Document: NUREG-0800
Document ID: 80fe9eee-2d6e-4a7e-b7dd-ec23aab2d39f
Document Type: srp
Title: STRATEGIES AND GUIDANCE TO ADDRESS LOSS OF LARGE AREAS OF
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1211/ML121110138.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.4
CFR Part: 
CFR Title: 

Content:
or procedures that involve connecting various pieces of equipment with fittings, adapters, jumpers or other types of connectors, the application should have a commitment for the licensee to confirm by engineering evaluation or a demonstration that (1) hoses can be connected to each other and to pumps, adapters, and fittings, (2) electrical cables, connectors, and jumpers are compatible; and, (3) fire hoses and nozzles can be attached to lifting devices and/or secured in place as needed. 8. NEI 06-12, Revision 3 requires that many strategies have an engineering basis that provides reasonable assurance that the intended makeup rate and capacities can be provided. NEI 06-12, Revision 3 also states that this basis should be auditable, but not necessarily based on a quality-related calculation. Licensees for currently operating plants used a number of different methods for establishing an engineering basis for these strategies including engineering handbooks and computer models. The NRC staff found that all of these methods were acceptable for establishing an engineering basis. However, at many sites, the NRC inspectors found errors in implementing these methods. Some licensees failed to address system piping losses, elevation losses or nozzle operating pressure requirements in their calculations. For example, at one site, the licensee’s calculation for the containment flooding strategy failed to take into account the friction losses of the plant piping system, which included at least thirty-nine 90 degree elbows, seven 45 degree elbows, and 200 feet of 2.5 inch diameter piping. As a consequence, this strategy would not have provided the required 300 gpm. Some licensees chose to assume that a strategy would provide the required flow, but had not provided an auditable or documented engineering basis for this assumption. For example, at one site, the licensee assumed that providing 500 gpm flow for the SFP external makeup strategy was the worst case for pumping with the