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:
ation, obstructions, leakage, or significant structural cracks. (7) Seepage or Leakage: The faces, abutments, and toes of the concrete structures should be examined for evidence of seepage or abnormal leakage, and records of the flow of downstream springs should be reviewed for unusual variation with the reservoir pool level. The sources of seepage should be determined, if possible. (8) Deterioration of Monolithic Joints-Construction Joints: All monolithic construction joints should be examined to determine the condition of the joint and filler material, any movement of joints, or any indication of distress or leakage. (9) Deterioration of Foundation: The foundation should be visually examined to the extent possible for damage or for the possible undermining of the downstream toe. (10) Condition of Abutments: The abutments should be examined for signs of instability or excessive weathering. Pre-Decisional DG-1245, Page 9 b. Embankment Structures The American Society of Civil Engineers (ASCE), U.S. Army Corps of Engineers (USACE), FEMA, and similar standards development organizations and regulatory agencies have published guidelines for the inspection of embankments and dams. These guidelines may aid with the development of an inspection and monitoring program. Dams and other water control structures should be inspected according to intervals specified by the regulatory agency under normal conditions and after unusual events (such as extreme rainfall and earthquakes). Such inspections will provide the best opportunity for the early detection of potential problems, including the following: (1) Settlement: The embankments and downstream toe areas should be examined for any evidence of unusual localized or overall settlement, depressions, or sink holes. Trending of survey 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,