Safeguards systems and measures are determined through diversion scenario analysis based on the facility design information submitted to the IAEA when a new nuclear facility is introduced. While the concept of safeguards-by-design (SBD), which considers the safeguards from the design phase for a facility operator to minimize unplanned changes or disruption to facility operations as well as for the IAEA to increase the efficiency and effectiveness in safeguards implementation, has been emphasized for more than a decade, there is no practical tool or guidance on how to apply it. In this study, we develop a diversion path analysis tool and introduce how to apply SBD using it. A diversion path analysis tool was developed based on the elements that constitute diversion and the algorithm generated based on the initial information of facility and nuclear material flow. The results of utilizing the analysis tool depending on a different level of facility information and the safeguards set-ups were compared through examples. Taking a typical light water reactor as an example, the test analyzed the automatic generation of dedicated routes, configuration of safeguards measures, and diversion path analysis. Through this, the application and limitations of the analysis tool are discussed, and ideas for utilization according to the SBD concept and necessary regulatory guidance are proposed. The results of this study are expected to be directly utilized to domestic nuclear control during the regulation process for a construction of new nuclear power systems, and furthermore, to enhance national credibility in the engagement with the IAEA for implementation of safeguards.

Nuclear Material Accountancy (NMA) system quantitatively evaluates whether nuclear material is diverted or not. Material balance is evaluated based on nuclear material measurements based on this system and these processes are based on statistical techniques. Therefore, it is possible to evaluate the performance based on modeling and simulation technique from the development stage. In the performance evaluation, several diversion scenarios are established, nuclear material diversion is attempted in a virtual simulation environment according to these scenarios, and the detection probability is evaluated. Therefore, one of the important things is to derive vulnerable diversion scenario in advance. However, in actual facilities, it is not easy to manually derive weak scenario because there are numerous factors that affect detection performance. In this study, reinforcement learning has been applied to automatically derive vulnerable diversion scenarios from virtual NMA system. Reinforcement learning trains agents to take optimal actions in a virtual environment, and based on this, it is possible to develop an agent that attempt to divert nuclear materials according to optimal weak scenario in the NMA system. A somewhat simple NMA system model has been considered to confirm the applicability of reinforcement learning in this study. The simple model performs 10 consecutive material balance evaluations per year and has the characteristic of increasing MUF uncertainty according to balance period. The expected vulnerable diversion scenario is a case where the amount of diverted nuclear material increases in proportion to the size of the MUF uncertainty, and total amount of diverted nuclear material was assumed to be 8 kg, which corresponds to one significant quantity of plutonium. Virtual NMA system model (environment) and a divertor (agent) attempting to divert nuclear material were modeled to apply reinforcement learning. The agent is designed to receive a negative reward if an action attempting to divert is detected by the NMA system. Reinforcement learning automatically trains the agent to receive the maximum reward, and through this, the weakest diversion scenario can be derived. As a result of the study, it was confirmed that the agent was trained to attempt to divert nuclear material in a direction with a low detection probability in this system model. Through these results, it is found that it was possible to sufficiently derive weak scenarios based on reinforcement learning. This technique considered in this study can suggest methods to derive and supplement weak diversion scenarios in NMA system in advance. However, in order to apply this technology smoothly, there are still issues to be solved, and further research will be needed in the future.

To evaluate the safeguards system or performance in a facility, it is crucial to analyze the diversion path for nuclear materials. However, diversion paths can range from the extremely simplified to the complicated depending on the level of knowledge and the specific person conducting the analysis. This study developed the diversion path analysis tools using an event tree and fault tree method to generating diversion paths systematically. The essential components of the diversion path were reviewed, and a logical flow was developed for systematically creating the diversion path. An algorithm was created based on the facility design components and logical flow, as well as the initial information of the nuclear materials and material flows. The event tree and fault tree analysis tools were used to test the path generation algorithm. The usage and limitations of these two logic methods are discussed, and ideas to incorporate the logic algorithm into practical program tools are suggested. The tests were analyzed on a typical light water reactor as an example, including automatic generation of dedicated pathways, configuration of safeguards measures, and analyzing paths with strategies for avoiding safeguard systems. The results led to the development of a draft pathway analyzer program that can be applied to general nuclear systems. The results of this study will be used to develop a program module that can systematically generate diversion paths using the event tree and fault tree method. It can help to guide and provide practical tools for implementing SBD.

