Document: NUREG-0800
Document ID: 228b9b6e-c81e-4d76-9b8e-12f6c3bd7fa1
Document Type: srp
Title: and Regulatory Guide 1.92,(Reference 10) "Combining Modal Responses
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070336.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.2
CFR Part: 
CFR Title: 

Content:
the Category I piping system, adjacent non-Category I piping should be analyzed according to the same seismic criteria as applicable to the Category I piping system. For non-Category I piping systems attached to Category I piping systems, the dynamic effects of the non-Category I piping should be simulated in the modeling of the Category I piping. The attached non-Category I piping, up to the first anchor beyond the interface, should also be designed in such a manner that during an earthquake of SSE intensity it will not cause a failure of the Category I piping. l. Criteria Used for Damping Regulatory Guide 1.61,(Reference 9) "Damping Values for Seismic Design of 41 Nuclear Power Plants," provides acceptable values which may be used. The use of alternate damping values requires justification.The damping values for piping described in ASME Code Case N-411 are also acceptable as supplemented in the regulatory position in Regulatory Guide 1.84. The methods for analysis of damping should be consistent with those described in SRP Section 3.7.2.42 3. Relevant requirements of GDC General Design Criteria 1 and 4 are met as given below. The following guidelines, in addition to Regulatory Guide 1.20 (Reference 7), apply to 43 the analytical solutions to predict vibrations of reactor internals for prototype plants. Generally, this analysis is required only for prototype designs. DRAFT Rev. 3 - April 1996 3.9.2-14 a. The results of vibration calculations for a prototype reactor should consist of the following: (1) Dynamic responses to operating transients at critical locations of the internal structures should be determined and, in particular, at the locations where vibration sensors will be mounted on the reactor internals. For each location, the maximum response, the modal contribution to the total response, and the response causing the maximum stress amplitude should be calculated. (2) The dynamic properties of internal structures, including the natural frequencies, the