MEASURING METHOD FOR FUEL ELEMENT INTERVAL

• Main Author: URATA MEGUMI
• Format: Patent
• Language: English
• Published: 06.04.1992
• Subjects: MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; NUCLEAR REACTORS; PHYSICS; TESTING

PURPOSE:To measure the interval assuredly by once measurement by obtaining the distance from a fiber scope to the minimum interval part between fuel elements with a strain-gage type gap sensor. CONSTITUTION:When an interval 31 between fuel rods is <= 1 mm and a signal indicating the inability of measurement with a strain-gage type gap sensor is obtained, an interval-sensor driving part 20 is immediately stopped. The operation is changed to the measurement with a fiber scope 9. Since the distance from the strain-gage type sensor to the fiber scope 9 is obtained beforehand, the interval between the fuel rods is obtained from the scope of a monitoring TV. When the interval on the monitoring TV and the interval which is obtained beforehand are narrow and the interval, for which the signal indicating the inability of measurement with the strain-gage type gap sensor is indicated, is the interval, for which the fiber scope is not set, the interval-measuring-sensor driving part 20 is moved back once. The fiber scope is moved to the intended position and inserted again. Then, the measurement is performed. In this way the measurement from the narrow interval to the wide interval can be performed by one attachment without replacing the strain-gage type gap sensor and the fiber scope 9, and the measuring time is largely shortened.