New techniques for modeling the reliability of reactor pressure vessels
In recent years several probabilistic fracture mechanics codes, including the VISA code, have been developed to predict the reliability of reactor pressure vessels. This paper describes several new modeling techniques used in a second generation of the VISA code entitled VISA-II. Results are presented that show the sensitivity of vessel reliability predictions to such factors as inservice inspection to detect flaws, random positioning of flaws within the vessel wall thickness, and fluence distributions that vary throughout the vessel. The algorithms used to implement these modeling techniques are also described. Other new options in VISA-II are also described in this paper. The effect of vessel cladding has been included in the heat transfer, stress, and fracture mechanics solutions in VISA-II. The algorithms for simulating flaws has been changed to consider an entire vessel rather than a single flaw in a single weld. The flaw distribution was changed to include the distribution of both flaw depth and length. A menu of several alternate equations has been included to predict the shift in RT/sub NDT/. For flaws that arrest and later re-initiate, an option was also included to allow correlating the current arrest toughness with subsequent initiation toughnesses.
- OSTI ID:
- 7090213
- Report Number(s):
- CONF-860722-
- Country of Publication:
- United States
- Language:
- English
Similar Records
VISA-II: a computer code for predicting the probability of reactor pressure vessel failure
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Related Subjects
220200* -- Nuclear Reactor Technology-- Components & Accessories
ALGORITHMS
COMPUTER CODES
COMPUTERIZED SIMULATION
CONTAINERS
CRACK PROPAGATION
DEFECTS
ENERGY TRANSFER
FRACTURE MECHANICS
FRACTURE PROPERTIES
FUEL-CLADDING INTERACTIONS
HEAT TRANSFER
JOINTS
MATHEMATICAL LOGIC
MECHANICAL PROPERTIES
MECHANICS
PRESSURE VESSELS
REACTOR SAFETY
REACTOR VESSELS
RELIABILITY
SAFETY
SIMULATION
STRESSES
V CODES
WELDED JOINTS