To provide a fuel storing rack material enabling high-density storage, and enduring long-term use in a storage pool.
Concerning a relationship between Cr concentration in a matrix and stress corrosion crack occurrence of austenitic stainless steel including boron, when the Cr concentration in the matrix is ≤16%, the stress corrosion crack occurs and corrosion is reduced. From a relationship of a Cr decreasing amount in the matrix to boron addition, the minimum Cr amount (MCr) required for ensuring the corrosion resistance of use material by addition B amount (MB) required for enhancing storage density is decided by a following expression; MCr>16+3MB. According to this invention, even if increasing the B addition amount for enhancing storage density, fuel storing rack material having enough corrosion resistance under a fuel storing condition can be obtained.
SUZUKI YOSHIYASU
TSUBOTA MOTOJI
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