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:
ulative 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 should include examination of the trend of critical failure mechanisms, human errors, and common mode failures. b. All diesel generator unit failures, valid or in- valid, should be reported3 consistent with the licensee's reporting requirements. This report should (1) identify the diesel generator unit involved, (2) identify the failure as being the nth f'ailure in the last 100 valid tests, (3) describe the cause of failure, (4) describe the corrective measures taken, (5) indicate the length of time the diesel generator unit was un- available, (6) define the current surveillance test inter- val, and (7) verify that the test interval is in confor- mance with the schedule of Regulatory Position C.2.d. If the number of failures in the last 100 valid tests is seven or more, the reliability of the diesel ' See Regulatory Guide 1.16, "Reporting of Operating Infor- mation." generator units requires special evaluation, and the information provided on the report form should be supplemented, as needed, by additional narrative material that: (1) Identifies the reported failure as the 7th or greater failure in the last 100 valid tests, (2) Describes corrective measures, taken or planned, to increase the reliability of the generator units, (3) Provides an assessment of the existing reliability of electric power to engineered-safety- ieature equipment, (4) Provides the licensee's basis for continued plant operation if that is planned, and (5) Provides a summary of all tests (valid and in- valid) that occurred within the time period over which the last 100 valid tests were performed, and verifies that surveillance testing during this period was in conformance with the schedule of Regulatory Position C.2.d. Invalid failures experienced during trouble- shooting should be included in