Document: NUREG-0800
Document ID: 29fa664a-a42c-4ff0-8ae1-3798f7f23c23
Document Type: srp
Title: TURBINE MISSILES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070373.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.5.1.3
CFR Part: 
CFR Title: 

Content:
accordance with the criteria of SRP Section 3.5.3. b. The effect of fracture toughness properties on the failure probability of the low pressure turbine wheels is reviewed by the MTEB. c. The turbine overspeed protection system and its testing are evaluated by the MEB (turbine steam valve reliability) and the PSB (tripping and overspeed sensing systems). d. The identification of plant essential systems to be protected against turbine missiles is reviewed by the ASB. DRAFT Rev. 3 - April 1996 3.5.1.3-14 4. For Construction Permit applications docketed prior to 11/15/76 and to all Operating License reviews, a summary should be prepared of the following items: a. Identification of all safety-related targets vulnerable to turbine missiles. b. MTEB findings regarding turbine disc and rotor integrity and inservice inspection program. c. When appropriate, SEB evaluation of credit for missile barriers. d. PSB findings regarding turbine overspeed protection system. e. A general value impact assessment of localized missile shielding(CP's and OL's) and/or system relocation (CP's only). f. Identification of additional plant requirements, if any. 5. High trajectory turbine missiles are characterized by their nearly vertical trajectories. Missiles ejected more than a few degrees from the vertical, either have sufficient speed such that they land offsite, or their speeds are low enough so that their impact on most plant structures is not a significant hazard. The probability of a high trajectory turbine missile landing within a few hundred feet from the turbine is on the order of 10 per -7 square foot of horizontal target area. Consequently the risk from high trajectory turbine missiles is insignificant unless the vulnerable target area is on the order of 10 square feet 4 or more.37 2. Values calculated by the applicant for turbine missile generation probability are reviewed and compared with the acceptance criteria offered in subsection II. The applicant's methods and analyses