국내 석탄 연소 발전소 내 작업종사자의 입자 흡입에 따른 내부피폭 방사선량 평가

이도연,진용호,곽민우,김지우,김광표 (사)한국방사선산업학회 2023 방사선산업학회지 Vol.17 No.2

Coal-fired power plants handle large quantities of coal, one of the most prominent NORM,and the coal ash produced after the coal is burned can be tens of times more radioactive than thecoal. Workers in these industries may be exposed to internal exposure by inhalation of particles whilehandling NORM. This study evaluated the size, concentration, particle shape and density, and radioactivityconcentrations of airborne suspended particles in the main processes of a coal-fired power plant. Finally,the internal radiation dose to workers from particle inhalation was evaluated. For this purpose, airborneparticles were collected by size using a multi-stage particle collector to determine the size, shape, andconcentration of particles. Samples of coal and coal ash were collected to measure the density andradioactivity of particles. The dose conversion factor and annual radionuclide inhalation amount werederived based on the characteristics of the particles. Finally, the internal radiation dose due to particleinhalation was evaluated. Overall, the internal radiation dose to workers in the main processes of coalfiredpower plants A and B ranged from 1.47×10-5~1.12×10-3 mSv y-1. Due to the effect of dust generatedduring loading operations, the internal radiation dose of fly ash loading processes in both coal-fired powerplants A and B was higher than that of other processes. In the case of workers in the coal storage yard atpower plants A and B, the characteristic values such as particle size, airborne concentration, and workingtime were the same, but due to the difference in radioactivity concentration and density depending onthe origin of the coal, the internal radiation dose by origin was different, and the highest was found wheninhaling coal imported from Australia among the five origins. In addition, the main nuclide contributingthe most to the internal radiation dose from the main processes in the coal-fired power plants wasthorium due to differences in dose conversion factors. However, considering the external radiation doseof workers in coal-fired power plants presented in overseas research cases, the annual effective dose ofworkers in the main processes of power plants A and B does not exceed 1 mSv y-1, which is the dose limitfor the general public notified by the Nuclear Safety Act. The results of this study can be utilized to identifythe internal exposure levels of workers in domestic coal-fired power plants and will contribute to theestablishment of a data base for a differential safety management system for NORM-handling industriesin the future.

The End of Coal in the United States?

