Pub Date : 2023-03-30DOI: 10.14407/jrpr.2022.00073
Sang-Hyun Lee, Su‐Bin Oh, Chun-Ji Kim, C. Jin, Hyun-Ha Lee
Background: High-fidelity meteorological data is a prerequisite for the realistic simulation of atmospheric dispersion of radioactive materials near nuclear power plants (NPPs). However, many meteorological models frequently overestimate near-surface wind speeds, failing to represent local meteorological conditions near NPPs. This study presents a new high-resolution (approximately 1 km) meteorological downscaling method for modeling short-range (< 100 km) atmospheric dispersion of accidental NPP plumes.Materials and Methods: Six considerations from literature reviews have been suggested for a new dynamic downscaling method. The dynamic downscaling method is developed based on the Weather Research and Forecasting (WRF) model version 3.6.1, applying high-resolution land-use and topography data. In addition, a new subgrid-scale topographic drag parameterization has been implemented for a realistic representation of the atmospheric surface-layer momentum transfer. Finally, a year-long simulation for the Kori and Wolsong NPPs, located in southeastern coastal areas, has been made for 2016 and evaluated against operational surface meteorological measurements and the NPPs’ on-site weather stations.Results and Discussion: The new dynamic downscaling method can represent multiscale atmospheric motions from the synoptic to the boundary-layer scales and produce three-dimensional local meteorological fields near the NPPs with a 1.2 km grid resolution. Comparing the year-long simulation against the measurements showed a salient improvement in simulating near-surface wind fields by reducing the root mean square error of approximately 1 m/s. Furthermore, the improved wind field simulation led to a better agreement in the Eulerian estimate of the local atmospheric dispersion. The new subgrid-scale topographic drag parameterization was essential for improved performance, suggesting the importance of the subgrid-scale momentum interactions in the atmospheric surface layer.Conclusion: A new dynamic downscaling method has been developed to produce high-resolution local meteorological fields around the Kori and Wolsong NPPs, which can be used in short-range atmospheric dispersion modeling near the NPPs.
背景:高保真气象数据是真实模拟核电站附近放射性物质大气扩散的先决条件。然而，许多气象模式经常高估近地面风速，不能代表核电站附近的当地气象条件。本文提出了一种新的高分辨率(约1公里)气象降尺度方法，用于模拟NPP事故羽流的近距离(< 100公里)大气扩散。材料和方法:从文献综述中提出了一种新的动态降尺度方法的六个考虑因素。基于WRF (Weather Research and Forecasting, WRF)模式3.6.1版，应用高分辨率土地利用和地形数据，开发了动态降尺度方法。此外，本文还提出了一种新的亚栅格尺度地形阻力参数化方法，以真实地表征大气表层动量传递。最后，对位于东南沿海地区的古里核电站和月松核电站进行了为期一年的2016年模拟，并根据实际地面气象测量和核电站现场气象站进行了评估。结果与讨论:新的动态降尺度方法可以表示从天气尺度到边界层尺度的多尺度大气运动，并能生成网格分辨率为1.2 km的核电站附近三维局地气象场。将一年的模拟结果与实测结果进行比较，结果表明，模拟近地面风场的均方根误差降低了约1 m/s。此外，改进后的风场模拟结果与欧拉法对局地大气弥散的估计更加吻合。新的亚网格尺度地形阻力参数化对于提高性能至关重要，这表明大气表层亚网格尺度动量相互作用的重要性。结论:建立了一种新的动态降尺度方法，在古里核电站和月松核电站周围建立了高分辨率的局地气象场，可用于核电站附近的近程大气弥散模拟。
{"title":"Development of a Dynamic Downscaling Method for Use in Short-Range Atmospheric Dispersion Modeling Near Nuclear Power Plants","authors":"Sang-Hyun Lee, Su‐Bin Oh, Chun-Ji Kim, C. Jin, Hyun-Ha Lee","doi":"10.14407/jrpr.2022.00073","DOIUrl":"https://doi.org/10.14407/jrpr.2022.00073","url":null,"abstract":"Background: High-fidelity meteorological data is a prerequisite for the realistic simulation of atmospheric dispersion of radioactive materials near nuclear power plants (NPPs). However, many meteorological models frequently overestimate near-surface wind speeds, failing to represent local meteorological conditions near NPPs. This study presents a new high-resolution (approximately 1 km) meteorological downscaling method for modeling short-range (< 100 km) atmospheric dispersion of accidental NPP plumes.Materials and Methods: Six considerations from literature reviews have been suggested for a new dynamic downscaling method. The dynamic downscaling method is developed based on the Weather Research and Forecasting (WRF) model version 3.6.1, applying high-resolution land-use and topography data. In addition, a new subgrid-scale topographic drag parameterization has been implemented for a realistic representation of the atmospheric surface-layer momentum transfer. Finally, a year-long simulation for the Kori and Wolsong NPPs, located in southeastern coastal areas, has been made for 2016 and evaluated against operational surface meteorological measurements and the NPPs’ on-site weather stations.Results and Discussion: The new dynamic downscaling method can represent multiscale atmospheric motions from the synoptic to the boundary-layer scales and produce three-dimensional local meteorological fields near the NPPs with a 1.2 km grid resolution. Comparing the year-long simulation against the measurements showed a salient improvement in simulating near-surface wind fields by reducing the root mean square error of approximately 1 m/s. Furthermore, the improved wind field simulation led to a better agreement in the Eulerian estimate of the local atmospheric dispersion. The new subgrid-scale topographic drag parameterization was essential for improved performance, suggesting the importance of the subgrid-scale momentum interactions in the atmospheric surface layer.Conclusion: A new dynamic downscaling method has been developed to produce high-resolution local meteorological fields around the Kori and Wolsong NPPs, which can be used in short-range atmospheric dispersion modeling near the NPPs.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81314578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-30DOI: 10.14407/jrpr.2022.00129
