Document: NUREG-0800
Document ID: 3d8f7691-e488-4083-af2f-eef689c0ec98
Document Type: srp
Title: ASME CODE CLASS 1, 2, AND 3 COMPONENTS AND COMPONENT SUPPORTS,
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0704/ML070430397.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.3
CFR Part: 
CFR Title: 

Content:
ASME Code. Design Loads - Those pressures, temperatures, and mechanical loads selected as the design basis for a component. Functional System - That configuration of components which, irrespective of ASME Code Class designation or combination of ASME Code Class designations, performs a particular function (i.e., each emergency core cooling system performs a single particular function and yet each may be comprised of some components which are ASME Class 1 and other components which are ASME Code Class 2). LOCA - Loss-of-Coolant Accidents - Defined in Appendix A of 10 CFR Part 50 as "those postulated accidents that result from the loss of reactor coolant, at a rate in excess of the capability of the reactor coolant makeup system, from breaks in the reactor coolant pressure boundary, up to and including a break equivalent in size to the double-ended rupture of the largest pipe of the reactor coolant system." This condition includes the loads from the postulated pipe break, itself, and also any associated system transients or dynamic effects resulting from the postulated pipe break. 3.9.3-25 Revision 2 - March 2007 MS/FWPB - Main Steam and Feedwater Pipe Breaks - Postulated breaks in the main steam and feedwater lines. For a BWR plant this may be considered as a LOCA event depending on the break location. This condition includes the loads from the postulated pipe break, itself, and also any associated system transients or dynamic effects resulting from the postulated pipe break. OBE - Operating Basis Earthquake - Defined in Section III of Appendix S of 10 CFR Part 50 as "that earthquake which, considering the regional and local geology and seismology and specific characteristics of local subsurface material, could reasonably be expected to affect the plant site during the operating life of the plant. It is that earthquake which produces the vibratory ground motion for which those features of the nuclear power plant, necessary for continued operation without undue risk