radiation protection of non-human species in China are discussed.

Assessment of radiation impact on Stellaria graminea cenopopulations in the zone of the Eastern Ural Radioactive Trace

The seed progeny of the little starwort (Stellaria graminea) growing in the zone of the Eastern Ural Radioactive Trace (EURT) and in background areas was studied. The radiation exposure of this species in the EURT zone was three orders of magnitude higher than in the background. Evidence was obtained for high interannual variation in seed viability and tolerance to additional acute irradiation, but no specific connection was revealed between these parameters and radioactive contamination level in plant habitats. Weather conditions are an important source of variation in seed viability, but significant influence of temperature and precipitation was revealed only for cenopopulations of the EURT. The proportion of seedlings with morphoses in samples from the EURT was found to be increased; additional irradiation facilitated the detection of latent abnormalities. A negative correlation between seedling survival rate and the content of low-molecular antioxidants in the seedlings was revealed in all test areas. The allozyme structure of starwort cenopopulation was analyzed for the first time. A directed switch of allele frequencies at loci Pgi-2 and Fdh was revealed in samples from the EURT.

Radiological Impact of Oil Spilled Environment: a Case Study of the Eriemu well 13 and 19 Oil Spillage in Ughelli Region of Delta State, Nigeria

A six years of radiation impact assessment in an oil spillage environment and the host communities in Ughelli region of delta state have been conducted, using a digilert nuclear radiation monitor meter and a geographical positioning system (GPS). Measurements were made in 20 sites, 6 host communities and a control sample spread across the affected area. Measured average location values ranged between 0.010 mRh -1 (0.532 mSv y -1 ) to 0.019 mRh -1 (1.010 mSv y -1 ). The yearly exposure rate ranged between 0.013±0.006 mRh -1 (0.692±0.080 mSvy -1 ) to 0.016±0.005 mRh -1 (0.851±0.100 mSv y -1 ) in the oil spillage area. The host communities' values ranged between 0.011 mRh -1 (0.585 mSv y -1 ) to 0.015 mRh -1 (0.798 mSv y -1 ) with an average value of 0.010 mRh -1 (0.532 mSv y -1 ) recorded at the control sample. The radiation levels within these oil spillage areas and the host communities were of 55% and 33.3% respectively above the normal background level of 0.013 mRh -1 . The average equivalent dose rate obtained was higher than the 0.478 ηSv/y normal background level but was within the safe limit of 0.05 Sv y -1 recommended by ICRP and NCRP. These values obtained will not pose any immediate radiological health hazard to the host communities and workers within this environment.

Application of the ERICA Integrated Approach to the Drigg coastal sand dunes

The EC-funded project ‘Environmental Risks from Ionising Contaminants: Assessment and Management’ (ERICA) developed an ‘Integrated Approach’ for assessing the impact of ionising radiation on ecosystems. This paper presents the application of the ERICA Integrated Approach, supported by a software programme (the ERICA Tool) and guidance documentation, to an assessment of the Drigg coastal sand dunes (Cumbria, UK). Targeted sampling provided site-specific data for sand dune biota, including amphibians and reptiles. Radionuclides reported included 90Sr, 99Tc, 137Cs, 238Pu, 239+240Pu and 241Am. Site-specific data were compared to predictions derived using the ERICA Tool. Some under- and over-predictions of biota activity concentrations were identified but can be explained by the specific ecological characteristics and contamination mechanism of the dunes. Overall, the results indicated no significant impact of ionising radiation on the sand dune biota and the Integrated Approach was found to be a flexible and effective means of conducting a radiation impact assessment.

Methodology for Prediction of Near-Earth Space Radiation Effects on Optical Glasses

Prediction of near-Earth space radiation impact on spectral transmission of optical glasses remains an issue after several decades of research. The very wide range of multicomponent commercial glasses, radiation types, total doses, doses rates, etc. question the possibility of ab initio assessment of radiation impact. It has been proposed that a pragmatic parametric approach has merit in such a situation. We use BK7 glass as an example to demonstrate how the problem can be approached. Based on a sequence of transmission spectra measured in the course of and after gamma-irradiation (Co 6 0 source), we show how to find the required parameterization set. Taking into account the number of optical glasses used in space optical instruments, it is proposed that the first step toward a useful radiation effects database consists of the elaboration of a uniformly applicable methodology for testing of optical glasses. We believe that our work can serve as a basis for that methodology.