This standard addresses the design bases for light water reactor@ nuclear power plant structures and components essential for the protection of public health and safety from the potential adverse effects of pipe whip@ jet impingement@ pressurization of compartments outside containment@ environmental conditions and flooding associated with a postulated pipe rupture. The design bases for missile protection and the design bases for containment pressurization are not within this standard.2 2Guidance on the design basis for missile protection and the design basis for containment pressurization exists in draft form. See proposed standard Plant Design Against Missiles. ANS58.1; Assigned Correspondent: Mrs. M. D. Weber@ American Nuclear Society. 555 North Kensington Avenue@ La Grange Park@ Ill. 60525; and proposed standard Pressure/temperature Transient Analysis for Light Water Reactor Containments ANS-56.4@ Assigned Correspondent: Mr. R. W. Mitchell@ Combustion Engineering@ Inc.@ i000 Prospect Hill Road@ Windsor@ Com. 06095.