• Nuclear Engineering and Technology
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• 제54권3호
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• pp.781-789
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• 2022

KHNP had licensed Dynamic Control rod Reactivity Measurement (DCRM) method using detector current signals of PWRs in 2006. The method has been applied to all PWRs in Korea for about 15 years successfully. However, the original method was inapplicable to PWRs using low-sensitivity integral fission chamber as ex-core detectors because of their pulse pile-up and the nonlinearity of the mean-square voltage at low power region. Therefore, to overcome this disadvantage, a modified method, DCRM-EK, was developed using kinetics behavior after equilibrium condition where the pulse counts maintain the maximum value before pulse pile-up. Overall measurement, analysis procedure, and related computer codes were changed slightly to reflect the site test condition. The new method was applied to a total of 15 control rods of 1000 MWe and 1400 MWe PWRs in Korea with worths in the range of 200 pcm -1200 pcm. The results show the average difference of -0.4% and the maximum difference of 7.1% compared to the design values. Therefore, the new DCRM-EK will be applied to PWRs using low sensitivity integral fission chambers, and also can replace the original DCRM when the evaluation fails by big noises present in current or voltage signals of uncompensated/compensated ion chambers.

• 방사선산업학회지
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• 제18권1호
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• pp.1-7
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• 2024

The International Commission on Radiological Protection (ICRP) lowered the annual equivalent dose limit of lens of the eye for radiation workers from 150 to 20 mSv in April 2011. This trend of lowering the equivalent dose limit for radiation workers has been observed worldwide, including international organizations such as the International Atomic Energy Agency (IAEA), International Organization for Standardization (ISO) and the European Commission (EC). In 2016, the Nuclear Safety and Security Commission of South Korea published research results that included a proposal for lowering the equivalent dose limit of lens of the eye for radiation workers in line with the ICRP recommendation. However, as of now, South Korea's Nuclear Safety Act and related regulations still specify an annual equivalent dose limit of lens of the eye as 150 mSv for radiation workers. The IAEA and ISO have issued guidelines regarding radiation protection for lens of the eye and recommended a dose level for the lens of the eye at 5 or 6 mSv per year for periodic monitoring of the equivalent dose for the lens of the eye.

• 방사선산업학회지
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• 제10권1호
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• pp.7-12
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• 2016

Ikaros, a transcription factor containing zinc-finger motif, has known as a critical regulator of hematopoiesis in immune system. Ikaros protein modulates the transcription of target genes via binding to the regulatory elements of the genes promoters. However the regulatory function of Ikaros in other organelle except nuclear remains to be determined. This study explored radiation-induced modulatory function of Ikaros in cytoplasm. The results showed that Ikaros protein lost its DNA binding ability after LDIR (low-dose ionizing radiation) exposure. Cell fractionation and Western blot analysis showed that Ikaros protein was translocated into cytoplasm from nuclear by LDIR. This was confirmed by immunofluorescence assay. We identified Autotaxin as a novel protein which potentially interacts with Ikaros through in vitro protein-binding screening. Co-immunoprecipitation assay revealed that Ikaros and Autotaxin are able to bind each other. Autotaxin is a crucial enzyme generating lysophosphatidic acid (LPA), a phospholipid mediator, which has potential regulatory effects on immune cell growth and motility. Our results indicate that LDIR potentially regulates immune system via protein-protein interaction of Ikaros and Autotaxin.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4809-4818
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• 2022

The decommissioning project of a nuclear facility is a large-scale process that is expected to take about 15 years or longer. The range of risks to be considered is large and complex, then, it is expected that various risks will arise in decision-making by area during the project. Therefore, in this study, the risk family derived from the Decommissioning Risk Management (DRiMa) project was reconstructed into a decommissioning project risk profile suitable for the Kori Unit 1. Two criteria of uncertainty and importance are considered in order to prioritize the selected 26 risks of decommissioning project. The uncertainty is scored according to the relevant laws and decommissioning plan preparation guidelines, and the project importance is scored according to the degree to which it primarily affects the triple constraints of the project. The results of risks are divided into high, medium, and low. Among them, 10 risks are identified as medium level and 16 risks are identified as low level. 10 risks, which are medium levels, are classified in five categories: End state of decommissioning project, Management of waste and materials, Decommissioning strategy and technology, Legal and regulatory framework, and Safety. This study is a preliminary assessment of the risk of the decommissioning project that could be considered in the preparation stage. Therefore, we expect that the project risks considered in this study can be used as an initial data for reevaluation by reflecting the detail project progress in future studies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.152-153
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• 2011

