Document: NUREG-0800
Document ID: b6b57a00-5b85-4f0c-965c-ca89ef4265e7
Document Type: srp
Title: DETERMINATION OF RUPTURE LOCATIONS AND DYNAMIC EFFECTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1608/ML16088A041.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.6.2
CFR Part: 
CFR Title: 

Content:
often changes during a blowdown process as the pressure and temperature ratios between source and exterior fluid changes. The jet plume geometry also changes during blowdown, with a wide expansion at high pressure ratios (source pressure/external pressure) and a smaller expansion at lower pressure ratios. The staff determines that the applicant’s proposed methodologies conservatively capture all SSCs that might be impacted by the varying jet plume areas and fluid states throughout blowdown. The staff also determines that the applicant’s methodologies used to assess the loads capture the worst-case static and oscillatory loads that may occur for all possible loading directions, including situations in which instabilities and coupling to acoustic wave reflections lead to amplifications of oscillatory loads, particularly in impinging jets close to nearby SSCs. These 3.6.2-18 Revision 3 – December 2016 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