Revisit of LLD Requirements for Airborne Discharges From PWRs in Line With Effluent Concentration Limit

Soyun Kim,Jae Hak Cheong 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1

Radioactive effluent discharged from the nuclear power plant (NPP) during normal operation is controlled by the discharge limit in terms of radioactivity concentration (Bq·m?3) and dose constraints in Korea. To ensure compliance with discharge limits of effluents, the licensee operates radioactive effluent monitoring systems in each discharge point to detect radioactivity and control discharge. The predetermined regulatory requirements of analytical sensitivities for sampling devices in the monitoring system are established in various countries to guarantee the performance of the monitoring systems. In Korea, Lower Limits of Detection (LLD) are selected as the regulatory requirements and adopted from the United States Nuclear Regulatory Commission (USNRC) NUREG-1301. The International Atomic Energy Agency stated that the detection limits have to be low enough (e.g., less than 1% of discharge limits) to safely demonstrate compliance with the discharge limits. However, no technical background of LLD has been explained regarding the compliance with discharge limits in Korea. Thus, it is necessary to analyze the compatibility of discharge limits and detection limits. The USNRC Regulatory Guide 1.21 has stated the risk-informed approach for effluent control by identifying the principal radionuclides whose radiological impact is more than 1% of discharge limits. In 2017, Cheong proposed the methodology and derived risk-based detection limits for liquid effluents from Korean NPPs. In 2019, Choi derived risk-based detection limits for liquid and gaseous effluents based on APR 1400 Design Control Document (DCD). The methodology of those studies can derive the detection limit for each principal radionuclide that is comparable to 1% to 10% of discharge limits. However, the previous study based on APR 1400 DCD was for the discharge limits of the US and didn’t consider the multiple discharge points in the reactor. Therefore, this study preliminarily derived the risk-based detection limits consistent with Korean Effluent Concentration Limits for gaseous effluents reflecting the characteristics of each discharge point. Also, this study confirmed the validity of risk-based detection limits and current LLD. This study is expected to be basic research for detection limits of Korean NPPs in line with international safety standards.

하수처리수 방류 하천의 물환경과 저서성 대형무척추동물 군집 생태 연구

손정원 ( Jung-won Son ),곽진숙 ( Jin-suk Kwag ),조갑제 ( Gab-je Cho ),류동춘 ( Dong-choon Ryou ) 한국물환경학회(구 한국수질보전학회) 2021 한국물환경학회지 Vol.37 No.3

Water quality, benthic macroinvertebrate communities, and other factors were investigated to explore the effects of the effluent discharge from a sewage treatment plant into Jwagwang stream in Busan in 2019. During the study period, the flow rate of this stream was in the range of 10,400 ㎥/day to 52,200 ㎥/day except for the discharge of about 24,000 ㎥/day of the effluent. After discharge, the flow velocity increased by about 65% and the water depth increased by about 40%. At sites downstream of the discharge point, BOD, COD, TOC, T-N, T-P, and other water quality values were worse than those of the upstream sites. The periphytic algal chlorophyll-a concentrations in the natural substrata were higher than those of the upstream sites, especially in May and August. However, at sites downstream of the discharge point, the individual numbers of Annelida were decreased and individual numbers of the insecta of arthropoda were increased. Also, species numbers and the diversity and dominance indexes were improved in the sites downstream of the discharge point. The functional feeding groups (FFGs) of collector-filterers were increased and the habitat orientation groups (HOGs) of sprawlers, burrowers, and clingers were especially increased at the sites with additional reclaimed wastewater effluent flow. Regardless of the effluent discharge, BMI, an indicator of ecological stream health using benthic macroinvertebrate species, did not show large gaps between the study points. Although the water quality of the sites downstream of the discharge point was much worse than those upstream, their ecosystem soundness was better than those of the upstream sites from an ecological perspective.

