Fracture Mechanics

Contributors: Dr. Frederick (Bud) Brust, Mohammed Uddin, David Rudland, Robert Kurth, Cedric Sallaberry, and Gery Wilkowski

Thursday August 8, 2019

The objective of this tutorial is to introduce some of the key aspects in conducting fracture mechanics analyses for the integrity of nuclear plant systems.  An in-depth presentation on this would take longer time than the whole SMiRT conference, so we hope to show some basics, a few pragmatic applications, and make some commentary on key aspects to watch out for.

The tutorial will be divided into two parts as described below with an Introduction by Mr. Michael Mayfield retired Division Director of USNRC New Reactor Office.

Introductory Comments by Mr. Michael Mayfield on “Fracture Mechanics Applications to Past Reactor Design, Maintaining the Current Fleet of US LWRs, and Potential Advanced Reactor Needs”.

 

1.        Deterministic evaluations of fracture mechanics evaluations for piping and components

This session is an introduction to some material aspects (for piping and fittings), introduction to elastic and plastic fracture mechanics and limit-load concepts, how residual stresses can be important, leak-before break aspects, and stability of cracks in pipe systems with flaws.

Speakers:  Drs. Frederick (Bud) Brust and Mohammad Uddin

 

2.       Introduction to Probabilisic Fracture Mechanics

This introductory presentation of Probabilistic Fracture Mechanics (PFM) will offer a high-level description of PFM within a historical perspective.  The rationale for these early applications will inform the need for the development of new PFM models that have occurred over the last 20 years.  These needs arose from both a technical perspective and regulatory requirements to allow for risk-informed decisions.  Both sources will be included in the tutorial.  The most common probabilistic methods and their application in the nuclear piping and vessel area will be presented.  It will conclude with an outline of the necessary components for a PFM model as learned by the presenters from their own practical experiences when dealing with PFM.

Speakers:  Drs. David Rudland, Robert Kurth, and Cedric Sallaberry