수용자의 급증에 따른 시설 내 교정에 대한 반성과 위치추적시스템 등 과학기술의 발전에 따라 효과적으로 시설 내 교정을 대체할 수 있는 제재수단으로 전자감독제도 가 도입되게 되었다. 즉 전자감독제도는 사회 내 교정이론과 과학기술의 결합점이다. 전자감독제도는 외국에서는 교도소 과밀문제 해소, 교도소 신설비용의 절감, 단기자유 형의 대체 목적으로 도입되었으나, 우리나라에서는 2008년 성범죄자에 대한 감시목 적과 재범방지목적으로 도입되었다. 이후 대상범죄가 확대되는 과정을 거쳐, 2020년 일반사범에 대한 가석방에도 도입되어 대상이 대폭 확대되었다. 대상자의 전면 확대 로 2020년 피부착자 수가 2배 이상 증가하였으나, 부착명령 기간은 3월 미만이 전해 의 42명에서 1,137명으로 대폭 증가한 것으로 나타났다. 위 증가된 부분은 모두 일반 사범 가석방자로 보이고, 전체 가석방자 수는 2020년의 경우 전해에 비하여 증가하지 않았다. 전자감독장치 부착대상의 확대가 당초 의도한 교도소 과밀화에는 전혀 도움 이 되지 못하고, 오히려 전담인력에 대한 과중한 관리 부담만 증가시킨 것이다. 단기부착명령의 남발은 제도의 목적달성 보다는 부작용만 발생시키므로 현행법 하에서도 일반사범 가석방자에 대한 3월 미만 부착명령을 가급적 제한하여 운영하고, 향후 법 개정에 이를 반영할 필요가 있다. 19세기 교정시설에서 20세기 교정공무원이 21세기 수용자를 관리하고 있다는 현실에 비추어 보면 전자감독제도는 21세기 사회 내 교정 수단이다. 일반사범 가석방자에게 단기 부착명령을 남발하는 것은 21세기 교정수단을 20세기 사고의 틀에 가두어 두는 것에 불과하다. 전자감독제도의 장점을 극대화시키 기 위해서는 현행법은 후방형 전자감독제도만 채택하고 있으나 과감하게 전방형 전자 감독제도를 도입할 필요성이 있다. 가석방에 기계적으로 단기 부착명령을 남발하는 탁상행정, 책임회피행정을 지양하고, 발부기관과 집행기관의 상호 유기적 소통과 법개 정을 통한 전방형 전자감독제도의 도입으로 전자감독제도의 올바른 정착을 기대해 본다.

PURPOSES : The purpose of this study was to investigate the long-term trend of internal strain within the continuously reinforced concrete pavement (CRCP) based on measurements. METHODS : The strains of the concrete and reinforcing bars were measured at two induced cracks and one construction joint. The analysis was performed using data accumulated over five years from the concrete placement. The effects of the initial construction conditions were investigated by comparing the strains and stresses at each location. RESULTS : In the long-term behavior, the highest tensile strains of the concrete and rebar were observed from December to January, and the lowest tensile or the highest compressive strain was observed from July to August. A lower rebar stress was measured in the construction joint, which has a higher steel ratio than that of cracks. As the distance from the crack and joint increased, the rebar strains decreased. Higher tensile strains of the concrete and rebar were measured where a higher concrete setting temperature occurred. A gradual decrease in the maximum concrete tensile strain was observed in the five-year measurements. However, in the case of reinforcing bars, stress reduction with time was not observed in the long-term behavior. CONCLUSIONS : Although a gradual decrease in concrete strain was revealed by long-term measurements, it is predicted that minimizing the concrete setting temperature to reduce the initial tensile strain could effectively increase the fatigue strength of CRCP

복숭아는 대표적인 여름 과일이자 알레르기를 유발하는 식품으로 밀폐되고 집약적인 생산환경으로 인해 시설 내 유기분 진, 농약, 복숭아털이 발생하기 때문에, 열악한 작업환경으로 인한 작업자들이 어려움을 많이 겪고 있다. 본 연구에서는 복 숭아 선별작업장에서 발생하는 미세먼지를 위치별, 작업별, 입경별로 모니터링함으로써 저감 및 대책 마련을 위한 기초자 료를 확보하고자 하였다. 미세먼지 모니터링 결과 지역별로 는 선별과정에서 미세먼지의 발생이 높은 것으로 나타났으며, 주로 기계적인 과정을 통하여 발생하는 10μm 이상의 미세먼 지로 나타났다. 본 연구를 바탕으로 향후 작업환경의 개선을 위해서 공정 중 미세먼지가 주로 발생하는 지역 및 미세먼지 의 물리적 특성을 고려하여 저감시설 및 개인보호구의 착용이 요구된다.