Near-Field Mixing Characteristics of Submerged Effluent Discharges into Masan Bay

Kang, See-Whan,You, Seung-Hyup,Na, Jung-Yul Korea Institute of Ocean Science Technology 2000 Ocean and Polar Research Vol.22 No.1

Hydrodynamic mixing characteristics of submerged effluent discharges into Masan Bay were investigated by both field observations and numerical model simulations. CORMIX model, a length-scale mixing model, was adopted to obtain the near-field dilution and wastefield characteristics of the effluent discharges into Masan Bay. Model predictions of the near-field dilution rates were in a good agreement with field observations in summer and winter seasons. Seasonal variations in the dilution rates showed that the highest dilution rate was obtained in winter while the lowest dilution rate was in summer. As the effluent discharges are increased with the treatment capacity expansion to be completed by 2011, the dilution rates are expected to be much reduced and the near-field stability of the wastefields will become unstable due to the increased effluent discharges.

멀티 플라즈마 공정을 이용한 하수 미생물의 불활성화

김동석 ( Dong Seog Kim ),박영식 ( Young Seek Park ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.5

For the field application of dielectric barrier discharge plasma reactor, a multi-plasma reactor was investigated for the inactivation of microorganisms in sewage. We also considered the possibility of degradation of non-biodegradable matter (UV254) and total organic carbon (TOC) in sewage. The multi-plasma reactor in this study was divided into high voltage neon transformers, gas supply unit and three plasma modules (consist of discharge, ground electrode and quartz dielectric tube). The experimental results showed that the inactivation of microorganisms with treated water type ranked in the following order: distilled water > synthetic sewage effluent >> real sewage effluent. The dissolved various components in the real sewage effluent highly influenced the performance of the inactivation of microorganisms. After continuous plasma treatment for 10 min at 180 V, residual microorganisms appeared below 2 log and UV254 absorbance (showing a non-biodegradable substance in water) and TOC removal rate were 27.5% and 8.5%, respectively. Therefore, when the sewage effluent is treated with plasma, it can be expected the inactivation of microorganisms and additional improvement of water quality. It was observed that the NH4+-N and PO43--P concentrations of sewage was kept at the constant plasma discharging for 30 min. On the other hand, NO3--N concentration was increased with proceeding of the plasma discharge.