Melissa Powers 강원대학교 비교법학연구소 2018 환경법과 정책 Vol.21 No.-

미국 전력 시스템이 구축된 이래로 1800년대 후반부터 20세기 초반까지 석탄은 미국에 상당한 양의 에너지를 공급해 왔다. 의회가 1969년 NEPA 법을 통과한 뒤 에너지 프로젝트는 환경영향평가를 받게 되었다. 미국은 1970년의 청정대기법(CAA)과 1972년의 청정수질법(CWA)을 입법하며 오염주범인 석탄 및 석유 발전소들을 규제하기 시작하였다. 원자력과 재생가능에너지(규모는 작지만)는 화석연료를 대체할 준비를 시작하였다. 이론적으로 미국의 환경법의 발전은, 특히 과학자와 규제기관이 인간의 건강과 환경에 미치는 석탄 오염의 유해한 영향을 보다 명확하게 이해하기 시작했기 때문에 석탄 채굴 및 사용의 확장을 제한했어야 했다. 그러나 환경규제들은 기본적으로 미국의 에너지 믹스에 영향을 주기에는 너무나도 약했다. 청정대기법이 약 30년간 지속된 1990년대 후반까지 석탄화력발전은 사실 깨끗하지도, 보다 효율적이지도 않았다. 미국의 석탄 붐(coal rush)은 2001년 에너지 회사와 전력회사가 수십 개를 건설하기 시작하면서 200개가 넘는 새로운 석탄발전소를 건설하기 시작하며 나타났다. 이러한 상황의 몇 가지 요인은, 에너지 소비 예측이 전기소비량이 크게 증가할 것이라는 점과 부시 행정부의 석탄발전소에 대한 환경 규제 최소화 결정 등이었다. 그러나 석탄화력발전소에 대한 환경단체(시에라클럽)의 반대운동은 오바마 행정부에서 석탄화력발전소에 대한 오염물질 배출규제를 목적으로 하는 규칙을 채택하기에 이르렀고, 에너지 시장 역시 천연가스와 재생에너지 가격의 하락으로 석탄에 대해 덜 우호적이게 되었다. 또한 규제당국도 전력회사가 석탄화력발전소에 투자하는 것을 허용함으로 인해 전기소비자의 리스크가 점차 커질 수 있다는 점을 인식하기 시작했다. 트럼프 행정부가 취임 한 이래, 환경규제의 역행(roll back), 석탄개발 및 석탄수출을 촉진하는 새로운 명령, 그리고 석탄 및 원자력이 경쟁력을 잃은 에너지 시장을 두 번이나 교란하는 등 석탄 사업을 부활시키기 위해 노력해 왔다. 그러나 오히려 트럼프 행정부 첫 해 동안 재생가능한 자원에 의해 공급된 전력의 비율은 계속 증가했으며, 단기 에너지 예측에 따라도 재생 에너지가 계속 증가할 것으로 예상된다. 석탄의 시대가 끝이 오고 이러한 정황을 긍정적으로 바라봄과 동시에 미국의 탈석탄 전환의 이야기는 여러 가지 면에서 주의를 요구한다. 첫째, 수십 년에 걸친 부적절한 규제로 기후, 환경 및 인간 건강에 치명적인 영향을 미쳤다는 점, 둘째, 재생에너지가 정부의 개입이 아니었다면 훨씬 더 일찍 석탄 및 천연가스와 가격경쟁력을 가졌을 것이라는 점, 그리고 마지막으로 재생가능 및 저장 기술은 신뢰할만한 수준이며, 기후변화는 화석연료에 대한 새로운 투자를 위험하게 만들 정도로 충분히 위험하다는 점이다. 앞으로 정부는 석탄에서 탄소제로 에너지원으로 전환하는 과정에서 미국의 시행착오를 건너뛸 수 있는 에너지 계획을 수립해야 한다. Since the establishment of the U.S. electricity system in the late 1800s through the first half of the 20th century, coal supplied a substantial amount of U.S. energy. Congress had passed the National Environmental Policy Act (NEPA) in 1969, which subjected many new energy projects to environmental review. The passage of the Clean Air Act in 1970 and the Clean Water Act in 1972 seemed destined to restrict pollution from many of the country’s dirty coal-and oil-fired power plants. Nuclear power, and to a much lesser extent, renewable energy, were waiting in the wings, ready to displace fossil fuels. In theory, the development of U.S. environmental laws should have limited the expansion of coal mining and use, particularly as scientists and regulatory agencies began to develop a clearer understanding of the harmful effects of coal pollution on human health and the environment. Environmental regulations, however, were generally too weak to affect the energy mix of the United States. By the late-1990s, despite nearly 30 years of Clean Air Act regulation, coal plants had not become substantially cleaner or more efficient. The U.S. coal rush appears to have gotten its start in 2001, when energy companies and electric utilities initiated efforts to build dozens, and then more than 200, new coal-fired power plants. Some of the factors in this situation were that energy consumption forecasts would significantly increase electricity consumption and the Bush administrations decision to minimize environmental regulations for coal-fired power plants. However, opposition movements by environmental groups(Sierra Club) to coal-fired power plants have led to the Obama administration adopting rules aimed at regulating pollutant emissions to coal-fired power plants. The energy market also showed a less favorable situation for coal due to dropping prices of natural gas and renewable energy. And also, state regulators began to recognize the risks to ratepayers of allowing utilities to invest in new coal-fired power plants. Since taking office, the Trump Administration has tried to revive the coal industry, through regulatory rollbacks, new orders that promote coal exploration on federal lands and coal exports to foreign countries, and through two assaults on competitive wholesale energy markets in which coal and nuclear power plants are no longer competitive. Nevertheless, the percentage of electricity supplied by renewable resources continued to climb during the first year of the Trump Administration, and short-term energy forecasts suggested that renewables would continue to grow. While it appears that the end of coal is finally coming, and while we should look at coal’s end as a positive development, the U.S. transition away from coal should serve as a cautionary tale in many ways. First, the decades of inadequate regulation have had devastating impacts on the climate, the environment, and human health. Second, although renewable energy has finally become cost-competitive with coal and natural gas, it is likely this would have happened much earlier, if not for the intervention of the government. Third, renewable and storage technologies have advanced enough to be reliable, and climate change has advanced enough to make any new investments in fossil fuels risky. Governments should therefore develop energy plans that will leapfrog over coal to zero-carbon sources.

