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:
n of the detailed strike and damage analyses The MTEB will also review the adequacy of turbine disk integrity in accordance with SRP Section 10.2.3.21 1. In accordance with 10 CFR Part 50, Appendix A, General Design Criterion 4 (GDC 4), nuclear power plant structures, systems, and components important to safety shall be appropriately protected against dynamic effects, including those caused by missiles. Failure of large steam turbines in the main turbine generator has the potential to eject high-energy missiles that can produce such damage. The staff's overall safety objective is to ensure that structures, systems, and components important to safety are adequately protected from the effects of turbine missiles. Accordingly, consideration should be given to safety-related systems (i.e., those structures, systems, or components necessary to perform required safety functions) to ensure the following: a. The integrity of the reactor coolant pressure boundary; b. The capability to shut down and maintain the reactor in a safe condition; and c. The capability to prevent accidents that could result in potential offsite exposures, which represent a significant fraction of the guideline exposures specified in 10 CFR Part 100, "Reactor Site Criteria." Examples of safety-related systems that should be protected are described in Regulatory Guide 1.117. 2. The probability of unacceptable damage resulting from turbine missiles, P , is expressed 4 as the product of (a) the probability of turbine failure resulting in the ejection of turbine disk (or internal structure) fragments through the turbine casing, P ; (b) the probability of 1 ejected missiles perforating intervening barriers and striking safety-related structures, systems, or components, P ; and (c) the probability of struck structures, systems, or 2 components failing to perform their safety function, P . Stated in mathematical terms, 3 P = P × P × P . 4 1 2 3 In accordance with the guidance provided in SRP Section 2.2.3