Boiling Water Reactor Core Shroud Acoustic Loads Resulting From a Recirculation Outlet Line Break Loss of Coolant Accident: A Case Study

Acoustic loads caused by a postulated Recirculation Line Break Loss of Coolant Accident are one of the required design basis events that must be considered for stress analyses of Boiling Water Reactor internal components such as Jet Pumps and Core Shrouds. These acoustic loads must also be considered for fracture mechanics evaluations performed to assess allowable operating periods for flaws detected during in-service inspections. Acoustic loads methods generally utilized in the past have been 1-D or simplified 2-D models of the domain of interest. In some cases sophisticated nuclear thermal-hydraulic codes are used to obtain the acoustic response to the LOCA event. The present paper summarizes a case study of a RLB LOCA acoustic loads analysis of a BWR core shroud using 3-D linear acoustic finite element analysis. Representative loads are presented at each circumferential shroud weld location. The results presented in this paper can be used to assess the general order of magnitude of the loads which can be expected for similar BWR designs.