Modular condenser replacement at ANO-1 solves operating problems and improves performance
After 22 years of operation, the condenser tube bundles and waterboxes at Arkansas Nuclear One, Unit 1 (ANO-1) had deteriorated significantly, impairing operating performance, reducing condenser reliability and increasing maintenance cost. An extensive condition assessment performed in 1995 revealed a 34% wall loss on the original Admiralty tubing and an erosion rate of 1.7% annually. Additionally, Arkansas Nuclear One was considering an 8% power uprate, which would place additional duty on the main condenser. As a result, it was decided to completely reconstruct the four condenser tube bundles serving the two low-pressure turbines at Arkansas Nuclear One. An evaluation of the available condenser tube materials was performed to determine which material was best suited for service in the single pass, single pressure condenser at ANO-1. All copper based materials were excluded from consideration due to the detrimental effect copper has on secondary chemistry and more specifically steam generator integrity. Titanium and a variety of stainless steel materials were evaluated, and ultimately titanium was selected as the replacement condenser tube material for the rebuilt condenser tube bundles due primarily to its corrosion resistance and extensive operating experience in condenser service. An impressed current cathodic protection system and epoxy waterbox coating was also installed to prevent galvanic corrosion of the carbon steel waterboxes. The cathodic protection system included local alarm indication to alert plant operating staff of any system malfunction that could result in titanium hydrating. A comparison of the heat transfer characteristics of the existing condenser design with Admiralty tubes and a new tube bundle design with titanium tubes concluded that a new tube bundle design was required to optimize the condenser performance and accommodate the anticipated 8% power uprate. This paper will discuss the condenser optimization program from the design state to final installation. Further, it was decided to completely shop fabricate these four titanium tube bundles to minimize the site erection schedule. Each bundle measuring over 44 ft. (13.5 m) long, over 13 ft, (4 m) wide, and nearly 18 ft. (5.5 m) tall, weighed 195,000 lbs (88,450 kg). The weight and size of the bundles created a variety of fabrication, transportation and installation challenges that required extensive advanced planning, scheduling and coordination. The complete installation of the redesigned condenser tube bundles and waterboxes was accomplished during the Fourteenth Refueling Outage of ANO-1 in 1997.
- Research Organization:
- Entergy Operations, Inc., Russelville, AR (US)
- OSTI ID:
- 20014125
- Resource Relation:
- Conference: 1999 International Joint Power Generation Conference, Burlingame, CA (US), 07/25/1999--07/28/1999; Other Information: PBD: 1999; Related Information: In: Proceedings of the 1999 international joint power generation conference (PWR-Vol. 34). Volume 2: Power, by Penfield, S.R. Jr.; Hayes, R.H.; McMullen, R. [ed.], 752 pages.
- Country of Publication:
- United States
- Language:
- English
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