국내 석탄연소 발전소에서 취급하는 천연방사성물질의 방사능 농도 분석

김용건,김시영,지승우,박일,김민준,김광표 (사)한국방사선산업학회 2016 방사선산업학회지 Vol.10 No.4

Coals and coal ashes, raw materials and by-products, in coal-fired power plants contain naturally occurring radioactive materials (NORM). They may give rise to internal exposure to workers due to inhalation of airborne particulates containing radioactive materials. It is necessary to characterize radioactivity concentrations of the materials for assessment of radiation dose to the workers. The objective of the present study was to analyze radioactivity concentrations of coals and by-products at four coal-fired plants in Korea. High purity germanium detector was employed for analysis of uranium series, thorium series, and potassium 40 in the materials. Radioactivity concentrations of 226Ra, 228Ra, and 40K were 2~53 Bq kg-1, 3~64 Bq kg-1, and 14 ~ 431 Bq kg-1 respectively in coal samples. For coal ashes, the radioactivity concentrations were 77~ 133 Bq kg-1, 77~105 Bq kg-1, and 252~372 Bq kg-1 in fly ash samples and 54~91 Bq kg-1, 46~83 Bq kg-1, and 205~462 Bq kg-1 in bottom ash samples. For flue gas desulfurization (FGD) gypsum, the radioactivity concentrations were 3~5 Bq kg-1, 2~3 Bq kg-1, and 22~47 Bq kg-1. Radioactivity was enhanced in coal ash compared with coal due to combustion of organic matters in the coal. Radioactivity enhancement factors for 226Ra, 228Ra, and 40K were 2.1~11.3, 2.0~13.1, and 1.4~7.4 for fly ash and 2.0~9.2, 2.0~10.0, 1.9~7.7 for bottom ash. The database established in this study can be used as basic data for internal dose assessment of workers at coal-fired power plants. In addition, the findings can be used as a basic data for development of safety standard and guide of Natural Radiation Safety Management Act.

석탄화력발전소에서 산업재해 통계분석을 통한 안전관리 개선방안 연구

윤여송 ( Yeo-song Yoon ),박재영 ( Jae-young Park ) 대한설비관리학회 2020 대한설비관리학회지 Vol.25 No.1

Domestic Coal-Fired Power Plant Industry according to industrial accidents by industry from 2008 to 2017, the number of workers killed every year is about 6 and the number of injured workers is about 95. The increase in industrial accidents in the coal-fired power plant industry is not leading to an appropriate statistical analysis of industrial accidents occurring in the coal-fired power plant industry. Accordingly, in this study, industrial accidents of five domestic power generation coal-fired power plants were analyzed in various ways from 2008 to 2017, and high-risk accident types and work improvement plans were identified. Based on this, high-risk accident types were identified and suggested improvement measures. For the basic data of the preceding research, the public report from the special investigation committee during the coal-fired power plant in 2019 and the data surveyed from the safety diagnosis joint service of the five coal-fired power plants in 2019 were cited. The statistical analysis results from this study quantified the actual injuries, deaths, injuries and mortality rates of 10 years for each power plant headquarters and partner companies of the 5th coal-fired power plant. Using the statistical analysis method, the severity of industrial accidents was identified by identifying the increase and decrease according to the period, the comparison with the same industry, the correlation of social phenomena, the correlations between the injured and the deaths of the five development companies. As a result of the improvement measures for high risk type of disaster, 4M (man, machine, media, management) method was used to analyze the causes of the disaster, and as a result of the analysis, it was found that the equipment factor and the work factor occupy a large proportion of the causes of the fall. Therefore, improvement measures for falling accident prevention were presented as common matters, and improvement measures that could cover the causes of fall in terms of equipment and work were presented. It is expected to be used as an improvement in statistical analysis of industrial accidents and safety education data for power generation industry.

