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:
action to reduce P to meet the 1 appropriate Case A criterion before returning the turbine to service. Exemptions may be granted for valid technical reasons or to mitigate severe economic hardship. C 10 < P < 10 10 < P < 10 If this condition is reached during -3 -2 1 -4 -3 1 operation, the turbine must be isolated from the steam supply within 60 days, at which time the licensee must take action to reduce P to meet the appropriate 1 Case A criterion before returning the turbine to service. D 10 < P 10 < P If this condition is reached during -2 1 -3 1 operation, the turbine must be isolated from the steam supply within 6 days, at which time the licensee must take action to reduce P to meet the appropriate 1 Case A criterion before returning the turbine to service. 5. 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 volumetric disk inspection interval for design speed failure and inservice valve testing interval for destructive overspeed failure) for each turbine. These probabilities will be used to establish inspection and test schedules that meet NRC safety objectives.26 6. Applicants are expected to commit to the following program if turbines are obtained from manufacturers that have not submitted, or received NRC approval for, reports DRAFT Rev. 3 - April 1996 3.5.1.3-8 describing their methods and procedures for calculating turbine missile generation probabilities: a. An inservice inspection program should be used to detect disk flaws that could lead to brittle failure at or below design speed in the steam turbine rotor assembly. The turbine rotor design should facilitate inservice inspection of all high-stress