At Nuclear Power Plant (NPP), aging management is performed as part of the Periodic Safety Review (PSR) in accordance with the Nuclear Safety Act. The purpose of the aging management program (AMP) is to manage the integrity of structures, systems and components (SSCs) in NPPs over time and use. Through this, aging deterioration is mitigated to increase equipment life and secure long-term operation safety. Fuel Oil Chemistry is one of the AMPs. Through this program, aging management is performed for storage tanks, piping and other metal components that contact with diesel fuel oil. The program is focused on managing loss of material due to general, pitting, crevice, and microbiologically-influenced corrosion (MIC) and fouling that leads to corrosion of the diesel fuel tank internal surfaces. The fuel oil aging management method currently applied to NPPs in Korea measures the concentration of water and particulate contamination in the oil, analyzed the trend, and periodically cleans and inspect the inside of tanks. Among them, in monitoring MIC, a direct analysis and monitoring of the amount of microorganisms may be more effective. In this study, a method for improving the MIC monitoring system for diesel fuel oil systems was reviewed by reviewing reference documents including NUREG 1801 and examining the methods actually applied in US NPPs.

Around the world, Nuclear Power Plants (NPPs) have been operated since the 1950s and are used as a major power source. In Korea, Kori unit 1 stared commercial operation for the first time in 1978, and as of 2023, 25 units of NPPs are in operation. NPPs produce electricity for about 40 to 60 years after receiving an operating license, and after securing safety through a safety evaluation, the operating period is extended. NPPs that operate for a long time are systematically evaluated for safety at regular intervals through Periodic Safety Review (PSR) recommended by the IAEA. In Korea, PSR has been introduced and performed since 2000. This study reviewed the process of the PSR by comparing with the international PSR procedure. The PSR process is established through the IAEA SSG-25 document and proceeds in the order of establishment of basis document - individual factor evaluation - global assessment - integrated improvement plan. In Korea, PSR is carried out in a similar process, but there are some differences from the IAEA’s procedure. The safety factor review is conducted under the agreement of basis document between the licensee and the regulatory body, but the prior agreement procedure with the regulatory body is not reflected in Korea. As a result, if the licensee and the regulatory body have different opinions on the current licensing basis and the modern safety standards after the evaluation is performed, a difference may occur in the review results and safety enhancement items, which may lead to inefficient PSR progress. PSR is conducted for the continuous safe operation and management of NPPs, and it is important to refer to overseas standards and cases. Although procedures, guidelines, and regulatory requirements are in place in Korea, continuous review and improvement are required. It is necessary to improve procedures such as basis document and global assessment in order to more efficiently carry out PSR evaluation by regulatory agency and licensee’s safety enhancement actions of domestic NPPs

Among domestic Nuclear Power Plants (NPPs), there are a total of 10 nuclear power plants whose operating license expires by 2030, excluding Kori unit 1 and Wolsong unit 1, which are permanently shut downed. Continued operation of these nuclear power plants is being reviewed as a government task. For continued operation, nuclear power plant owners must prepare periodic safety review and other evaluation reports to receive reviews to maintain safety even during continued operation. In the safety evaluation of NPP, it is important to refer to overseas cases and operation experiences. In this study, the matters of radioactive waste management for continued operation of NPP was considered by analyzing the safety evaluation reports and safety enhancements of license renewal of NPP in USA, Radioactive waste generated from NPPs can be classified into solid, liquid, and gaseous states. Radioactive waste generated during the operation and maintenance of power plants is classified, stored and treated in the radioactive waste management system according to the source. Equipment and monitors related to radioactive waste management are continuously operated, managed, inspected according to standards and maintain their original functions. Various activities to reduce the generation and emission of radioactive waste from NPPs are performed. After reviewing the NRC’s safety evaluation report on the application documents for license renewal of US NPPs (Sequoyah, Byron and braidwood) the evaluation details and matters requiring enhancement for the radioactive waste management system were confirmed. As a major check, selective leaching occurred in the body of the gray cast iron valve and the heat exchanger shell containing the copper alloy exposed to the radioactive waste liquid. Selective leaching causes loss of material and may interfere with the original function of the facility, so management is required. For the safe operation and management of NPPs, it is important to refer to overseas cases and experiences. Among the safety evaluations for the continued operation of domestic NPPs, in the field of the radioactive waste management system, if the case of the US NPP is referred to, the review by the regulatory body and the action taken by the licensee will be more efficient.