Specification of Chemical Properties of Feed Coal and Bottom Ash Collected at a Coal-fired Power Plant

Ma, Chang-Jin,Kim, Jong-Ho,Kim, Ki-Hyun,Tohno, Susumu,Kasahara, Mikio Korean Society for Atmospheric Environment 2010 Asian Journal of Atmospheric Environment (AJAE) Vol.4 No.2

In order to offer a better understanding of air pollution of China as well as East Asia we attempted to characterize the chemical properties of the raw coal materials mined in China and their combusted bottom ashes generated from coal fired power plant. To this end, we measured the chemical characteristics of individual bottom ashes and feed coal fragments collected at a coal fired power generator which was operated with the raw coal dug at a coal mine in China. The chemical properties of these two sample types were determined by a synchrotron radiation X-ray fluorescence (SR-XRF) microprobe method. Through an application of such technique, it was possible to draw the 2D elemental maps in and/or on raw coal fragments and fired bottom ashes. The pulverized fine pieces of feed coal mainly consisted of mineral components such as Fe, Ca, Ti, Ca, and Si, while Fe was detected as overwhelming majority. The elemental mass of combusted bottom ash shows strong enrichment of many elements that exist naturally in coal. There were significant variations in chemical properties of ash-to-ash and fragment-to-fragment. Although we were not able to clearly distinguish As and Pb peaks because of the folding in their X-ray energies, these two elements can be used as tracers of coal fire origin.

노후 석탄화력발전소 가동중단에 따른 발전소 주변지역의 초미세먼지 농도 감소효과 분석

이동규 ( Donggyu Yi ),성재훈 ( Jae-hoon Sung ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2018 자원·환경경제연구 Vol.27 No.2

정부는 준공된 지 30년 이상 경과한 8기의 노후 석탄화력발전소를 2017년 6월 한 달간 가동중단하였다. 이번 정부의 조치는 일종의 정책실험으로 자연실험에 가까운 특성을 가지고 있다. 본고는 이러한 정책실험의 특성을 이용하여 가동중단 조치에 따른 초미세먼지 농도변화의 인과적 효과를 분석하였다. 이를 위해 본 연구에서는 정책대상 발전기 중 2기가 위치한 영동화력발전소 인근 지점을 실험군으로, 그곳에서 약 40km 거리를 가진 삼척 지점을 대조군으로하여 이중차분법을 실행하였다. 해당 대조군은 발전소 지역과 지리적, 지형적 특성은 유사하나 해당 발전소에서 배출된 초미세먼지로부터의 직접적인 영향은 크지 않다는 특징을 가지고 있다. 분석 결과, 이번 가동중단 조치로 영동석탄화력발전소 주변지역은 3.7~4.4μg/㎥의 초미세먼지 농도 감소효과가 발생한 것으로 분석되었다. Korean government temporarily shut down the coal-fired power plants built before 30 years and more from 6/1/2017 to 6/31/2017. This treatment provides a credible natural experiment regarding the regional PM_2.5 concentration and coal-fired generators. Based on this feature of the treatment, this study analyzed the causality between the old coal-fired power plants and regional PM_2.5 concentration. To be specific, we categorized two pollution monitoring stations nearby coal-fired power plants in Yeongdong into a treatment station and a control station based on the distance from the power plants. The control station is similar to the treatment station geographically and topographically, but its PM_2.5 concentration would not be directly affected by coal-fired power plants in Yeongdong. A difference-in-difference method was applied to identify the effects of the old coal-fire power plants on regional PM_2.5 concentration. The results show that the temporary shutdown would decrease PM_2.5 concentration nearby coal-fired power plants in Yeongdong by 3.7~4.4μg/㎥.

Comparison of PMtotal, PM10, PM2.5, NOx, and SO2 Emission Factors from Coal-fired Power Plants per Load Change

유정훈,송지한,DoYoung Lee,MyeongSang Yu,JongHan Jung,Sung Nam Chun,GaYoung Lee,김종호 한국대기환경학회 2021 Asian Journal of Atmospheric Environment (AJAE) Vol.15 No.3

