Document: NUREG-0800
Document ID: 1dbfaffa-d13d-47e0-9536-f667eb85f6b8
Document Type: srp
Title: CONDENSATE AND FEEDWATER SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350091.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.4.7
CFR Part: 
CFR Title: 

Content:
dition, experience sustains maintaining preoperational tests to verify the absence of SGWH. More recently, Westinghouse and Combustion Engineering have introduced steam generators of the preheat type, wherein the majority of feedwater enters the steam generator at the bottom through a preheater section. The potential for condensation-induced water hammer in preheat steam generators was studied by BNL and reported in NUREG/CR-1606, "An Evaluation of Condensation-Induced Water Hammer in Preheat Steam Generators," June 1980. This report, citing the lack of definitive experimental and analytical results, recommended full scale verification tests to demonstrate the absence of damaging water hammer in preheat steam generators and connecting feedwater piping (i.e., preoperational tests). 10.4.7-8 Rev. 3 - April 1984 B&W steam generators, which are a "once through" flow design, have generally not reported water hammer occurrence. However, in May 1982, several B&W plants (following inservice inspection) reported damaged internal auxiliary feedwater headers and support structures. The cause was attributed to steam pocket collapse. The internal auxiliary feedring design concept is similar to CE & W top feedring concepts which have experienced water hammer before corrective design measures were implemented. For these B&W plants, the OTSG's are being modified to return to the previous design using auxiliary feedwater injection manifolds which are external to the steam generator. The staff believes that SGWH evidence and studies performed to date warrant the establishment of design guidelines for steam generators and the associated piping. Guidelines have been developed that may be used to reduce the probability of a damaging steam condensation induced water hammer, particularly for the Westinghouse and Combustion Engineeering PWR designs which use top-feed steam generators. BRANCH TECHNICAL POSITION In CP and OL application reviews, the staff requires the applicant to provide