원자력발전소(원전) 터빈발전기에서 생산된 전력은 송전망과 발전소 운전에 필요한 기기 작동을 위해 소내로 공급되도록 설계되어 있다. 최근 신규원전의 전원 공급을 위해 가동중 원전의 송전선로 휴전 작업시 운영기술지침서의 운전제한시간을 초과한 휴전작업에 대한 안전성 문제가 대두되었다. 본 논문에서는 정상운전중인 원전의 송전선로 1개 휴전 작업중 운전중인 송전선로 상실시 리스크를 분석하여 허용기준 만족 여부를 평가하고, 리스크관리 대책을 수립하여 전력계통의 신뢰성 및 안전성 향상에 기여하고자 한다.

• 전기학회논문지P
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• 제64권4호
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• pp.251-255
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• 2015

Chiller system plays an important role of maintaining room temperature constantly by supplying chilled water to Heating, Ventilating and Air Conditioning(HVAC)or area room cooler equipment during plant normal operation or accident condition. Chiller failures are one of the most frequently occurring equipment failures. If the types of chiller failures are analyzed and grouped thoroughly, it would be helpful to make chiller maintenance strategy at the plants. That would enhance equipment reliability of chiller in the end. In this paper, chiller failure data during three years were analyzed and categorized by specific failure code. In addition, the various proposals to improve equipment reliability of chiller were suggested such as Preventive Maintenance Optimization(PMO) strategy and performance monitoring reinforcement and so on.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 추계 학술대회 논문집
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• pp.79-86
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• 2005

In PSR on the Kori 3&4 NPP, The low level radioactive waste resin from SGBD demineralizer is more than $65\%$ of total waste resin in NPP So, it needs to be improved. The secondary cooling water pH control methods are used ammonia-AVT from the first. According to changing ETA which is better than ammonia, SGBD cation load is increased about 2-3 times. Waste resin product is also increased in proportion to the SGBD cation load. To reduce the waste volume, new cation resin exchange criteria is confirmed that demineralizer is almost saturated.

• Nuclear Engineering and Technology
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• 제33권5호
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• pp.539-546
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• 2001

Systematic procedure of developing radionuclide release scenarios was established based on FEP list and Interaction Matrix for near-surface LILW repository. FEPs were screened by experts＇review in terms of domestic situation and combined into scenarios on the basis of Interaction Matrix analysis. Under the assumption of design scenario, The system domain was divided into three sections: Near-field, Far-field and Biosphere. Sub-scenarios for each section were developed, and then scenarios for entire system were built up with sub-scenarios of each section. Finally, sixteen design scenarios for near-surface repository were evaluated A reference scenario and other noteworthy scenarios were selected through experts＇scenario screening.

• 한국수소및신에너지학회논문집
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• 제23권2호
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• pp.191-197
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• 2012

The hydrogen storage is one of the key technologies to achieve the successful hydrogen economy and a chain to connect hydrogen production to its utilization. In this paper, characteristics and strong candidates of hydrogen storage technologies were analyzed from the objective information of patents. Also, the hydrogen storage technology trends and gaps were assessed using statistical or qualitative analysis. In this study the patents applied in Korea, Japan, US and EU from 10 or 20 years ago to 2011 were analyzed. The result of patent analysis could be used for developing or searching for promising technology of the hydrogen storage.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2012년도 춘계학술발표회 초록집
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• pp.143-146
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• 2012

가스계 소화설비의 배관이 장거리 배관인 경우 소화약제 저장탱크의 선택밸브가 개방된 다음 소화약제가 화재지역에 방출될 때 까지 일정시간이 소요된다. 또한 소화약제 배관 내부의 공기와 소화약제가 함께 화재지역에 방출되어 소화약제 농도가 희석되므로 소화효과가 감소한다. 이러한 문제점을 해결하기 위하여 소화약제 배관이 방화지역으로 연결되는 지점에서 대기로 연결되는 공기 방출배관과 방출장치를 설치하여 가스계 소화설비의 소화효과를 높일 수 있는 설비 개선방안을 마련하였다.