본 연구에서는 우라늄 폐촉매 처리 공정에서 발생하는 우라늄 함유 폐기물 대상으로 유리-세라믹 매질 구조의 대형 디스크 소결체 형태로 제작 시, 최종 제작된 소결체의 비등방향 수축 특성 및 변형율 변화를 연구하였다. 본 연구에서는 최대 직경 40 cm를 갖는 다양한 크기 원형 디스크 형태와 원형 디스크의 1/4 크기의 부채꼴 형 소결체를 제작하여 이들의 비등방성 수축 특성을 평가하였다. 60 MPa 압력하에서 만들어지는 성형체는 소결 시 성형체의 크기 및 형태에 관계없이 높은 등방성 수축하였다. 제조된 전체 소결체에 대한 비등방성율은 평균 1.6%이었고 이때 평균 부피 감용율은 37.4% 이었다. 이러한 결과 로부터 국내에서 발생한 우라늄 폐촉매를 처리하기 위한 공정에서 발생하는 우라늄 함유 폐기물은 대형 디스크 형태의 유리-세라믹 매질 형태로 고형화함으로써 높은 안정성과 부피감용 효과를 가지며 200 L 드럼에 포장될 수 있음이 확인되었다.

향후 원자력시설 해체 시 막대한 양의 해체 콘크리트 폐기물이 발생할 수 있음을 감안하였을 때, 방사성 콘크리트 폐기물의 최적 처리기술에 대한 면밀한 검토와 향후 기술개발 방향에 대한 논의는 반드시 필요하다. 본 논문에서는 방사성 콘크리트 폐기물의 국내외 발생 사례를 종합해 보고, 처리 대상이 되는 방사성 콘크리트 폐기물의 특성을 검토하였다. 또한, 종래의 방사성 콘크리트 처리기술로써 기계적 제염기술, 화학적 제염기술, 부피감용기술, 재활용 및 고화기술에 대한 국내외 적용 사례를 정리하고 기술 개발 동향을 살펴봄으로써 기존 기술의 한계점을 파악하고 기술 고도화 방향을 고찰해 보고자 한다.

본 연구에서는 고염/고방사성 폐액 내 함유된 주요 고방사성핵종인 Cs 제거를 목적으로 고효율의 복합 흡착제(potassium cobalt ferrocyanide (PCFC)-loaded chabazite (CHA)) 합성 및 이의 적용성을 평가하였다. 복합 흡착제는 Cs을 비롯한 다 른 입자를 수용할 수 있는 CHA를 지지체로 선정하였으며, CoCl2 및 K4Fe(CN)6 용액의 단계적인 함침/침전을 통해 PCFC를 CHA 세공 내에 고정화함으로써 합성하였다. 복합 흡착제의 합성 시 평균 입자크기가 10 ㎛ 이상의 CHA를 지지체로 사용할 경우, PCFC 입자는 안정적인 형태로 고정화되었다. 또한, 합성 시 복합 흡착제의 정제를 증가시키는 세척 방법을 최적화함으로써, 복합 흡착제의 물리적 안정성이 향상되었다. 최적의 합성법을 통해 얻은 복합 흡착제에 의한 Cs 흡착 시, 담수(무염 조건) 및 해수(고염 조건)에서 모두 빠른 흡착 속도를 보였으며, 염 농도와 무관하게 비교적 높은 분배계수 값(104 mL·g-1 이상)을 나타내었다. 그러므로, 본 연구에서 합성한 복합 흡착제는 CHA 및 PCFC가 각각 가지고 있는 물리적 안정성과 Cs 에 높은 선택성 등을 고려하여 촤적화한 소재이며, 고염/고방사성폐액에 함유되어 있는 Cs을 고효율로 신속하게 제거할 수 있음을 알 수 있다.

