Document: NRC Regulatory Guide
Document ID: b6726dc6-2968-4ca9-a925-c831eaaecc69
Document Type: regulatory_guide
Title: 03/2007
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0702/ML070260029.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.61
CFR Part: 
CFR Title: 

Content:
tric Advanced Boiling Water Reactor Design in 1994 [Ref. 6], Combustion Engineering System 80+ Design in 1992 [Ref. 7], and Westinghouse AP600 Design in 1998 [Ref. 8]. Regulatory Position 2 in Section C of this revised guide provides the piping damping values that resulted from the staff’s experience with ASME Code Case N–411 and application reviews of new reactor designs. Electrical Distribution System Damping Regulatory Guide 1.61 did not originally provide damping values for cable tray or conduit systems. Historically, the nuclear power industry used the damping values for bolted steel structures for seismic design of cable tray and conduit systems. In the late 1980s, however, the NRC staff reviewed the results of the cable tray test at the Comanche Peak Steam Electrical Station [Ref. 9]. Regulatory Position 3 in Section C of this revised guide provides the damping values that resulted from the staff’s review of data from the Comanche Peak test [Ref. 10] and two safety evaluation reports [Refs. 9, 11]. Heating Ventilation and Air Conditioning Duct Damping The damping values for heating ventilation and air conditioning (HVAC) systems are consistent with the guidance provided for bolted steel structures. Because no tests of welded duct construction have been identified, the damping values are the same as for welded steel structures, and Regulatory Position 4 in Section C of this revised guide provides these same damping values. In addition, the NRC provides related information on HVAC duct damping in NUREG/CR-6919, “Recommendations for Revision of Seismic Damping Values in Regulatory Guide 1.61” [Ref. 12]. Mechanical and Electrical Component Damping NUREG/CR-6919 [Ref. 12] considers guidance in American Society of Civil Engineers (ASCE) Standard 43-05, “Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities” [Ref. 13], and Non-Mandatory Appendix N, “Dynamic Analysis Methods,” to Section III, Division 1, of the ASME