E. Han, Y. Choi
Background: An effective communication strategy for reducing conflicts in South Korea has been designed through the analysis of public perception and communication variables on nuclear power under the conditions of rapidly changing nuclear power policies.Materials and Methods: This study conducted both qualitative research through group discussions based on social psychology and quantitative research through surveys.Results and Discussion: Nuclear power plant (NPP) area residents in favor of nuclear power indicated higher levels of communication, safety perception, and contribution than those against it. NPP area residents trusted the civilian expert groups (18.3%) and local government (17.3%) the most, while metropolitan city residents trusted the Nuclear Safety and Security Commission and the Korea Institute of Nuclear Safety (20.7%) the most. In determining nuclear power policy, both the NPP area residents (18.1%) and metropolitan city residents (17.1%) prioritized safety, health, and the environment. While metropolitan city residents thought that energy security and economic growth (16.4%) were important, NPP area residents thought the current issue of spent fuel rods (14.1%) to be important.Conclusion: It is necessary for the nuclear power industry to have and actively implement communication and conflict resolution strategies based on the patterns obtained in the study results.
{"title":"Public Perception and Communication Patterns Pertaining to Nuclear Power in Korea: Focusing on the Transition Period from Pro-nuclear to De-nuclear Policy","authors":"E. Han, Y. Choi","doi":"10.14407/jrpr.2022.00129","DOIUrl":"https://doi.org/10.14407/jrpr.2022.00129","url":null,"abstract":"Background: An effective communication strategy for reducing conflicts in South Korea has been designed through the analysis of public perception and communication variables on nuclear power under the conditions of rapidly changing nuclear power policies.Materials and Methods: This study conducted both qualitative research through group discussions based on social psychology and quantitative research through surveys.Results and Discussion: Nuclear power plant (NPP) area residents in favor of nuclear power indicated higher levels of communication, safety perception, and contribution than those against it. NPP area residents trusted the civilian expert groups (18.3%) and local government (17.3%) the most, while metropolitan city residents trusted the Nuclear Safety and Security Commission and the Korea Institute of Nuclear Safety (20.7%) the most. In determining nuclear power policy, both the NPP area residents (18.1%) and metropolitan city residents (17.1%) prioritized safety, health, and the environment. While metropolitan city residents thought that energy security and economic growth (16.4%) were important, NPP area residents thought the current issue of spent fuel rods (14.1%) to be important.Conclusion: It is necessary for the nuclear power industry to have and actively implement communication and conflict resolution strategies based on the patterns obtained in the study results.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77033485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-30DOI: 10.14407/jrpr.2021.00297
F. Paquet
Internal dosimetry is a discipline which brings together a set of knowledge, tools and procedures for calculating the dose received after incorporation of radionuclides into the body. Several steps are necessary to calculate the committed effective dose (CED) for workers or members of the public. Each step uses the best available knowledge in the field of radionuclide biokinetics, energy deposition in organs and tissues, the efficiency of radiation to cause a stochastic effect, or in the contributions of individual organs and tissues to overall detriment from radiation. In all these fields, knowledge is abundant and supported by many works initiated several decades ago. That makes the CED a very robust quantity, representing exposure for reference persons in reference situation of exposure and to be used for optimization and assessment of compliance with dose limits. However, the CED suffers from certain limitations, accepted by the International Commission on Radiological Protection (ICRP) for reasons of simplification. Some of its limitations deserve to be overcome and the ICRP is continuously working on this. Beyond the efforts to make the CED an even more reliable and precise tool, there is an increasing demand for personalized dosimetry, particularly in the medical field. To respond to this demand, currently available tools in dosimetry can be adjusted. However, this would require coupling these efforts with a better assessment of the individual risk, which would then have to consider the physiology of the persons concerned but also their lifestyle and medical history. Dosimetry and risk assessment are closely linked and can only be developed in parallel. This paper presents the state of the art of internal dosimetry knowledge and the limitations to be overcome both to make the CED more precise and to develop other dosimetric quantities, which would make it possible to better approximate the individual dose.
