Methodology for time-dependent reliability analysis of accident sequences and complex reactor systems

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5383909

Paula, H M

The work presented here is of direct use in probabilistic risk assessment (PRA) and is of value to utilities as well as the Nuclear Regulatory Commission (NRC). Specifically, this report presents a methodology and a computer program to calculate the expected number of occurrences for each accident sequence in an event tree. The methodology evaluates the time-dependent (instantaneous) and the average behavior of the accident sequence. The methodology accounts for standby safety system and component failures that occur (a) before they are demanded, (b) upon demand, and (c) during the mission (system operation). With respect to failures that occur during the mission, this methodology is unique in the sense that it models components that can be repaired during the mission. The expected number of system failures during the mission provides an upper bound for the probability of a system failure to run - the mission unreliability. The basic event modeling includes components that are continuously monitored, periodically tested, and those that are not tested or are otherwise nonrepairable. The computer program ASA allows practical applications of the method developed. This work represents a required extension of the presently available methodology and allows a more realistic PRA of nuclear power plants.

• Research Organization: Tennessee Univ., Knoxville (USA)
• OSTI ID: 5383909
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
COMPUTER CALCULATIONS
FAILURE MODE ANALYSIS
MAINTENANCE
PROBABILISTIC ESTIMATION
REACTOR ACCIDENTS
REACTOR MAINTENANCE
REACTOR SAFETY
RISK ASSESSMENT
SAFETY
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS