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:
haracterization of Debris Transport in Water,” issued August 2002 (Ref. 17), provides test results on the transport of various types, sizes, and shapes of debris with variables of flume water depth, turbulence intensity, flow patterns, fluid temperature, simultaneous presence of combinations of debris, types of obstructions, extent of congestion, and height of curbs. NUREG/CR-6916, “Hydraulic Transport of Coating Debris,” issued December 2006 (Ref. 18), provides test results on the transport of protective coating debris. DG-1385, Page 10 Flow during pool fill or longer -term recirculation may sweep debris pieces too large or dense to remain in suspension along the floor toward the ECCS strainer. Trash racks, debris curbs, and debris interceptors upstream of the ECCS strainers may decrease the amount of debris reaching the strainer. Some debris interceptor designs may also reduce the transport of fine, suspendable debris; however, it can be difficult to demonstrate the effectiveness of such interceptors in capturing fine debris. ECCS strainers and any trash racks, debris interceptors, or similar design features credited in the strainer performance analysis should be strong enough to withstand seismic events, resist jet impingement loads, resist impact loads that could be imposed by missiles generated by a LOCA and withstand the differential pressure loads imposed by the accumulation of debris. Materials for ECCS strainers, debris interceptors, and other design features should be able to withstand long periods of inactivity (i.e., no submergence) and periods of operation involving partial or full submergence in fluids that may contain chemically reactive materials. It is important to isolate the ECCS strainers from high-energy pipelines to protect against internally generated missiles, and it is necessary to shield the ECCS strainers, debris interceptors, and other credited design features from impacts of ruptured high-energy piping and associated jet