{"title":"Internal Dosimetry: State of the Art and Research Needed","authors":"F. Paquet","doi":"10.14407/jrpr.2021.00297","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00297","url":null,"abstract":"Internal dosimetry is a discipline which brings together a set of knowledge, tools and procedures for calculating the dose received after incorporation of radionuclides into the body. Several steps are necessary to calculate the committed effective dose (CED) for workers or members of the public. Each step uses the best available knowledge in the field of radionuclide biokinetics, energy deposition in organs and tissues, the efficiency of radiation to cause a stochastic effect, or in the contributions of individual organs and tissues to overall detriment from radiation. In all these fields, knowledge is abundant and supported by many works initiated several decades ago. That makes the CED a very robust quantity, representing exposure for reference persons in reference situation of exposure and to be used for optimization and assessment of compliance with dose limits. However, the CED suffers from certain limitations, accepted by the International Commission on Radiological Protection (ICRP) for reasons of simplification. Some of its limitations deserve to be overcome and the ICRP is continuously working on this. Beyond the efforts to make the CED an even more reliable and precise tool, there is an increasing demand for personalized dosimetry, particularly in the medical field. To respond to this demand, currently available tools in dosimetry can be adjusted. However, this would require coupling these efforts with a better assessment of the individual risk, which would then have to consider the physiology of the persons concerned but also their lifestyle and medical history. Dosimetry and risk assessment are closely linked and can only be developed in parallel. This paper presents the state of the art of internal dosimetry knowledge and the limitations to be overcome both to make the CED more precise and to develop other dosimetric quantities, which would make it possible to better approximate the individual dose.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78951701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-30DOI: 10.14407/jrpr.2021.00269
Gwang-Ho Kim, Jae-Hwan Cho
Background: The aim of the present study was to determine radioactive concentrations in fertilizers known to contain essential nutrients. Results of this study could be used as basic data to monitor the impact of chemical fertilizers on the environment and public health. Nitrogen fertilizers, calcium fertilizers, sulfur fertilizers, phosphate acid fertilizers, and potassium chloride fertilizers were used in this study.Materials and Methods: Five chemical fertilizers were pulverized, placed in polyethylene containers, and weighed. The time to measure each specimen was set to be 3,600 seconds for a scintillator-based gamma-ray spectroscopy system. Concentration of gamma radionuclide was analyzed based on obtained spectra. At the end of the measurement, the spectrum file was stored and used to calculate radioactive concentrations using a gamma-ray spectrometer software.Results and Discussion: In the nitrogen fertilizer, 3.49 ± 5.71 Bq/kg of 137Cs, 34.43 ± 7.61 Bq/kg of 134Cs, and 569.16 ± 91.15 of 40K were detected whereas 131I was not detected. In the calcium fertilizer, 5.74 ± 4.40 Bq/kg of 137Cs (the highest concentration among all fertilizers), 22.37 ± 5.39 Bq/kg of 134Cs, and 433.67 ± 64.24 Bq/kg of 40K were detected whereas 131I was not detected. In the sulfur fertilizer, 347.31 ± 55.73 Bq/kg of 40K, 19.42 ± 4.53 Bq/kg of 134Cs, 2.21 ± 3.49 of 137Cs, and 0.04 ± 0.22 Bq/Kg of 131I were detected. In the phosphoric acid fertilizer, 70,007.34 ± 844.18 Bq/kg of 40K (the highest concentration among all fertilizers) and 46.07 ± 70.40 Bq/kg of 134Cs were detected whereas neither 137Cs nor 131I was detected. In the potassium chloride fertilizer, 12,827.92 ± 1542.19 Bq/kg of 40K was and 94.76 ± 128.79 Bq/kg of 134Cs were detected whereas neither 137Cs nor 131I was detected. The present study examined inorganic fertilizers produced by a single manufacturer. There might be different results according to the country and area from which fertilizers are imported. Further studies about inorganic fertilizers in more detail are needed to create measures to reduce 40K.Conclusion: Measures are needed to reduce radiation exposure to 40K contained in fertilizers including phosphoric acid and potassium chloride fertilizers.
