Document: NUREG-0800
Document ID: 63f62189-691f-402d-9ac9-41fb60ec2261
Document Type: srp
Title: DETERMINATION OF RUPTURE LOCATIONS AND DYNAMIC EFFECTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1423/ML14230A035.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.2
CFR Part: 
CFR Title: 

Content:
upling to acoustic wave reflections lead to amplifications of oscillatory loads, particularly in impinging jets close to nearby SSCs. These amplifications occur at discrete frequencies associated with the diameter of the pipe break, the jet flow velocity, and the distance between the jet source and impingement surface. The staff determines that the applicant’s methodologies capture conservatively the effects of any reflections of both blast waves and jets within enclosed regions. The blast wave and jet impingement loads may be based on upper bounds inferred from measurements, from detailed simulations such as computational fluid dynamics, or from worst-case assessments of the source conditions. The staff determines the suitability of the selected method for the proposed design. The staff also reviews the application to ensure that the applicant has established conservatism through convergence studies (when numerical methods are used), comparison to rigorous measurement data, or by bounding approaches based on fundamental hydrodynamic and thermodynamic laws. The applicant’s structural analyses should include both static and dynamic analyses and be of sufficient fidelity to capture the motion and stresses within SSCs in the proposed plant design. Dynamic analyses of SSCs may generally use a structural damping coefficient of no greater than 1 percent, with higher damping specifications substantiated by rigorous testing data. The staff also reviews the application to verify that the applicant’s procedure for addressing the uncertainties in the frequencies of structural resonances, as well as within oscillatory loads, is specified and evaluated to demonstrate that worst-case coupling between loads and structural response is assessed. Any bias errors in the loading and structural evaluation procedures are properly accounted for. Moreover, the staff determines that the applicant’s resulting structure responses for all the applicable SSCs are within the allowable