• Nuclear Engineering and Technology
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• 제44권6호
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• pp.597-610
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• 2012

The passive auxiliary feedwater system (PAFS) is one of the advanced safety features adopted in the APR+, which is intended to completely replace the conventional active auxiliary feedwater system. With an aim of validating the cooling and operational performance of PAFS, an experimental program is in progress at KAERI, which is composed of two kinds of tests; the separate effect test and the integral effect test. The separate effect test, PASCAL ($\underline{P}$AF$\underline{S}$ $\underline{C}$ondensing Heat Removal $\underline{A}$ssessment $\underline{L}$oop), is being performed to experimentally investigate the condensation heat transfer and natural convection phenomena in PAFS. A single, nearly-horizontal U-tube, whose dimensions are the same as the prototypic U-tube of the APR+ PAFS, is simulated in the PASCAL test. The PASCAL experimental result showed that the present design of PAFS satisfied the heat removal requirement for cooling down the reactor core during the anticipated accident transients. The integral effect test is in progress to confirm the operational performance of PAFS, coupled with the reactor coolant systems using the ATLAS facility. As the first integral effect test, an FLB (feedwater line break) accident was simulated for the APR+. From the integral effect test result, it could be concluded that the APR+ has the capability of coping with the hypothetical FLB accident by adopting PAFS and proper set-points of its operation.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.1926-1938
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• 2020

We validated the performance of RELAP MOD3.3 code regarding the hybrid SIT with available experimental data. The concept of the hybrid SIT is to connect the pressurizer to SIT to utilize the water inside SIT in the case of SBO or SB-LOCA combined with TLOFW. We investigated how well RELAP5 code predicts the physical phenomena in terms of the equilibrium time, stratification, condensation against Separate Effect Test (SET) data. We also conducted the validation of RELAP5 code against Integrated Effect Test (IET) experimental data produced by the ATLAS facility. We followed conventional approach for code validation of IET data, which are pre-test and post-test calculation. RELAP5 code shows substantial difference with changing number of nodes. The increase of the number of nodes tends to reduce the condensation rate at the interface between liquid and vapor inside the hybrid SIT. The environmental heat loss also contributes to the large discrepancy between the simulation results of RELAP5 and the experimental data.

• Nuclear Engineering and Technology
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• 제49권7호
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• pp.1537-1546
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• 2017

Many thermal-hydraulic tests have been conducted at the Korea Atomic Energy Research Institute for verification of the SMART (System-integrated Modular Advanced ReacTor) design, the standard design approval of which was issued by the Korean regulatory body. In this paper, the contributions of these tests to the standard design approval of SMART are discussed. First, an integral effect test facility named VISTA-ITL (Experimental Verification by Integral Simulation of Transients and Accidents-Integral Test Loop) has been utilized to assess the TASS/SMR-S (Transient and Set-point Simulation/Small and Medium) safety analysis code and confirm its conservatism, to support standard design approval, and to construct a database for the SMART design optimization. In addition, many separate effect tests have been performed. The reactor internal flow test has been conducted using the SCOP (SMART COre flow distribution and Pressure drop test) facility to evaluate the reactor internal flow and pressure distributions. An ECC (Emergency Core Coolant) performance test has been carried out using the SWAT (SMART ECC Water Asymmetric Two-phase choking test) facility to evaluate the safety injection performance and to validate the thermal-hydraulic model used in the safety analysis code. The Freon CHF (Critical Heat Flux) test has been performed using the FTHEL (Freon Thermal Hydraulic Experimental Loop) facility to construct a database from the $5{\times}5$ rod bundle Freon CHF tests and to evaluate the DNBR (Departure from Nucleate Boiling Ratio) model in the safety analysis and core design codes. These test results were used for standard design approval of SMART to verify its design bases, design tools, and analysis methodology.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권2호
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• pp.1-6
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• 2014