{"title":"Radioactive Concentrations in Chemical Fertilizers","authors":"Gwang-Ho Kim, Jae-Hwan Cho","doi":"10.14407/jrpr.2021.00269","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00269","url":null,"abstract":"Background: The aim of the present study was to determine radioactive concentrations in fertilizers known to contain essential nutrients. Results of this study could be used as basic data to monitor the impact of chemical fertilizers on the environment and public health. Nitrogen fertilizers, calcium fertilizers, sulfur fertilizers, phosphate acid fertilizers, and potassium chloride fertilizers were used in this study.Materials and Methods: Five chemical fertilizers were pulverized, placed in polyethylene containers, and weighed. The time to measure each specimen was set to be 3,600 seconds for a scintillator-based gamma-ray spectroscopy system. Concentration of gamma radionuclide was analyzed based on obtained spectra. At the end of the measurement, the spectrum file was stored and used to calculate radioactive concentrations using a gamma-ray spectrometer software.Results and Discussion: In the nitrogen fertilizer, 3.49 ± 5.71 Bq/kg of 137Cs, 34.43 ± 7.61 Bq/kg of 134Cs, and 569.16 ± 91.15 of 40K were detected whereas 131I was not detected. In the calcium fertilizer, 5.74 ± 4.40 Bq/kg of 137Cs (the highest concentration among all fertilizers), 22.37 ± 5.39 Bq/kg of 134Cs, and 433.67 ± 64.24 Bq/kg of 40K were detected whereas 131I was not detected. In the sulfur fertilizer, 347.31 ± 55.73 Bq/kg of 40K, 19.42 ± 4.53 Bq/kg of 134Cs, 2.21 ± 3.49 of 137Cs, and 0.04 ± 0.22 Bq/Kg of 131I were detected. In the phosphoric acid fertilizer, 70,007.34 ± 844.18 Bq/kg of 40K (the highest concentration among all fertilizers) and 46.07 ± 70.40 Bq/kg of 134Cs were detected whereas neither 137Cs nor 131I was detected. In the potassium chloride fertilizer, 12,827.92 ± 1542.19 Bq/kg of 40K was and 94.76 ± 128.79 Bq/kg of 134Cs were detected whereas neither 137Cs nor 131I was detected. The present study examined inorganic fertilizers produced by a single manufacturer. There might be different results according to the country and area from which fertilizers are imported. Further studies about inorganic fertilizers in more detail are needed to create measures to reduce 40K.Conclusion: Measures are needed to reduce radiation exposure to 40K contained in fertilizers including phosphoric acid and potassium chloride fertilizers.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77653728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-30DOI: 10.14407/jrpr.2021.00213
Saïdou-, S. Tokonami, M. Hosoda, A. Simo, J. Hell, O. German, Esmel Gislere Oscar Meless
Background: The current study reports measurements of activity concentrations of radon (222Rn) and thoron (220Rn) in dwellings, followed by inhalation dose assessment of the public, and then by the development of regulation and the national radon action plan (NRAP) in Cameroon.Materials and Methods: Radon, thoron, and thoron progeny measurements were carried out from 2014 to 2017 using radon-thoron discriminative detectors (commercially RADUET) in 450 dwellings and thoron progeny monitors in 350 dwellings. From 2019 to 2020, radon track detectors (commercially RADTRAK) were deployed in 1,400 dwellings. It was found that activity concentrations of radon range in 1,850 houses from 10 to 2,620 Bq/m3 with a geometric mean of 76 Bq/m3.Results and Discussion: Activity concentrations of thoron range from 20 to 700 Bq/m3 with a geometric mean of 107 Bq/m3. Thoron equilibrium factor ranges from 0.01 to 0.6, with an arithmetic mean of 0.09 that is higher than the default value of 0.02 given by UNSCEAR. On average, 49%, 9%, and 2% of all surveyed houses have radon concentrations above 100, 200, and 300 Bq/m3, respectively. The average contribution of thoron to the inhalation dose due to radon and thoron exposure is about 40%. Thus, thoron cannot be neglected in dose assessment to avoid biased results in radio-epidemiological studies. Only radon was considered in the drafted regulation and in the NRAP adopted in October 2020. Reference levels of 300 Bq/m3 and 1,000 Bq/m3 were recommended for dwellings and workplaces.Conclusion: Priority actions for the coming years include the following: radon risk mapping, promotion of a protection policy against radon in buildings, integration of the radon prevention and mitigation into the training of construction specialists, mitigation of dwellings and workplaces with high radon levels, increased public awareness of the health risks associated with radon, and development of programs on the scientific and technical aspects.
