Document: NUREG-0800
Document ID: 97120913-d26f-4324-ab62-22f3f5b73925
Document Type: srp
Title: and 8.3.2.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600410.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
voltage associated with the rated maximum voltage and with a rated inherent transient recovery voltage as described in IEEE Std C37.013 for system- source faults and generator-source faults. The rated asymmetrical current-interrupting capability is demonstrated within the same conditions as the symmetrical current. The circuit breaker should have, as a minimum, the capability of interrupting the maximum asymmetrical and symmetrical fault current available at the instant of primary arcing contact separation. This current should be calculated by assuming a bolted three phase fault at a point on the system which causes the maximum amount of fault current flowing through the generator circuit breaker. The fault current interrupting 8.2-32 Revision 4 - March 2007 capability (short circuit current rating) of the circuit breaker should be demonstrated by performing a series of tests similar to those called for in IEEE Std C37.013. The tests should include close/open (CO) operations and should be performed at the circuit breaker minimum rated air pressure and control voltage and with a rated transient recovery voltage as described in the standard for system-source faults and generator- source faults. (iv) Rated Transient Recovery Voltage (TRV). The ability to withstand rated TRVs, as specified in IEEE Std C37.013 for rated symmetrical and asymmetrical currents, is demonstrated during short-circuit tests. Both inherent circuit transient recovery voltage and power frequency recovery voltage must be considered when demonstrating the rating of a generator circuit breaker. Additional information and guidance on TRV is provided in IEEE Std C37.011 (Reference J). (v) Short-Time Current-Carrying Capability. The generator circuit breaker shall be capable of carrying for a period of time Ts equals 1 second, any short-circuit current determined from the envelope of the current wave at the time of the maximum crest, whose value does not exceed 2.74 times the rated short-circuit