Influence of Ni-Mn contents on the embrittlement of PWR RPV model steels irradiated to high fluences relevant for LTO beyond 60 years

First-principles calculation of self-interstitial atom-impurity atom interactions in ferritic steel

“…This has been confirmed by the results of previous studies. For example [13], in a study of Cu-and P-rich clusters in neutron-irradiated RPV steel, a depleted zone of both elements was found around the clusters, and the area of the Cu element was much larger than the area of the P element. This explains the decrease in the percentage of P atoms in the clusters detected in the experiments with increasing irradiation fluence.…”

“…Reaction pressure vessel (RPV) steel is a typical ferritic steel and serves as an important component in nuclear reactors. Complex solute defective nanoclusters generated by neutron irradiation are the main cause of its embrittlement [5,7,[10][11][12][13][14][15][16]. Among them, Cu [7,10,11,13,14] and P [7,10,17], as impurity elements that are difficult to remove completely from RPV steel, have received * Author to whom any correspondence should be addressed.…”

“…Complex solute defective nanoclusters generated by neutron irradiation are the main cause of its embrittlement [5,7,[10][11][12][13][14][15][16]. Among them, Cu [7,10,11,13,14] and P [7,10,17], as impurity elements that are difficult to remove completely from RPV steel, have received * Author to whom any correspondence should be addressed. special attention because of their particularly pronounced effects.…”

The development of prediction model on irradiation embitterment for low Cu RPV steels

“…On the other hand, previous irradiation supervision data and experimental reactor data corresponded to a relatively short operating time (smaller fluence range) of nuclear power plants [ 3 , 10 ]. With the further development of nuclear power technology, long term operation and life extension of nuclear power plants have become a new requirement.…”

“…Therefore, neutron fluence will inevitably increase with the increase of operation time and thus exceed the applicable scope of previous prediction model. Moreover, with the development of embrittlement mechanism, new embrittlement influencing factors (for example, the influence of Ni–Mn-(Si) precipitates on embrittlement at high fluence condition) have been recognized [ 10 , 11 ]. New embrittlement mechanism should be added into the prediction model.…”