Secondary System Return to Service Following the Refurbishment Outage at the Point Lepreau Generating Station

摘要

During the latter portion of 2012, the Point Lepreau Generating Station (PLGS) was returned to service following a mid-life refurbishment that commenced in 2008. The plant achieved criticality following refurbishment on 2012 July 25 (30 years to the day of first criticality in 1982) and commercial operation re-commenced on 2012 November 24. In addition to the refurbishment activities for the reactor core that entailed the complete replacement of all 380 fuel channels and associated inlet and outlet feeder pipes, significant refurbishment work was undertaken on the secondary side of the plant. The major activities on the secondary side included replacement of the turbine rotors with the intent of achieving an additional 3-5% power output, a complete re-tubing of the titanium condensers and replacement of the tube-sheets, and dismantling and inspection of the reheaters. The extended duration of the refurbishment outage due to issues with installation of the calandria tubes, an inadvertent incident that caused the low-pressure turbine rotors to be dropped into the Bay of Fundy and the discovery of organic contamination on the turbine rotors prior to restart led to a comprehensive plan for secondary system clean-up and restart following the refurbishment outage. The secondary system at PLGS typically operates on AVT chemistry treatment with morpholine and includes a full-flow condensate polishing plant, which was intended to be run continuously during system clean-up and plant restart. During the initial plant run-up, the morpholine chemistry was exchanged with ammonia to improve upon condensate polisher run times. This paper describes the comprehensive plan that was implemented during the return-to-service of the secondary system and presents the results and lessons learned from the clean-up of the system including impacts on FAC, corrosion product transport and condensate polisher performance.