Backed by the rapidly-growing economy, China sends the most tourists to Korea. Accordingly, growing consumption of Chinese tourists is strongly drawing attention of the Korean retail industry. Academia has conducted more relevant researches, such as effective branding of Korean Wave, and services to attract tourists. Despite a series of efforts, including specialized tour products and language services, there have been an increasing number of Chinese visitors complaining about their experience in Korea and Chinese tourists are urgently demanding improvements. Hence, comprehending sophisticated consumption behavior of Chinese tourists is becoming more important than ever before. Also, it needs to explore how shopping experiential value that they experience while purchasing fashion goods in Korea affects their satisfaction of the store and product. Previous literature has shown that perceived shopping value has a positive effect on customer satisfaction and behavioral intention (Mathwick et al., 2001). Previous domestic studies that targeted Chinese tourists have focused on investigating the shopping motivation and satisfaction (Ko, 2011) and market segmentation of Chinese tourist shoppers (Oh, 2014). Previous studies have approached this problem mainly from its cognitive aspect and few studies have focused on the emotional aspect during shopping. This study suggests that emotional behavior mediates the relationship between shopping experiential value and consumer attitude toward products and stores. According to the Korea Tourism Organization, the ratio of male to female Chinese tourists visiting Korea changed from 69:31 in 1995 to 59:41 in 2005. In 2013, female Chinese tourists outnumbered males at a ratio of 41:59. The number of Chinese female tourists continues to increase. Females are known to be more involved in fashion consumption. Hence, this study is conducted on 550 Chinese female tourists who have shopping experiences during their visit to Korea. The ages of the respondents range from 20 to over 50 years old, with a mean age of 33.5 years. Their shopping experiential value is measured by visual appeal, crowding, economic benefits, and service excellence, and is expected to trigger emotions of entertainment and escapism. Variables including entertainment and escapism are measured using the Experiential Value Scale developed by Mathwick et al. (2001). This study finds that three experiential values (visual appeal, crowding, and service excellence) have positive influences on entertainment. For example, customers feel greater entertainment when visual appeal, service excellence and/or the number of customers in the store is greater. The emotion of entertainment turns out to have positive impacts on both store satisfaction and product satisfaction. According to the examination of how shopping experiential values affect escapism, crowding and economic benefits have a positive impact, whereas visual appeal and service excellence have a negative impact on escapism. Previous studies define escapism as an emotion of which customers are absorbed by entertaining activities and satisfied with shopping. This study assumes that all the shopping experiential values may have a positive impact on escapism. Escapism is a status where customers are deeply occupied with shopping without thinking of anything as if they were in another world, and a much stronger emotion of entertainment than usual pleasure from shopping. This study finds that the higher visual appeal and service excellence tends to generate the lower the escapism. This may be attributable to the fact that the survey was examined only on Chinese tourists. The respondents were asked to recall the most memorable item among the fashion products that they purchased during their visit to Korea. Their shopping experiences varied widely from well-organized malls, like department stores and duty free shops, to crowded environments, like Dongdaemun, traditional markets and subway stores. As a result, different experiential values have different impacts on escapism. Economic benefits and crowding which are experienced during shopping help to absorb in shopping, and these are likely to have positive impacts on escapism. On the other hand, visual appeal and service excellence may have different influences on escapism according to the shopping environment that Chinese consumers experienced. For example, Dongdaemun or subway stores are less visually appealing than department stores or duty free shops, but trigger stronger sense of escapism. Because survey questions to measure service excellence include Chinese (language) proficiency of sales staff, it is expected that higher language proficiency level of sales staff tends to generate lower degree of escapism, the sense of feeling that one is indeed in foreign country like Korea, for customers. Escapism has negative impacts on both product and store attitudes. Escapism is a status of absorption in which customers are emotionally occupied with pleasant feelings, and purchases along with a high escapism are likely to be less rational and more impulsive. In particular, this study examines tourist shoppers, and the respondents evaluate products they purchased in another country after they return home, and this may have caused the negative attitude toward products and shops. In fact, some previous studies found that overly positive emotions have negative impacts on purchase behavior (Liljander &Standvik, 1997; Andrade, 2005). This study confirms that the shopping experiential values perceived by Chinese tourists affect their product and store attitudes through the emotions of entertainment and escapism. It is particularly notable that this study verifies diverse roles of different emotions such as entertainment and escapism in the context of tourist shopping. This study employs empirical analysis on tourists, and provides practical implications including the importance of shopping experiential values for developing retail strategies.

가금에서의 스트레스 지표는 혈중 corticosterone의 농도, heterohphil/lymphocyte 비율 뿐만 아니라 사료 및 물의 섭취량, 체중, 산란율, 이상행동 등도 포함된다. 사육온도, 바닥형태, 사육밀도, 수송, 부리자르기, 제한급이, 질병 등이 사육현장에서 가금이 경험할 수 있는 스트레스 요인이 될 수 있다. 다양한 스트레스 지표 중에서 특정 지표만으로 스트레스의 여부를 평가하는 것은 오류를 범할 수 있으므로 동시에 여러 지표를 이용하여 평가하는 것이 스트레스에 대한 평가의 신뢰도를 향상시킬 수 있다.

본 연구의 목적은 경상남도 하동에서 생산된 녹차의 사료적인 가치를 평가하는 것이다. 먼저, 하동에서 생산되는 녹차의 특성을 이해하기 위하여 일반성분, 항산화 활성 및 항균성활성 분석을 행하였으며, 녹차는 조단백질을 20%이상, 조섬유를 약 19% 함유하고 있으며, 높은 항산화 및 항균활성을 보였다. 68주령 하이라인브라운 레그혼 96수를 개체별 케이지에 수용하여 8주간의 사양실험을 수행하였을 때, 사료에 첨가된 녹차(1% 까지)는 산란계의 사료섭취량, 사료요구율 및 헨데이 난생산성(%)에 대한 영향이 없었다. 녹차는 급여 3-4주에 일시적으로 정상란의 산란율을 감소시켰고, 5-6주에 난중을 증가시켰다. 급여후기에 계란의 신선도(Haugh unit)의 감소를 지연시켰다(P<0.05). 녹차 급여는 난각강도와 무게에 영향을 미치지 않았다. 사료 중 녹차의 함량이 증가함에 따라 혈중 creatinine 과 amylase의 농도와 칼슘의 함량이 유의적으로 감소하였다(P<0.05). 따라서 이상의 결과는 하동녹차는 산란계의 사료에 충분히 이용 가능한 것으로 사료된다.