공공수역 수질개선을 위한 공공하수처리시설 관리제도의 합리적 개선방안 연구

김익재 ( Ik Jae Kim ),김호정,한대호,김교범,곽효은 한국환경정책평가연구원 2017 기본연구보고서 Vol.2017 No.-

그동안 수질오염원관리에 지대한 역할을 한 공공하수처리시설의 여러 한계점들이 최근 부각되고 있다. 공공수역의 수질개선이라는 큰 틀에서 여러 한계점들을 진단하면 제도적 혹은 기술적 개선점으로 크게 구분할 수 있을 것이다. 그 중 생분해성 유기물질 외에도 공공수역의 물환경에 큰 영향을 미치는 기존 또는 신규 화학물질에 대한 하수처리시설의 관리개선은 그 공통분모로 볼 수 있다. 많은 선진국은 중금속, 의약물질 및 개인위생물질(PPCPs)등과 같은 미량유해물질이 하수처리시설로 유입·배출되는 경로를 이미 제도를 통해 적정하게 관리하고 있거나 모니터링을 추가 확대하여 공공수역의 물환경 건강성과 국민의 건강보호를 위해 정부 차원에서 다양한 노력을 펼치고 있다. 더 나아가 유럽은 미규제물질에 대한 목록을 선정하여 집중관리대상의 우선순위를 선정하는 등 공공수역의 수질보호와 하수처리시설 관리제도의 선진화 추세를 보이고 있다. 반면 우리나라의 현행 하수처리장 관리제도는 산업폐수 연계처리 등의 원인으로 유입·방류되어 물환경 위해성 가중시키는 (독성)화학물질에 대한 기준은 부재하고, 관련 제도 수립을 위한 현황조사도 초기단계 수준에 머물고 있다. 현행 ‘산업폐수의 공공하수처리시설 연계처리 지침’은 공공하수처리장으로 산업폐수 연계처리를 허용하여 시설 중복투자를 막는 경제적 인센티브를 부여하고 있고, 산업체 및 지자체의 비용절감을 유도하기 위해 낮은 배출허용기준을 적용하는 혜택을 부여하고 있다. 그러나 매년 산업폐수 연계처리 유입량은 증가하는 추세이고, 유입되는 수질오염물질의 종류나 농도는 제도의 부재로 조사가 거의 되지 않고 있는 실정이다. 또한 특정 수질유해물질 등에 대한 대상물질도 지속적으로 추가되고 있고, 녹조와 같은 수질악화를 예방하기 위해서 총인(TP)과 같은 방류수수질 기준농도는 강화했으며, 하수처리수 재이용도 권장하고 있지만, 오히려 공공수역 및 친수용수의 수질위해성과 깊은 연관되어 있는 하수처리방류수 혹은 수질오염원 관리의 개선은 아직 많이 미흡한 것으로 판단된다. 본 연구는 이러한 공공수역 수질개선 측면의 현행 하수처리시설의 제도적 한계점을 상세히 분석하고 또한 공공수역 수질오염원의 규제 강화 순응도에 대한 주제를 균형적 시선으로 추진하였다. 특히 본 연구는 공공하수처리장으로 유입된 후 적정한 관리기준의 부재로 공공수역으로 방류되는 오염물질의 거동을 중금속 중심으로 살펴보았다. 즉 공공하수처리시설로 연계처리되는 산업체의 현황을 분석하여 현재 공공수역으로 유입되는 폐수 배출 업소 및 오염원 배출 현황을 조사하였고, 공공수역의 오염 실태를 확인하기 위해 지자체에서 실제 운영 중인 공공하수처리장에서 발생한 슬러지의 성분을 분석하여 중금속 등에 대한 오염 현황 조사를 수행하였다. 본 보고서의 각 장별 주요 연구내용과 결과는 다음과 같다. 보고서의 2장에서는 공공수역의 수질개선을 위한 국내외 공공하수처리장의 현황 및 제도를 살펴보고, 이를 통한 시사점을 다루었다. 우리나라는 공공하수처리장의 BOD 유입부하 관리 및 저감에 집중하여 법적기준에 부합하는 처리수를 방류하고 있다. 최근 EU 등 선진국은 하수처리장 방류수질을 포함하여 신규 수질오염물질이 공공수역에 미치는 위해성을 인지하고, 관심 또는 우선관리 오염물질(watch list, priority pollutants)로 지정하는 등 엄격한 수준의 오염원 체계로 발전하고 있음을 알 수 있다. 따라서 우리나라도 각종 형태의 화학물질을 함유하여 처리장으로 유입되는 오염원 검토 및 위해성 평가를 위한 제도개선 검토를 서둘러야 할 것으로 사료된다. 3장에서는 제도적인 측면의 접근을 통해 국내 공공하수처리장 관리정책의 현황과 한계점을 제시하였다. 특히 공공하수처리시설로의 연계처리 지침에 대해 정리하였으며, 「하수도법」, 「수질 및 수생태계에 관한 법령」 및 배출허용기준 등을 상세하게 살펴보고, 각각의 법에서 충돌하는 부분에 대한 수정(안)을 제시하는 등 제도적 한계점으로 인해 발생하는 공공수역의 오염에 대한 연구를 수행하였다. 특히 연계처리 지침에서 제시하는 배출허용기준 ‘나’ 기준 적용으로 인해 중금속 및 특정 수질유해물질에 대한 기준 항목이 배제됨으로써 수질오염이 발생할 가능성이 높다. 또한 연계처리는 폐수처리시설 및 공공하수처리시설의 방류수 수질기준과 비교하여 상대적으로 완화된 것으로, 이를 악용하는 폐수배출시설이 존재할 것이다. 연계처리 시 효율적인 전처리 운영방안, 유역하수도 정비계획과 총량제방류수 수질항목에서 중금속 항목의 도입 등을 신중하게 검토할 필요가 있다. 4장에서는 공공수역을 오염시키는 배출시설에 대한 특성을 구체적으로 분석하였으며, 연구의 주요 결과로 산업계 하수처리장 연계처리를 수행하는 지역 및 처리규모별 현황을 분석하였다. 또한 ‘전국오염원조사자료’를 이용하여 전국 산업체 5만 8,711개소(2015년 기준) 중 연계처리 업소 1만 7,325개소(31.1%)에 대하여 중금속 함유 여부 및 배출허용기준(‘나’기준) 초과 대상 산업체에 대한 분석을 실시하였다. 전체 배출업소의 약 4.2%가 중금속함유 폐수를 하수처리장으로 연계하는 것으로 나타났다. 폐수를 간접배출하는 업소는 폐수처리 전과 후 대부분 중금속 항목에서 그 수가 미미하거나 비율이 낮았으나 연계처리하는 산업체는 구리 2,094개소(연계처리 배출업소수의 12.1%)로 나타났다. 또한 3개의 지자체에서 하수처리장 탈수슬러지의 유해물질을 시험한 결과, 하수슬러지 내에 중금속이 다량 검출된 것을 알 수 있었다. 이는 중금속이 최소한 산업폐수 연계처리에 간접적 영향을 미치는 것으로 볼 수 있으며, 하수처리과정에서 발생한 슬러지와 방류수는 공공수역에 심각한 영향을 미치는 오염원이라고 판단된다. 이러한 위험성의 향후 대응을 위해 하수처리시설 공법별 처리효율을 나타내었다. 본 연구는 오염 발생 원인자 및 발생 오염원에 대한 모니터링 및 원인 규명에 대한 접근으로도 정책적 활용에 의미를 가진다. 덧붙여 공공수역의 수질개선을 위하여 공공하수처리장, 물재이용, 그리고 관련 통계수집 및 생산의 관점에서 제도적 개선점을 제언하였다. 덧붙여 2011년 마련된 산업폐수의 연계처리 지침 개정을 위한 주요 내용안을 제시하였으며, 중금속 및 미규제 신규물질에 대한 해외 선진국의 규제 동향을 정리함으로써 이를 근거로 향후 우리나라에 미규제 신규물질의 규제 및 방류수 수질기준 선진화를 위한 정책도구로 활용될 수 있는 정책방향을 제시하였다. In surveying of water quality and the public wastewater treatment, particularly on the industrial wastewater treatment, there are two pillars of challenges: technical inefficiency and institutional indolence. As the amount of public sewage treatment combined with industrial wastewater continue to increase, the institutional safety nets to patrol and execute the violation activities are inadequate, resulting a cycle of contamination. In Korea, with the increasing demand of the public awareness, the discharged water quality standards have been continued to addressed. With a stronger regulation, a range of chemical substances threatening water quality have been annexed. However, the violation cases of the reinforced environmental laws and ordinances have continued appeared due to the lack of enforcement and compliance with regulations of wastewater discharges. These violations can be a direct and potential risk factor to the water pollution in the public water system, further the public