With an environment unlike any other, nuclear power plants have specific material requirements to prevent product deterioration and failures. Meggitt offers a variety of high quality, durable solutions to fulfill the demands of nuclear plants for permanent or walkaround data collection. Wilcoxon Research vibration sensors and cable assemblies are available in various radiation-hardened configurations. For balance of plant applications in safe zones, Wilcoxon has a large variety of sensors with top or side exit connectors, sensors with compact sizes for machinery with limited monitoring space, high temperature sensors, a variety of junction and switch boxes and water resistant cable assemblies rated up to IP68.
Nuclear power plants utilize vibration monitoring to ensure continuous power generation and safety for personnel and equipment, and prevent radiation leaks. Expensive and crucial machinery including cold water feed pumps, pressurized water reactors, and steam generators operate more efficiently as a result of condition monitoring. Meggitt has developed new radiation-hardened vibration sensors and cable assemblies to meet specific requirements for the reliability of monitoring equipment in nuclear environments.
“The increased need for nuclear power plant output reliability and operational safety calls for increased monitoring of machinery,” says Tom Smith, vice president of sales and marketing for Wilcoxon Research Products. “Our radiation-resistant sensors and cable assemblies provide reliable data that plant personnel can trust when evaluating machine condition, potentially preventing an environmental disaster or loss of power production.”
The conditions of nuclear power plants can cause deterioration of equipment. Wilcoxon accelerometers are designed to perform continuously in harsh environments without degradation. Mechanical components used in Wilcoxon 793R series sensors were subjected to gamma radiation exposure in excess of 2 x 107 RADs without degraded sensor performance. Wilcoxon radiation-hardened sensors can tolerate a cumulative radiation exposure of 1 x 107 RADs, still meeting original manufacturing specifications, and are operable up to 248 degrees Fahrenheit (120 degrees Celsius). Model 797R is a side exit, low profile IsoRing accelerometer with tight sensitivity tolerance of 100 mV/g, ±5 percent. Its velocity transducer houses ultra low-noise electronics for clear signals at very low vibration levels, and has a frequency range of 2 Hertz to 7 kilohertz.
To ensure reliable data output, Meggitt manufactures Wilcoxon J9T2 cable assemblies with Tefzel® coating for high energy radiation-resistant protection. Tefzel meets the IEEE 383 Standard for Qualifying Class 1E Electric Cables and Field Splices for Nuclear Power Generating Stations, and is approved for nuclear power plant use. Impervious to most solvents and chemicals, Tefzel is hydrolytically stable and usable up to 302 degrees Fahrenheit (150 degrees Celsius). The R6QN-0-J9T2 cable-connector assembly offers a molded polychloroprene boot and Tefzel insert suited for radioactive environments. A tight and impenetrable seal between cable and sensor protects the transfer of data.
For permanent sensor installation and portable data collection, IP66 rated CB2 and CB4 connection boxes can be used in wet environments where the presence of water jets exists. Meggitt also produces a wide range of Wilcoxon VibraLINK switch boxes, available with NEMA 4X-rated thermoplastic or stainless steel boxes. Additional options include cable grip and BOV meters for centralized data collection. Vibration monitoring solutions for nuclear environments are offered by Meggitt backed by extensive industry knowledge, excellent customer service and product reliability.
Wilcoxon Research molded polychloroprene boot connectors use multiple ribbed seals that grip the sensor creating an airtight, waterproof seal. The connector can operate in continuous immersion and is successfully tested up to 100 psi (230 feet/70 meters). With the inclusion of a Tefzel insert, the connector can operate in temperatures from -49 to 219 degrees Fahrenheit (-45 to 104 degrees Celsius), and is highly resistant to most nuclear exposure. Wilcoxon twisted, braided shielded pair J9T2 cable offers superior durability with a thick Tefzel jacketed covering rated from -112 to 302 degree Fahrenheit (-80 to 150 degrees Celsius).When paired with the connector, the IP68 rated assembly offers the most rugged and lasting protection in nuclear radiation environments.
To adhere with safety and environmental guidelines, accelerometers can be permanently installed and wired to collection points in safe zones. Remote monitoring of potentially contaminated machinery can then be performed successfully. Wilcoxon Research junction and switch boxes are designed for easy installation, safety, and fast data collection. A variety of enclosures are available including cable reduction boxes which minimize the number of cables that must be run long distances. BNC connection boxes (2 to 4 channels) and expandable switch boxes (12, 24, 36, or 48 channels per box) are also available. VibraLINK (6 or 12 channel) junction boxes come with terminal switch inputs, BNC outputs and a rugged stainless steel exterior.
The cold water feed pumps, pressurized water reactors, and steam generators of today’s nuclear power facilities are crucial components to the utility infrastructure for millions of people around the globe. In order to maximize their potential and lay the groundwork for tomorrow’s innovations, reliable monitoring systems will be the pivotal tools engineers and operations technicians turn to. Wilcoxon Research’s technology is prepared. ■
Shalvi Desai is the marketing communications specialist for Wilcoxon Research Products and Meggitt Sensing Systems.
For more information, visit www.wilcoxon.com or www.meggitt.com.
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