Sensitivity Studies of the Probabilistic Fracture Mechanics Model Used in FAVOR (NUREG-1808)
On this page:
Download complete document
This page includes links to files in non-HTML format. See Plugins, Viewers, and Other Tools for more information.
Manuscript Completed: May 2006
Date Published: March 2010
M. EricksonKirk1, T. Dickson2, T. Mintz3, F. Simonen4
2Oak Ridge National Laboratory
Oak Ridge, TN 37831-6170
3Southwest Research Institute
San Antonio, TX 78227-1301
4Pacific Northwest National Laboratory
Richland, WA 99352
1Office of Nuclear Regulatory Research
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001
During plant operation, the walls of reactor pressure vessels (RPVs) are exposed to neutron radiation, resulting in localized embrittlement of the vessel steel and weld materials in the core area. If an embrittled RPV had an existing flaw of critical size and certain severe system transients were to occur, the flaw could very rapidly propagate through the vessel, resulting in a through-wall crack and challenging the integrity of the RPV. The severe transients of concern, known as pressurized thermal shock (PTS), are characterized by a rapid cooling (i.e., thermal shock) of the internal RPV surface in combination with repressurization of the RPV. Advancements in our understanding and knowledge of materials behavior, our ability to realistically model plant systems and operational characteristics, and our ability to better evaluate PTS transients to estimate loads on vessel walls led the U.S. Nuclear Regulatory Commission (NRC) to realize that the earlier analysis, conducted in the course of developing the PTS Rule in the 1980s, contained significant conservatisms.
This report, which describes sensitivity studies performed on the probabilistic fracture mechanics model, is one of a series of 21 other documents detailing the results of the NRC study.