• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.2
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• pp.93-99
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• 1999

SCAI(spent CANDU fuel bundle serial number identifier) was developed to read serial numbers of spent fuel bundles in the spent fuel storage. For the purpose of effectively identifying the serial number of fuel bundle. SCAI was composed of underwater camera & light part. guiding & supporting part and control & monitor part. So it is easy to assemble and disassemble, and operate. It was tested to read serial numbers of spent fuel bundles loaded in basket during the recent spent fuel transfer campaign at Wolsong Unit 1. And it was also applied to read serial numbers of spent fuel bundles discharging from the initial core at Wolsong Unit 3 by slight change of camera and light. Inspectors could easily operate SCAI after several practices in the storage pond, which was a user friendly. And SCAI provided clear and immediate picture for identification of serial numbers of spent fuel bundles. It was interally evaluated that SCAI greatly contributed to cut inspection efforts for national and international safeguards at Wolsong power plant.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.884-893
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• 2019

Spent fuel racks are steel structures used in the storage of the spent fuel removed from the nuclear power reactor. Rack units are submerged in the depths of the spent fuel pool to keep the fuel cool. Their free-standing design isolates their bases from the pool floor reducing structural stresses in case of seismic event. However, these singular features complicate their seismic analysis which involves a transient dynamic response with geometrical nonlinearities and fluid-structure interactions. An accurate estimation of the response is essential to achieve a safe pool layout and a reliable structural design. An analysis methodology based on the hydrodynamic mass concept and implicit integration algorithms was developed ad-hoc, but some dispersion of results still remains. In order to validate the analysis methodology, vibration tests are carried out on a reduced scale mock-up of a 2-rack system. The two rack mockups are submerged in free-standing conditions inside a rigid pool tank loaded with fake fuel assemblies and subjected to accelerations on a unidirectional shaking table. This article compares the experimental data with the numerical outputs of a finite element model built in ANSYS Mechanical. The in-phase motion of both units is highlighted and the water coupling effect is detailed. Results show a good agreement validating the methodology.

• Journal of Welding and Joining
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• v.19 no.1
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• pp.88-94
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• 2001

DUPIC (Direct use of spent PWR fuel in CANDU reactors) nuclear fuel is a CANDU fuel fabricated remotely from spent PWR fuel materials in a hot cell. The soundness of the end closure welds of nuclear fuel elements is an important factor for the safety and performance of nuclear fuel. To evaluate the soundness of the end closure welds of DUPIC fuel element, a precise X-ray inspection system is developed using a micro-focus X-ray generator with an image intensifier and a real time camera system. The fuel elements made of Zircaloy-4 and stainless steel by an Nd:YAG laser welding and a TIG welding aye inspected by the developed inspection system. The soundness of the welds of the fuel elements was confirmed by the X-ray inspection process, and the irradiation test of DUPIC fuel elements has been successfully completed at the HANARO research reactor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1343-1344
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• 2013

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.341-341
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• 1999

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.1
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• pp.119-126
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• 2022

This study provides technical information about the nuclear fuel handling process, which consists of various subprocesses starting from new fuel receipt to spent fuel shipment at a nuclear power plant and the design requirements of fuel handling equipment. The fuel handling system is an integrated system of equipment, tools, and procedures that allow refueling, handling and storage of fuel assemblies, which comprise the fuel handling process. The understanding and reaffirming of detailed code requirements are requested for application to the design of the fuel handling and storage facility. We reviewed the design requirements of the fuel handling equipment for its adequate cooling, prevention of criticality, its operability and maintainability, and for the prevention of fuel damage and radiological release. Furthermore, we discussed additional technical issues related to upgrading the current code requirements based on the modification of the fuel handling equipment. The suggested information provided in this paper would be beneficial to enhance the safety and the reliability of the fuel handling equipment during the handling of new and spent fuel.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.167-181
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• 2019

Currently, the development of evaluation technology for vibration and shock load characteristics and spent nuclear fuel structural integrity under normal conditions of transport is being conducted in the Republic of Korea. This is the first such research conducted in the Republic of Korea and, thus, previous international studies need to be investigated and will be referred to in the ongoing project. Before 2000, several studies related to measurement of vibration and shock loads on spent nuclear fuel were conducted in the US. US national research institutes conducted uniaxial fuel assembly shaker tests, concrete block tests, and multi-axis fuel assembly tests between 2009 and 2016. In 2017, multi-modal transportation tests including road, sea, and rail transport were also performed by research institutes from the US, Spain and the Republic of Korea. Therefore, test preparation procedures, acceleration and strain measurement results, and finite-element and multi-body dynamics analysis were investigated. Based on the measured strain data, the preliminary conclusion was obtained that the measured strain was too small to cause damage to spent nuclear fuel rods. However, this conclusion is a preliminary conclusion that only reviews part of the results; a detailed review is being conducted in the US. The investigation of international studies on spent nuclear fuel structural integrity tests considering vibration and shock loads under normal conditions of transport in the US will be useful data for the project being conducted in the Republic of Korea.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.4
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• pp.427-433
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• 2007

A structural model of the spent nuclear fuel disposal canister for the pressurized water reactor(PWR) for about 10,000 years long term deposition at a 500m deep granitic bedrock repository has been developed. However this developed structural model of the spent nuclear fuel disposal canister is too heavy to handle without any structural safety problem. Hence a lighter structural model of the spent nuclear fuel disposal canister which is easy to handle has been tried to develop very much. One of the reasons which made the structural model heavy is considered to be due to the severe adaptation of the design conditions like external loads and safety factor etc. to the canister design. Hence a complementary analysis to alleviate such severe design conditions is required for the reduction of the canister weight. In this study, a complementary structural analysis for the spent nuclear fuel disposal canister is carried out changing the design conditions such as external loads and safety factors to recalculate the design parameters like diameter and thickness etc. of the canister. The complementary analysis results shows that the diameter of canister can be shortened from 122cm to 102cm to reduce the weight of the spent nuclear fuel disposal canister.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.4
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• pp.333-349
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• 2013

As the capacity of spent nuclear fuel storage pool at reactor sites becomes saturated in ten years, long term dry storage strategy has been recently discussed as an alternative option in Korea. In this study, we reviewed safety-criteria-related research results on spent nuclear fuel performance and integrity under long-term dry storage and proposed the direction and the scope of future domestic research and development. Creep and hydride effect in relation to the embrittlement are known to be the major degradation mechanisms of the spent fuels during the long term dry storage. However, recent research results showed that hydride reorientation and hydride embrittlement are one of the most critical factors to the spent fuel integrity. Accordingly safety criteria of US and Japan for the storage system are basically founded on those mechanisms. However, in Korea, not only in-pile but out-of-pile experimental data have not been generated to understand fuel cladding degradation and to determine the criteria to ensure the safety. In addition, the transient behavior of the spent fuel during transportation also needs to be thoroughly examined. Therefore, various experimental research and development will be required to establish our own safety criteria for future long-term dry storage of domestic spent fuels.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.331-336
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• 2011

When the Fukushima nuclear power plant accident occurred in March, a hydrogen explosion in the reactor building at the 4th unit of Fukushima plants lead 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 potential criticality in the fuel storage pool by coolant loss may yield more severe situation than the similar accident happened inside the reactor vessel. In the paper, the safety state of the spent fuel storage pool and rack structures of the domestic nuclear plants would be reviewed and compared with the Fukushima plant case by engineering viewpoint of potential severe accidents.