Document: NRC Regulatory Guide
Document ID: 6f0a99f2-d25a-44e3-b7f2-3286449a9752
Document Type: regulatory_guide
Title: Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident (Rev. 5)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2126/ML21266A185.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.82
CFR Part: 
CFR Title: 

Content:
. 1.1.1.11 ECCS strainers and suction inlets for pumps required for long-term ECCS, CSS, or suppression pool cooling functions should be designed to prevent degradation of pump performance through air ingestion, flashing, and other adverse hydraulic effects (e.g., circulatory flow patterns, high-intake head losses, and gas void intrusion). 1.1.1.12 Advanced strainer designs have demonstrated capabilities that simple flat plate and basket-type strainers and screens do not have. The performance characteristics and effectiveness of such designs should be supported by appropriate test data for the intended application. 1.1.1.13 Prototypical head loss testing should be performed to verify suction strainer designs. Section C.1.3.12 provides guidance on prototypical head loss testing. 1.1.2 Minimizing Debris The debris and chemical reaction products (see Sections C.1.3.3 and C.1.3.10) that could accumulate on the suction strainer should be minimized. This is most easily accomplished during the design process and maintained through administrative controls. 1.1.2.1 Licensees should maintain debris source terms below the amount assumed in the strainer performance and other associated analyses. For example, cleanliness programs should ensure that the assumed latent debris and suppression pool sludge loading is not exceeded, and controls should be maintained to ensure that problematic debris (e.g., insulations, signage, coatings, foreign materials, and chemically reactive materials) is not introduced into containment to an extent that would exceed the analytically assumed values. In addition, permanent plant changes that may affect materials inside containment should be programmatically controlled so as not to change the analytical assumptions and numerical inputs of the licensee analyses. 1.1.2.2 When latent debris is a significant source (i.e., contributes more than a minimal amount to strainer head loss) that can affect strainer performance or create downstream effects,