The Ministry of Oceans and Fisheries promoted the installation of eel-ladder for the purpose of creating inland water resources. Currently, eel-ladder have been installed and operated at the Geumgang Estuary Bank (2018), Yeongam Embankment (2019), and Asanman Embankment (2020). In this study, the number of glass eels in eel-ladder in 2021 was monitored and factors affecting the rise that from ocean to river of eels were investigated. Glass eels in eel-ladder were found when the salinity was relatively low, and they started when the freshwater and seawater temperatures were above 20℃. Comparing the number of occurrences by year, the largest number of glass eels was observed in 2021, but it is judged that this is not according to the distribution of glass eels in sea, but rather as a result of the investigator’s eel-ladder repair and guidance on illegal fishing.

본 연구에서는 2021년 전남, 전북을 대상으로 23개소에서 어류 4종(향어, 비단잉어, 참붕어, 금붕어) 총 1,115마리에 대하여 병원체 감염 여부를 조사하였다. 법정전염병 3종(SVC, Spring viraemia of carp, EUS, Epizootic ulcerative syndrome, and KHVD, Koi herpesvirus disease)을 분 석한 결과, 조사한 모든 시료에서 법정전염병이 검출되지 않아 전라권에서 조사한 잉어과어 류는 청정국 또는 청정지역 선언에 중요한 정보를 제공할 것이다.

In 2005, groundwater contamination due to unplanned releases of radioactive materials from the US. Nuclear Power Plants (NPPs) such as Braidwood and Indian Point was confirmed. The following year, in 2006, The Nuclear Regulatory Commission (NRC) established a task force team to investigate the history of unplanned release of all NPP in the US. As a results 217 events of unplanned release including leaks and spills were identified in the US NPPs. The NRC regulates the radioactivity concentration of off-site groundwater by setting a reporting levels (RLs), and if exceeds the RLs, the licensee must report within 30 days. When the off-site groundwater is used as drinking water or non-drinking water, the RLs for tritium in groundwater are 740 Bq·L−1 or 1,110 Bq·L−1, respectively. Whereas the NRC does not set the RLs for on-site groundwater. The Nuclear Energy Institute (NEI) issued the guidance document “Industry groundwater protection initiative” NEI 07-07 in 2007. And the members of the NEI promised with regulatory body and local governments to implement groundwater monitoring/protection program according to the NEI 07-07. The document states that when the on-site groundwater is used as drinking water, the RL (740 Bq·L−1) for off-site groundwater will be applied and the licensee voluntarily reported to the NRC. And also, NPPs are setting the Investigation Level (IL) below the RP and the IL is various among the NPPs. The IL is the standard by which detailed investigations are implemented when the level (radioactivity concentration) is exceeded.

Recently, an international issue due to the discharge of contaminated water from the Fukushima has been highlighted. Since the Fukushima nuclear power plant accident in japan, marine environmental radioactivity survey has been strengthened with increased sampling frequency and range for seawater in territorial waters. And a stationary underwater radiation monitoring system including floating equipment-based system such as oceanographic buoys, tidal stations have been deployed on-site to detect abnormal radiological events. However, stationary monitoring systems may be insufficient for the early detection of abnormal radioactivity over a wide area, since it is a passive way of waiting for radioactive materials to spread in the ocean. So, our team developed a ship-mounted seawater gammaray monitoring system that can be operated remotely and in real time. In this study, it includes a detailed description of the design, installation, monitoring method, and operation of the system.

