Document: NUREG-0800
Document ID: 90914152-fc84-4413-a5f5-aa75efd21205
Document Type: srp
Title: TURBINE MISSILES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600395.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.5.1.3
CFR Part: 
CFR Title: 

Content:
testing and inspection is a reliable method for ensuring that the objective of precluding generation of turbine missiles (and hence the possibility of damage to safety-related structures, systems, and components by those missiles) can be met. The NRC safety objective for turbine missiles (i.e., P4 should be < 10-7 per year per plant) is best expressed in terms of either of two sets of criteria applied to missile generation probability, P1. All applicants are expected to commit to operating criteria (see Table 3.5.1.3-1) appropriate to the applicable turbine orientation. One set of criteria should be applied to favorably oriented turbines; the other should be applied to unfavorably oriented turbines. This approach places responsibility on the applicant for initially demonstrating, and thereafter maintaining, an NRC-specified turbine reliability. Accordingly, the applicant should commit to conduct appropriate inservice inspection and testing throughout the life of the plant. Accordingly, the applicant should demonstrate the capability to perform visual, surface, and volumetric (ultrasonic) examinations suitable for inservice inspection of turbine rotors and shafts and provide reports, as required, describing the applicant's methods for determining turbine missile generation probabilities (NUREG-1048 Supplement No 6; Letter from C. Rossi (NRC) to J. Martin (Westinghouse Electric Corporation); and NUREG-0887) for NRC review and approval. 4. Applicants obtaining turbines from manufacturers that have prepared NRC-approved reports to describe their methods and procedures for calculating turbine missile generation probabilities are expected to meet criteria appropriate to the orientation of the turbine (see Table 3.5.1.3-1). Turbine manufacturers should provide applicants with tables of missile generation probabilities versus time (inservice visual, surface, and 3.5.1.3-6 Revision 3 - March 2007 volumetric rotor inspection interval for design speed failure and inservice