• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.232-237
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• 2009

Norovirus surrogate (feline calicivirus) was inactivated by treatment at 50,000 psi for 60 sec by 6.8-$log_{10}TCID_{50}mL^{-1}$. Tissue obtained from oyster (digestive gland, gill and mantle) was qualitatively destroyed and distorted by treatment at pressure greater than 5,000 psi for 60 sec. High pressure treatment induced progressive changes in the color of the oyster adductor muscle. High pressure treatment effectively reduced norovirus surrogate but induced conformational changes in the tissue and color of oyster flesh.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.492-500
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• 2004

The purpose of this study is localization of safety relief valves fur Nuclear Service through technical development with overall design, fabrication, inspection, capacity certification test and functional qualification test of safety relief valves in accordance with KEPIC MN Code(or ASME Sec.III ). The safely relief valve is the important equipment used to protect the pressure vessel, the steam generator and the other pressure facility from overpressure by discharging the operating medium when the pressure of system is reaching the design pressure of the system. But we're depending on technology of the other country up to the present time. Because we don't have our own technologies, we have been spent the great time and money on installing and repairing safety relief valve at nuclear power plant. Therefore we have to achieve the development of safety relief valves for Nuclear Service with our own technologies.

• Nuclear Engineering and Technology
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• v.36 no.4
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• pp.285-294
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• 2004

Pressure wave propagation in the discharge piping with a sparger submerged in a water pool, following the opening of a safety relief valve, is analyzed. To predict the pressure transient behavior, a RELAP5/MOD3 code is used. The applicability of the RELAP5 code and the adequacy of the present modeling scheme are confirmed by simulating the applicable experiment on a water hammer with voiding. As a base case, the modeling scheme was used to calculate the wave propagation inside a vertical pipe with sparger holes and submerged within a water pool. In addition, the effects on wave propagation of geometric factors, such as the loss coefficient, the pipe configuration, and the subdivision of sparger pipe, are investigated. The effects of inflow conditions, such as water slug inflow and the slow opening of a safety relief valve are also examined.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.22-29
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• 2008

This paper provides the evaluation method for the pressure vessel with internal wall-thinning defect, which is based on ASME design criteria. Pressure vessel has wall-thinning partially and patch reinforcement has been attached for reliable operating. However, present partial wall thinning could be through wall thinning at the next inspection time with present corrosion progress speed. Therefore safety margin was calculated for various conditions from present wall-thinning condition to additive patch reinforced condition via two-dimensional and three-dimensional, geometrically linear FE analyses using elastic materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.324-328
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• 2019

There are several dedicated individual chambers for sports that are supplied and used, but none of them are multi-pressured all-in-one chambers that can provide a sport-multi environment simultaneously. In this study, we design a multi-pressure (positive / atmospheric / negative pressure) integrated chamber that can be used for the sport-multi-artificial environment system. We presented new chamber designs with enlarged space for the tall users and then carried out structural analysis with maximum stress and structural safety. Under the targeted allowable pressure conditions, maximum stresses occurred at the joint of the shell and the entrance, the structural safety of the chamber was evaluated with the allowable stress of its material. As a result of the structural analysis of the multi-pressure integrated chamber, the maximum stress for the positive pressure and negative pressure conditions was much smaller than the allowable stress of its material. And as a result of the structural safety evaluation, it was confirmed that the design of the final prototype for the chamber was structurally safe by satisfying the safety factor of 2 or more.

• Journal of the Korean Institute of Gas
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• v.9 no.3 s.28
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• pp.32-37
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• 2005

Hose bands, which are used in LPG (Liquefied Petroleum Gas) or LNG (Liquefied Natural Gas) facilities for home use to join low pressure hoses with fuse-cocks (or regulators), should give a tight connection to prevent a gas leakage from hose connection parts. In this paper, hydraulic pressure tests and pull force tests were carried out to evaluate the performance and swaging length of hose bands. Experimental results showed that the swaging force of ear type bands were higher than those of spring bands and also showed that the optimal swaging length was about 1${\~}$2 mm from the hose end.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.16-27
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• 2018

Since 2014, the Korean government has begun distributing LPG pipelines and LPG tankers to mountainous or island areas where it is difficult to open urban gas supply chains. When installing LPG supply facilities at village level and county level, it supplied consumers with 10 times higher quasi-low pressure (25 kPa to 100 kPa) than conventional gas supply pressure, increasing the risk of gas accident. Due to the pressure that is 10 times higher than the conventional gas supply pressure, large amounts of gas are released at a faster rate when leaked. In order to secure safety of quasi-low-pressure gas pipes, excess flow valves for quasi-low-pressure gas pipes are not developed and are not supplied in Korea. Therefore, Korea Gas Safety Corporation is investigating the performance standards and products of the excess flow valves in order to localize the excess flow valves.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.5
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• pp.453-458
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• 2020

In this study, ethylene-propylene-diene monomer (EPDM) rubbers reinforced with various particle size of carbon black were prepared and tested. We followed recently published CSA/ANSI CHMC2 standard "the test methods for evaluating material compatibility in compressed hydrogen applications-polyemr". Measurement of change in hardness, tensile strength and volume were performed after exposure to maximum operating pressure, 87.5 MPa, for 168 hours (1 week). Once EPDM was exposed to high-pressure hydrogen, the samples experience volume increase and degradation of the physical properties. Also, after the dissolved hydrogen was fully eliminated from the specimens, the hardness and the tensile properties were not recovered. The rubber reinforced with smaller sizes of carbon black particles showed less volume expansion and decrease of physical properties. As a result, smaller particle size of carbon black filler led to more resistance to high-pressure hydrogen.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.48-55
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• 2015

A variety of safety issues were investigated for chemical reactors using a toluene solvent in case of a fire at small to middle scale chemical plants. The issues covered the operation of pressure-relieving valves and the subsequent discharges of the toluene to the atmosphere either directly or through an absorber, which represent the current practice at most small chemical plants. It was shown that the safety valve on the reactor may not operate within about twenty minutes after an external fire breaks out, but, once relieved, the toluene vapor released directly to the atmosphere may form a large explosion range on the ground. It was also shown that if the discharge is routed to an existing absorber used for the scrubbing of volatile organic compounds or dusts, the column may not operate normally due to excessive pressure drops or flooding, resulting in the hazardous release of toluene vapors. This study proposed two ways of alleviating these risks. The first is to ruduce the discharge itself from the safety valve by using adequate insulation and protection covers on the reactor and then introduce it into the circulation water at the bottom of the absorber through a dip linet pipe equipped with a ring-shaped sparger. This will enhance the condensation of toluene vapors with the reduced effluent vapors treated in the packing layers above. The second is to install a separate quench drum to condense the routed toluene vapors more effectively than the existing absorber.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.40-44
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• 2015

Sensitivity on the reactor safety was evaluated for the safety margin and time delay applied to the opening pressure of liquid relief valve(LRV) of the primary heat transport system(PHTS) in the pressurized heavy water reactor(PHWR) type nuclear power plant. Since the LRV is the pressure boundary for the PHTS in the safety analysis, the operating of LRV has a significant effect on the safety analysis results. Therefore it is required during the regulatory review of Wolsong Unit 1 safety analysis to find the safety effect of the application of safety margin and time delay to the LRV opening pressure for the safety analysis of PHTS pressurizing events.