{"title":"From Radon and Thoron Measurements, Inhalation Dose Assessment to National Regulation and Radon Action Plan in Cameroon","authors":"Saïdou-, S. Tokonami, M. Hosoda, A. Simo, J. Hell, O. German, Esmel Gislere Oscar Meless","doi":"10.14407/jrpr.2021.00213","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00213","url":null,"abstract":"Background: The current study reports measurements of activity concentrations of radon (222Rn) and thoron (220Rn) in dwellings, followed by inhalation dose assessment of the public, and then by the development of regulation and the national radon action plan (NRAP) in Cameroon.Materials and Methods: Radon, thoron, and thoron progeny measurements were carried out from 2014 to 2017 using radon-thoron discriminative detectors (commercially RADUET) in 450 dwellings and thoron progeny monitors in 350 dwellings. From 2019 to 2020, radon track detectors (commercially RADTRAK) were deployed in 1,400 dwellings. It was found that activity concentrations of radon range in 1,850 houses from 10 to 2,620 Bq/m3 with a geometric mean of 76 Bq/m3.Results and Discussion: Activity concentrations of thoron range from 20 to 700 Bq/m3 with a geometric mean of 107 Bq/m3. Thoron equilibrium factor ranges from 0.01 to 0.6, with an arithmetic mean of 0.09 that is higher than the default value of 0.02 given by UNSCEAR. On average, 49%, 9%, and 2% of all surveyed houses have radon concentrations above 100, 200, and 300 Bq/m3, respectively. The average contribution of thoron to the inhalation dose due to radon and thoron exposure is about 40%. Thus, thoron cannot be neglected in dose assessment to avoid biased results in radio-epidemiological studies. Only radon was considered in the drafted regulation and in the NRAP adopted in October 2020. Reference levels of 300 Bq/m3 and 1,000 Bq/m3 were recommended for dwellings and workplaces.Conclusion: Priority actions for the coming years include the following: radon risk mapping, promotion of a protection policy against radon in buildings, integration of the radon prevention and mitigation into the training of construction specialists, mitigation of dwellings and workplaces with high radon levels, increased public awareness of the health risks associated with radon, and development of programs on the scientific and technical aspects.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90269019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-30DOI: 10.14407/jrpr.2021.00332
Jieun Lee, Hyojin Kim, Y. Kye, Dong-yeon Lee, W. Jo, C. Lee, Jung-Ki Kim, Y. Kang
Background: The accident at the Fukushima Daiichi nuclear power plant increased the level of anxiety related to the radioactive contamination of various foods sourced in Japan. Particularly, after the accident, the detection of artificial radionuclides in locally produced foods raised food safety concerns. In this study, the radioactivity concentrations and annual ingestions of 40K and 137Cs in food products commonly and frequently consumed by the general public were investigated, and the annual effective dose of each was evaluated.Materials and Methods: The 2016–2018 data from the Radiation Safety Management Report released by the Korea Nuclear Safety Technology Center was referenced for the evaluation of the amounts of 40K and 137Cs contained in food. Using the food-ingestion survey mentioned above as a reference, we selected 62 foods to include in our radioactivity concentration and dose assessment. We also developed a questionnaire and evaluated the responses from the subjects who answered the questionnaire.Results and Discussion: The radioactivity concentration of 137Cs was found to be close to or below the level of minimum detectable activity. Additionally, the annual ingestion of 62 foods was 294.77 kg/yr, the effective doses from 40K and 137Cs were 136.4 and 0.163 μSv/yr, respectively.Conclusion: Thus, the findings confirmed that the effective dose from 40K and 137Cs in food tends to be lower than the effective dose limit of 1 mSv/yr suggested by the International Commission on Radiological Protection (ICRP) Publication 60. The questionnaire developed in this study is expected to be useful for estimating the annual effective dose status of Korean adults who consume foods containing 40K and 137Cs.
{"title":"Development of Self-Questionnaire for Internal Dose Assessment by Food Ingestion","authors":"Jieun Lee, Hyojin Kim, Y. Kye, Dong-yeon Lee, W. Jo, C. Lee, Jung-Ki Kim, Y. Kang","doi":"10.14407/jrpr.2021.00332","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00332","url":null,"abstract":"Background: The accident at the Fukushima Daiichi nuclear power plant increased the level of anxiety related to the radioactive contamination of various foods sourced in Japan. Particularly, after the accident, the detection of artificial radionuclides in locally produced foods raised food safety concerns. In this study, the radioactivity concentrations and annual ingestions of 40K and 137Cs in food products commonly and frequently consumed by the general public were investigated, and the annual effective dose of each was evaluated.Materials and Methods: The 2016–2018 data from the Radiation Safety Management Report released by the Korea Nuclear Safety Technology Center was referenced for the evaluation of the amounts of 40K and 137Cs contained in food. Using the food-ingestion survey mentioned above as a reference, we selected 62 foods to include in our radioactivity concentration and dose assessment. We also developed a questionnaire and evaluated the responses from the subjects who answered the questionnaire.Results and Discussion: The radioactivity concentration of 137Cs was found to be close to or below the level of minimum detectable activity. Additionally, the annual ingestion of 62 foods was 294.77 kg/yr, the effective doses from 40K and 137Cs were 136.4 and 0.163 μSv/yr, respectively.Conclusion: Thus, the findings confirmed that the effective dose from 40K and 137Cs in food tends to be lower than the effective dose limit of 1 mSv/yr suggested by the International Commission on Radiological Protection (ICRP) Publication 60. The questionnaire developed in this study is expected to be useful for estimating the annual effective dose status of Korean adults who consume foods containing 40K and 137Cs.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82861773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-30DOI: 10.14407/jrpr.2022.00122
