Defines standard
Replaced/Superseded by document(s)
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| File | MIME type | Size (KB) | Language | Download | |
|---|---|---|---|---|---|
| Handbook of Parameter Estimation for Probabilistic Risk Assessment .pdf | application/pdf | 1.05 MB | English | DOWNLOAD! |
Provides definitions
Cover images
Abstract
Probabilistic risk assessment (PRA) is a mature technology that can provide a quantitative assessment of the risk from accidents in nuclear power plants. It involves the development of models that delineate the response of systems and operators to accident initiating events. Additional models are generated to identify the component failure modes required to cause the accident mitigating systems to fail. Each component failure mode is represented as an individual "basic event" in the systems models. Estimates of risk are obtained by propagating the uncertainty distributions for each of the parameters through the PRA models.
The data analysis portion of a nuclear power plant PRA provides estimates of the parameters used to determine the frequencies and probabilities of the various events modeled in a PRA. This handbook provides guidance on sources of information and methods for estimating the parameters used in PRA models and for quantifying the uncertainties in the estimates. This includes determination of both plant-specific and generic estimates for initiating event frequencies, component failure rates and unavailabilities, and equipment non-recovery probabilities.
Foreword
During the last several years, both the U.S. Nuclear Regulatory Commission (NRC) and the nuclear industry have recognized that probabilistic risk assessment (PRA) has evolved to the point where it can be used in a variety of applications including as a tool in the regulatory decision-making process. The increased use of PRA has led to the conclusion that the PRA scope and model must be commensurate with the applications. Several procedural guides and standards have been and are being developed that identify requirements for the PRA models. For example, the "Standard For Probabilistic Risk Assessment For Nuclear Power Plant Applications" published by The American Society of Mechanical Engineers (ASME) in 2002 (ASME-RA-S-2002) defines requirements for PRA analysis used to develop riskinformed decisions for commercial nuclear power plants, and describes a process for applying these requirements in specific applications. This handbook was generated to support these documents by providing a compendium of good practices that a PRA analyst can use to generate the parameter distributions required for quantifying PRA models.