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:
dix A, General Design Criterion 46, "Testing of Cooling Water System." 7. Regulatory Guide 1.29, "Seismic Design Classification." 8. Branch Technical Position ASB 10-2, "Design Guidelines for Avoiding Water Hammer in Steam Generators," attached to SRP Section 10.4.7.88 9. Generic Letter 80-95, "Final Edition of NUREG-0619, 'BWR Feedwater Nozzle and Control Rod Drive Return Line Nozzle Cracking.'"89 10. Generic Letter 81-11, "BWR Feedwater Nozzle Cracking."90 11. Generic Letter 89-08, "Erosion/Corrosion-Induced Pipe Wall Thinning."91 12. NUREG-0619, "BWR Feedwater Nozzle and Control Rod Drive Return Line Nozzle Cracking."92 13. NUREG-0927, Revision 1, "Evaluation of Water Hammer Occurrences in Nuclear Power Plants," March 1984.93 14. EPRI NP-3944, "Erosion/Corrosion in Nuclear Plant Steam Piping: Causes and Inspection Guidelines."94 DRAFT Rev. 4 - April 1996 10.4.7-12 BRANCH TECHNICAL POSITION ASB 10-2 DESIGN GUIDELINES FOR AVOIDING WATER HAMMERS IN STEAM GENERATORS BACKGROUND Plant operational experience has shown that top-feed steam generators containing feedwater spargers with bottom drain holes incur steam-condensation-induced water hammers. This type of water hammer has frequently occurred after the feedwater sparger was uncovered (due to some plant transient) and cold auxiliary feedwater flow was subsequently initiated. The initiation of the auxiliary feedwater flow into the steam generator produces a water slug in the sparger or feedwater piping, which is then accelerated by the unbalanced pressures produced by the condensation of a steam pocket in the line. The resultant impulse could be of a sufficient magnitude to cause damage to the steam generator internal components and feedwater systems piping. The most damaging of such water hammer incidents occurred at Indian Point No. 2 in 1973, where the water hammer loads resulted in rupture of an 18-inch 46-cm (18-in) feedwater 95 pipe and damage to the containment inner liner. The repeated occurrence of such