Document: NUREG-0800
Document ID: fde4aca8-91fc-456b-a158-beaedf808cb2
Document Type: srp
Title: STEAM GENERATOR PROGRAM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0703/ML070380194.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.2.2
CFR Part: 
CFR Title: 

Content:
ength of each tube must be inspectable using currently available nondestructive examination methods and techniques capable of finding the forms of degradation that may occur during the service life of the steam generators. The design of the steam generators should permit tubes with unacceptable flaws to be removed from service to ensure that tube integrity will be maintained. Tubes with unacceptable flaws should also be capable of being stabilized if it is determined that a plugged tube potentially may sever (as a result of continued degradation) and subsequently affect the integrity of an active tube. Access to both the primary and secondary sides of the steam generator tubes is required because conditions may exist on either side of the steam generator tubes that could affect their structural and leakage integrity. This should include, for example, access to the secondary face of the tubesheet, open tube lanes, feedwater inlet area (e.g., J-tubes or preheater inlet), and other locations that may impair tube integrity. Degradation of secondary side internals can result in the generation of loose parts, inadequate tube support, and mechanical damage to the tubes. In addition, the introduction of foreign objects (including loose parts) into the steam generator during fabrication, maintenance, or operation of the steam generators could impact tube integrity. Sludge buildup and deposits on the tubes can increase the susceptibility of the tubing to corrosion and make it more difficult to inspect the tubing (e.g., because of noise in eddy current data or obstructions in a visual inspection). As a result, the design of the steam generators is considered acceptable for the purposes of implementing the steam generator program if it (1) ensures that all steam generator tubes are accessible for periodic inspection, testing, and repair (including 5.4.2.2-5 Revision 2 - March 2007 plugging and stabilizing), (2) permits an inspection of the full length of every tube, using