Decay Heat Estimation of Spent Fuel Assemblies for Decommissioning of Kori Units 3 and 4

Wonjune Mah,Chang-Lak Kim,Sun-kee Lee 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

This paper mainly focuses on the maximum decay heat estimation generated from spent fuel assemblies in the spent fuel pool of Kori units 3&4 at the beginning decommissioning. It is assumed that the spent fuel pool is fully occupied with 2,260 spent fuel assemblies, same as its design capacity. In addition, equally 56.5 spent fuel assemblies have been generated per year. The minimum cooling time is five years considering the transition phase between the permanent shutdown and the amendment of Operating License for decommissioning. Sending and receiving of spent fuel assemblies to/from other units are neglected. Seven representative spent fuel assembly groups are established based on the burnup rate and cooling time. Conservatively high values for the burnup rates and low values for the cooling times are applied. Calculation of the decay heat of each representative group has been performed by using ORIGEN decay solver of SCALE. Then, total decay heat has been calculated based on this. Group 1, 2, and 3 contain comparatively old spent fuel assemblies with 45 GWd/tU burnup rate and 20~30 cooling years. The calculation shows 489~586 watts of decay heat per assembly. Group 4, 5, 6, and 7 contain comparatively new spent fuel assemblies with 55 GWd/tU burnup rate and 5~20 cooling years. The calculation shows 741~1,483 watts of decay heat per assembly. The total maximum decay heat therefore is estimated as 1,609,459 watts.

Aliveness detection based on multispectral analysis for touchless fingerprint recognition

Wonjune Lee,Jungin Lee,Heeseung Choi,Jaihie Kim 대한전자공학회 2010 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

Recently, several researches in touchless fingerprint recognition system has been carried out. However, the touchless system is still vulnerable to spoof attacks by artificial fingerprints. In this paper, we introduce an aliveness detection method with multispectral analysis in touchless fingerprint recognition system. Our fingerprint acquisition device includes green, yellow and red illuminations for capturing the fingerprint images. Multispectral properties, especially reflectance of finger are extracted from the acquired fingerprint images under the each of illuminations. These features which can discriminate between live and fake fingerprint images are used and Support Vector Machine (SVM) is applied to classify live and spoof fingerprint image. In our data set, proposed method achieved 0% EER (Equal Error Rate). The results show that our approach can provide an efficient and effective aliveness detection method in the touchless fingerprint image recognition system.

Sensor Network for Pipeline Leakage Detection in Nuclear Power Plant

Wonjune Lee(이원준),Sunghyun Cho(조성현) 대한전자공학회 2017 전자공학회논문지 Vol.54 No.12

원자력 발전소 매설 배관은 시설 노후화로 인한 누수를 피하기 어렵다. 매설 배관의 누수는 경제적 손실 및 인명 피해로 이어질 수 있기 때문에 실시간 누수 탐지 시스템은 매우 중요하다. 기존 전통적인 누수 탐지 시스템은 대부분 누수 탐지 도구등을 활용하여 작업자가 일일이 확인하는 방법이었다. 이에 본 논문에서는 매설 배관 누수를 실시간으로 자동 탐지할 수 있는 센서 네트워크 시스템을 제안한다. 배관의 누수를 탐지하는 기존의 대표적 방법은 두 가지가 있다. 첫 째는 청음봉을 이용한 물리적 방법이고 다른 하나는 배관 양단의 센서로부터 진동 신호를 수신하여 상호상관함수를 계산하여 누수를 탐지하는 방법이다. 그러나 두 가지 방법 모두 실시간에 탐지에 취약하고 전문지식이 있는 전문가가 필요하다는 단점이 있다. 이를 해결하기 위해서 다양한 연구가 진행되었으나 대부분 복잡한 필터링 알고리즘이 필요하여 실시간 시스템에 사용하기에 부적합한 단계이다. 본 논문에서는 앞서 살펴본 문제점들을 해결하기 위해 향상된 누수탐지 방법을 기반으로 한 지능형 센서 네트워크 구조를 제안한다. 제안하는 방법의 성능 분석을 위해 실제 구축한 필드 테스트 및 시뮬레이션을 진행하였다. 시뮬레이션 및 필드 테스트에서는 다양한 형태의 네트워크 토폴로지에 대해 누수 탐지 데이터 전송 지연 및 패킷 전송 성공률 등을 측정하였다. 시뮬레이션 결과 네트워크 그리드 크기가 5 이하일 경우에는 선형 네트워크 구조가 더 유리하였고 네트워크 그리드 크기가 5보다 큰 경우에는 애드-혹 네트워크 구조가 전송 지연 감소에 더 유리함을 보였다. It is important to apply real-time remote sensing system for premature pipeline leakage detection of nuclear power plant because of economic damage and human injury due to leakage. There are two typical methods to detect pipeline leakage. One is the physical method using acoustic rod and the other is cross-correlation method by receiving vibration signals from sensors at both ends. In the former method, it needs a specialist with expertise in listening and is hard to process in real-time. The latter method is greatly vulnerable to noise signals. There are a lot of efforts to solve the limitation. However, most of the methods proposed so far are not suitable for practical systems because those require additional filtering algorithms. The filtering algorithms are difficult to process in real time and thus not suitable for nuclear power plants. In order to solve the above problems, we propose an intelligent sensor network system based on the leakage detection with improved cross-correlation function. For the performance evaluation, we implement the testbed and simulation. The field test and simulation results show that the ad-hoc structure is superior than the linear structure when the grid size is less than 5, whereas the linear structure is more advantageous when the grid size is greater than 5.