The objective of this study was to find the effect of the mixture of the nonionic surfactant and bioactive agent that solubilizes trichlorobenzene (TCB) present as a contaminant for surfactant-enhanced soil flushing (SESF). Three different nonionic surfactants and two different bioactive agents were obtained from four companies. Separate funnel experiments and shaker table agitation / centrifugation experiments were used for the test. Based on the separate funnel experimental results, three suitable mixture agents (APG + OSE, Brij 35 + MOSE, T-Maz 60 + MOSE) were selected. In the shaker table agitation / centrifugation experiments, these three different mixture agents were reduced to one (T-Maz 60 +MOSE). The maximum removal (95%) of TCB was obtained using a mixture of the nonionic surfactant and bioactive agent. Therefore, the used test methods and results can be used for SESF.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2702-2713
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• 2022

A steam generator tube rupture accompanying a core damage may cause the fission product to be released to environment bypassing the containment. In such an accident, the steam generator is the major path of the radioactive aerosol release. AEOLUS facility, the scaled-down model of Korean type steam generator, was built to examine the aerosol removal in the steam generator during the steam generator tube rupture accident. Integral and separate effect tests were performed with the facility for the dry and flooded conditions, and the decontamination factors were presented for different tube configurations and submergences. The dry test results were compared with the existing test results and with the analyses to investigate the aerosol retention physics by the tube bundle, with respect to the particle size and the bundle geometry. In the flooded tests, the effect of submergence were shown and the retention in the jet injection region were presented with respect to the Stokes number. The test results are planned to be used to constitute the aerosol retention model, specifically applicable for the analysis of the steam generator tube rupture accident in Korean nuclear power plants to evaluate realistic fission product behavior.

• 한국가정과교육학회지
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• 제12권2호
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• pp.1-14
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• 2000

The purposes of this study were to identify the adolescent’s perception to grandparent’s clothing behavior, the effect of grandparent’s clothing behavior on the attitudes toward their grand parents, and the variables related to the adolescent’s attitudes toward their grandparent affecting grandparent’s clothing behavior. The results of this study may provide the foundations for the continuing family educational material to promote the grandparent-grandchildren relationship. Questionnaires were distributed to middle and high school students in Chonbuk Province through school teachers from June 9th 18th. 1999. and 485 questionnaires were analysed. Frequencies percentages, factor analysis. Cronbach’s a. t-test, F-test. and Duncan’s Multiple Range test were used for data analysis. The results were as follows: 1. The adolescent’s perception level of grandparent’s clothing behavior was higher when grandparents were younger. healthier and wealthier. in separate living status. and in case of younger and more female adolescents. In case of separate living status. the adolescent’s perception level was higher when grandparent and adolescent contacted frequently. 2. The adolescent’s perception level of grandparent’s clothing behavior was favorable when their total attitude toward grandparent was positive, especially in economic, intellectual. personality, and family relation aspects. 3. The effects of the perception of grandparent’s clothing behavior on the adolescent attitude toward their grandparent were higher in case of grandmother. female adolescent. and separate living status, less educated. and in worse health status grandparent.

• Korean Chemical Engineering Research
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• 제43권6호
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• pp.722-727
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• 2005

Dow99Ca350, MFG-220, Finex CS-10GC는 이온 교환 수지로써, 당 분리에 주로 사용되며, 모두 poly styrene DVB를 기본 골격으로 술폰산염, 혹은 술폰산을 작용기로 하고 있다. 이 분리 수지들은 이미 제당 산업의 연속 분리 공정에서 사용되고 있으며, 이에 대해 본 실험은 온도의 영향으로 인한 Dow99Ca350, MFG-220과 Finex CS-10GC의 분리수지에서 당의 체류 혹은 흡착 특성 변화를 알아보기 위하여 수행되었다. 당 분리의 시료로써 사용된 물질은 과당과 포도당으로써 위의 분리 수지와 함께 제당 산업에서 널리 사용된다. Dow99Ca350의 팽윤 시험, 공극률 시험, 펄스 시험, 전단 분석을 통해 온도에 대한 영향을 확인하였다. MFG-220, Finex CS-10GC의 경우, 펄스 시험을 통해 온도 변화에 의한 크로마토그램의 변화를 알아보았다. 실험의 결과 Dow99Ca350, MFG-220과 Finex CS-10GC는 과당과 포도당 각각 최대 1.76, 3.37％의 체류 시간 변화를 보임으로써 온도에 안정적인 경향성을 보였다.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.1066-1080
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• 2024

