Case Study - Mid-Atlantic Nuclear Power Plant

Challenge:

This 1675 MW nuclear power plant suffered extensive fouling that impaired optimal power production and created burdensome operating and maintenance conditions. Maintaining the system and reliability of performance were key factors as well as an interest in enhancing current performance to even higher levels. The plant was experiencing fouling problems in the main cooling water intake system with the most significant problems in the intake bays, the pipes between the main cooling water pumps and the condensers, and in the condenser inlet and outlet water boxes. The plant experienced a broad range of fouling problems from macro-fouling and micro-fouling to scaling and sedimentation.

Treatment:

Mexel products were used to establish a preventive layer to maintain the cleanliness of the water circuit. Mexel USA conducted a six month trial using proprietary Mexel dosing equipment and emulsion to reduce and prevent fouling. The Mexel system was applied to one of the twelve circulating pump circuits in the plant. Once the water circuit was cleaned, Mexel’s treatment provided a molecular coating on the interior surfaces to prevent build-ups that allow fouling to occur. Injection occurred behind the trash racks, before the travelling screens and circulating pump, in order to treat a single intake tunnel feeding one half of one condensers. The trial treated 200,000 gpm of cooling water dosing Mexel at a rate of 4.5 ppm on a schedule of 2 days out of three during the trial, for 25 - 30 minutes per day. The Mexel process equipment performed without problem and the entire operation required minimal space in the waterfront area of the plant.

 

 

 

 

 

 

 

 

 

 

 

 

 

The picture to the left shows a water outlet box treated with Mexel and the right picture shows an untreated water outlet box.

Results:

The trial was deemed highly successful by plant personnel and management. Mexel succeeded in significantly reducing fouling in challenging conditions in which a wide variety of other treatments and coatings had failed. Before the trial was completed, management directed that planning begin on options for full plant implementation. The Mexel technology was able to successfully prevent the vast majority of the fouling. This reduction significantly improved maintenance requirements and operating performance throughout the treated cooling water circuit. Financial projections based on eliminating the amount down-power time during the summer season indicate that Mexel will be an attractive investment. While developing plans for full plant installation, the trial was extended to a second year and expanded to two water intakes and a full condenser circuit. The second year of the trial will be used to further optimize treatment protocols and document performance improvements.