STEAM GENERATOR FOR SODIUM-COOLED FAST REACTOR HAVING FUNCTION OF DETECTING BREAKAGE OF HEAT TRANSFER TUBE ONLINE

摘要

PPROBLEM TO BE SOLVED: To provide a steam generator including a heat transfer tube of double-walled tube structure having superior heat transferring efficiency, and a breakage detecting section for detecting the existence of breakage of the heat transfer tube online in real time, in the helical coil type steam generator for the sodium-cooled fast reactor. PSOLUTION: The heat transfer tube of the steam generator for the sodium-cooled fast reactor includes an inner tube made of a first material, an outer tube closely kept into contact with the inner tube, and made of a second material having a coefficient of thermal expansion lower than that of the first material, and a plurality of helium flowing grooves formed long in the longitudinal direction of the heat transfer tube between the inner tube and the outer tube to allow helium to flow therein. By such constitution, the inner tube and the outer tube are simultaneously thermally expanded regardless of temperature difference between the inner tube and the outer tube found when a steam generator is normally operated, a degree of adhesion of the inner tube and the outer tube is not lowered. Accordingly, the degradation of the heat transferring efficiency of the heat transfer tube can be prevented. PCOPYRIGHT: (C)2010,JPO&INPIT