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:
are far longer than those estimated by the standard, extending the zone of influence of the jet and the number of SSCs that could be impacted by a supersonic jet. For example, tests in the Seimens-KWU facility in Karlstein, Germany showed that significant damage from steam jets can occur as far as 25 pipe diameters from a rupture.1 Distribution of Pressure within the Jet Plume Appendix C and Appendix D of ANSI/ANS Standard 58.2 describe the assumptions used for defining the special pressure distribution within a jet cross section for various jet conditions. It assumes a uniform pressure distribution over the cross section of a nonexpanding jet. For an expanding jet, the standard assumes variable (not uniform) pressure over the cross section of the expanding jet. In developing the formulas for the spatial distribution of pressure through an expanding jet cross section, the standard generally assumes that the pressure within a jet cross section is maximum at the jet centerline. However, this assumption is valid near the break, but far from the break, the pressure variation is quite different, often peaking near the outer edges of the jet. Therefore, applying the standard’s formulas could lead to nonconservative pressures away from the jet centerline. Jet Dynamic Loading including Potential Feedback Amplification and Resonance Effects Furthermore, unsteadiness in free jets, especially supersonic jets, tends to propagate in the shear layer and induce time-varying oscillatory loads on obstacles in the flow path. Pressures and densities vary nonmonotonically with distance along the axis of a typical supersonic jet, feeding and interacting with shear layer unsteadiness. In addition, for a typical supersonic jet, interaction with obstructions will lead to backward-propagating transient shock and expansion waves that will cause further unsteadiness in downstream shear layers. Moreover, synchronization of the transient waves with the shear layer vortices emanating from the