Document: NUREG-0800
Document ID: 0b1da184-7029-4886-9101-d5e6755a79ad
Document Type: srp
Title: Revision 4 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0708/ML070850324.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10
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CFR Title: 

Content:
lear Regulatory Commission, Washington, DC 20555, Attention: Reproduction and Distribution Services Section, or by fax to (301) 415-2289; or by email to DISTRIBUTION@nrc.gov. Electronic copies of this section are available through the NRC's public Web site at http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0800/, or in the NRC's Agencywide Documents Access and Management System (ADAMS), at http://www.nrc.gov/reading-rm/adams.html, under Accession # ML070850324. NUREG-0800 U.S. NUCLEAR REGULATORY COMMISSION STANDARD REVIEW PLAN BRANCH TECHNICAL POSITION 10-2 DESIGN GUIDELINES FOR AVOIDING WATER HAMMERS IN STEAM GENERATORS REVIEW RESPONSIBILITIES Primary - Organization responsible for the review of power conversion systems Secondary - None A. 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 a 46-cm (18-in) feedwater pipe and damage to the containment inner liner. The repeated occurrence of such water hammers and the potential severity of such flow instabilities resulted in the NRC engaging Creare, Inc., in 1976 to evaluate causes and effects, to develop recommendations for avoidance of top-feed steam generator water