Document: NRC Regulatory Guide
Document ID: 1d715751-9321-4481-a46f-4ff802a5efe0
Document Type: regulatory_guide
Title: Service Limits and Loading Combinations for Class 1 Linear-Type Supports + HISTORY – HISTORY 10/2006 – DG-1168 , Proposed Revision 2
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063000449.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.124
CFR Part: 
CFR Title: 

Content:
staff considers acceptable for use in implementing specific parts of the agency’s regulations, to explain techniques that the staff uses in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations, and compliance with regulatory guides is not required. The NRC issues regulatory guides in draft form to solicit public comment and involve the public in developing the agency’s regulatory positions. Draft regulatory guides have not received complete staff review and, therefore, they do not represent official NRC staff positions. This regulatory guide contains information collections that are covered by the requirements of 10 CFR Part 50 which the Office of Management and Budget (OMB) approved under OMB control number 3150-0011. The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number. B. DISCUSSION Background Load-bearing members classified as component supports are essential to the safety of nuclear power plants because they hold components in place during the loadings associated with normal and upset plant conditions under the stress of specified seismic events, thereby permitting system components to function properly. Load-bearing members also prevent excessive component movement during the loadings associated with emergency and faulted plant conditions combined with the specified seismic event, thus helping to mitigate the consequences of system damage. Component supports are deformation-sensitive because large deformations can significantly change the stress distribution in the support system and its supported components. To provide uniform requirements for construction, the component supports should, as a minimum, have the same ASME Code classification as that of the supported components. This guide delineates levels of