Document: NUREG-0800
Document ID: 7024eeeb-1819-4d56-9b72-fb63eab3836b
Document Type: srp
Title: and 3.9.3.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1006/ML100620981.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
l. For the lower vent portion of the drywell, the following conditions apply: i. If the main reinforcement of the drywell is carried down between the vent holes, and the reinforced concrete section is relied upon for structural purposes, the criteria that apply to concrete portions of the drywell as described above will apply. ii. If the main reinforcement of the drywell is terminated above the vent holes, and two steel plates lining both faces of the drywell are used for structural purposes, the criteria that apply to steel portions of the drywell as described above will apply. iii. If other structural systems are used in the vent region, the loads and load combinations are reviewed and judged on a case-by-case basis. 4. Design and Analysis Procedures The design and analysis procedures used for the containment internal structures are acceptable if found to be in accordance with the following: A. PWR Dry Containment Internal Structures i. Primary Shield Wall and Reactor Cavity The design and analysis procedures used for the shield wall are acceptable if found to be in accordance with ACI 349 with additional guidance provided by RG 1.142. This code is based on the strength design method. The design and analysis of anchors (steel embedments) used for component and structural supports on concrete structures are acceptable if found to be in accordance with ACI 349, Appendix B, with additional guidance provided by RG 1.199. Analyses for LOCA loads applicable to the primary shield wall, such as the cavity differential pressure combined with pipe rupture reaction forces, are acceptable if these loads are treated as dynamic time-dependent loads. This requires that either a detailed time-history analysis be performed or a static analysis using the peak of the forcing function amplified by an appropriate chosen dynamic factor be employed. Elastic behavior of the wall should be maintained under the differential pressure. However, for the concentrated accident loads, such as