Document: NUREG-0800
Document ID: dfb421c6-cf9c-447e-ab71-dd0426ce50e5
Document Type: srp
Title: TURBINE MISSILES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340523.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.5.1.3
CFR Part: 
CFR Title: 

Content:
ponents important to safety shall be protected against the effects of missiles that might result from equipment failures, in this case the steam turbine. Consideration of turbine missile protection is relevant for essential systems, i.e., those structures, systems, and components necessary to ensure: - The integrity of the reactor coolant pressure boundary. - The capability to prevent accidents that could result in potential offsite exposures that are comparable to the guideline exposures of 10 CFR Part 100, "Reactor Site Criteria." - The capability to shut down the reactor and maintain it in a cold shutdown condition. Specific criteria necessary to meet the relevant requirements of GDC 4 are as follows: 1. Plant designs with a favorable turbine generator placement and orientation, and adhering to the guidelines presented in Regulatory Guide 1.115 (Ref. 2) will be considered to be adequately protected against turbine missile hazards. Exclusions of safety-related structures, systems, or components from low trajectory turbine missile strike zones constitutes adequate protection against low trajectory turbine missiles. In those cases where exclusion of safety-related targets from the low trajectory missile strike zones is impractical (e.g., location dictated by site character- istics, such as a water intake structure for the ultimate heat sink) target size, shielding ,or redundancy may be considered with respect to missile protection. the acceptance criterion is that the.combined strike and damage probability for these targets be less than 10-3 per turbine failure. 2. Plant designs with unfavorable turbine-generator placement and orientation, such that safety-related structures, systems, or components are within the low trajectory turbine missile strike zones and are susceptible to potential missile damage, should have sufficient missile protection in terms of one or more of the following: missile barriers target redundancy; turbine disc integrity; or overspeed