Even though it is emphasized to apply safeguards-by-design (SBD) concept in the early phase of the design of a new nuclear facilities, there is no clear guideline or tools for the practical SBD implementation. Generally known approach is trying to review whether there is any conflicts or shortcomings on a conceptual safeguards components in a design information. This study tries to build a systematic tools which can be easily applied to safeguards analysis. In evaluating the safeguards system or performance in a facility, it is essential to analyze the diversion path for nuclear materials. Diversion paths, however, can be either extremely simplified or complicated depending on the level of knowledge and purpose of specific person who do analyze in the field. In the context, this study discusses the applicability of an event tree and fault tree method to generating diversion paths systematically. The essential components constituting the diversion path were reviewed and the logical flow for systematically creating the diversion path was developed. The path generation algorithm based on the facility design components and logical flow as well as the initial information of the nuclear materials and material flows was test using event tree and fault tree analysis tools. The usage and limitation of the applicability of this two logic methods are discussed and idea to incorporate the logic algorithm into the practical program tools is suggested.The results will be used to develop a program module which can systematically generate diversion paths using the event tree and fault tree method.

In order to effectively and efficiently apply safeguards to new nuclear facilities, it is recommended to apply safeguards-by-design concept. In evaluating the safeguards in the early stage of the design of a facility, it is essential to analyze the diversion path for nuclear materials. This study suggests a simple method which can generate diversion paths. The essential components constituting the diversion path were reviewed and the logical flow for systematically creating the diversion path was developed. The path generation algorithm is based on this components and logical flow as well as the initial information of the nuclear materials and material flows in a planned facilities. The results will be used to develop a program module which can systematically generate diversion paths using the event tree and fault tree method.

A 14-year-old intact female, mixed dog was presented with hematuria and strangury. Mass in the abdominal cavity was seen on radiographs and ultrasound. On the cytological examination in the urethra, clusters of pleomorphic epithelial cell were found. Tissues of the urethra and the urinary bladder were obtained at the time laparotomy and determined the extent of the mass. Transitional cell carcinoma (TCC) of the urinary bladder was found in histopathologic characteristics. Urinary diversion after removal of a complete full section of the TCC in bladder wall was performed. Piroxicam, as a medical therapy for TCC, was orally administrated. Surgical operation and chemotherapy were selected with the goal of maintaining and improving quality of life.

유역 변경을 통한 수자원 확보방안으로 추진되고 있는 소규모 저류댐 건설에 대한 평가를 사례로 들어 자연 환경의 개발 계획에 대한 비용-편익 분석에 에머 지(Emergy)라고 하는 새로운 개념을 적용하였다. 에머지 개념은 환경 자원들이 우리 경제의 진정한 부에 기여하는 바를 평가하려는 시도이다. 에머지 평가를 위한 모델들은 시스템의 네트워크 특성들을 특별한 기호들을 이용하여 전체적으로 보여주는 모델링 언어인 에너지 시스템 언어(Energy Systems Language)를 이용하여 작성하였다. 제안된 댐 건설이 가져오는 대부분의 에머지 편익은 이 댐의 건설 목적인 용수 공급에 있었다. 댐의 건설로 형성될 호수의 생산성 증가로 인한 에머지 편익은 0.01% 미만으로 미미하였다. 주요 에머지 비용은 댐 건설비용 (28.2%), 유지관리비용 (27.2%), 사회적 혼란(22%), 수몰민의 이주비용(12.5%) 등으로 나타났다. 에머지 산출비율(Emergy yield ratio)은 퇴적물의 손실이 포함되지 않았을 경우 1.06, 퇴적물의 손실 포함되었을 경우 1.02로 나타나, 제안된 댐 건설의 순산출(Net yield) 은 그리 크지 않았다. 전통적인 비용-편익 분석 방법에 의한 비용-편익비(1.62)와 비교하여 볼 때, 에머지 개념을 이용한 비용-편익 평가에서는 제안된 댐의 편익이 낮게 나타났다. 이러한 에머지 산출비율은 생물종에 포함된 높은 에머지 때문에 시스템의 경계내에서 댐의 건설로 희귀 생물종의 손실이 일어난다면 1.0 미만으로 나타날 것이다. 이 경우 댐의 건설이 초래하는 에머지 비용은 에머지 편익보다 더 크게 될 것이다. 본 연구는 환경 자원이 감소하는 현 시점에 있어서 환경의 보다 나은 관리라는 측면에서 개발 계획들의 영향을 평가하는 데 적용될 수 있는 새로운 방법론을 소개하였다.

