• Title/Summary/Keyword: Hydro power

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ESTABLISHMENT OF A MAINTENANCE PROGRAM TO PREVENT LOSS OF OFFSITE POWER IN NUCLEAR POWER PLANTS

  • Lee, Eun-Chan;Na, Jang-Hwan
    • Nuclear Engineering and Technology
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    • v.45 no.6
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    • pp.791-794
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    • 2013
  • Since the Fukushima accident in 2011, the importance of the electrical systems in nuclear power plants (NPPs) has been emphasized. The result has been that NPP regulators are enhancing their monitoring of loss of offsite power (LOOP) events. Korea Hydro & Nuclear Power Co. (KHNP) is reviewing the status and issues related to LOOPs, and is attempting to establish specific countermeasures to prevent LOOPs, because they can have severe consequences in the complicated maintenance schedule during an outage. A starting point for preventing LOOPs is the control of the loss of voltage (LOV)-initiating components. In order to reflect this in the risk assessment program, an LOV monitor is being developed for use during plant outages.

THE SHORT-TERM EFFECTS OF LOW-DOSE-RATE RADIATION ON EL4 LYMPHOMA CELL

  • Bong, Jin-Jong;Kang, Yu-Mi;Shin, Suk-Chul;Choi, Moo-Hyun;Choi, Seung-Jin;Lee, Kyung-Mi;Kim, Hee-Sun
    • Journal of Radiation Protection and Research
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    • v.37 no.2
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    • pp.56-62
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    • 2012
  • To determine the biological effects of low-dose-rate radiation ($^{137}Cs$, 2.95 mGy/h) on EL4 lymphoma cells during 24 h, we investigated the expression of genes related to apoptosis, cell cycle arrest, DNA repair, iron transport, and ribonucleotide reductase. EL4 cells were continuously exposed to low-dose-rate radiation (total dose: 70.8 mGy) for 24 h. We analyzed cell proliferation and apoptosis by trypan blue exclusion and flow cytometry, gene expression by real-time PCR, and protein levels with the apoptosis ELISA kit. Apoptosis increased in the Low-dose-rate irradiated cells, but cell number did not differ between non- (Non-IR) and Low-dose-rate irradiated (LDR-IR) cells. In concordance with apoptotic rate, the transcriptional activity of ATM, p53, p21, and Parp was upregulated in the LDR-IR cells. Similarly, Phospho-p53 (Ser15), cleaved caspase 3 (Asp175), and cleaved Parp (Asp214) expression was upregulated in the LDR-IR cells. No difference was observed in the mRNA expression of DNA repair-related genes (Msh2, Msh3, Wrn, Lig4, Neil3, ERCC8, and ERCC6) between Non-IR and LDR-IR cells. Interestingly, the mRNA of Trfc was upregulated in the LDR-IR cells. Therefore, we suggest that short-term Low-dose-rate radiation activates apoptosis in EL4 lymphoma cells.

Conceptual Designs and Evaluation of the Treatment Process of Square and Cylindrical Concrete Re-Package Drums

  • Young Hwan Hwang;Sunghoon Hong;Seong-Sik Shin;Seokju Hwang;Jung-Kwon Son;Cheon-Woo Kim;Changgyu Kim;Kwang Soo Park;Taeseob Lim;Donghun Park
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.22 no.2
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    • pp.227-235
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    • 2024
  • After the permanent shut down of Kori Unit 1, various decommissioning activities will be implemented, including decontamination, segmentation, waste management, and site restoration. During the decommissioning period, waste management is among the most important activities to ensure that the process proceeds smoothly and within the expected timeframe. Furthermore, the radioactive waste generated during the operation should be sent to a disposal facility to complete the decommissioning project. Square and cylindrical concrete re-package drums were generated during the 1980s and 1990s. The square, containing boron concentrates, and cylindrical, containing spent resin, concrete re-package drums have been stored in a radioactive waste storage building. Homogeneous radioactive waste, including boron concentrates, spent resin, and sludge, should be solidified or packaged in high-integrity containers (HICs). This study investigates the sequential segmentation process for the separation of contaminated and non-contaminated regions, the re-packaging process of segmented or crushed cement-solidified boron concentrate, and re-packaging in HICs. The conceptual design evaluates the re-packaging plan for the segmented and crushed cement-solidified waste using HICs, which is acceptable in a disposal facility, and the quantity of generated HICs from the treatment process.

Effect Analysis on Self-supporting Energy of Newtown Sewage Treatment Facility for Low-carbon Green City (저탄소 녹색도시 조성을 위한 신도시 하수처리시설의 에너지 자립 효과 분석)

  • Ahn, Soo-Jeung;Hyun, Kyoung-Hak;Kim, Jong-Yeob;Choung, Youn-Kyoo
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.6
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    • pp.683-690
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    • 2010
  • Renewable and unutilized energy (biogas power generation, wind power, solar, small hydro-power, sewage heat source, etc.) seems to be suitable to install for the sewage treatment facilities. There are 357 sewage treatment plants in 2007. 17 plants among these have been operating for self-supporting energy by using solar power, small hydro-power and biogas in 2008. Newly built sewage treatment plant of 96,000 $m^3$/day for a newtown is expected to get up to energy consumption of 10 GWh/yr. If solar energy, small hydro-power and biogas-equipments were applied to the new treatment plant, self-supporting energy of the new sewage treatment plant will get up to 56.1%. As a results, about 2,379ton $CO_2$/yr $CO_2$ emission reduction can be expected by using renewable energy. These efforts for self-supporting energy will lead sewage treatment plant to new energy recycle center.

Performance and Internal Flow of a Cross-Flow Type Hydro Turbine for Wave Power Generation (파력발전용 횡류형 수력터빈의 성능 및 내부유동)

  • Choi, Young-Do;Cho, Young-Jin;Kim, You-Taek;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.3
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    • pp.22-29
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    • 2008
  • Clean and renewable energy technologies using ocean energy give us non-polluting alternatives to fossil and nuclear-fueled power plants to meet establishment of countermeasures against the global warming and growing demand for electrical energy. Among the ocean energy resources, wave power takes a growing interest because of its enormous amount of potential energy in the world. Therefore, various types of wave power conversion system to capture the energy of ocean waves have been developed. However, suitable turbine type is not normalized yet because of relatively low efficiency of the turbine systems. The purpose of this study is to investigate the internal flow and performance characteristics of a cross-flow type hydro turbine, which will be built in a caisson for wave power generation. Numerical simulation using a commercial CFD code is conducted to clarify the effects of the turbine rotation speed and flow rate variation on the turbine characteristics. The results show that the output power of the cross-flow type hydro turbine with symmetric nozzle shape is obtained mainly from Stage 2. Turbine inlet configuration should be designed to obtain large amount of flow rate because the static pressure and absolute tangential velocity are influenced considerably by inlet flow rate.