• Nuclear Engineering and Technology
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• v.45 no.4
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• pp.459-468
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• 2013

During a station blackout (SBO), the initiating event is a loss of Class IV and Class III power, causing the loss of the pumps, used in systems such as the primary heat transporting system (PHTS), moderator cooling, shield cooling, steam generator feed water, and re-circulating cooling water. The reference case of the SBO case does not credit any of these active heat sinks, but only relies on the passive heat sinks, particularly the initial water inventories of the PHTS, moderator, steam generator secondary side, end shields, and reactor vault. The reference analysis is followed by a series of sensitivity cases assuming certain system availabilities, in order to assess their mitigating effects. This paper also establishes the strategies to mitigate SBO accidents. Current studies and strategies use the computer code of the Integrated Severe Accident Analysis Code (ISAAC) for Wolsong plants. The analysis results demonstrate that appropriate strategies to mitigate SBO accidents are established and, in addition, the symptoms of the SBO processes are understood.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.144-155
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• 2023

The core catcher is used as a passive safety system in new generation nuclear power plants to create a space in the containment for the placing and cooling of the molten corium under various severe accidents. This research investigates the role of the core catcher in the VVER-1000 reactor containment system in mitigating the effects of core meltdown under various severe accidents within the context of the Ex-vessel Melt Retention (EVMR) strategy. Hence, a comparison study of three severe accidents is conducted, including Station Black-Out (SBO), SBO combined with the Large Break Loss of Coolant Accident (LB-LOCA), and SBO combined with the Small Break Loss of Coolant Accident (SB-LOCA). Numerical comparative simulations are performed for the aforementioned scenario with and without the EX-vessel core-catcher. The results showed that considering the EX-Vessel core catcher reduces the amount of hydrogen by about 18.2 percent in the case of SBO + LB-LOCA, and hydrogen production decreases by 12.4 percent in the case of SBO + SB-LOCA. Furthermore, in the presence of an EX-Vessel core-catcher, the production of gases such as CO and CO2 for the SBO accident is negligible. It was revealed that the greatest decrease in pressure and temperature of the containment is related to the SBO accident.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.679-683
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• 2006

A feeding trial was conducted with 10 sheep for 12 weeks to examine the effect of soybean oil (SBO) supplementation on long-chain fatty acids composition, especially cis9,trans11-conjugated linoleic acid (c9,t11-CLA) in fat tissues. Sheep were fed either a SBO supplemented diet (5%, DM basis) or a control diet without SBO. Chopped rye grass hay was fed as roughage. Concomitant increases in contents of total cholesterol (T-C) and HDL-cholesterol (HDL-C) in the plasma of sheep were observed from the SBO supplementation. The supplementation of SBO reduced (p<0.05) the proportions of $C_{16:1}$, $C_{17:0}$ and $C_{17:1}$ but increased (p<0.05) the proportions of $C_{18:0}$ and octadecenoic acid (t11-$C_{18:1}$) in the intramuscular fat. The $C_{18:0}$ proportion only in the subcutaneous fat was increased (p<0.05) by the SBO supplementation. The SBO supplementation slightly increased CLA proportion in the intramuscular fat and subcutaneous fat.

• Journal of the Korean Home Economics Association
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• v.30 no.4
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• pp.77-88
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• 1992

