Unavailability modeling and analysis of redundant safety systems

Technical Report · Mon Oct 01 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5622009· OSTI ID:5622009

Vaurio, J. K.; Sciaudone, D.

Analytical expressions have been developed to estimate the average unavailability of an m-out-of-n (m/n, 1 less than or equal to m less than or equal to n less than or equal to 4) standby safety system of a nuclear power plant. The expressions take into account contributions made by testing, repair, equipment failure, human error, and different testing schemes. A computer code, ICARUS, has been written to incorporate these analytical equations. The code is capable of calculating the average unavailability, optimum test interval, and relative contributions of testing, repair, and random failures for any of three testing schemes. After verification of the methodology and coding in ICARUS, a typical auxiliary feedwater system of a nuclear power plant was analyzed. The results show that the failure modes associated with testing and true demands contribute considerably to the unavailability and that diesel generators are the most critical components contributing to the overall unavailability of the system.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5622009
• Report Number(s): ANL-79-87
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
29 ENERGY PLANNING, POLICY, AND ECONOMY
290600 -- Energy Planning & Policy-- Nuclear Energy
AVAILABILITY
COMPUTER CALCULATIONS
ENGINEERED SAFETY SYSTEMS
MATHEMATICAL MODELS
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
POWER PLANTS
RELIABILITY
THERMAL POWER PLANTS