Radiographic analysis of the effect of external rotation on the correction angle in reverse step-cut osteotomy for cubitus varus deformity

Wonjune Chang,Sang Won Moon,Dae-Wook Kim,Seok Hahn,Youngbok Kim 대한견주관절의학회 2022 대한견주관절학회 학술대회논문집 Vol.2022 No.4

Repurposing a Spent Nuclear Fuel Cask for Disposal of Solid Intermediate Level Radioactive Waste From Decommissioning of a Nuclear Power Plant in Korea

Wonjune Mah,Chang-Lak Kim 한국방사성폐기물학회 2022 방사성폐기물학회지 Vol.20 No.3

Operating and decommissioning nuclear power plants generates radioactive waste. This radioactive waste can be categorized into several different levels, for example, low, intermediate, and high, according to the regulations. Currently, low and intermediate-level waste are stored in conventional 200-liter drums to be disposed. However, in Korea, the disposal of intermediate-level radioactive waste is virtually impossible as there are no available facilities. Furthermore, large-sized intermediate- level radioactive waste, such as reactor internals from decommissioning, need to be segmented into smaller sizes so they can be adequately stored in the conventional drums. This segmentation process requires additional costs and also produces secondary waste. Therefore, this paper suggests repurposing the no-longer-used spent nuclear fuel casks. The casks are larger in size than the conventional drums, thus requiring less segmentation of waste. Furthermore, the safety requirements of the spent nuclear fuel casks are severer than those of the drums. Hence, repurposed spent nuclear fuel casks could better address potential risks such as dropping, submerging, or a fire. In addition, the spent nuclear fuel casks need to be disposed in compliance with the regulations for low level radioactive waste. This cost may be avoided by repurposing the casks.

국공내전 후반기 중국공산당의 華北 중심 건국 방침과 定都문제의 향방

李沅埈(Wonjune Lee) 중국근현대사학회 2015 중국근현대사연구 Vol.65 No.-

This paper focuses on the process of which the CCP had decided to make Beijing their new capital. Due to the difficulties in acquiring archival materials on this matter, this article analyzes the CCP’s ‘North China-centered’ state establishment plan which was put into practice after March of 1948. Since then, the CCP set about unifying their North China base areas, and made the ‘North China Liberated Area’ and its’ ‘North China People’s Government’ the center of nation wide base areas. The establishment of the North China Liberated Area was the signal of the national base area unification process, and the North China People’s Government became the focus of the party’s new policies on the centralization of power, institutionalization, regularization which were promoted to prepare for the forthcoming state building. The fundamental object of the unification of the North China base areas in the mid 1948 was to realize the CCP’s North China-centered state establishment plan, and therefore it was a matter-of-course that the CCP had declared their plan of state establishment in September of 1948 when the North China Liberated Area unification process was successfully completed. Just at that moment, the CCP began to mention Beijing as another option for the site of the New People’s Consultative Conference. Mao Zedong wanted to open the conference at Beijing as far as the battlefront situation was allowed, and from the end of October 1948 he clearly pointed Beijing out as the site of the conference. In early 1949, PLA’s chief commanders and takeover cadres of Beijing were informed that the high authorities of the party had decided Beijing as their new capital, and this decision was officialized in March 1949. This paper concludes that the CCP’s North China-centered state establishment plan was materialized by the unification of the North China Liberated Area and this had formed the base on which the Communists had realized their plan to make Beijing as their new capital. Their are other diverse factors that are considered in deciding capitals, but the importance of the fact that capital cities should be located on the power base area of ‘the ruling force’ counts the most.