To investigate the oxidative stabilities of the ${\gamma}$-ray irradiated soybean during storage and heating and some physico-chemical characteristics of soybean and the extracted soybean oil (SBO) with/without the ${\gamma}$-ray irradiation were determined. The ${\gamma}$-ray level use in irradiation for soybean were 2.5, 5.0 and 10.0 KGY respectively and Acid Value, Peroxide Value, Conjugated Diene Value, Composed Fatty Acids amounts, and Trans Fatty Acid occurrence were determined for all samples, which were incubated at 45$\pm$1$^{\circ}C$ for 25 days heated at 180$\pm$1$^{\circ}C$ for 30 hours. And these values of the ${\gamma}$-ray treated samples were compared to those of nontreated samples. The results were obtained as follows : 1. According to the increased level of the ${\gamma}$-ray irradiation, there was little difference in Dielectric Constant, Viscosity, and the Induction Period by Rancimat. But, in case of 5.0 KGY, oxidative stability was increased more twice than that of non-irradiation. In the quantity of fatty Acids composition of the extracted soybean oil irradiated with 10.0 KGY, palmitic, oleic and linoleic acids were less increased thanb those of non-irradiation, while stearic, linolenic acids were decreased. In the case of 2.5 KGY irradiation, stearic and oleic acids were increased. 2. The Acid Value of SBO according to the ${\gamma}$-ray irradiation level was almost not change, but was 0.1 lower than that of non-irradiation during incubation (45$\pm$1$^{\circ}C$). The Peroxide Value of SBO with the ${\gamma}$-ray irradiation, was very lower than that of non-irradiation, but its effect on oxidative stability was better of SBO treated with 5.0 KGY and 10.0 KGY. In the Fatty Acids composition of SBO, palmitic, stearic, oleic acids were increased, while linoleic, linolenic acids were decreased during incubation(45$\pm$1$^{\circ}C$). This tendency was more obvious due to the ${\gamma}$-ray level. While heating(180$\pm$1$^{\circ}C$), the Acid Value of SBO treated with the ${\gamma}$-ray irradiation was decreased, the Acid Value of SBO irradiated with 2.5 KGY was the lowest. Also the peroxide Values of SBO treated with 5.0 KGY, 10.0 KGY were very lower than that of non-irradiation. Conjugated Diene Value of SBO was almost unchanged according to the ${\gamma}$-level and heating time. 3. When the methyl linoleate was irradiated with the ${\gamma}$-ray, the Trans Fatty Acid was little produced. In case of SBO with non-irradiation, the trans C18:1 was occured about 6.5~7.9%, but trans C18:2 and C18:3 were not shown, while SBO irradiated with the ${\gamma}$-ray 2.5, 5.0, 10.0 KGY, trans C18:3 and C18:2 amount in SBO were increased according to heating time, but trans C18:3 was little occured. As these results, the effects of the ${\gamma}$-ray irradiation to oil containing food were to cut down the energy for food storage and to increase oxdative stability during storge. And also it was shown to be the best that 10.0 KGY of the ${\gamma}$-ray irradiation would be applied to soybean.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.140-143
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• 1993

Station Blackout(SBO) event means the complete loss of alternating current(AC) electrical power to the essential & nonessential switchgear buses in a nuclear power plants. Since many safety systems in nuclear power plants depend upon alternative current power, the SBO event could be an important contributor to damage of reactor core. Therefore, the SBO events have been considered as a very important safety issues in a nuclear power plants. In this paper, as evaluating the design characteristics of offsite & emergency power systems, an acceptable minimum SBO duration is calculated. And it is presented that the design method for alternative AC(AAC) sources to cope with the SBO events.

• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.719-728
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• 2015

Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO) accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

• The KSFM Journal of Fluid Machinery
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• v.17 no.6
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• pp.104-108
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• 2014

The recent Fukushima nuclear power plant accidents shows that the core make up at high RCS pressure condition is very important to prevent core melting. The core make up flow at high pressure condition should be driven by gravity force or passive forces because the AC-powered safety features are not available during a Station Black Out (SBO) accident. The reactor Coolant System (RCS) mass inventory is continuously decreased by releasing steam through the pressurizer safety valves after reactor trip during a SBO accident. The core will be melted down within 2~3 hours without core make up action by active or passive mode. In the new design concept of a Hybrid Safety Injection Tank (Hybrid SIT) both for low and high RCS pressure conditions, the low pressure nitrogen gas serves as a charging pressure for a LBLOCA injection mode, while the PZR high pressure steam provides an equalizing pressure for a high pressure injection mode such as a SBO accident. After the pressure equalizing process by battery driven initiation valve at a high pressure SBO condition, the Hybrid SIT injection water will be passively injected into the reactor downcomer by gravity head. The SBO simulation by MARS code show that the core makeup injection flow through the Hybrid SIT continued up to the SIT empty condition, and the core heatup is delayed as much.

