By John Lojek, PE, Principal Engineer, Analysis and Testing, Westinghouse Electric Company, LLC and Kevin Ramsden, Nuclear Services Chief Engineer, Fauske & Associates
At the top of the containment vessel of pressurized water reactors, hundreds of spray nozzles are positioned to provide a mechanism for cooling during a postulated event. Since operation of the containment spray system is not feasible during normal operations, confirmation of the flow path is typically performed using gas flow. At our test facility, we were able to replicate the flow rate of one of these spray nozzles.
This high-speed video shows a sudden inrush of water with debris to the nozzle and an eventual steady-state nozzle spray flow. The design of the nozzle allows for a droplet size and flow rate to adequately cool containment to prevent over pressurization. The flow rate is about equal to 14 gpm or 5 - 6x the flow rate of a standard shower head. In this experiment, upstream pressure transmitters and flow meters provided information relevant to match the design conditions. A custom developed National Instruments LabVIEW program was used to monitor and acquire data. After baselining the facility, sensitivity studies were conducted to determine adequate nozzle performance. Utilizing a significant foundation of debris transport design and testing experience, the performance of a single spray nozzle with different debris conditions of varying size distributions was investigated.
Fauske & Associates and Westinghouse have long histories of thermal hydraulic testing and analysis and state-of-the-art laboratories that can be used for full-scale industrial testing services of power plant components and systems. This is one example of a type of test that can be conducted.
Solving and testing complex fluid problems are part of unique full service lab and engineering service capability.