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:
nly marginally to the debris loading for the ECCS sump. If debris generation and debris transport data have not been determined experimentally for a specific material, the material may be grouped with another material with similar physical and chemical characteristics existing in large quantities. For example, a small quantity of fibrous filtering material may be grouped with a substantial quantity of fibrous insulation debris, in which case the debris generation and transport data for the filter material need not be determined experimentally. However, such analyses are valid only if the small quantity of material does not have a significant effect when combined with other materials (e.g., it may not be valid to combine a small quantity of calcium silicate with fibrous debris). 1.3.3.3 All insulation (e.g., fibrous, calcium silicate, microporous, and reflective metallic); painted surfaces; fire barrier materials; and fibrous, cloth, plastic, or particulate materials within the ZOI should be considered as potential debris sources. Licensees should use applicable test DG-1385, Page 24 data as the basis for predicting the size distributions of the postulated debris. For breaks postulated in the vicinity of the containment penetrations, licensees should also consider the potential for debris generation from the packing materials used in the penetrations. In addition, licensees should consider breaks that could destroy the insulation installed on the reactor vessel and steam generators. Finally, licensees should consider the potential for particulate debris to be generated by the action of pipe rupture jets damaging paint or coatings and erosion of concrete at the point of impact. 1.3.3.4 In addition to debris generated by jet forces from the pipe rupture, the analyses should consider (1) debris existing before the pipe rupture that is transported to the suppression or containment pool, (2) debris created by the reactor pressure vessel environment (i.e., thermal and