RSICC CODE PACKAGE PSR-460
1. NAME AND TITLE
OCTAVIA: Code System to Calculate Pressure Vessel Failure Probabilities.
U.S. Nuclear Regulatory Commission, Washington, DC, through the Energy
Science and Technology Software Center, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
Fortran IV; IBM370 (P00460I037000).
4. NATURE OF PROBLEM SOLVED
OCTAVIA (Operationally Caused Transients And Vessel Integrity Analysis)
calculates the probability of pressure vessel failure from operationally-caused
pressure transients which can occur in a pressurized water reactor (PWR).
For specified vessel and operating environment characteristics the program
computes the failure pressure at which the vessel will fail for different-sized
flaws existing in the beltline and the probability of vessel failure per
reactor year due to the flaw. The probabilities are summed over the various
flaw sizes to obtain the total vessel failure probability. Sensitivity
studies can be performed to investigate different vessel or operating characteristics
in the same computer run.
5. METHOD OF SOLUTION
The analysis approach involves calculation of vessel failure pressures
using fracture mechanics methods and estimation of pressure-transient characteristics
using historical nuclear data. The pressure vessel is described by input
data, such as vessel wall thickness, inside radius, copper and phosphorus
content, residual stress, flaw sizes, fluence, and temperature. The failure
pressure for a given flaw is calculated using linear-elastic and elastic-plastic
methods. After obtaining the failure pressure for a given flaw size, the
probability evaluation is performed. The probabilities for the different
flow sizes are then summed to obtain the total probability of pressure
vessel failure from the various flaws which might exist in the vessel.
6. RESTRICTIONS OR LIMITATIONS
Maxima of 100 temperatures, 12 fluences and 8 flaw sizes with the program's
current dimensioning. Only axially oriented flaws in the vessel beltline
7. TYPICAL RUNNING TIME
The sample problem requires < 2 seconds on an IBM 9672.
8. COMPUTER HARDWARE REQUIREMENTS
OCTAVIA requires approximately 170K bytes of storage for execution of
the sample problem on an IBM370/195 or 3033.
9. COMPUTER SOFTWARE REQUIREMENTS
The code is written in Fortran IV for OS/370. It was executed at RSICC
on an IBM 9672, but plotting was not implemented. No changes were made
to the source when it was transferred to RSICC and released in March 2001.
a) Included in documentation:
W. E. Vesely, E. K. Lynn, and F. F. Goldberg, "The Octavia Computer
Code: PSR Reactor Vessel Failure Probabilities Due to Operationally Caused
Pressure Transients," NUREG-0258 (March 1978).
b) Background information:
J. G. Merkle, G. D. Whitman, and R. H. Bryan, "An Evaluation of the
HSST Program Intermediate Pressure Vessel Tests in Terms of Light-Water-Reactor
Pressure Vessel Safety," ORNL-TM-5090 (November 1975).
11. CONTENTS OF CODE PACKAGE
Included in the package are the referenced document in (10.a) and one
3.5" DOS formatted diskette which includes source code and sample problem
input. No executables are included with the package.
12. DATE OF ABSTRACT
KEYWORDS: PWR; REACTOR SAFETY