Recently severe drought caused the water shortage around the western parts of Chungcheongnamdo province, South Korea. A Diversion tunnel from the Geum river to the Boryong dam, which is the water supply dam for these areas has been proposed to solve this problem. This study examined hydraulic impacts on the Geum river associated with the diversion plan assuming the severe drought condition of 2015 would persist for the simulation period of 2016. The hydraulic simulation model was verified using hydrologic and hydraulic data including hourly discharges of the Geum river and its 8 tributaries, fluctuation of tidal level at the mouth of the river, withdrawals and return flows and operation records of the Geum river barrage since Feb. 1, 2015 through May 31, 2015. For the upstream boundary condition of the Geum river predicted inflow series using the nonlinear regression equation for 2015 discharge data was used. In order to estimate the effects of uncertainty in inflow prediction to the results total four inflow series consisting of upper limit flow, expected flow, lower limit flow and instream flow were used to examine hydraulic impacts of the diversion plan. The simulation showed that in cases of upper limit and expected flows there would be no problem in taking water from the Geum river mouth with a minimum water surface level of EL(+) 1.44 m. Meanwhile, the simulation also showed that in cases of lower limit flow and instream flow there would be some problems not only in taking water for water supply from the mouth of the Geum river but also operating the diversion facility itself with minimum water surface levels of EL(+) 0.94, 0.72, 0.43, and 0.14 m for the lower limit flow without/with diversion and the instream flow without/with diversion, respectively.

Defects of diversion tunnel have been analyzed by using the precise inspection for safety and diagnosis in 7 dams. Leakage from joint, crack, and material segregation is crucial damage in dam as well as crack, corrosion, and drainage system. Maintenances of diversion tunnel have been suggested with common and unique characteristics of defects.

전세계적으로 토사유출은 심각한 문제로 알려져 있다. 환경관리자, 농부 및 다른 토지소유자들을 위해 다양한 모델링 테크닉이 개발되어왔고, 토양유실 저감을 위해 다양한 site-specific 최적관리기법의 효율을 산정하여 활용하였다. 물리적기반인 WEPP 모형은 시 공간적으로 작은 유역과 필지에서 발생하는 토양유실을 산정할 수 있다. 그러므로 본 연구에서는 WEPP watershed version을 이용하여 강원도 홍천군 자운리에 위치한 연구지역에 빗물

북한강 수계의 경우 북한이 임남댐을 개발하여 유역변경식으로 물을 이용하고 있어 하류지역에서 여러 가지 문제가 나타나고 있다. 따라서 남 북한이 공유하천을 효과적으로 관리하기 위해서는 수량이나 수질 등 다양한 분야에서의 협력이 절실히 요구되고 있다. 그러나 남 북공유하천에서 상 하류국가간 물이용의 공평성을 실현하기 위한 노력은 매우 미흡한 실정이다. 본 논문에서는 남북공유하천의 공평한 물이용의 판단기준이 되는 수리권을 검토하기 위해 북한의 임남댐에 의한

국내에는 약 18,000여개의 댐이 있는 것으로 보고되고 있다. 이 중에서 대댐으로 분류되는 1,200여 개의 대댐은 비교적 양호하게 운영 관리되고 있으나, 지자체 등에서 관리하는 소규모의 댐들은 대부분 제체를 관통하는 복통을 갖고 있으며, 제도적 장치의 미비와 전문 인력의 부족으로 체계적인 유지관리가 거의 이루어지지 않고 있는 실정이다. 본 연구에서는 소규모 댐들에서 자주 발생하는 결함의 유형에 대해서 고찰하고, 결함의 보수보강을 통하여 소규모 댐의 안전을 확보할 수 있는 방법을 제시하고자 한다. 또한, 전기비저항 탐사를 통하여 결함의 진행정도를 파악하고, 보수보강 이후의 보수보강 효과를 판정하는 방법론을 제시하고자 하였다.

본 연구는 자연하천에서 유로변경 계획구간에 대한 수리특성을 수치모형시험을 통해 분석하는 것이다. 이 연구를 통해 하천공사 특히 홍수시 피해방지와 하천의 흐름특성을 파악하는 기보자료를 제공할 것이다. 본 연구에서는 수리특성분석을 위해 1차원 모형은 HEC-RAS 모형과 2차원 유한요소모형인 RMA2 모혀이 어떻게 유로만곡부의 흐름형태와 급경사면, 복잡한 하상형태 등의 하천 흐름특성에 영향을 미치는가를 분석하는데, HEC-RAS보다 더 효과적임을 알 수 있

6개의 수조와 1개의 펌프장을 갖고 있는 대심도 지하관로 배수시스템에서 발생하는 복잡한 서어징 현상을 강체수주이론에 의한 비선형 상태방정식에 의해서 해석하였다. 상태방정식은 각 수조에서의 유량연속방정식과 비선형항을 갖는 지하관로의 운동 방정식으로부터 구성된다. 홍수의 유입량과 펌프의 유출량을 장방형 펄스(pulse)로 하고 유출유량과 전유입유량이 같다고 한다면 비선형 상태방정식에 의한 각 수조수위의 진동은 선형화 방정식에 의한 결과와 잘 일치 하고 있다