| 摘要 |
PROBLEM TO BE SOLVED: To provide a boiling water reactor control rod which is more resistant to stress corrosion cracking and can prevent buckling of neutron absorbing metal rods.SOLUTION: A boiling water reactor control rod having a cruciform cross-sectional shape includes four blades, a tie rod, a handle, and a lower support member. The four blades extend from the tie rod in four directions. Each blade comprises a sheath 3 which is attached to the tie rod 4 and has an U-shaped cross-section, and a plurality of hafnium rods 5 located inside the sheath 3. The diameter of a lower portion of the hafnium rod 5 is smaller than that of an upper portion. A lower portion of the sheath 3 has a shape with a concave-convex pattern that is repeated both in a width direction of the blade 2 and in an axial direction of the control rod. The concave section formed on the sheath 3 is inserted into a space between the lower portions of two hafnium rods 5 adjacent to each other in the width direction of the blade 2, while the convex section formed on the sheath 3 reaches the vicinity of the periphery surface of the lower portions of the hafnium rod 5. |
