Document: NRC Regulatory Guide
Document ID: 47b09be1-4bf8-45f9-a099-7fed871c09bd
Document Type: regulatory_guide
Title: Plant-Specific, Risk-Informed Decisionmaking: Inservice Testing (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2114/ML21140A055.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.175
CFR Part: 
CFR Title: 

Content:
t will remain operable over the test interval. Assurance should be established that degradation is not significant for components placed on an extended test interval, and that failure rate assumptions for these components are not contradicted by test data. It should be clearly established that those test procedures and evaluation methods are implemented that reasonably ensure that degradation will be detected, and corrective action will be taken. 3.4 Feedback and Corrective Action The licensee’s corrective action program for this application should contain a performance-based feedback mechanism to ensure that if a particular component’s test strategy is adjusted in a way that is ineffective in detecting component degradation and failure, particularly potential CCF mechanisms, the RI-IST program weakness is promptly detected and corrected. Performance monitoring should be provided for SSCs with feedback to the RI-IST program for appropriate adjustments when needed. RG 1.175, Page 25 If component failures or degradation occur at a higher rate than assumed in the basis for the RI-IST program, the following basic steps should be followed to implement corrective action: a. The causes of the failures or degradation should be determined, and corrective action implemented. b. The component’s test effectiveness should be reevaluated, and the RI-IST program should be modified accordingly. The licensee’s corrective action program evaluates RI-IST components that either fail to meet the test acceptance criteria established by the licensee detailed in the RI-IST program plan or are otherwise determined to be in a nonconforming condition (e.g., a failure or degraded condition discovered during normal plant operation). An acceptable evaluation does the following: a. It complies with 10 CFR Part 50, Appendix B, Criterion XVI, “Corrective Action.” b. It promptly determines the impact of the failure or nonconforming condition on system or train operability and follows the