Document: NUREG-0800
Document ID: a2680f96-0e15-402d-89ab-688ff09806a8
Document Type: srp
Title: with respect to the specified station blackout event/duration.13
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070497.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.2
CFR Part: 
CFR Title: 

Content:
ions which use two generator circuit breakers in a parallel circuit, a test should be conducted to determine the time to reach the maximum permissible temperature on the most limiting component of the breaker when going from the rated continuous current to twice rated continuous current. i. Mechanical Operation Test A sufficient number of no-load mechanical operations should be performed by the circuit breaker to provide a reasonable indication of its mechanical reliability and life. The demonstrated life should be adequate for the plant life expectancy. 3. The availability of offsite power to the onsite loads for designs utilizing generator circuit breakers should be no less than comparable designs which utilize separate offsite power transformers to supply offsite power to the station loads. In this regard the trip selectivity between the generator circuit breakers and the switchyard high voltage generator circuit breakers should insure against unnecessary tripping of the switchyard generator circuit breakers during abnormal events in order to maintain offsite power to the station loads. 8.2-21 DRAFT Rev. 4 - April 1996 4. Load break switches should be designed to perform their intended function during steady-state operation, power system transients, and major faults. Except for item 2.C, the switches should have the same capabilities as defined in guideline 2 for generator circuit breakers. In addition, the symmetrical interrupting capability of the load break switch should be at least equal to the maximum identified peak loading capability of the station generator. C. Implementation The guidelines will be applied in the review of ORs, OLs, COLs, and CPs in accordance with the following (see also subsection V of this SRP section): 1. Guidelines 1 through 4 of Revision O to Appendix A of this SRP section do not apply to operating reactors as a backfit item. Operating reactors which install generator circuit breakers or load break switches to meet the requirements