Document: NUREG-0800
Document ID: 106978f1-fb10-4fa9-ad95-601f3c16bd36
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550072.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
basis that justifies taking no action. BTP 7-19-6 Revision 5 - March 2007 3. When a failure of a common element or signal source shared by the control system and RTS is postulated and the common-cause failure results in a plant response that requires reactor trip and also impairs the trip function, then diverse means that are not subject to or failed by the postulated failure should be provided to perform the RTS function. The diverse means should assure that the plant response calculated using best-estimate (realistic assumptions) analyses does not result in radiation release exceeding 10 percent of the 10 CFR 100 guideline value or violation of the integrity of the primary coolant pressure boundary. 4. When a failure of a common element or signal source shared by the control system and ESFAS is postulated and the common-cause failure results in a plant response that requires engineered safety features (ESF) and also impairs the ESF function, then diverse means that are not subject to or failed by the postulated failure should be provided to perform the ESF function. The diverse means should assure that the plant response calculated using best-estimate (realistic assumptions) analyses does not result in radiation release exceeding 10 percent of the 10 CFR 100 guideline value or violation of the integrity of the primary coolant pressure boundary. 5. No failure of monitoring or display systems should influence the functioning of the RTS or ESFAS. If plant monitoring system failure induces operators to attempt to operate the plant outside safety limits or in violation of the limiting conditions of operation, the analysis should demonstrate that such operator-induced transients will be compensated for by protection system function. The adequacy of the diversity provided with respect to the above criteria must be justified. Interconnections between the RTS and ESFAS (for interlocks providing for reactor trip if certain ESFs are initiated, ESF initiation when a reactor