Tritium and 14C are two most important radionuclides released from nuclear facilities to the environment, and 14C contributes dominant radiation dose to the population around nuclear power plants. This paper presents an overview of the production, pathway, species and levels of tritium and 14C in nuclear facilities, mainly nuclear power plants. The methods for sampling and collection of different species of tritium and 14C in the discharge gas from the stack in the nuclear facilities, atmosphere of the nuclear facilities and environment are presented, and the features of different methods are reviewed. The on-line monitoring methods of gaseous tritium and 14C in air and laboratory measurement methods for sensitive determination of tritium and 14C in collected samples, water and environmental solid samples are also discussed in detailed. Meanwhile, the challenges in the determination and speciation analysis of tritium and 14C are also highlighted.

Currently, researches are being actively conducted in assessing seismic performance of nuclear facilities in USA and Europe. In particular, applying this technique of assessing seismic performance to design of isolation systems in nuclear power plants is being performed and then ASCE 4 Draft (2013) is being revised accordingly in the United States. In order to satisfy the probabilistic performance objectives described by seismic responses with certain confidence levels (ASCE 43, 2005), the probability distributions of these responses have to be defined. What is the minimum number of input ground-motions to obtain the probability distribution precise enough to represent the unknown actual distribution? Theoretical basis, for how to determine the minimum number of input ground-motions for given a logarithmic standard deviation to approximate the unknown actual median of the log-normal distribution within a range of error at a certain level of confidence, is introduced by Huang et al. (2008). However, the relationship between the level of confidence and the range of error is not stated in the previous study. In this paper, based on careful reviews on the previous work, the relationship between the level of confidence and the range of error is logically and explicitly stated. Furthermore, this relationship is also applied to derive the minimum number of input ground-motions in order to approximate the unknown actual logarithmic standard deviation. Several recommendations are made for determining the minimum number of input ground-motions in probabilistic assessment on seismic performance of facilities in nuclear power plants.

North Carolina State University는 North Carolina의 주도 Raleigh에 위치에 있으며, 1887년 설립되어 1889년 72명의 학생이 등록한 이후 현재 약 34,000명의 학생과 8000명의 교수/교직원이 Engineering, Mathematics, Science, Technology, Education, 그리고 Research 분야 등을 이끌어 가고 있는 세계 명문대학 중 하나 입니다. Durham, Raleigh, 그리고 Chapel Hill의 중심에 위치한 Research Triangle Park(RTP)은 세계최고의 Research Park을 자랑 하고 있으며, RTP 주변으로 Duke University, North Carolina University at Chapel Hill, 그리고 North Carolina State University가 그 중심에 서 있습니다.

원자력시설 유지보수 및 해체시 다관절 매니퓰레이터 이상동작에 대한 작업자의 반응특성과 안전속도 수준을 다루고 있다. 매니퓰레이터 팔의 속도, 오류 가능성, 오류 형태와 같은 여러 가지 작업 조건에 따 라 작업자의 반응시간, 고장 경보(false alarm), 실패(miss) 횟수 등에 대한 작업자의 반응 특성을 분석하 였다. 매니퓰레이터 팔의 속도와 이상동작 형태는 반응시간에 영향을 주지만, 이상동작 가능성에 영향을 미치지 않았고, 두 요인 이상의 교호작용은 대체로 영향이 없었다. 매니퓰레이터 팔의 속도변화에 따른 반응시간 특성은 이상동작 형태에 따라 다르지만 대체로 약간 증가하는 추세를 보였다.