• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.9 no.4
• /
• pp.231-236
• /
• 2011

When the Fukushima nuclear power plant accident occurred in March of 2011, a hydrogen explosion in the reactor building at the 4th unit of Fukushima plants led to a big surprise because the full core of the unit 4 reactor had been moved and stored underwater at the spent nuclear fuel storage pool for periodic maintenance. It was because the possible criticality in the fuel storage pool by coolant loss may yield more severe situation than the similar accident happened inside the reactor vessel. Fortunately, it was assured to be evitable to an anxious situation by a look of water filled in the storage pool later. In the paper, the safety state of the spent fuel storage pool and rack structures of the domestic nuclear plants would be roughly reviewed and compared with the Fukushima plant case by engineering viewpoint of potential severe accidents.

• Advances in Energy Research
• /
• v.6 no.1
• /
• pp.75-90
• /
• 2019

Anthropogenic greenhouse gas emissions are rising rapidly despite efforts to curb release of such gases. One long term potential solution to offset these destructive emissions is the capture and storage of carbon dioxide. Partially depleted hydrocarbon reservoirs are attractive targets for permanent carbon dioxide disposal due to proven storage capacity and seal integrity, existing infrastructure. Optimum well completion design in depleted reservoirs requires understanding of prominent geomechanics issues with regard to rock-fluid interaction effects. Geomechanics plays a crucial role in the selection, design and operation of a storage facility and can improve the engineering performance, maintain safety and minimize environmental impact. In this paper, an integrated geomechanics workflow to evaluate reservoir caprock integrity is presented. This method integrates a reservoir simulation that typically computes variation in the reservoir pressure and temperature with geomechanical simulation which calculates variation in stresses. Coupling between these simulation modules is performed iteratively which in each simulation cycle, time dependent reservoir pressure and temperature obtained from three dimensional compositional reservoir models in ECLIPSE were transferred into finite element reservoir geomechanical models in ABAQUS and new porosity and permeability are obtained using volumetric strains for the next analysis step. Finally, efficiency of this approach is demonstrated through a case study of oil production and subsequent carbon storage in an oil reservoir. The methodology and overall workflow presented in this paper are expected to assist engineers with geomechanical assessments for reservoir optimum production and gas injection design for both natural gas and carbon dioxide storage in depleted reservoirs.

• Asia-Pacific Journal of Business
• /
• v.13 no.1
• /
• pp.263-275
• /
• 2022

Purpose - This study estimated the non-market value of pumped storage power generation using the contingent valuation method(CVM). Design/methodology/approach - CVM, a non-market value estimation method, was used. The perception of pumped storage power generation and the willingness to pay(WTP) for pumped storage power generation were investigated among 612 randomly selected households. Findings - It was analyzed that the average value per household was 7309.99 won/month, and the sources of these benefits were 1819.37 won due to the improvement of power generation efficiency, 1320.48 won due to the improvement of power system reliability, 2359.24 won due to the stabilization of electricity rates, 2110.89 won due to water resource management It was assumed that a circle occurred. If the average monthly benefit per household is expanded to cover countries across the country, it is estimated that the annual value to our society from pumped storage power generation will be KRW 1.796.6 trillion. Research implications or Originality - It is necessary to consider the operation of pumped-water power generation by reflecting the value of pumped-up power generation that is not evaluated in the market. Since Korea's electricity market is isolated in a state where it is impossible to connect with other countries, it may be vulnerable to a stable electricity operation system. Therefore, there is a need for a facility that can stably secure reserve power and produce power quickly when necessary. If pumped-water power generation is actively used for power operation, a more stable power system can be secured.

• Journal of Dairy Science and Biotechnology
• /
• v.22 no.1
• /
• pp.27-35
• /
• 2004

The shelf lift of market milk should be determined based on the flavor which is influenced by environmental and sanitary conditions of dairy farm, milk processing plant, and storage and transportation facility as well as compositional quality, such as protein and fat, of the milk itself. The legal shelf life of market milk is often limited by microbiological quality, e.g. total bacterial count, coliform count, and food poisoning bacteria. The bacteria involved with milk spoilage and poisoning are originated from bacteria contaminating milk after pasteurization or spores surviving the heat treatment of pasteurization. The important factors which influence the shelf life of market milk are microbiological quality of raw milk, pasteurization condition, post-pasteurization contamination, and temperature during storage and transportation. The organoleptic quality and shelf life of market milk should be further improved by satisfying the consumer's taste, which depends on somatic cell count and bacterial count of milk, feed quality, foreign substance in milk, and physical treatment during processing and transportation.

