Document: NUREG-0800
Document ID: 45eeca5d-838e-41bb-9ab1-5681c845852e
Document Type: srp
Title: TURBINE GENERATOR
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0703/ML070380204.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.2
CFR Part: 
CFR Title: 

Content:
defense provided by the turbine generator protection system to preclude excessive overspeeds should include diverse protection means. B. For normal speed-load control, the speed governor action of the electrohydraulic control system fully cuts off steam at approximately 103 percent of rated turbine speed by closing the control and intercept valves. C. A mechanical overspeed trip device will actuate the control, stop, and intercept valves at approximately 111 percent of rated speed. D. An independent and redundant backup electrical overspeed trip circuit senses the turbine speed by magnetic pickup and closes all valves associated with speed control at approximately 112 percent of rated speed. This backup electrical overspeed trip system may use the same sensing techniques as the electrohydraulic control system. However, the circuitry is reviewed to confirm that the control signals from the two systems are isolated from, and independent of, each other. 3. The main steam stop, control, reheat stop, and intercept valving arrangements and the valve closure times are reviewed to ensure that no single valve failure can disable or otherwise compromise the overspeed control function. 4. The capability to test essential components during TGS operation is reviewed. 5. The proposed inservice inspection program for essential speed control valves is reviewed to verify that it includes the provisions of subsection I of this SRP section. 6. For review of a DC application, the reviewer should follow the above procedures to verify that the design, including requirements and restrictions (e.g., interface requirements and site parameters), set forth in the final safety analysis report (FSAR) meets the acceptance criteria. DCs have referred to the FSAR as the design control document 10.2-7 Revision 3 - March 2007 (DCD). The reviewer should also consider the appropriateness of identified COL action items. The reviewer may identify additional COL action items; however, to ensure these COL