국방전략의 관점에서 본 1940년대 建都論爭

李沅埈(Wonjune Lee) 중국근현대사학회 2018 중국근현대사연구 Vol.79 No.-

In the capital debate of the 1940’s, Xi’an(西安), Beiping(北平), and Nanjing(南京) were the cities that earned the most support for the postwar China’s capital. This article has compared the three cities’ arguments from the perspective of defense strategy, and has found out that the arguments can generally be divided into three categories. People who supported Xi’an emphasized ‘inland defense(陆防lufang)’ based on the traditional defense strategy concept. On the contrary, people who supported Nanjing emphasized ‘maritime defense(海防haifang)’ based on the changed international situation since mid 19th century. Beiping was supported as China’s new capital on the basis that it was capable of countering both inland and maritime threats. The intellectuals who participated in the debate raised arguments based on their view of the future military threats facing China in the postwar years, and their claims can be generally classified into three categories, which are ‘inland defense strategy(陆防论)’, ‘maritime defense strategy(海防論)’, and ‘inland and maritime defense strategy(陸海兼顧論)’. In the viewpoint that both debates were focused on analyzing the military threats facing China and discussing what defense strategy to choose in the future, the 1940’s capital debate is historically similar to the defense strategy debate of 1874-75. The two debates bear historical resemblance in that the participants were absorbed in analyzing the major military threats confronting China and proposing which defense strategy(inland or maritime) China should adapt to confront it. Whether the core of the military threats facing China at the time was on the continent, at sea, or both, the people who participated in the debate presented appropriate alternatives based on their analysis. Although the alternatives showed a certain difference with the passage of time, they were fundamentally based on three categories, and in that point, the two debates could be discussed in the same historical context.

3D 오토인코더 기반의 뇌 자기공명영상에서 다발성 경화증 병변 검출

최원준(Wonjune Choi),박성수(Seongsu Park),김윤수(Yunsoo Kim),감진규(Jin Kyu Gahm) 한국멀티미디어학회 2021 멀티미디어학회논문지 Vol.24 No.8

1940년대의 北京 建都論과 戰後의 ‘新中國’ 구상

李沅埈(Wonjune Lee) 중국근현대사학회 2017 중국근현대사연구 Vol.76 No.-

Until Beijing was proclaimed as the new capital of the People’s Republic of China in October 1949, there were a number of controversies in the first half of the 20th century on China’s new capital. The debate of the 1940s was the most important one in its scale and influence. When the war against Japan was coming to an end, scholars and intellectuals of China argued on which city was the most appropriate for the capital city of postwar China. The debate had continued after the war, and it came to its’ peak in the National Assembly in December 1946. Different opinions and aspects on the postwar new state building were brought up, and therefore we can see what kind of ideas had competed for the construction of ‘New China’ in the 1940s Chinese society by analyzing this debate. Writers who supported Beijing as the new capital have argued that Beijing is suitable for the new capital based on military strategic considerations, economic aspects(industrialization), historical experience, geographical conditions, cultural characteristics, convenience of transportation, and climatic conditions, etc. These various reasons can be broadly integrated into three categories, which are ‘legacy of the past’, ‘present conditions’, ‘future prospects’. They have argued that Beijing should once again become the capital city based on China’s historical experience and the age old ideas derived from it. And also, Beijing’s geographical conditions, pleasant climate, convenient transportation and fully equipped urban facilities were considered to be more suitable for postwar capital than other cities in terms of ‘present conditions’. In addition, by predicting postwar China’s military dangers and establishing the major national construction projects, the authors argued that Beijing will be the best place to deal with these problems. They had anticipated the construction of a new nation through praising Beijing’s historical heritage, realistic conditions, and the possibility of the future. One important feature we can find is the inclination of thinking about China’s postwar national security. Not to speak of the military strategic point, even from the economic point of view, the authors insisted on industrialization for defense construction. Also, they had emphasized that it is beneficial for internal and external control even when they were analyzing the conveniences of traffic or geographical advantages. It is somewhat resonable in that in the Chinese society of the 1940s, which had been subjected to long-term warfare, the task of securing the safety of ‘New China’ became the first among others.

‘국가건설’과 ‘군중’

李沅埈(Wonjune Lee) 중국근현대사학회 2016 중국근현대사연구 Vol.69 No.-

At the end of 1948 when the Chinese Communists(CCP) were on the verge of victory in the long-lasted civil war, they had set about organizing the New Democracy Youth League(‘NDYL’). Though NDYL was basically similar in its functions to other mass organizations established under CCP’s control, it maintained closer relation with the party than any other organizations. It functioned as the main supply route of the party cadres, and although it was formally a mass organization, it was also treated similarly to the party. Based on these features, the NDYL mobilized the youth for the CCP’s ‘New Democracy’ revolution and their nation building projects However, the CCP had put the NDYL under firm control in order to enhance its efficiency in youth mobilization. The NDYL cadres and members were under tight surveillance and they were routinely educated and self-criticized in accordance with the party’s rectification campaign. Although it is true that the party leaders had emphasized the importance of the NDYL’s organizational independence, their limits of independent action was clearly drawn by the party. The NDYL functioned as a useful instrument for the CCP in establishing a firm foundation of party rule in the early period of PRC. Representing the youths’ political and social interests had also been defined as the NDYL’s main obligation, but it is undeniable that it was pushed out of the scene in the course of the CCP’s revolution and nation building strategy.