Pressurized Thermal Shock Experiments with Thick Vessels [chapter]

RH Bryan, JG Merkle, RK Nanstad, GC Robinson
Fracture Mechanics: Nineteenth Symposium  
Oak Ridge National Laboratory mT «^ nntn ->-, Oak Ridge, Tennessee 37831 Tl86 004821 The series of pressurized-thermal-shock experiments at the Oak Ridge National Laboratory was motivated by a concern for the behavior of flaws in reactor pressure vessels having welds or shells exhibiting low upper-shelf Charpy impact energies, ^8 J or less. Evaluations of overcooling accidents, however, involved consideration of other complexities that had not been explored under particularly realistic
more » ... realistic conditions. Issues that have an important impact on accident evaluation and are also amenable to investigation in pressurized-thermal-shock experiments are: effect of sequences of warm-prestressing and anti-warm-prestressing episodes on-crack initiation; behavior of cleavage fracture propagating into ductile regions; transient crack stabilization in ductile regions; and crack shape changes in bimetallic zones of clad vessels. The intermediate test vessels are geometrically suitable for fracture experiments that can be directly related to fracture phenomena in reactor pressure vessels. The vessels are sufficiently long and thick for testing the validity of methods of linear elastic fracture mechanics for cracks extending less than halfway through the wall.
doi:10.1520/stp33105s fatcat:tpzoz4kxmrhgffrze4w6fsf6hu