health. In terms of the management system of developed countries, management of new chemical substances such as heavy metal discharge and micro pollutant are throughly discussed and regulated when establishing environmental policy for public sewage treatment facilities. Furthermore, it is a trend indicating the advancement of water quality standards of discharged water by selecting a list of unregulated materials and prioritizing concentration target. This study investigated the behavior of contaminants released into public waters due to the lack of appropriate management standards after entering the public sewage facilities. In particular, we surveyed the current status of public sewage treatment facilities and pollutant sources flowing into public water system. In order to confirm the contamination status of public water quality, pollution status of heavy metals was surveyed through a sludge analysis at the public sewage treatment facilities. Through the “Guideline for the Linkage of Public Sewage Treatment Facilities of Industrial Wastewater”, the public sewage treatment facilities were allowed to be indirectly discharged, thereby preventing the overlap of financial resources on investment. However, the application of permissible low emission limits to induce cost savings for industry has caused the yearly increases in pollutant loads in the public sewage treatment facilities. This study analyzed the institutional limitations and carried out a study on the institutional adaptation and improvement as a balanced perspective of strengthening regulation of public water quality. The major contents of this report are as follows. In Chapter 2 of the report, the status and system of public sewage treatment facilities for improving the quality of water in the public waters were examined and implications were discussed. In Chapter 3, we have conducted the study on, the current status and limitation of public sewage management policies through the legal framework. We examined in detail of the “Sewage Law (act 14839, 2017)”, “The Law on Water Quality and Aquatic Ecosystems (act 14490, 2016)”, and the “Emission Standards (regulation 688, 2017)”in order to reinforce the guidelines for linkage to public sewage treatment facilities, and to investigate the pollution of the public waters system. In addition, the pollution due to the exclusion of criteria for heavy metals and specified substance harmful to the quality of water has been covered in detail by “The Application of the Emission Allowance Standard ‘Na’, presented in the linkage guidelines. In Chapter 4, we analyzed the characteristics of the pollutants that pollute of the public water quality, and analyzed the status of the area and the treatment scale that are connected to the industrial wastewater treatment facilities as the main results of the study. In addition, we analyzed 17,325 of the 55,711 industrial facilities in the nationwide industrial pollution sources by 2015, and analyzed the industries that exceeded the criteria for containing heavy metals and emission limit ‘Na’. Heavy metal discharge status of the discharge facility is shown. Heavy metals and certain harmful substances entered into the public sewage treatment plant are concentrated in the sludge generated in the sewage treatment process or discharged to the river to cause contamination of the river sediment. In order to cope with these risks, the occurrence and treatment status of sewage sluge by treatment type is shown. This study has implications for establishing a tangible policy to examine and monitor of the cause sources of pollution. In order to improve the systematic limitation, this study proposed revision of guidelines for the linkage of industrial wastewater. In addition, this study proposed revision of guidelines for the linkage of industrial wastewater to improve institutional limitations, and summarized the regulation trends of developed countries on heavy metals and unregulated new substances. Based on this, it suggested the direction of the improvement of the domestic system so that it can be used as a pro-active policy tool to estimate and regulate new substances for the future regulation of water quality standards of discharged water pollution.

