• Journal of the Korea Concrete Institute
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• v.24 no.4
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• pp.445-452
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• 2012

In this study, experimental research was carried out to evaluate the structural performance of the reinforced concrete beam using strengthening materials (embedded FRP rod, metal fittings) in existing reinforced concrete buildings. Seven reinforced concrete beams comprised of retrofitted embedded FRP rod (BCR series), embedded FRP rod with metal fittings (BCR-AC series), and standard specimen (BSS) were constructed and tested under monotonic loading. Design parameters of test specimens were amount of embedded FRP rod and metal fittings. The test results showed that the maximum load carrying capacity of specimens with embedded FRP rod (BCR series) and embedded FRP rod with metal fittings (BCR-AC series) increased by 21~55% and 21~63%, respectively, in comparison with the standard specimen BSS. BCR series test specimens failed by the adhesion slip and concrete cover separation. BCR-AC series test specimens failed by the adhesion slip due to the confining effect of metal fittings.

• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.855-864
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• 2017

The control rod assembly controls reactor power by adjusting its position during normal operation and shuts down chain reactions by its free drop under scram conditions. Therefore, the drop performance of the control rod assembly is important for the safety of a nuclear reactor. In this study, the drop performance of the conceptually designed control rod assembly for the prototype generation IV sodium-cooled fast reactor that is being developed at the Korea Atomic Energy Research Institute as a next-generation nuclear reactor was experimentally investigated. For the performance test, the test facility and test procedure were established first, and several free drop performance tests of the control rod assembly under different flow rate conditions were then carried out. Moreover, performance tests under several types and magnitudes of seismic loading conditions were also conducted to investigate the effects of seismic loading on the drop performance of the control rod assembly. The drop time of the conceptually designed control rod assembly for 0% of the tentatively designed flow rate was measured to be 1.527 seconds, and this agrees well with the analytically calculated drop time. It was also observed that the effect of seismic loading on the drop time was not significant.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.469-476
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• 2001

The Ν-value in the standard penetration test(SPT) is affected by the magnitude of the rod penetration energy transmitted from the falling hammer as well as the geotechnical characteristics of the ground. Understanding of the striking energy efficiency in the SPT equipment is getting important for that reason. The energy efficiencies of the doughnut hammer with the hydraulic lift system and the automatic trip hammer system were investigated through field tests using the instrumented rod and wave-signal acquisition systems including the pile driving analyzer(PDA) . The rod energy ratio, ΕR$\_$r/ was defined as the ratio of the energy delivered to the drilling rod to the potential free-fall energy of the hammer. It appears that the type of the hammer and lift/drop system had a strong influence on the energy transfer mechanism and ΕR$\_$r/ also varies according to the energy instrumentation system and the analysis methods.

• Nuclear Engineering and Technology
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• v.29 no.2
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• pp.175-180
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• 1997

It has been known that eater-side corrosion of fuel rods in nuclear reactor is accompanied with the metallic loss of wall thickness and hydrogen pickup in the fuel dadding tube. The fuel dad corrosion is one of the major factors to be controlled to maintain the fuel integrity during reactor operation. An oxide later thickness measuring device equipped with ECT probe system was developed by KAERI, and whose performance test was carried out in NDT(Non-destructive Test) hot-cell or PIE(Post Irradiation Examination) Facility. At first, the calibration/performance test was executed for the unirradiated standard specimen rod fabricated with several kinds of plastic thin films whose thickness ore predetermined, and the result of which showed a good precision within 10% of discrepancy. And then, hot test us peformed for the irradiated fuel rod selectively extracted from J44 fuel assembly discharged from Kori Unit-2. The data obtained with this device were compared with the metallographic result obtained from destructive examination in PIEF hot-cell on the same fuel rod to verify the validity of the measurement data.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.11
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• pp.124-131
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• 1996

The dynamic material property of Mn-B ally high-strength steel is investigated through the rod impact test which is one of simple test methods for the analysis of the material behavior under high-strain-rate. Rod impact test is performed to produce the deformed shape of rod and analyzed by the one-dimensional theory based on conservation law and the two-dimensional hydrocode AUTODYN-2D. The dynamic yield stress is determined and compared with the static yield stress to investigate the strain-rate sensitivity of Mn-B alloy high-strength steel.

• Journal of the Korean Magnetics Society
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• v.26 no.5
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• pp.154-158
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• 2016

A CRDM (Control Rod Drive Mechanism) is an electromagnetic device which drives a control rod assembly linearly to regulate the reactivity of a nuclear core. An RPIS (Rod Position Indication System) is used as a position indicator for a control rod assembly of a CRDM of SMART, and an RPIS consists of permanent magnets and reed switches. SMART is designed for the maximum coolant temperature of $350^{\circ}C$, and the permanent magnets are installed inside of the reactor. The reed switches and electrical circuit are installed outside of the reactor on the other hand. Test coil for a reed switch is test equipment for quality verification of a reed switch, and a test coil consists of a coil and core. In this study, magnetic property of test coil and permanent magnet on a reed switch is compared by using finite element electromagnetic simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.152-159
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• 2001

This paper presents a development of the recoil rod pull force measurement system suing the load cell with a sleeve normally available in the recoil system test. The commercial load cell cannot be used in the test of recoil system floating the breach contact point freely in the air. The load cell is designed and manufactured to meet the recoil system test condition. Theoretical analysis and experimental results show that the accuracy of the developed measurement system is within $\pm$0.5%. We notice that the measurement technique proposed in this paper is accurate and useful in the recoil rod pull force measurement of the recoil system.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.71-78
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• 2002

The N-value from the standard penetration test(SPT) is affected by the magnitude of the rod penetration energy transmitted from the falling hammer as well as the geotechnical characteristics of the ground. Understanding of the striking energy efficiency in the SPT equipment is getting important for that reason. The energy efficiencies of the various type of equipment were investigated through field tests using the instrumented rod and wave-signal acquisition systems including the pile driving analyzer(PDA). The rod energy ratio, ERr was defined as the ratio of the energy delivered to the drilling rod to the potential free-fall energy of the hammer. It appears that the type of the hammer and lift/drop system had a strong influence on the energy transfer mechanism and ERr also varies according to the energy instrumentation system and the analysis methods.

• Journal of Korean Association for Spatial Structures
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• v.23 no.4
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• pp.51-58
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• 2023

In this study, the displacement dependence, strength, and energy dissipation capacity of the steel rod damper were evaluated. The test variables are the number of steel rod dampers and the lateral deformation prevention details. From test results, it was evaluated that the displacement dependence conditions in the structural design code were satisfied. The maximum strength and energy dissipation capacity increased linearly as the number of steel rod increased. In addition, the maximum strength and energy dissipation capacity were evaluated by more than 20 times increased by using of the lateral deformation prevention details.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.141-144
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• 2006

In this study, we developed a decladding device which separates 250 mm length of simulated nuclear spent fuel rod into the pallets and the pieces of the hulls after inserting the rod cut into the module with several pairs of blades. To improve the performance of the equipment, we considered some mechanisms to prevent the rod cut from being exposed or bounced into the hot-cell, to reduce the operation time, and to insert the rods automatically. It is expected that the newly developed system will contribute to prevent radioactive pollution in the hot-cell, reduce the operation time, and to increase the safety of the operators. As a result of the performance test for some mockup fuel rod cuts in the ACP(Advanced Spent Fuel Control Process) facility, it was verified that the decladding device could be applied to the actual fuel rod cut. And it will be able to use for a scale-up facility in the future.