• Journal of the Korean Society for Heat Treatment
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• v.18 no.2
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• pp.112-118
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• 2005

Study was focused on the effect of the cooling rate on the embrittlement behavior of Zircaloy-4 cladding simulated Loss Of Coolant Accident (LOCA) environment. Claddings were oxidized at given temperature and given time followed by various water quenching in the range of $0.6^{\circ}C$ and $100^{\circ}C$ per second. Cladding failed after water quenching above the threshold oxidation. Threshold oxidation was decreased as the cooling rate increased, which is due to the matensite structure formed during fast cooling rate.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.177-177
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.364.2-364.2
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.448-449
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.176-176
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.173.1-173
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.169-169
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• 2002

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1345-1354
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• 2019

Clogging of sump strainers that filter the recirculation water in containment after a loss-of-coolant accident (LOCA) seriously impedes the continued cooling of nuclear reactor cores. In experiments examining the corrosion of aluminium alloy 6061, a common material in containment equipment, in borated solutions simulating the water chemistry of sump water after a LOCA, we found that Fe-bearing intermetallic particles, which were initially buried in the Al matrix, were progressively exposed as corrosion continued. Their cathodic nature $vis-{\grave{a}}-vis$ the Al matrix provoked continuous trenching around them until they were finally released into the test solution. Such particles released from Al alloy components in a reactor containment after a LOCA will be transported to the sump entrance with the recirculation flow and trapped by the debris bed that typically forms on the strainer surface, potentially aggravating strainer clogging. These Fe-bearing intermetallic particles, many of which had a rod or thin strip-like geometry, were identified to be mainly the cubic phase ${\alpha}_c-Al(Fe,Mn)Si$ with an average size of about $2.15{\mu}m$; 11.5 g of particles with a volume of about $3.2cm^3$ would be released with the dissolution of every 1 kg 6061 aluminium alloy.

• Computers and Concrete
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• v.14 no.2
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• pp.127-143
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• 2014

LOCA (Loss Of Coolant Accident) is one of the most important utmost accidents for Prestressed Concrete Containment Vessel (PCCV) due to its coupled effect of high temperature and inner pressure. In this paper, heat conduction analysis is used to obtain the LOCA temperature distribution of PCCV. Then the elastic internal force of PCCV under LOCA temperature is analyzed by using both simplified theoretical method and FEM (finite element methods) method. Considering the coupled effect of LOCA temperature, a nonlinear elasto-plasitic analysis is conducted for PCCV under utmost internal pressure considering three failure criteria. Results show that the LOCA temperature distribution is strongly nonlinear along the shell thickness at the early time; the moment result of simplified analysis is well coincident with the one of numerical analysis at weak constraint area; while in the strong constrained area, the value of moments and membrane forces fluctuate dramatically; the simplified and numerical analysis both show that the maximum moment occurs at 6hrs after LOCA.; the strain of PCCV under LOCA temperature is larger than the one of no temperature under elasto-plastic analysis; the LOCA temperature of 6hrs has the greatest influence on the ultimate bearing capacity with 8.43% decrease for failure criteria 1 and 2.65% decrease for failure criteria 3.

• Computational Structural Engineering
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• v.11 no.1
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• pp.153-160
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• 1998

A small break loss of coolant accident is postulated as a pressurized thermal shock accident in this study. From the temperature and pressure histories of coolant, distributions of the temperature and stress in a vessel wall are analytically calculated. The stress intensity factor and fracture toughness of the vessel wall are determined at the crack tip using the ASME code method and they are compared to check if cracking is expected to occur during the transient postulated. The maximum allowable reference nil-ductility transition temperatures are determined for various crack sizes and the results are discussed.