Document: NUREG-0800
Document ID: 2768345e-44b7-48d8-bfa7-69652aa4faa8
Document Type: srp
Title: CONCRETE CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1319/ML13198A245.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.8.1
CFR Part: 
CFR Title: 

Content:
t shell, within which the localized or transient load is located, should then be analyzed, using the results obtained from the analysis of the overall vessel behavior as boundary conditions. D. Creep, Shrinkage, and Cracking of Concrete. Creep and shrinkage values for concrete should be established by tests performed on the concrete to be used in the containment structure or from data obtained on completed containments constructed of the same kind of concrete. In establishing these values, the analysis should consider the differences in the environment between the test samples and the actual concrete in the structure. For some containments, cracking of concrete is expected to occur based on the structural integrity test performed in accordance with Article CC-6000 of the ASME Code. Also, based on load combinations that include the design pressure load with earthquake loads, additional concrete cracking would be expected to occur. Concrete cracking can cause redistribution of member forces because of the various loadings applied to the structure. Concrete cracking can also affect the stiffness of the containment and cause shifting of the natural frequency, 3.8.1-14 Revision 4 - September 2013 thereby affecting the response/loads used to design the containment. Accordingly, the analysis used to calculate the dynamic response of the containment resulting from dynamic loads such as earthquake and hydrodynamic loads (if applicable) needs to consider the potential effects of concrete cracking, if significant. The approach used should include the effect of redistribution of the various loads caused by concrete cracking. With improvements in the development of computer programs for analysis of concrete structures, the evaluation of concrete cracking can be analyzed directly within the finite element model. Alternatively, additional analyses can treat the effect of concrete cracking by determining the response of the containment to variation in the stiffness characteristics