Microcomputer applications of, and modifications to, the modular fault trees

Technical Report · Sat Oct 01 00:00:00 EDT 1994

DOI:https://doi.org/10.2172/10196705· OSTI ID:10196705

Zimmerman, T. L.; Graves, N. L.; Payne, Jr., A. C.; Whitehead, D. W. ^[1]

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1. Sandia National Labs., Albuquerque, NM (United States)

The LaSalle Probabilistic Risk Assessment was the first major application of the modular logic fault trees after the IREP program. In the process of performing the analysis, many errors were discovered in the fault tree modules that led to difficulties in combining the modules to form the final system fault trees. These errors are corrected in the revised modules listed in this report. In addition, the application of the modules in terms of editing them and forming them into the system fault trees was inefficient. Originally, the editing had to be done line by line and no error checking was performed by the computer. This led to many typos and other logic errors in the construction of the modular fault tree files. Two programs were written to help alleviate this problem: (1) MODEDIT - This program allows an operator to retrieve a file for editing, edit the file for the plant specific application, perform some general error checking while the file is being modified, and store the file for later use, and (2) INDEX - This program checks that the modules that are supposed to form one fault tree all link up appropriately before the files are,loaded onto the mainframe computer. Lastly, the modules were not designed for relay type logic common in BWR designs but for solid state type logic. Some additional modules were defined for modeling relay logic, and an explanation and example of their use are included in this report.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Div. of Safety Issue Resolution; Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 10196705
• Report Number(s): NUREG/CR--4838; SAND--88-1887; ON: TI95003493; BR: GB0103012
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
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22 GENERAL STUDIES OF NUCLEAR REACTORS
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99 GENERAL AND MISCELLANEOUS
990200
DIAGRAMS
FAULT TREE ANALYSIS
LA SALLE COUNTY-1 REACTOR
LA SALLE COUNTY-2 REACTOR
M CODES
MATHEMATICS AND COMPUTERS
MODIFICATIONS
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
BOILING WATER COOLED
REACTOR SAFETY
RISK ASSESSMENT