Low and intermediate radioactive wastes in South Korea have been disposed in Wolsong Low and Intermediate Level Radioactive Waste Disposal Center (WLDC), Gyeongju. This repository structure is planned to be operated few hundred years while toxicity of the waste is sufficiently decayed. The structural integrity of the repository is required to protect the waste in safe. The integrity of the structure is commonly estimated using acoustic emission (AE) method. The integrity of the structure using AE is obtained by following process: 1) Estimation of maximum acoustic crack energy of the structure, 2) Acoustic signal measurement and filtering, and 3) Measurement of simultaneous acoustic cracking energy. The damage of the structure can be obtained from cumulative cracking energy from the structure divided by the predicted maximum cracking energy of the structure. Estimation of maximum cracking energy is gained by the specimens whose components are identical to the repository structure. The cracking energy of the different specimens are obtained during uniaxial compressive test and volume of the specimen is calculated. Then, the fractal coefficient for the structure is obtained and the maximum crack energy of the target structure can be calculated. The specimens whose diameters vary from 50 mm to 150 mm and heights are twice of the diameter are made with same recipe of WLDC silo concrete. The uniaxial compression test is conducted with loading rate of 0.1 mm·min−1. The fractal coefficient is obtained by least square method from the volume-cumulative energy relationship.

The disposing method of the low-intermediate-level radioactive waste, near-surface disposal facilities are generally used. This disposal method refers to a method of constructing a concrete structure on the surface of the ground, putting radioactive waste in it, and covering it with an engineered barrier to isolate human life. Among these, engineered barriers mean covering multiple layers of heterogeneous materials such as sand, clay, and gravel. Engineering barriers have the purpose of delaying the release of radioactive materials into the natural environment as much as possible, and maintaining the isolation of radioactive waste and human life for as long as possible. In this study, the design and construction method of the facility to demonstrate the performance of the engineered barrier that isolates the surface disposal facility from nature was described. In addition, the design and construction method of monitoring technology that can monitor the safety of engineered barriers by measuring information such as moisture, temperature, and slope safety in real time was also explained.

With the development of the nuclear industry and the increase in the use of radioactive materials, the generation of radioactive waste is increasing. As the generation of radioactive waste increases, the occurrence of related safety accidents is also increasing, and it is necessary to develop a radioactive waste monitoring technology to prevent such accidents in advance and efficiently manage radioactive waste. In Information and Communication Technology (ICT), various ICT technologies such as Internet of Things (IoT), Augmented Reality (AR), and Virtual Reality (VR) that can help with the safety management of these radioactive wastes are being developed. In this study, a radioactive waste monitoring technology was developed using ICT technology, such as management of the entire cycle history of waste using Quick Response (QR) codes, and development of AR visualization technology for small packages of radioactive waste. In addition, by using IoT technology to collect desired data from sensors and store the results, after the waste drum is loaded in the waste storage, a technology was developed to track and monitor the history and movement of the waste drum from repackaging to transfer to the storage. The data required for monitoring the radioactive waste drum includes location information, whether the drum is open or closed, temperature and humidity, etc. To collect this information, a drum monitoring technology was built with a 2.4 G wireless router, an anchor constituting a virtual zone, a tag to be mounted on the drum container, and a WNT server that collects sensor data. The network tool provided by WirePas was used for network configuration, and the status of gateways and nodes can be monitored by interworking with the WNT server. The configured IoT sensor technology were tested in a waste storage environment. Four anchors were installed and linked to the network to match the virtual zone and the real storage zone, and it was confirmed whether the movement of the tag was recorded on the network while moving the tag including the IoT sensor for analyzing location information. Based on these research results, it can contribute to the safety management of radioactive waste and establishment of Waste Acceptance Criteria (WCP) by and managing the history and monitoring the waste in the entire cycle from repackaging to disposal.