광양만 표층온배수의 확산 특성

김종규(J.K. Kim),곽경일(G.I. Kwak),김명원(M.W. Kim) 한국해양환경·에너지학회 2006 한국해양환경·에너지학회 학술대회논문집 Vol.2006 No.-

본 연구는 광양만의 흥수기 전후의 표층온배수의 확산 특성을 고조, 중조 및 저조시의 CTD 관측자료분석을 통하여 온배수와 섬진강 담수 방류량의 변동에 따른 수평 및 연직구조로 파악하였다. 그 결과 광양만 표층온배수의 확산 특성은 전반적으로 해수 유동구조와 섬진강의 유출량, 그리고 하구역에 인접한 대단위 산업단지에서의 온배수에 의해 복잡한 형태를 파악할 수 있었다. A study on the spatial and temporal distributions of surface thermal effluents in Seomjin River estuary and Gwangyang Bay executed to grasp in 2005(July) and 2006(February, May, August, September). The distribution of surface thermal effluents during the spring tide show well the tidal current and thermal effluents effect to the expansion of Seomjin River discharges.

섬진강 하구역의 해수순환 및 온배수 확산 특성

김명원(M.W.Kim),김종규(J.K.Kim) 한국해양환경·에너지학회 2012 한국해양환경·에너지학회 학술대회논문집 Vol.2012 No.11

섬진강 하구역의 해수유동 및 온배수 확산 특성을 현장관측과 3차원 수치모델(EFDC)을 이용하여 파악하였다. 섬진강 하구역의 해수유동 특성은 전반적으로 섬진강 유출량의 계절적 변동, 해수유동 구조 및 온배수 등에 의해 복잡한 형태를 보이는 것을 파악할 수 있었고, 이들 자료는 광양만 해양환경 변화 및 섬진강 하구역 관리의 기초자료로 사용될 수 있을 것으로 판단된다. In this study we try to identify the three-dimensional characteristics of Seomjin River discharges to consider their physical properties using seasonal field observation during spring tide and three-dimensional numerical modeling with EFDC(Environmental Fluid Dynamics Code). A EFDC and observed CTD data was used to predict the seasonal mixing behavior of Seomjin River and thermal discharges. The tidal elevation boundary conditions of the four main tidal harmonic(M2, S2, K1, O1) constituents on the open boundary and river discharges at the river boundary are considered in this study. The open boundary conditions are evaluated from the observation data of tide and tidal current near the open boundary. The circulation characteristics of Seomjin River discharges show well the three-dimensional tidal current and thermal effluents effect to the seasonal variation of river discharges.

