Document: NRC Regulatory Guide
Document ID: 1731a882-b0c5-418d-b65e-55646c26be5c
Document Type: regulatory_guide
Title: 03/2007
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0703/ML070380553.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.9
CFR Part: 
CFR Title: 

Content:
y buses, and (2) the emergency diesel generator starts on the autostart signal from its standby conditions; attains the required voltage and frequency, and energizes permanently connected loads within acceptable limits and time; energizes all autoconnected shutdown loads through the load sequencer; and operates for greater than or equal to 5 minutes. If the required safety loads are not available, one or more equivalent load(s) may be used. 2.2.6 Combined SIAS and LOOP Test Clause 7.5.6 of IEEE Std 387-1995 should be modified to read as follows: This test involves demonstrating that emergency diesel generator can satisfactorily respond to a LOOP in conjunction with SIAS in whatever sequence they might occur [e.g., loss-of-coolant accident (LOCA) followed by delayed LOOP or LOOP followed by LOCA]. A simultaneous LOOP/LOCA event would be demonstrated by verifying that the diesel generator unit starts on the auto-start signal from its standby conditions, attains the frequency and voltage within acceptable limits and time, energizes the auto-connected shutdown loads through the load sequencer within the acceptable limits of pump start time, and operates for a minimum of 5 minutes. 2.2.7 Largest Load Rejection Test Clause 7.5.7 of IEEE Std-1995 should be supplemented as follows: This test involves demonstrating the emergency diesel generator’s capability to reject a load equal to loss of the largest single load while operating at its design load power factor and verify that the frequency and voltage requirements are met and the unit will not trip on overspeed. Rev. 4 of RG 1.9, Page 12 2.2.8 Design-Load Rejection Test Clause 7.5.8 of IEEE Std-1995 should be supplemented as follows: This test involves demonstrating the emergency diesel generator’s capability to reject a load equal to 90–100 percent of the continuous rating while operating at its design load power factor and verify that the voltage requirements are met and that the unit will not trip on overspeed.