Practice E 185 defines the minimum requirements for light-water reactor surveillance program Charpy V-notch specimens and Practice E 2215 describes the evaluation of test specimens from surveillance capsules. It may be desirable to extend the original surveillance program beyond available specimens for plant aging management issues, such as plant license renewal, to better define existing data, or to determine fracture toughness of a material when no standard fracture toughness test specimens are available. The ability to reconstitute the broken halves of existing specimens can provide such data.
Charpy-sized specimens are typically machined from virgin material, that is, material not previously mechanically tested. There are occasions that exist when either (1) no full size specimen blanks are available or (2) the material available with the desired history (such as having been subjected to irradiation) is not sufficient for the machining of full-size specimens, or both.
An approach to this problem, which is addressed in this guide, is to fabricate new specimens using the broken halves of previously irradiated and tested specimens or other material irradiated for this purpose. In this guide, the central segment of each new specimen utilizes a broken half of a previously tested specimen and end tabs that are welded to the central segment, or the central section may simply be a piece of virgin material shorter than a Charpy-sized specimen. While specifically addressing reconstitution of irradiated pressure vessel steel, this guide can also provide guidance for reconstitution of Charpy-sized specimens for other situations involving material availability.
Область применения1.1 This guide covers procedures for the reconstitution of ferritic pressure boundary steels used in nuclear power plant applications, Type A Charpy (Test Methods E 23) specimens and specimens suitable for testing in three point bending in accordance with Test Methods E 1921 or E 1820. Materials from irradiation programs (principally broken specimens) are reconstituted by welding end tabs of similar material onto remachined specimen sections that were unaffected by the initial test. Guidelines are given for the selection of suitable specimen halves and end tab materials, for dimensional control, and for avoidance of overheating the notch area. A comprehensive overview of the reconstitution methodologies can be found in Ref (1).
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.