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:
scribed in Regulatory Position 2.2.2 and loaded as described in Regulatory Position 2.2.3 at least once every 31 days (with the maximum allowable extension not to exceed 25 percent of the surveillance interval). 2.3.2.2 Six-Month (or 184-Day) Testing This test may substitute for a monthly test. To demonstrate the capability of the emergency diesel generator to start from standby conditions and provide the necessary power to mitigate a LOCA coincident with a LOOP, each diesel generator should be started from standby conditions once every 6 months as described in Clause 7.5.3 of IEEE Std 387-1995. This will verify that the diesel generator reaches the required voltage and frequency within acceptable limits and time as specified in the plant technical specifications. Following this test, the emergency diesel generator should be loaded as described in Clause 7.5.2 of IEEE Std 387-1995 (see also Table 1). 2.3.2.3 Refueling Outage Testing The capability of the overall emergency diesel generator design should be demonstrated during every refueling outage (or at a frequency of not more than every 24 months) by performing the tests identified in Table 1. Certain tests may be conducted during the operating mode with NRC approval if the tests can be safely performed without increasing the probability of plant trip, loss of power to the safety buses, or LOOP. 2.3.2.4 Ten-Year Testing This testing involves demonstrating that the trains of standby electric power are independent at a frequency of once every 10 years (during a plant shutdown) or after any modifications that could affect emergency diesel generator independence (whichever is shorter) by starting all redundant units simultaneously to identify certain common-failure modes undetected in single diesel generator unit tests (see also Table 1). 3. Reporting Criteria Licensees must conform to the reporting requirements of 10 CFR Part 21, “Reporting of Defects and Noncompliance” (Ref. 2); 10 CFR 50.72, “Immediate