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:
the reheat steam stop and intercept valves should protect the turbine from exceeding set speeds and should protect the reactor system from abnormal surges. The reheat stop and intercept valves should be capable of closure concurrent with the main steam stop valves, or of sequential closure within an appropriate time limit, to ensure that turbine overspeed is controlled within acceptable limits. The valve arrangements and valve closure times should be structured so that a failure of any single valve to close will not result in excessive turbine overspeed in the event of a TGS trip signal. C. The TGS should have the capability to permit periodic testing of components important to safety while the unit is operating at rated load. 2. An inservice inspection program for main steam and reheat valves should be established and should include the following provisions: 10.2-5 Revision 3 - March 2007 A. At intervals of approximately 3-1/3 years, during refueling or maintenance shutdowns coinciding with the inservice inspection schedule required by Section XI of the American Society of Mechanical Engineers (ASME) Code for reactor components, at least one main steam stop valve, one main steam control valve, one reheat stop valve, and one reheat intercept valve should be dismantled, and visual and surface examinations should be conducted of valve seats, disks, and stems. If this process detects unacceptable flaws or excessive corrosion in a valve, all other valves of that type should be dismantled and inspected. Valve bushings should be inspected and cleaned, and bore diameters should be checked for proper clearance. B. Main steam stop and control valves should be exercised at a frequency recommended by the turbine vendor or valve manufacturer. 3. The arrangement of connection joints between the low-pressure turbine exhaust and the main condenser should prevent adverse effects on any safety-related equipment in the turbine room in the event of a rupture (it is preferable not to