Contact-Free FA Placement Checking in VVER

Abstract

A method of contact-free determination of FA elevations to check FA placement for purposes of better operational safety of VVER-440 and -1000 is proposed. The method includes scanning specially shaped light beams over the flat tops of the assemblies, recording the reflected signal with a TV camera, and processing the information in a computer. The measurement setup developed on the basis of this method can record a difference of 0.1 mm between the elevations of the flat tops to within 1% with admissible dispersion of 1–1.5 mm. The scanning and output of elevation information are accomplished in 10–15 min. The measurement setup to be used in the water medium of the loading zone of a nuclear reactor is implemented using radiation-resistant elements.