Condenser on-line leak-detection system development

Technical Report · Fri Nov 01 00:00:00 EST 1991

OSTI ID:6019833

Condenser tube leaks have been the number one source of impurities in most utility steam cycles. The impurities lead to corrosion of feedwater systems, boilers, and turbines. EPRI recommends sodium in the condensate be less than 3 ppb, which means less than one gallon leakage per day in some cases. The location of leaks requires isolation of the condenser water box and is costly because of power reduction. On-line detection using tracer can cut down the isolation time and, therefore, offers cost advantages to utilities. The on-line leak detection technique utilizes the concepts developed by EPRI for targeted chlorination''. Sulfur hexafluoride (SF{sub 6}), helium gases, and perfluorocarbon liquid were considered as tracers. Laboratory studies were conducted to evaluate the practicability of injecting water with dissolved SF{sub 6} gas, SF{sub 6} bubbles, and dissolved SF{sub 6} gas in perfluorocarbon liquid. Both static and dynamic tests were conducted in a condenser model. It was determined that water entrained with SF{sub 6} bubbles offered the most practical method of injection, followed by dissolved SF{sub 6} gas in perfluorocarbon. A conceptual design was developed that utilizes a water lance, a swivel arrangement in the waterbox manhole cover, a tracer targeting and mixing system, and a tracer gas detection system at the air ejector exhaust. A successful demonstration of targeted leak detection using a waterjet lance with SF{sub 6} was conducted at Carolina Power Light Company's Asheville Steam Electric Station Unit 1. A measurable artificially created leak was detected and located using this system with the condenser on-line. 2 refs., 39 figs., 6 tabs.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Stone and Webster Engineering Corp., Boston, MA (United States)
• Sponsoring Organization: EPRI; Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 6019833
• Report Number(s): EPRI-GS-7350
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
CONDENSERS
MAINTENANCE
EPRI
FOSSIL-FUEL POWER PLANTS
HELIUM
LEAK DETECTORS
LEAK TESTING
SULFUR FLUORIDES
TRACER TECHNIQUES
ELEMENTS
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
GASES
HALIDES
HALOGEN COMPOUNDS
ISOTOPE APPLICATIONS
NONMETALS
POWER PLANTS
RARE GASES
SULFUR COMPOUNDS
TESTING
THERMAL POWER PLANTS
200104* - Fossil-Fueled Power Plants- Components
220200 - Nuclear Reactor Technology- Components & Accessories