SMART100 has a containment pressure and radioactivity suppression system (CPRSS) for passive containment cooling system (PCCS). This prevents overheating and over-pressurization of a containment through direct contact condensation in an in-containment refueling water storage tank (IRWST) and wall condensation in a CPRSS heat exchanger (CHX) in an emergency cool-down tank (ECT). The Korea Atomic Energy Research Institute (KAERI) constructed scaled-down test facilities, SISTA1 and SISTA2, for the thermal-hydraulic validation of the SMART100 CPRSS. Three separate effect tests were performed using SISTA1 to confirm the heat removal characteristics of SMART100 CPRSS. When the low mass flux steam with or without non-condensable gas is released into an IRWST, the conditions for mitigation of the chugging phenomenon were identified, and the physical variables were quantified by the 3D reconstruction method. The local behavior of the non-condensable gas was measured after condensation inside heat exchanger using a traverse system. Stratification of non-condensable gas occurred in large tank of the natural circulation loop. SISTA2 was used to simulate a small break loss-of-coolant accident (SBLCOA) transient. Since the test apparatus was a metal tank, compensations of initial heat transfer to the material and effect of heat loss during long-term operation were important for simulating cooling performance of SMART100 CPRSS. The pressure of SMART100 CPRSS was maintained below the design limit for 3 days even under sufficiently conservative conditions of an SBLOCA transient.

• 한국지진공학회논문집
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• 제20권1호
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• pp.1-8
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• 2016

Permanent deformation plays a key role in performance based earthquake resistant design. In order to estimate permanent deformation after earthquake, it is essential to secure reliable response history analysis(RHA) as well as earthquake scenario. This study focuses on permanent deformation of an inverted T-type wall under earthquake. The study is composed of two separate parts. The first one is on the verification of RHA and the second one is on an effect of input earthquake motion. The former is discussed in this paper and the latter in the companion paper. The verification is conducted via geotechnical dynamic centrifuge test in prototype scale. Response of wall stem, ground motions behind the wall obtained from RHA matched pretty well with physical test performed under centrifugal acceleration of 50g. The rigorously verified RHA is used for parametric study to investigate an effect of input earthquake motion selection in the companion paper.

• Advances in concrete construction
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• 제13권3호
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• pp.265-279
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• 2022

The roughness of substrate concrete interfaces before new concrete placement has a major effect on the interface bond behaviour. However, there are challenges associated with the consistency of the final roughness interface prepared using conventional roughness preparation methods which influences the interface bond performance. In this study, five quantitative interface roughness textures with different roughness tooth angles, depths, and tooth distribution were created to ensure consistency of interface roughness and to evaluate the bond behaviour at a precast and new concrete interface using the splitting tensile test, slant shear test, and double-shear test. In addition, smooth interface specimens and two separate the pitting interface roughness were also utilized. Obtained results indicate that the quantitative roughness has a very limited effect on the interface tensile bond strength if no extra micro-roughness or bonding agent is added at the interface. The roughness method however causes enhanced shear bond strength at the interface. Increased tooth depth improved both the tensile and shear bond strength of the interfaces, while the tooth distribution mainly influenced the shear bond strength. Major failure modes of the test specimens include interface failure, splitting cracks, and sliding failure, and are influenced by the tooth depth and tooth distribution. Furthermore, the interface properties were obtained and presented while a comparison between the different testing methods, in terms of bond strength, was performed.