Document: NUREG-0800
Document ID: e75b7685-2a36-4e9b-a431-02d166dcf372
Document Type: srp
Title: LOSS OF NONEMERGENCY AC POWER TO THE STATION AUXILIARIES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070681.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.2.6
CFR Part: 
CFR Title: 

Content:
ng that the minimum departure from nucleate boiling ratio (DNBR) remains above the 95/95 DNBR limit for PWRs and the 33 critical power ratio (CPR) remains above the minimum critical power ratio (MCPR) 34 35 safety limit for BWRs based on acceptable correlations (see SRP Section 4.4). 3. An incident of moderate frequency should not generate a more serious plant condition without other faults occurring independently. 4. An incident of moderate frequency in combination with any single active component failure, or single operator error, shall be considered and is an event for which an estimate of the number of potential fuel failures shall be provided for radiological dose calculations. For such accidents, fuel failures must be assumed for all rods for which the DNBR or CPR falls below those values cited above for cladding integrity unless it can be shown, based on an acceptable fuel damage model (see SRP Section 4.2), that fewer failures occur. There shall be no loss of function of any fission product barrier other than the fuel cladding. 5. To meet the requirements of General Design Criteria 10 and 15, the positions of Regulatory Guide 1.105, "Instrument Spans and Setpoints for Safety-Related Systems,"36 are used with regard to their impact on the plant response to the type of transient addressed in this SRP section. 6. The most limiting plant systems single failure, as defined in the "Definitions and Explanations" of Appendix A to 10 CFR Part 50, shall be identified and assumed in the analysis and shall satisfy the positions of Regulatory Guide 1.53 (Ref. 14).37 The applicant's analysis of the loss of ac power transient should be based on an acceptable model. Models which have been approved by the NRC are identified in References 2 through 8. References 19 through 23 are acceptable computer codes for non-LOCA transient analysis for CE80+ applications. References 24 and 25 are acceptable transient analysis computer codes 38 for Advanced Boiling Water Reactor (ABWR)