Seoryeong Park, M. Hammig, M. Jeong
Background: The conventional cerium-doped Gd2Al2Ga3O12 (GAGG(Ce)) scintillator-based gamma-ray imager has a bulky detector, which can lead to incorrect positioning of the gammaray source if the shielding against background radiation is not appropriately designed. In addition, portability is important in complex environments such as inside nuclear power plants, yet existing gamma-ray imager based on a tungsten mask tends to be weighty and therefore difficult to handle. Motivated by the need to develop a system that is not sensitive to background radiation and is portable, we changed the material of the scintillator and the coded aperture.Materials and Methods: The existing GAGG(Ce) was replaced with Bi4Ge3O12 (BGO), a scintillator with high gamma-ray detection efficiency but low energy resolution, and replaced the tungsten (W) used in the existing coded aperture with lead (Pb). Each BGO scintillator is pixelated with 144 elements (12 × 12), and each pixel has an area of 4 mm × 4 mm and the scintillator thickness ranges from 5 to 20 mm (5, 10, and 20 mm). A coded aperture consisting of Pb with a thickness of 20 mm was applied to the BGO scintillators of all thicknesses.Results and Discussion: Spectroscopic characterization, imaging performance, and image quality evaluation revealed the 10 mm-thick BGO scintillators enabled the portable gamma-ray imager to deliver optimal performance. Although its performance is slightly inferior to that of existing GAGG(Ce)-based gamma-ray imager, the results confirmed that the manufacturing cost and the system’s overall weight can be reduced.Conclusion: Despite the spectral characteristics, imaging system performance, and image quality is slightly lower than that of GAGG(Ce), the results show that BGO scintillators are preferable for gamma-ray imaging systems in terms of cost and ease of deployment, and the proposed design is well worth applying to systems intended for use in areas that do not require high precision.
{"title":"Comparison of Characteristics of Gamma-Ray Imager Based on Coded Aperture by Varying the Thickness of the BGO Scintillator","authors":"Seoryeong Park, M. Hammig, M. Jeong","doi":"10.14407/jrpr.2022.00122","DOIUrl":"https://doi.org/10.14407/jrpr.2022.00122","url":null,"abstract":"Background: The conventional cerium-doped Gd2Al2Ga3O12 (GAGG(Ce)) scintillator-based gamma-ray imager has a bulky detector, which can lead to incorrect positioning of the gammaray source if the shielding against background radiation is not appropriately designed. In addition, portability is important in complex environments such as inside nuclear power plants, yet existing gamma-ray imager based on a tungsten mask tends to be weighty and therefore difficult to handle. Motivated by the need to develop a system that is not sensitive to background radiation and is portable, we changed the material of the scintillator and the coded aperture.Materials and Methods: The existing GAGG(Ce) was replaced with Bi4Ge3O12 (BGO), a scintillator with high gamma-ray detection efficiency but low energy resolution, and replaced the tungsten (W) used in the existing coded aperture with lead (Pb). Each BGO scintillator is pixelated with 144 elements (12 × 12), and each pixel has an area of 4 mm × 4 mm and the scintillator thickness ranges from 5 to 20 mm (5, 10, and 20 mm). A coded aperture consisting of Pb with a thickness of 20 mm was applied to the BGO scintillators of all thicknesses.Results and Discussion: Spectroscopic characterization, imaging performance, and image quality evaluation revealed the 10 mm-thick BGO scintillators enabled the portable gamma-ray imager to deliver optimal performance. Although its performance is slightly inferior to that of existing GAGG(Ce)-based gamma-ray imager, the results confirmed that the manufacturing cost and the system’s overall weight can be reduced.Conclusion: Despite the spectral characteristics, imaging system performance, and image quality is slightly lower than that of GAGG(Ce), the results show that BGO scintillators are preferable for gamma-ray imaging systems in terms of cost and ease of deployment, and the proposed design is well worth applying to systems intended for use in areas that do not require high precision.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86135512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-06DOI: 10.14407/jrpr.2021.00339
M. Chun, Hyeong-min Jin, Sung Young Lee, O. Kwon, C. Choi, Jong Min Park, Jung-in Kim
Background: This study investigated the characteristics of optically stimulated luminescence dosimeters (OSLDs) with fully filled deep electron/hole traps in the kV energy ranges. Materials and Methods: The experimental group consisted of InLight nanoDots, whose deep electron/hole traps were fully filled with 5 kGy pre-irradiation (OSLD exp ), whereas the non-pre-irradiated OSLDs were arranged as a control group (OSLD cont ). Absorbed doses for 75, 80, 85, 90, 95, 100, and 105 kVp with 200 mA and 40 ms were measured and defined as the unit doses for each energy value. A bleaching device equipped with a 520-nm long-pass filter was used, and the strong beam mode was used to read out signal counts. The characteristics were investigated in terms of fading, dose sensitivities according to the accumulated doses, and dose linearity. Results and Discussion: In OSLD exp , the average normalized counts (sensitivities) were 12.7%, 14.0%, 15.0%, 10.2%, 18.0%, 17.9%, and 17.3% higher compared with those in OSLD cont for 75, 80, 90, 95, 100, and 105 kVp, respectively. The dose accumulation and bleaching time did not significantly alter the sensitivity, regardless of the filling of deep traps for all radiation qualities. Both OSLD exp and OSLD cont exhibited good linearity, by showing coefficients determination (R 2 ) > 0.99. The OSL sensitivities can be increased by filling of deep electron/hole traps in the energy ranges between 75 and 105 kVp, and they exhibited no significant variations according to the bleaching time.
