INSPECTING METHOD FOR REACTOR FUEL GUIDE PIN

• Main Authors: TANAKA KOJI, SUYAMA SHOJI, MIKI SUSUMU, YAMASHITA TAKANOBU, IDEO KOJI
• Format: Patent
• Language: English
• Published: 12.11.1996
• Edition: 6
• Subjects: GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; NUCLEAR REACTORS; PHYSICS; REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGYGENERATION, TRANSMISSION OR DISTRIBUTION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TESTING

PURPOSE: To provide a method capable of accurately inspecting the structural integrity of a fuel guide pin including a screw clearance groove section and a screw section base end regardless of the coupling degree of the fuel guide pin into the insertion hole of a core plate. CONSTITUTION: The direct projection method from the outer periphery of a fuel guide pin 1 for detecting cracks on the pin neck lower section la' of the pin 1, the single reflection method from the outer periphery of the pin 1 for detecting cracks on a screw clearance groove section 1b' and a screw section base end 1c', and the incidence method from a core plate 3 are concurrently used. The shape echo generated when a shoulder section 1g near a screw section 1b is used as a reflection source is detected by the direct projection method, it is compared with the shape echo of a comparison test piece having the same shape and size as those of the fuel guide pin 1, and the pressure contact degree between the fuel guide pin 1 and the insertion hole 3a of the core plate 3 by cold fit is detected in advance. The detected result of the pressure contact degree is used for correcting the flaw detection sensitivity by selectively empolying the single reflection method and incidence method.