섬진강 하구역 잔차류의 시공간적 변동 특성

김명원(Myeongwon Kim),김종규(Jongkyu Kim),이문옥(Moon-Ock Lee) 한국해양환경·에너지학회 2012 한국해양환경공학회 학술대회논문집 Vol.2012 No.5

n this study we try to identify the residual current characteristics of Seomjin River dischanges to consider their physical properties using seasonal field observation during spring tide and three-dimensional numerical modeling with EFDC(Environmental Fluic Dynamics Code). A EFDC and observed data was used to predict the seasonal residual current behavior of Seomjin River discharges. The tidal elevation boundary conditions of the four main tidal harmonic(M2, S3, K1, O1) constituents on the open boundary and river discharges at the river boundary are considered in this study. The open boundary conditions are evaluated from the observation data on tide and tidal current near the open boundary. The seasonal residual current show well the three-dimensional tidal current and thermal effluents effect to the seasonal variation of river discharges.

Comparative Analysis of Methodologies for Dose Assessment due to the Radioactive Effluents: USNRC Regulatory Guide 1.109 and UNSCEAR 2016 Methodology

Soyun Kim,Jae Hak Cheong 한국방사성폐기물학회 2021 한국방사성폐기물학회 학술논문요약집 Vol.2021 No.06

Comparison of the Amount of Carbon-14 Radioactive Effluents Discharged From Korean PWRs and PHWRs and Its Resulting Public Dose

Hwa Pyoung Kim,Seong Jun Kim,Jin Ho Son,Chang Ju Song,Wo Suk Choi,Ji Ung Kim,Tae Young Kong 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

As of 2023, there are a total of 24 nuclear power plants (NPPs) in operation in Korea, with 21 pressurized water reactors (PWRs) and three pressurized heavy water reactors (PHWRs). Korean NPPs discharge radioactive effluents into the environment every year. Radioactive effluents from NPPs contain various radionuclides and materials, including 3H, 14C, Noble gas, particulates, and iodine Among the radioactive effluents discharged from Korean NPPs, 14C is a pure beta emitter with a half-life of 5,730 years. The human body can inhale and ingest 14C to cause internal exposure. In addition, the amount of 14C present in the environment is decreasing, but the amount of 14C discharged from NPPs is increasing. 14C discharged to the environment can be inhaled and ingested by the public around NPPs through various pathways. For this reason, it is very important to monitor and manage 14C because it affects the dose of the public around NPPs. Therefore, this study compared and analyzed the average emissions of 14C discharged from PWRs and PHWRs during the recent 10 years (2012-2021). An average of the public dose due to 14C released from NPPs depending on the reactor types from 2012 to 2021 was also compared. It is inevitable to discharge radioactive effluents while operating NPPs. Korea Hydro & Nuclear Power (KHNP) manages and monitors radioactive effluents released into the environment. According to a survey and analysis of 14C discharged from PWRs and PHWRs and the average dose of the public over the recent 10-year (2012-2021) around Korean NPPs, 14C released from PWR accounted for 3.1% of the total discharge but accounted for more than 93.67% of the total public dose. In addition, 14C discharged from PHWRs accounted for 1.12% of the total discharge, but its resulting dose to the public accounted for more than 83.87% of the total public dose. As a result of analyzing the public dose due to 14C from 2012 to 2021, it was gradually increasing every year. Based on these results, monitoring and managing 14C discharge and its resulting doses to the public are important in the future.