During decommissioning of a nuclear power plant, a large amount of radioactive waste is produced, and it is known to cost more than 300 billion won to dispose the waste. To reduce the disposal cost, it is essential to minimize the number of radioactive waste drums, which can be achieved by detecting and removing hotspot contaminations in the radioactive waste drums. Therefore, a Compton CT system for radioactive waste monitoring is under development, which provides the images of both the internal structure of the drum and the radioactive hotspot(s) in the drum. Based on the acquired information, the activity of hotspots can be estimated. The performance of the system is affected by various geometry factors. Therefore, it is essential to determine optimal configuration by evaluating the effects of the factors on the performance of the system. In the present study, we determined the optimum value of the factors and then predicted the performance of the optimized system by using a simulator based on the Geant4 Monte Carlo simulation. For optimization, the factors were evaluated in terms of structural similarity index measure (SSIM) and measurement time. The considered factors were the activity of the CT source, source to object distance (SOD), object to detector distance (ODD), and projection angle. The simulation result showed that the activities of the CT sources were determined as 23 mCi for 137Cs and 9.6 mCi for 60Co. The optimal SOD and ODD were 180 cm and 40 cm, respectively. The optimal projection angle was evaluated as 4° since it achieves the SSIM of 0.95 faster than other projection angles. With the optimized parameters, the performance of the system was evaluated using the IAEA gamma CT standard phantom containing a hotspot of 137Cs (7.02 μCi). The Compton image was reconstructed using the back-projection algorithm, and the CT image was reconstructed using the filtered back-projection algorithm. The result showed that the location of the hotspot in the Compton image was well identified at the true position. The acquired CT image also well represented the internal structure of the phantom, and the estimated mean linear attenuation coefficient value (μ= 0.0789 cm−1) of the phantom was close to the true value (μ= 0.0752 cm−1). In addition, the hotspot activity estimated by combining the information of the Compton image and CT image was 8.06 μCi. Hence, it was found that the Compton CT system provides essential information for radioactive waste drums.

In order to monitor the long-term condition of structures in nuclear waste disposal system and evaluate the degree of damage, it is necessary to secure quantitative monitoring, diagnosis, and prediction technology. However, at present, only simple monitoring or deterioration evaluation of the structure is being performed. Recently, there is a trend to develop monitoring systems using artificial intelligence algorithms, such as to introduce artificial intelligence-based failure diagnosis technology in nuclear power plant facilities. An artificial intelligence algorithm was applied to distinguish the noise signal and the destructive signal collected in the field. This can minimize false alarms in the monitoring system. However, it is difficult to apply artificial intelligence to industrial sites only by learning through laboratory data. Therefore, a database of noise signals and destructive signals was constructed through laboratory data, and signals effective for quantitative soundness determination of structures were separated and learned. In addition, an adaptive artificial intelligence algorithm was developed to enable additional learning and adaptive learning using field data, and its performance was verified through experiments.

High level nuclear waste (HLW) is surely disposed in repository in safe by being separated from human life zone. Deep geological disposal method is one of the most potent disposal method. Deep geological repository is exposed to high pressure and groundwater saturation due to its depth over 500 m. And it is also exposed to high temperature and radiation by spent fuels. Thus, HLW repository suffers extremely complex thermo-hydro-mechanical-radioactive condition. Long-term integrity of repository should be verified because the expected lifetime of the repository is over 10,000 years. However, the integrity of monitoring sensors are not reach the endurance lifetime of the repository with present technology. And the disposal condition, thermo-hydro-mechanical-radioactive, should shorten the estimated lifetime of the monitoring sensors. Therefore, it is necessary to improve the long-term integrity of the monitoring sensors. Although long-term tests are required to identify the prolonged durability of monitoring sensors, accelerated tests can help curtail test period. Accelerated tests is classified into accelerated stress test and accelerated degradation test and their methodology and theories are investigated. Their tests are design and proceed by following process: 1) identify failure modes, 2) select accelerated stress parameter, 3) Determine stress level, 4) Determine testing time and number of specimens, 5) Define measurement paremeter and failure criteria, 6) Suggest measurement method and measurement duration. Literature reviews were conducted to identify the influence of the disposal conditions such as thermo-hydro-mechnical-radioactive on integrity of material and monitoring sensors. The investigated data reported in this paper will be utilized to verify the improvement of integrity of monitoring sensors.

The high-level nuclear waste disposal system is a structure with a very long life expectancy, and deterioration and cracking of the structure may occur over time. In addition, the high-level nuclear waste disposal system is in complex extreme conditions such as high temperature, groundwater, and radiation. Therefore, we need to develop a highly durable monitoring sensor that can detect the deterioration and crack of structures in extreme conditions. Since the durability of a sensor is closely related to the sensor lifetime, it is essential to predict the sensor lifetime accurately. The sensor lifetime can be predicted through the reliability qualification test. Among them, the accelerated life test conducted under harsh conditions is widely used as a method to shorten the test period. The major factor in carrying out the accelerated life test is to set the appropriate harsh conditions. Therefore, this study experimentally derived the operating limit of the monitoring sensor. It is essential to set the proper harsh conditions when performing the accelerated life test. Through this study, it is judged that it will be helpful in determining the appropriate stress level when performing the accelerated life test for accurate lifetime prediction.