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:
oss evaluation should consider the filtration of particulate, fibrous, chemical, and coating debris by the accumulated debris bed. The head loss characteristics of a debris bed depend on the types and quantities of the debris, strainer approach velocities, and LOCA-related hydrodynamic phenomena in the suppression pool. The determination of the total debris load should also consider chemical reaction products (e.g., precipitates) that may form from interaction between the post-LOCA environment and plant materials. Plants that credit the standby liquid control system or equivalent to inject boron into the primary system should include the potential chemical reaction products resulting from the use of that system. The flowchart (Figure 2) on the following page illustrates the input logic and information considered during head loss testing and design of an ECCS suction strainer. Guidance for each step in the process can be found in the applicable regulatory positions in Section C. DG-1385, Page 13 Figure 2: Flowchart for steps in qualification of a suction strainer Debris Generation • Selection of Limiting Breaks • ZOI • Unqualified Coatings • Chemical Effects • Latent Debris Test Matrix • Maximum Debris Load • Thin-Bed Loading • Procedural Variations • Repeat Tests • Vortex Test Debris Transport • Blowdown • Washdown • Pool Fillup • Recirculation Recirculation Hydraulic Parameters • System(s) Flow • Temperature • Timing Debris Load • Maximum Debris Quantity • Debris Characteristics • Minimum Filtering Bed Test Facility Design • Representative Test Module • Representative Test Tank Geometry • Representative Water Level Conservative Test Procedure • Debris Preparation • Debris Addition and Sequencing • Test Tank Flow Characteristics Prototype Strainer Head Loss Testing Debris Penetration Assessment NPSH Evaluation • Minimum Margins Strainer Qualification • Plant Head Loss Assessment • Head Loss < NPSH Margin •