Document: NUREG-0800
Document ID: a4637484-a66d-4066-b2e7-77b0ea7d3187
Document Type: srp
Title: 2.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070601.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.4.9.16
CFR Part: 
CFR Title: 

Content:
application reviews, the staff requires the applicant to provide the following design capability and verification: Top-Feed Steam Generator Designs To eliminate or reduce possible water hammer in the feedwater system: a. Prevent or delay water draining from the feed ring following a drop in steam generator water level by means such as top discharge J-Tubes and limiting feed ring seal assembly leakage. b. Minimize the volume of feedwater piping external to the steam generator which could pocket steam using the shortest possible (less than seven feet 2.1 m (7 ft)) horizontal 100 run of inlet piping to the steam generator feed ring. c. Perform tests acceptable to NRC to verify that unacceptable feedwater hammer will not occur using the plant operating procedures for normal and emergency restoration of steam generator water level following loss of normal feedwater and possible draining of the feed ring. Provide the procedures for these tests for approval before conducting the tests and submit the results from such tests. d. Implement pipe refill flow limits where practical. Preheat Steam Generator Designs 1. Minimize the horizontal lengths of feedwater piping between the steam generator and the vertical run of piping by providing downward turning elbows immediately upstream of the main and auxiliary feedwater nozzles. 2. Provide a check valve upstream of the auxiliary feedwater connection to the top feedwater line. 3. Maintain the top feedwater line full at all times. 4. Perform tests acceptable to NRC to verify that unacceptable feedwater hammer will not occur using plant operating procedures for normal and emergency restoration of steam generator water level following loss of normal feedwater. Also perform a water hammer test at the power level at which feedwater flow is transferred from the auxiliary feedwater nozzle to the main feedwater nozzle. The test shall be performed*% of power by using pumping feedwater through the auxiliary feedwater (top) nozzle at the