Semi-mechanistic analytical model for radiation embrittlement and re-embrittlement data analysis

Studies of radiation embrittlement of model alloys by thermoelectric measurements and Positron Annihilation Spectroscopy

“…This conclusion can be drawn by the fact that the amount of copper and phosphorus are rather low and nickel is known to enhance matrix damage. Material damage due to direct matrix damage, expressed as the transition temperature shift, is normally described as a power ½ of the damage parameter [14]. By plotting the increase of MLT for MA-175, we can see that indeed, a power ½ function of the dose follows very well the available data, indicating that the MLT shift could be related to matrix damage; see Fig.…”

“…Surprisingly, the MLT increase seems again to be a good qualitative indicator of the process kinetic. To be mentioned is the fact that by neutron irradiation MA-175 resulted much more sensitive to neutron radiation than MA-635 (almost the double shift on DBTT was obtained) [5,14]. The results for MA-440, where the expected damage is mainly copper precipitation enhanced by nickel, in combination with significant matrix damage, are unexpectedly not showing any saturating trend.…”

Fluence rate effect semi-mechanistic modelling on WWER-type RPV welds

“…This model has been developed for model alloys [10,11] irradiated in the HFR research reactor in Petten (The Netherlands), and it has been recently successfully tested on WWER-440 materials reembrittlement [12].…”

Study of radiation-induced degradation of RPV steels and model alloys by positron annihilation and Mössbauer spectroscopy

“…It is generally accepted that even in the Western RPV steel types containing more than 0.1 wt% of Cu, Cu-and P-rich precipitates play a dominant role in thermal and neutron embrittlement. In the case of WWER-type RPV steels, several studies [9][10][11][12][13][14] have suggested that carbide formation is an important additional microstructural mechanism. The contribution of Ni content to irradiation hardening and embrittlement was until recently not fully realised.…”

“…The different semi-mechanistic models for prediction of WWER RPV steels have been taken into the consideration. The recently published a semi-mechanistic model (1) of radiation damage [12] and standard models for WWER-440 (2) and WWER-1000 (3) according to the Russian Guides…”