• Korean journal of food and cookery science
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• v.14 no.4
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• pp.380-387
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• 1998

The stability of red pepper seed oils during storage at 20${\pm}$3$^{\circ}C$, 40${\pm}$3$^{\circ}C$ and heating at 140${\pm}$3$^{\circ}C$ or 180${\pm}$3$^{\circ}C$ were measured to evaluate red pepper seed oil as a cooking oil. Two species of red pepper seeds (native, improved) were dried by either sunlight or heating to prepare the oil samples of NS (native, sunlight-dried), IS (improved, sunlight-dried), NF (native, heated), and IF (improved, heated). During storage at 20${\pm}$3$^{\circ}C$ or 40${\pm}$ 3$^{\circ}C$, acid values (AV) of all red pepper seed oils were higher than that of soy bean oil (SBO), however, peroxide values (POV) were similar to SBO. Antioxidative stability of NS was better than SBO but IF was not. By the heat treatments at 140${\pm}$3$^{\circ}C$ or 180${\pm}$3$^{\circ}C$, NS was identified to have better antioxidative stability than SBO and IF was the lowest. In sensory evaluation of each deep-fat fried potato-chip at 180${\pm}$5$^{\circ}C$, potato-chips fried in NS were better than that of SBO for color, taste, and flavor. NS-fried potato-chips got the highest score in overall acceptance (p<0.05), however, those of IF showed little acceptance. When blended oils (SBO: NOS, 0, 25, 50, 75%) were used, 50% blended oil was the best for taste, color, flavor, cripness, and total acceptance.

• Food Engineering Progress
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• v.14 no.1
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• pp.27-34
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• 2010

Multilayer edible coatings was applied to lemon with beeswax-hydroxypropyl methylcellulose (BW-HPMC), soybean oil-carboxymethyl cellulose (SBO-CMC), and carnaubawax-shellac-locust bean gum (CW-SL-LBG), respectively. The multilayer was composed of two layers of the same material, but the outer layer only contained vitamins C and E as antioxidants. Coating amounts built on lemon peel were measured to be large in the order of CW-SLLBG> BW-HPMC> SBO-CMC. The coated lemons were stored at 30${^{\circ}C}$ for 12 days. CW-SL-LBG showed the least change during the storage in weight loss, rotten rate, firmness, and browning. Whereas SBO-CMC had the least change in pH, soluble solid amount, and titratable acidity. In a sensory test, CW-SL-LBG was evaluated to be the best in the attributes such as spoilage, glossiness, color, firmness, and flavor. Overall CW-SL-LBG was judged to be the best for multilayerd coating with vitamin C and E on lemon.

• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.541-546
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• 2010

This study was to investigate the dry bond strengths of the plywoods manufactured with 3 hours ozonized soybean oil (SBO)/polymeric methylene diphenyl diisocyanate (pMDI) adhesive at mid and high curing temperature. In results of the dry bonding strengths of the 3 hrs-ozonized SBO mixed with pMDI at high curing temperature were respectively the strengths of weight ratio of 3hrs-ozonized SBO : pMDI, 1 : 0.5, 4.74 kgf/$cm^2$, 1 : 0.75, 7.14 kgf/$cm^2$ 1 : 1, 9.29 kgf/$cm^2$, 1 : 2, 16.53 kgf/$cm^2$, 1 : 3, 17.42 kgf/$cm^2$, and 1 : 4, 16.75 kgf/$cm^2$. Therefore, it was found that the equivalent ratio was formed approximately between 3 hrs-ozonized SBO : pMDI 1 : 2 and 1 : 3. The dry bonding strengths of the 3hrs-ozonized SBO mixed with pMDI at medium curing temperature were respectively the strengths of weight ratio of 3 hrs-ozonized SBO : pMDI, 1 : 0.5, 3.16 kgf/$cm^2$, 1 : 0.75, 6.13 kgf/$cm^2$ 1 : 1, 8.18 kgf/$cm^2$, 1 : 2, 11.82 kgf/$cm^2$. In this experiment the higher bonding strength at high curing temperature was shown approximately between 3 hrs-ozonized SBO : pMDI 1 : 2 and 1 : 3. If this wood adhesive is used at high curing temperature, it is possibile to bond the plywoods.