Steam flow inside the main steam lines of a Boiling Water Reactor can generate high-amplitude pressure oscillations due to coupling between the separated shear layer at the mouth of the safety relief valves (SRVs) and the acoustic modes of the side branches where the SRVs are mounted. It is known that certain combinations of flow velocities and main steam line geometries are capable of generating self-excited pressure oscilations with very high amplitudes, which can jeopardize the structural integrity of main steam system components, such as safety valves, or reactor internals such as steam dryers.
Innomerics has developed a non-invasive modification of the SRV nozzle that completely eliminates these acoustic resonances, without affecting the performance of the
valve. Unlike acoustic dampers and other alternative mitigation devices, the Acoustic Shield does not require performing any work inside the drywell, so full acoustic resonance mitigation is achieved without any personnel radiation exposure and without the need for permanent changes to the configuration of the main steam lines and SRV standpipes.
For more information about Acoustic Shield and its main features, please do not hesitate to contact us.