Document: NUREG-0800
Document ID: c1d42ca1-cc58-40db-812c-918554bfa81b
Document Type: srp
Title: FEEDWATER SYSTEM PIPE BREAKS INSIDE AND OUTSIDE CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070704.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.2.8
CFR Part: 
CFR Title: 

Content:
particular nuclear steam supply system and sensitivity studies will be required to determine the most conservative combination of power level and plant operating mode. These sensitivity studies may be presented in a generic report and referenced if considered applicable. b. The assumptions as to whether offsite power is lost and the time of loss should be made conservatively. Offsite power may be lost simultaneously with the occurrence of the pipe break, the loss may occur during the accident, or offsite power may not be lost. A study should be made to determine the most conservative assumption appropriate to the plant design being reviewed. The study should take account of the effects that loss of offsite power has on reactor coolant and main feedwater pump trips and on the initiation of auxiliary feedwater, and the resulting modification of the sequence of events. c. The effects of the postulated feedwater line breaks on other systems (pipe whip, jet impingement, reaction forces, temperature, humidity, etc.) should be considered in a manner consistent with the intent of Branch Technical Positions ASB 3-1 and MEB 3-1 (Ref. 5).38 d. The worst single active component failure should be assumed to have occurred in the systems required to control the transient. For new applications, loss of offsite power DRAFT Rev. 2 - April 1996 15.2.8-8 (LOOP) should not be considered a single failure; feedwater pipe breaks should be analyzed with and without LOOP, as discussed in assumption b above, in combination with a single active failure. (This position is based upon interpretation of GDC 17, as documented in the Final Safety Evaluation Report for the ABB-CE System 80+ design certification.) 39 e. The maximum rod worth should be assumed to be held in the fully withdrawn position, per GDC 25. An appropriate rod reactivity worth versus rod position curve should be assumed. f. The core burnup (time in core life) should be selected to yield the most limiting combination of moderator