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Purpose of Core Shroud Replacement |
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It is vitally importance to maintain the stable operation of Nuclear Power Plants now, and well into the future. The discovery of core shroud cracking in the BWR in 1990 led to heightened awareness and enhanced shroud inspection programs worldwide. This inspection initiative revealed that Stress Corrosion Cracking (SCC) of core shroud was becoming an issue for the entire BWR industry.
SCC is caused by the proper combination of Material, Residual Stress and Water Chemistry. Tokyo Electric Power Company decided to replace the core shroud with the more SCC resistant 316L material for the preventative maintenance of their plants. |
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Core Shroud |
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The core shroud is the cylindrical stainless steel structure in the Reactor Pressure Vessel (RPV) that surrounds the fuels, control rods and other core components (reactor core). The core shroud directs cooling water flow through the jet pumps, into the bottom head region and up through the reactor core. |
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Construction of RPV |
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Shape of Core Shroud |
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The core shroud is a cylinder that surrounds the reactor core. The top guide and core plate rest on the shroud to provide horizontal support for the fuel assemblies. |
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