{"title":"Effects of Fully Filling Deep Electron/Hole Traps in Optically Stimulated Luminescence Dosimeters in the Kilovoltage Energy Range","authors":"M. Chun, Hyeong-min Jin, Sung Young Lee, O. Kwon, C. Choi, Jong Min Park, Jung-in Kim","doi":"10.14407/jrpr.2021.00339","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00339","url":null,"abstract":"Background: This study investigated the characteristics of optically stimulated luminescence dosimeters (OSLDs) with fully filled deep electron/hole traps in the kV energy ranges. Materials and Methods: The experimental group consisted of InLight nanoDots, whose deep electron/hole traps were fully filled with 5 kGy pre-irradiation (OSLD exp ), whereas the non-pre-irradiated OSLDs were arranged as a control group (OSLD cont ). Absorbed doses for 75, 80, 85, 90, 95, 100, and 105 kVp with 200 mA and 40 ms were measured and defined as the unit doses for each energy value. A bleaching device equipped with a 520-nm long-pass filter was used, and the strong beam mode was used to read out signal counts. The characteristics were investigated in terms of fading, dose sensitivities according to the accumulated doses, and dose linearity. Results and Discussion: In OSLD exp , the average normalized counts (sensitivities) were 12.7%, 14.0%, 15.0%, 10.2%, 18.0%, 17.9%, and 17.3% higher compared with those in OSLD cont for 75, 80, 90, 95, 100, and 105 kVp, respectively. The dose accumulation and bleaching time did not significantly alter the sensitivity, regardless of the filling of deep traps for all radiation qualities. Both OSLD exp and OSLD cont exhibited good linearity, by showing coefficients determination (R 2 ) > 0.99. The OSL sensitivities can be increased by filling of deep electron/hole traps in the energy ranges between 75 and 105 kVp, and they exhibited no significant variations according to the bleaching time.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88030704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.14407/jrpr.2021.00409
I. Kawaguchi, H. Kido, Yoshito Watanabe
Background: After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, biological alterations in the natural biota, including morphological changes of fir trees in forests surrounding the power plant, have been reported. Focusing on the terminal buds involved in the morphological formation of fir trees, this study developed a method for estimating the absorbed radiation dose rate using radionuclide distribution measurements from tree organs.Materials and Methods: A phantom composed of three-dimensional (3D) tree organs was constructed for the three upper whorls of the fir tree. A terminal bud was evaluated using Monte Carlo simulations for the absorbed dose rate of radionuclides in the tree organs of the whorls. Evaluation of the absorbed dose targeted 131I, 134Cs, and 137Cs, the main radionuclides subsequent to the FDNPP accident. The dose contribution from each tree organ was calculated separately using dose coefficients (DC), which express the ratio between the average activity concentration of a radionuclide in each tree organ and the dose rate at the terminal bud.Results and Discussion: The dose estimation indicated that the radionuclides in the terminal bud and bud scale contributed to the absorbed dose rate mainly by beta rays, whereas those in 1-year-old trunk/branches and leaves were contributed by gamma rays. However, the dose contribution from radionuclides in the lower trunk/branches and leaves was negligible.Conclusion: The fir tree model provides organ-specific DC values, which are satisfactory for the practical calculation of the absorbed dose rate of radiation from inside the tree. These calculations are based on the measurement of radionuclide concentrations in tree organs on the 1-year-old leader shoots of fir trees. With the addition of direct gamma ray measurements of the absorbed dose rate from the tree environment, the total absorbed dose rate was estimated in the terminal bud of fir trees in contaminated forests.
