FLUeS - Leak detection on CANDU secondary side piping: experience at Point Lepreau and Gentilly-2

Due to regulatory concerns for the protection of the Control Rooms (CR) against the possible consequences of a Steam/Feedwater pipe break at the Point Lepreau Generating Station (PLGS) and at Gentilly-2 (G2), NB Power and Hydro Quebec have each installed an on-line leak detection system on their Secondary Side Piping (SSP) in close proximity to these rooms. After laboratory testing three prospective systems, the Siemens FLUeS system was selected and installed in 1999 at both sites. Both systems have been in-service since December 1999 (G2) and June 2000 (PLGS), and both have met the necessary requirements. The main features of the FLUeS system are: a robust and low maintenance design; simple installation of all field components; high sensitivity (2.5 kg/h leak rate and better); short response time (40 minutes and better); and high locating accuracy (few meters). Both FLUeS systems are of identical design, except for the amount of tubing connected. The system at PLGS is the largest FLUeS system ever installed, operating 1700 m of total tubing (700m of monitored pipes and 1000 m of connector tubes). (author)