• 한국철도학회논문집
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• 제18권1호
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• pp.71-80
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• 2015

도심 통근용 지하철은 출퇴근시간에 기관사 한 사람이 맡고 있는 인원이 약3,000명 이상에 달하여 비상상황 발생 시 기관사의 조치 능력에 따라 수많은 사람들의 생명과 재산이 좌우된다. 2003년 2월 대구지하철 화재 참사 이래 철도에서의 안전 확보가 사회문제화되어 이를 개선하고자 2004년 10월 철도안전법이 제정되고 철도종사자의 핵심인 기관사의 면허제가 도입되어 2006년 7월부터 시행되었다. 본 연구는 기관사 면허제가 시행되어 8년이 지난 이 시점에서 운전업무에 종사하는 기관사들과 이들 상급자들의 인식조사를 통하여 기관사 면허제의 시행효과를 경험적으로 규명해보고자 한다. 또한, 통계 분석을 통하여 면허제의 시행효과를 더 높일 수 있는 방안들을 찾아 정책적 제안을 하고자 한다.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.819-823
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• 2024

The main criteria used in NEI 18-04 to define SSCs as risk-significant include (1) the SSC is required to keep all LBEs within the F-C target, and (2) the total frequency with the SSC failed exceeds 1% of the limit for at least one of the three cumulative risk metrics used for evaluating the integrated plant risk. The first one is a reasonable criterion in determining the risk significant SSCs. However, the second criterion may not be adequate to serve the purpose of determining the risk significance of SSCs. In the second criterion, the cumulative risk metric values representing the integrated plant risk (less the preventive and mitigative effects of the SSC being evaluated) are compared to a risk limit that represents a very small contribution to the overall integrated plant risk, which corresponds appropriately to the contributions from individual SSCs. The easiest approach to redefine the NEI 18-04 definition of risk-significant SSCs in relation to the integrated plant risk metrics is to compare the difference, between the risk metric value calculated with the SSC failed and the risk metric value calculated with the SSC credited, with 1% of the risk limit established for the integrated plant risk metrics.

• Nuclear Engineering and Technology
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• 제47권3호
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• pp.240-252
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• 2015

In the original licensing application for the prototype fast-breeder reactor, MONJU, the event progression during an unprotected loss of flow (ULOF), which is one of the technically inconceivable events postulated beyond design basis, was evaluated. Through this evaluation, it was confirmed that radiological consequences could be suitably limited even if mechanical energy was released. Following the Fukushima-Daiichi accident, a new nuclear safety regulation has become effective in Japan. The conformity of MONJU to this new regulation should hence be investigated. The objectives of the present study are to conduct a preliminary evaluation of ULOF for MONJU, reflecting the knowledge obtained after the original licensing application through CABRI experiments and EAGLE projects, and to gain the prospect of in-vessel retention for the conformity of MONJU to the new regulation. The preliminary evaluation in the present study showed that no significant mechanical energy release would take place, and that thermal failure of the reactor vessel could be avoided by the stable cooling of disrupted-core materials. This result suggests that the prospect of in-vessel retention against ULOF, which lies within the bounds of the original licensing evaluation and conforms to the new nuclear safety regulation, will be gained.