The existing Class A metallic materials qualified in the ASME Section III, Division 5 rules for high temperature nuclear reactors do not have optimal corrosion resistance for reactor coolants which is a major constraint on long life designs. A near term solution to this limitation is the use of cladded components – overlay the Class A materials with a thin layer of some corrosion resistant material. However, this necessitates the development of a design method for cladded components without requiring long-term testing of clad materials. In two other PVP papers, the development of such design method along with complete set of design rules and clad selection criteria will be presented. However, the developed design rules and clad selection criteria assume perfect bonding between the clad and base materials. In reality the clad/base debonding may occur before the end of the design life of the component. Therefore, this paper focuses on developing a general acceptance test for checking whether the mechanical integrity of the clad/ base metal interface will be retained till the end of the design life. This work proposes to perform temperature cycling tests on cladded buttons of 12.7 mm diameter and a few mm thickness. A simple analytical expression will be provided to determine the temperature range for the temperature cycling tests so that the clad/base interface shear stress intensity at the edge of the cladded button mimics the maximum interface shear stress intensity experienced by the component during the design transients. The paper will also discuss determination of the clad/base interface shear stress in finite element calculations.


Acceptance Criteria for the Mechanical Integrity of Clad/base Metal Interface for High Temperature Nuclear Reactor Cladded Components

Division / Sponsors: 
Pressure Vessels & Piping (PVP)


Paper Proceedings: https://asmedigitalcollection.asme.org/PVP/PVP2020/volume/83815

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