{"title":"Dose Estimation Model for Terminal Buds in Radioactively Contaminated Fir Trees","authors":"I. Kawaguchi, H. Kido, Yoshito Watanabe","doi":"10.14407/jrpr.2021.00409","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00409","url":null,"abstract":"Background: After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, biological alterations in the natural biota, including morphological changes of fir trees in forests surrounding the power plant, have been reported. Focusing on the terminal buds involved in the morphological formation of fir trees, this study developed a method for estimating the absorbed radiation dose rate using radionuclide distribution measurements from tree organs.Materials and Methods: A phantom composed of three-dimensional (3D) tree organs was constructed for the three upper whorls of the fir tree. A terminal bud was evaluated using Monte Carlo simulations for the absorbed dose rate of radionuclides in the tree organs of the whorls. Evaluation of the absorbed dose targeted 131I, 134Cs, and 137Cs, the main radionuclides subsequent to the FDNPP accident. The dose contribution from each tree organ was calculated separately using dose coefficients (DC), which express the ratio between the average activity concentration of a radionuclide in each tree organ and the dose rate at the terminal bud.Results and Discussion: The dose estimation indicated that the radionuclides in the terminal bud and bud scale contributed to the absorbed dose rate mainly by beta rays, whereas those in 1-year-old trunk/branches and leaves were contributed by gamma rays. However, the dose contribution from radionuclides in the lower trunk/branches and leaves was negligible.Conclusion: The fir tree model provides organ-specific DC values, which are satisfactory for the practical calculation of the absorbed dose rate of radiation from inside the tree. These calculations are based on the measurement of radionuclide concentrations in tree organs on the 1-year-old leader shoots of fir trees. With the addition of direct gamma ray measurements of the absorbed dose rate from the tree environment, the total absorbed dose rate was estimated in the terminal bud of fir trees in contaminated forests.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76036866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.14407/jrpr.2021.00402
Zhao Peng, Ning Gao, Bingzhi Wu, Zhi Chen, X. G. Xu
The exciting advancement related to the “modeling of digital human” in terms of a computational phantom for radiation dose calculations has to do with the latest hype related to deep learning. The advent of deep learning or artificial intelligence (AI) technology involving convolutional neural networks has brought an unprecedented level of innovation to the field of organ segmentation. In addition, graphics processing units (GPUs) are utilized as boosters for both real-time Monte Carlo simulations and AI-based image segmentation applications. These advancements provide the feasibility of creating three-dimensional (3D) geometric details of the human anatomy from tomographic imaging and performing Monte Carlo radiation transport simulations using increasingly fast and inexpensive computers. This review first introduces the history of three types of computational human phantoms: stylized medical internal radiation dosimetry (MIRD) phantoms, voxelized tomographic phantoms, and boundary representation (BREP) deformable phantoms. Then, the development of a person-specific phantom is demonstrated by introducing AI-based organ autosegmentation technology. Next, a new development in GPU-based Monte Carlo radiation dose calculations is introduced. Examples of applying computational phantoms and a new Monte Carlo code named ARCHER (Accelerated Radiation- transport Computations in Heterogeneous EnviRonments) to problems in radiation protection, imaging, and radiotherapy are presented from research projects performed by students at the Rensselaer Polytechnic Institute (RPI) and University of Science and Technology of China (USTC). Finally, this review discusses challenges and future research opportunities. We found that, owing to the latest computer hardware and AI technology, computational human body models are moving closer to real human anatomy structures for accurate radiation dose calculations.
{"title":"A Review of Computational Phantoms for Quality Assurance in Radiology and Radiotherapy in the Deep-Learning Era","authors":"Zhao Peng, Ning Gao, Bingzhi Wu, Zhi Chen, X. G. Xu","doi":"10.14407/jrpr.2021.00402","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00402","url":null,"abstract":"The exciting advancement related to the “modeling of digital human” in terms of a computational phantom for radiation dose calculations has to do with the latest hype related to deep learning. The advent of deep learning or artificial intelligence (AI) technology involving convolutional neural networks has brought an unprecedented level of innovation to the field of organ segmentation. In addition, graphics processing units (GPUs) are utilized as boosters for both real-time Monte Carlo simulations and AI-based image segmentation applications. These advancements provide the feasibility of creating three-dimensional (3D) geometric details of the human anatomy from tomographic imaging and performing Monte Carlo radiation transport simulations using increasingly fast and inexpensive computers. This review first introduces the history of three types of computational human phantoms: stylized medical internal radiation dosimetry (MIRD) phantoms, voxelized tomographic phantoms, and boundary representation (BREP) deformable phantoms. Then, the development of a person-specific phantom is demonstrated by introducing AI-based organ autosegmentation technology. Next, a new development in GPU-based Monte Carlo radiation dose calculations is introduced. Examples of applying computational phantoms and a new Monte Carlo code named ARCHER (Accelerated Radiation- transport Computations in Heterogeneous EnviRonments) to problems in radiation protection, imaging, and radiotherapy are presented from research projects performed by students at the Rensselaer Polytechnic Institute (RPI) and University of Science and Technology of China (USTC). Finally, this review discusses challenges and future research opportunities. We found that, owing to the latest computer hardware and AI technology, computational human body models are moving closer to real human anatomy structures for accurate radiation dose calculations.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78187476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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