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:
ith GDC 45, the water control structures should be designed and instrumented to facilitate the inspection and monitoring program discussed below. The features and instrumentation should be designed to withstand the same design basis as the water control structure itself. 2. Inspection of Inaccessible Areas The inspection and monitoring program should address detection of aging affects for inaccessible, below- grade, and submerged concrete structural elements. For plants with non-aggressive raw water and groundwater/soil (pH > 5.5, chlorides < 500 parts per million [ppm], or sulfates < 1500 ppm), the program should require (a) evaluation of the acceptability of inaccessible areas when conditions exist in accessible areas that could indicate the presence of, or result in, degradation to such inaccessible areas and (b) examination of representative samples of the exposed portions of the below-grade concrete when excavated for any reason. Submerged concrete structures should be inspected during periods of low tide or when dewatered and accessible. 3. Inspectors Engineers experienced in the investigation, design, construction, and operation of water control structures should direct the inspection and monitoring program. The field inspection team should include engineers, engineering geologists, or other specialists who can recognize and assess signs of possible distress (e.g., structural joint movement, piezometric fluctuations, seepage variations, settlement and horizontal misalignments, slope movement, cracking of concrete, erosion, and corrosion of equipment and conduits) and recommend appropriate mitigating measures. 4. Engineering Data Compilation To facilitate the inspections and monitoring, the following engineering data related to the design, construction, and operation of the water-control structures should be assembled and, to the extent practicable, included in the initial inspection report discussed in Section C.10 of this RG.1 This data should include the