Document: NUREG-0800
Document ID: 81a2e18b-7311-4c4e-822e-8dfe1b0ba7aa
Document Type: srp
Title: REACTOR PRESSURE VESSEL INTERNALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0702/ML070230009.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.5
CFR Part: 
CFR Title: 

Content:
s performed; (2) requirements of GDC 2 that systems and components essential to the prevention of accidents that can could affect the public health and safety or to mitigation of their consequences be designed to withstand the effects of earthquakes combined with the effects of normal or accident conditions; and (3) requirements of GDCs 40 and 42 for protection of engineered safety features against dynamic effects and missiles that might ensue from plant equipment failures as well as the effects of a loss of coolant accident. Technical Evaluation Potential adverse flow effects on nuclear power plant SSCs can ensue from various flow excitation mechanisms like fluid-elastic instability, vortex-induced vibration, flow-excited acoustic resonance, and turbulent buffeting. For example, reactor vessel and main steam system piping and components (including the steam dryer, safety relief and power-operated valves, and pipe supports) in BWR nuclear power plants can be damaged by pressure fluctuations and vibration from flow-excited acoustic resonances within the main steam system or reactor vessel. The flow-excited acoustic resonance phenomenon also can occur in PWR nuclear power plants with damage to plant piping and components. Sampling probes in feedwater and condensate systems in nuclear power plants are also susceptible to adverse flow effects. 3.9.5-12 Revision 3 - March 2007 The staff reviews evaluations of the potential for adverse flow effects on plant SSCs by applicants for the construction and operation of nuclear power plants under 10 CFR Part 50 or Part 52. The staff reviews the evaluation by operating nuclear power plant licensees of the potential for adverse flow effects on plant SSCs of proposed changes in licensed operating conditions (e.g., in support of a power uprate license amendment request) or planned major plant modifications (e.g., replacement of a steam generator at a PWR nuclear power plant). The staff reviews the program established by applicants