Seismically Induced Relay Chatter Risk Analysis for the Advanced Test Reactor
Seismically Induced Relay Chatter Risk Analysis for the Advanced Test Reactor

Author:

Publisher:

Published: 1992

Total Pages: 4

ISBN-13:

DOWNLOAD EBOOK

A seismic probabilistic risk assessment (PRA) was performed as part of the Level I PRA for the Department of Energy (DOE) Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory (INEL). This seismic PRA included a comprehensive and efficient seismically-induced relay chatter risk analysis. The key elements to this comprehensive and efficient seismically-induced relay chatter analysis included (1) screening procedures to identify the critical relays to be evaluated, (2) streamlined seismic fragility evaluation, and (3) comprehensive seismic risk evaluation using detailed event trees and fault trees. These key elements were performed to provide a core fuel damage frequency evaluation due to seismically induced relay chatter. A sensitivity analysis was performed to evaluate the impact of including seismically-induced relay chatter events in the seismic PRA. The systems analysis was performed by EG & G Idaho, Inc. and the fragilities for the relays were developed by EQE Engineering Consultants.

PSA '93
PSA '93

Author: American Nuclear Society

Publisher:

Published: 1993

Total Pages: 764

ISBN-13:

DOWNLOAD EBOOK

System Response to Relay Chatter
System Response to Relay Chatter

Author:

Publisher:

Published: 1992

Total Pages: 5

ISBN-13:

DOWNLOAD EBOOK

An important aspect of the qualification of safety related systems, is the assessment of the possibility and consequences of seismic or vibration induced relay chatter. The current rules, contained in ANSI/IEEE C37.98 and the SQUG GIP, consider as seismic induced ''failure'' of a relay, a chatter contact in excess of 2 milliseconds. While this rule is clear in defining ''failure'' of single relay, the definition of ''failure'' becomes more problematic when we consider the alignment of an assembly of relays in series or parallel, and the effects of chatter on the function of the system in which the relays are mounted. In this paper, we report a method, based on system test and probabilities analysis, used to assess ''failure'' by relay chatter in an assembly of relays which control an electric motor. 2 refs.

Advanced Test Reactor Probabilistic Risk Assessment Methodology and Results Summary
Advanced Test Reactor Probabilistic Risk Assessment Methodology and Results Summary

Author:

Publisher:

Published: 1992

Total Pages: 100

ISBN-13:

DOWNLOAD EBOOK

The Advanced Test Reactor (ATR) probabilistic risk assessment (PRA) Level 1 report documents a comprehensive and state-of-the-art study to establish and reduce the risk associated with operation of the ATR, expressed as a mean frequency of fuel damage. The ATR Level 1 PRA effort is unique and outstanding because of its consistent and state-of-the-art treatment of all facets of the risk study, its comprehensive and cost-effective risk reduction effort while the risk baseline was being established, and its thorough and comprehensive documentation. The PRA includes many improvements to the state-of-the-art, including the following: establishment of a comprehensive generic data base for component failures, treatment of initiating event frequencies given significant plant improvements in recent years, performance of efficient identification and screening of fire and flood events using code-assisted vital area analysis, identification and treatment of significant seismic-fire-flood-wind interactions, and modeling of large loss-of-coolant accidents (LOCAs) and experiment loop ruptures leading to direct damage of the ATR core. 18 refs.

Experimental Evaluation of Earthquake Induced Relay Chattering
Experimental Evaluation of Earthquake Induced Relay Chattering

Author:

Publisher:

Published: 1990

Total Pages: 15

ISBN-13:

DOWNLOAD EBOOK

An experimental evaluation of relay performance under vibratory environments is discussed in this paper. Single frequency excitation was used for most tests. Limited tests were performed with random multifrequency inputs. The capacity of each relay was established based on a two-millisecond chatter criterion. The experimental techniques are described and the effects of parameters in controlling the relay capacity levels are illustrated with test data. A wide variation of the capacity levels was observed due to the influence of parameters related to the design of the relay and nature of the input motion. 3 refs., 15 figs.

Advanced Test Reactor Probabilistic Risk Assessment
Advanced Test Reactor Probabilistic Risk Assessment

Author:

Publisher:

Published: 1993

Total Pages: 6

ISBN-13:

DOWNLOAD EBOOK

This report discusses Level 1 probabilistic risk assessment (PRA) incorporating a full-scope external events analysis which has been completed for the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory.