Flamanville EPR RPV’s Heads Carbon Segregation: Characterization of the Segregation in the Heads

Abstract

To characterize the mechanical properties of the residual carbon segregation of the Flamanville EPR RPV heads, a testing program has been defined by Framatome using three sacrificial representative heads. The first step of this program was a 3D characterization of the carbon content inside each piece. A specific strategy has been defined using two methods for the carbon measuring: - In situ measurements using a mobile arc spark spectrometer. This device allows a higher number of non-destructive measurements in a particularly constrained environment and in a short time, - Conventional spectrometry performed on chips sampled from the pieces. This technique is more accurate but is destructive and more time consuming. Also, to consolidate the representativeness of the sacrificial vessels heads, the results were analysed using a geostatistical approach. This paper presents how these two techniques have been used to characterize the carbon content in the segregated part of the pieces and the conclusion of the geostatistical analyses.