• Journal of Korean Institute of Industrial Engineers
• /
• v.26 no.4
• /
• pp.384-391
• /
• 2000

Most of the previous works on classical location models are based on the assumption that the value(or utilities) of inventory remains constants over time. In this study a special case of location problem is studied for both ameliorating and deteriorating items in two-echelon supply-chain management such as agricultural and fishery products. The objective of this study is to determine the minimum number of storage facilities among a discrete set of location sites so that the probability for each customer to be covered is not less than a critical value. We have formulated this problem using stochastic set-covering problem which can be solved by 0-1 programming method. Also we developed a computer program and applied to a set of problems for fish culture storage and distribution centers and the sample results well show the impact of ameliorating and deteriorating rate on the location problem. For the further study, a graphical user-interface with visualization for input and output is needed to be developed.

• Proceedings of the KIPE Conference
• /
• 2019.07a
• /
• pp.307-308
• /
• 2019

The Pohang Light Source (PLS) - II is a 3 GeV third-generation synchrotron radiation facility. To inject electron beam from LINAC, a kicker modulator system and kicker magnets are installed in the PLS-II storage ring tunnel. The injected beam then falls into the storage ring beam dynamic aperture. This paper describes the design and implementation of the solid-state kicker modulator for PLS-II. The solid-state kicker modulator is consisted of high voltage solid state switch stacks. the technical considerations of the solid-state switch stacking for kicker modulator is discussed. The achieved capability of the solid-state kicker modulator demonstrates that is fulfills the design requirement of providing half-sine pulsed current of 10kA (peak), 6us (Base-width), with jitter < 2ns (Standard deviation). simulation and experimental results are presented to demonstrate the performance of the solid-state kicker modulator.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.11a
• /
• pp.343-344
• /
• 2018

KAERI has about 185 tons of $D-UF_6$ from 1986 and it being stored 16 48Y type cylinders inside of storage building. The $D-UF_6$ cylinders should be transported to other countries for the deconversion into stable materials such as $U_3O_8$ in order to enhance the storage safety and disposal. For the transportation to other country and loading the cylinders to the deconversion facility, the sampling process is essential. The design and procedure for the sampling are now developing, and environmental effect evaluation and risk evaluation works will be performed to acquire license for the sampling.

• Nuclear Engineering and Technology
• /
• v.53 no.5
• /
• pp.1464-1478
• /
• 2021

Selective Production of Exotic Species is an innovative plant for advanced nuclear physic studies. A radioactive beam, generated by using an UCx target-ion source system, is ionized, selected and accelerated for experimental objects. Very high vacuum conditions and appropriate safety systems to storage exhaust gases are required to avoid radiological risk for operators and people. In this paper, Failure Mode, Effects, and Criticality Analysis of a preliminary design of high activity gas recovery system is performed by using a modified Fuzzy Risk Priority Number to rank the most critical components in terms of failures and human errors. Comparisons between fuzzy approach and classic application allow to show that Fuzzy Risk Priority Number is able to enhance the focus of risk assessments and to improve the safety of complex and innovative systems such as those under consideration.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.10 no.2
• /
• pp.117-123
• /
• 2012

In order to dispose of the LILW(low and intermediate level radioactive waste) stored at KAERI, the radwaste drum assay system will be introduced to evaluate the radioisotopes inventory of stored drums. At present, the construction project of the dedicated assay facility to operate it and carry out routine maintenance of that equipment has been conducting at the radwaste treatment facility. Since that facility will be constructed in front of a 1st radwaste storage facility as well as the radwaste drums to be assayed and the transmission source in the radwaste drum assay system are in that facility, they could act as the radioactive sources and then, would affect the dose rate at the inside and the outside of the facility. Therefore, the radiation shielding should be evaluated through the concrete wall near to the radioactive sources whether the wall thickness is sufficient against the regulations. In this study, the radiation safety for the concrete wall around the radiation controlled area in the radwaste drum assay facility was evaluated by the MCNP code. From the evaluation results, the thickness of those concrete walls which are under consideration of about 30 cm was enough to shield the radiation from the radioactive sources.

• 한국가스학회:학술대회논문집
• /
• 1997.09a
• /
• pp.162-167
• /
• 1997