Document: NRC Regulatory Guide
Document ID: 08964ae0-0fa8-4e51-af44-0c6a1ee6e94c
Document Type: regulatory_guide
Title: Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1221/ML12216A011.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.108
CFR Part: 
CFR Title: 

Content:
sign should not be considered valid tests or failures. (3) Successful starts, including those initiated by bona fide signals, followed by successful loading (se- quential or manual) to at least 50% of continuous rating and continued operation for at least one hour should be considered valid successful tests. (4) Successful starts that are terminated inten- tionally without loading, as defined in (3) above, should not be considered valid tests or failures. (5) Successful starts followed by an unsuccessful loading attempt should be considered valid tests and failures, except as noted in (2) above. (6) Tests that are terminated intentionally before completion as defined in (3) above because of an alarmed abnormal condition that would ultimate- ly have resulted in diesel generator damage or failure should be considered valid tests and failures. I 1.108-3 (7) Tests performed in the process of troubleshooting should not be considered valid tests. Tests that are performed to verify correction of the problem should be considered valid tests and succes- ses or failures, as appropriate. (8) Cranking and venting procedures that lead to the discovery of conditions (e.g., excessive water or oil in a cylinder) that would have resulted in the failure of the diesel generator unit during test or dur- ing response to a bona fide signal should be con- sidered a valid test and failure. 3. Records and Reports a. All start attempts, including those from bona fide signals, should be logged. The log should describe each occurrence in sufficient detail to permit independent determination of statistical validity in accordance with Regulatory Position C.2.e. Maintenance, repair, and out-of-service-time histories, as well as cumulative maintenance and operating data, should also be logged. Cumulative statistical analyses of diesel generator unit test results, together with results of operation of the diesel generator unit when required by actual demand, should be maintained. These analyses