https://yse.yabesh.ir/std/handle/yse/116 2026-04-25T11:03:35Z https://yse.yabesh.ir/std/handle/yse/236759 ANS 2.23; English -- Nuclear Power Plant Response to an Earthquake ANS - American Nuclear Society Scope: This standard1) is a major update of ANSI/ANS-2.23-2002 (R2009) [1]2). It describes actions that the owner of a nuclear power plant shall take to prepare for and respond to a felt earthquake at the plant(s), including the need for plant shutdown; actions to determine the readiness of the plant to resume operation; and those evaluations necessary to verify the long-term integrity of safety-related (SR) and important structures, systems, and components (SSCs). It also includes a consensus definition of operating basis earthquake (OBE) exceedance, beyond which U.S. regulations require plant shutdown. Application of this revised standard provides a comprehensive, balanced plan for the response of a nuclear power plant to an earthquake. This standard does not cover those operator actions that are performed in connection with safe operation and control of the nuclear power plant during and following an earthquake. These operations are specified in plant operating procedures, emergency procedures, alarm response procedures, and other conditions of the plant’s license. Likewise, it does not cover required reporting and communications with the U.S. Nuclear Regulatory Commission (NRC). It is not applicable to nuclear facilities other than licensed nuclear power plants. Purpose The purpose of this standard is to specify actions that shall be included in plant-specific procedures that describe actions to be taken in preparation for and response to a felt earthquake at the plant. The objectives of these procedures are to determine the following: • the effects of the earthquake on the physical condition of the nuclear power plant; • whether shutdown of the plant is required, based on observed damage to the plant or because the OBE has been exceeded; • the readiness of the plant to shut down if shutdown is required due to an earthquake; • the readiness of the plant to resume operation from a shutdown condition based on physical inspections and tests and the successful completion of operability tests and analytical evaluations, where required, that demonstrate that the limiting conditions for operation as defined in the plant technical specifications are met. The combination of the preparatory, short-term, post-shutdown, and long-term actions provides a rational, experience-based approach for determining the real damage potential of a felt and recorded earthquake, a systematic methodology for assessing plant readiness for restart based on physical inspections and tests and on realistic criteria for assuring the long-term integrity of the power plant. These actions also minimize the likelihood of prolonged plant shutdowns following nondamaging seismic disturbances and place primary emphasis on the physical and functional conditions of the plant as a measure of restart readiness, as opposed to relying primarily upon analytical evaluations and instrumental data alone. 1) The current standard, ANSI/ANS-2.23-2016, is herein referred to as “this standard.” 2) Numbers in brackets refer to corresponding reference numbers in Sec. 10, “References.” 2016-01-01T00:00:00Z https://yse.yabesh.ir/std/handle/yse/236698 ANS 2.2; English -- Earthquake Instrumentation Criteria for Nuclear Power Plants ANS - American Nuclear Society Scope: This standard specifies the required earthquake instrumentation at the site and on Seismic Category I structures of light-water-cooled, land-based nuclear power plants. It may be used for guidance at other types of nuclear facilities. This standard does not address the following: (1) instrumentation to shut down a nuclear power plant automatically at a predetermined parameter of the ground motion or the in-structure response; (2) procedures for evaluating records obtained from seismic instrumentation and instructions for the treatment of data. These procedures and instructions are specified in ANSI/ANS-2.23-2016 [1]1); (3) instrumentation for nuclear power plant designs incorporating base isolation techniques Purpose This standard defines the minimum requirements for an earthquake instrumentation system to be installed at nuclear power plants. These instruments are intended to provide timely (within 4 hours) information on the earthquake ground motion at the site and the corresponding response vibratory motion of Seismic Category I structures, when subjected to earthquake ground motion. By comparing this information with the vibratory motions used in the facility’s seismic design,2) an evaluation can be made as to whether or not the design basis vibratory motions have been exceeded. 1)Numbers in brackets refer to corresponding numbers in Sec. 10, “References.” 2)Appendix A provides an overview of applicable licensing practices used in the issuance of early site permits and combined licenses. 2016-01-01T00:00:00Z https://yse.yabesh.ir/std/handle/yse/235528 ANS 18.1; English -- Radioactive Source Term for Normal Operation of Light Water Reactors ANS - American Nuclear Society Scope: This standard provides a set of typical radionuclide concentrations for estimating the radioactivity in the principal fluid systems of light water reactors and for projecting the expected releases of radioactivity from nuclear plants. It is not intended that the values be used as the sole basis for design but be used in environmental reports and elsewhere where expected operating conditions over the life of the plant would be appropriate. Purpose The purpose of this standard is to provide a uniform approach, applicable to light water–cooled nuclear power plants, for the determination of expected concentrations in fluid streams. Through application of this standard, a common basis for the determination of radioactive source terms for normal operating conditions is established, with the goal of providing a consistent approach for those involved in the design of these facilities. Utilization of this standard is expected to aid the licensing process and the public\'s understanding of the impact of nuclear power relative to radionuclide concentrations and possible releases to the environment.   2016-01-01T00:00:00Z https://yse.yabesh.ir/std/handle/yse/234489 ANS 15.11; English -- Radiation Protection at Research Reactor Facilities ANS - American Nuclear Society Scope: This standard establishes the elements of a radiation protection program and the criteria necessary to provide an acceptable level of radiation protection for personnel at research reactor facilities and the public consistent with keeping exposures and releases as low as is reasonably achievable (ALARA). 2016-01-01T00:00:00Z