Document: NUREG-0800
Document ID: 7e9d3620-7a94-488e-b2d5-992282113080
Document Type: srp
Title: NUREG408OO
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350480.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
Position to provide guidance and to establish uniform requirements for acceptable designs of auxiliary feedwater systems. B. BRANCH TECHNICAL POSITION The auxiliary feedwater system should be capable of satisfying the system functional requirements after a postulated break in the auxiliary feedwater piping inside containment together with a single electrical failure. The basis for the position is that an auxiliary feedwater piping break would result in tripping the unit and, in turn, might cause loss of offsite power. Standard staff assumptions for analyzing postulated accidents include the assumption of loss of offsite power if the affected unit generator is tripped by the accident. Such a circumstance would leave the plant without adequate means for removal of afterheat even though the reactor coolant pressure boundary was intact, an unacceptable result. Plant heat removal systems must, in any postulated piping break, be capable of removing afterheat to the ultimate heat sink assuming a single electrical (active) failure anywhere in the auxiliary feedwater system or in the onsite power system. C. REFERENCES None 7A-10 Rev. 2 - July 1981 BRANCH TECHNICAL POSITION ICSB 14 SPURIOUS WITHDRAWALS OF SINGLE CONTROL RODS IN PRESSURIZED WATER REACTORS A. BACKGROUND Recent operating experience with PWRs and subsequent reviews of PWR designs with regard to the requirements of General Design Criteria 20 and 25 have shown that single failures can cause inadvertent single rod withdrawals. The intent of this Branch Technical Position is to provide specific guidance toward an acceptable interpretation and application of GDC 20 and 25. B. BRANCH TECHNICAL POSITION GDC 20 requires that the protection system shall be designed to initiate automatically the operation of appropriate systems including the reactivity control systems, to assure that specified acceptable fuel design limits are not exceeded as a result of anticipated operational occurrences. GDC 25 requires these limits