Document: NRC Regulatory Guide
Document ID: 8b2255d1-47a9-4dfe-ba41-568c561a89ee
Document Type: regulatory_guide
Title: Inspection of Water-Control Structures Associated with Nuclear Power Plants + HISTORY – HISTORY 01/2015 – DG-1245 , Proposed Revision 2 (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1325/ML13255A435.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.127
CFR Part: 
CFR Title: 

Content:
ey data may help identify settlement over long time periods. (2) Slope Stability: Embankment slopes should be examined for irregularities in alignment and variances from originally constructed slopes, unusual changes from original crest alignment and elevation, evidence of movement at or beyond the toe, and surface cracks that indicate movement. (3) Seepage: The downstream face of abutments, embankment slopes and toes, contacts between the embankment and structure, and the downstream valley areas should be examined for evidence of existing or past seepage. The sources of seepage should be investigated to determine cause and potential severity affecting dam safety under operating conditions. The presence on slopes of animal burrows and vegetative growth that might cause detrimental seepage or piping should be examined. (4) Clogging of, and Inappropriate Materials in, Drainage Systems: All drainage systems should be examined to determine whether the systems can freely pass discharge and ensure that the discharge water is not carrying embankment or foundation material. Systems used to monitor drainage should be examined to ensure that they are operational and functioning properly. (5) Gullies and Notches in Slope: The slope protection should be examined for erosion-formed gullies and wave-formed notches and benches that have reduced the embankment cross-section or exposed less wave-resistant materials. The adequacy of slope protection against waves, currents, and surface runoff that may occur at the site should be evaluated. The condition of vegetative or any other protective covers should be evaluated, where pertinent. c. Spillway Structures and Outlet Works The inspection and monitoring program for the spillway should cover the structures and features, including bulkheads and flashboards, of service and auxiliary spillways for conditions that may impose operational constraints on the spillway. The outlet works inspection and monitoring program should include