For two bituminous coal-fired power plants with 500 MW and pulverized coal combustion type, the concentration of PMtotal, >PM10, PM2.5-10, PM2.5, NOx, and SO2 was measured, and their emission factors were calculated through field measurement. The measurement points started from the boiler downstream and continued to the air pollution control devices (APCDs) that are installed in series, namely, the selected catalytic reduction system (SCR), air preheater (APH), electrostatic precipitator (ESP) and wet flue gas desulfurization system (WFGD). The measurement was performed at one point for more than three times by using the Korean standard method for air pollutants. However, all measurement points, except for the stacks, were not representative of the standard test method. In addition, the PM concentration was too high to reduce the collection time due to isokinetic sampling. There is a limitation of how representative the measurement results can be. During the field measurement period, the power production rate of the two coal-fired power plants was 91.6% and 79.2% in the P-1 and P-2, respectively. Moreover, in the P-2, with a low power production rate, the concentration of PMtotal, PM10, PM2.5, and NOx was found to be low, and the emission factor calculated by dividing the measured concentration value by the fuel usage was also estimated to be low. Such results are due to the coal combustion chamber and various types of APCD being operated at a lower-load condition than the design capacity. In turn, the number of pollutants generated was less, and the removal efficiency of the pollutant became high. However, it was found that the concentration of SO2 generated and the emission factor are more significantly affected by the sulfur content of the coal than the load factor change. To this end, reducing the operation load of the coal-fired power plant improves the combustion efficiency and APCDs performance and decreases the emission factor, resulting in more reduction of the air pollutants than that based on the simple calculation.

석탄화력발전소 작업자의 소음과 온열 스트레스에 대한 노출 평가

권지운,장광명,김성호,김세동,장미연,노지원,박승현 한국산업보건학회 2023 한국산업보건학회지 Vol.33 No.4

Objectives: This study evaluated occupational exposures to noise and heat stress during routine non-outage works in three coal-fired power plants in the Republic of Korea. Methods: The data were collected during the summer of 2020. Full shift noise exposure of 52 workers were measured using noise dosimeters. Heat stress of 16 worksites were measured for 70 minutes using wet-bulb globe temperature monitors. Results: The noise dosimetry results revealed time-weighted averages that ranged from 47.5 to 88.9 dBA. 2 out of 52 noise measurements exceeded 85 dBA. Based on the arithmetic mean, the coal service group showed the highest level at 80.2 dBA by job tasks. Noise exposures exceeding 85 dBA were measured in the coal service and plant operator group. Heat stress index measurements ranged from 20.3℃ to 37.2℃. 1 out of 9 indices measured in coal facilities and 4 out of 7 indices measured in boiler house exceeded 1 hour TWA during moderate work. Heat stress indices measured from boiler houses were significantly higher than those measured from coal equipment. Conclusions: The results show that overexposure to noise and heat stress may be encountered during routine non-outage work activities in coal-fired power plants. Appropriate actions should be taken to reduce future health outcome from occupational exposure to noise and heat stress in the industry.

Research on risk management in the coal-fired power generation enterprise

Dai Qinghui,Li Sha 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

The paper analyzes the risks which may emerge in the generate electricity enterprise in the process of reforming, such as the system policy risk, coal supply risk, production operation risk, environmental protection risk, administrative supervision risk, electric power price risk,market power risk and credit risk, etc. The fuzzy comprehensive evaluation model of the coal-fired power generation enterprise is set up in this paper. Then, the paper puts forward certain of risk-evading measure, in combination with the characteristics of luck camp of the coal-fired power generation enterprise.

석탄 등급에 따른 석탄 화력-초임계 CO₂ Brayton 발전 사이클의 성능 비교

박성호(Sung-Ho PARK),임동렬(Dong-Ryul RHIM),김수현(Su-Hyun KIM),염충섭(Choongsub YEOM) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

Researches and efforts to improve the efficiency of coal-fired power plants have been in progress consistently. Based on the conventional steam Rankine cycle applied to the coal-fired power plants, developments for more efficient power cycles such as supercritical steam (SC) and ultra-supercritical steam (USC) cycles have been actively performed. Among the various technologies to improve the efficiency of coal-fired power plants, the supercritical CO₂ Brayton cycle has been regarded as a promising candidate for the conventional steam Rankine cycle. In this research, process design and modeling of coal-fired power plants with both circulating fluidized bed combustion (CFBC) boiler and supercritical CO₂ Brayton cycle were conducted under ASPEN Plus environments. In order to quantitatively compare the results derived from the low rank coal (CASE 1) and high rank coal (CASE 2), total electric power consumptions and gross powers were investigated closely, and the system net efficiency was also calculated with total auxiliaries as a parasitic load. The net efficiency of the CASE 1 using a high rank coal is 4.84% higher than for the CASE 2 with a low rank coal.