Characterization of 08Cr16Ni11Mo3 stainless steel irradiated in the BN-350 reactor

Void swelling of AISI 321 analog stainless steel irradiated at low dpa rates in the BN-350 reactor

“…This component was similar in irradiation history to that of the hexagonal blanket assembly constructed from the AISI 316 analog previously reported in Ref. [14].…”

“…Following an earlier prediction concerning higher-than-expected swelling in PWRs [6,7], a number of recent studies by Garner and coworkers have shown that void swelling in austenitic stainless steels actually increases at lower dpa rates [8][9][10][11][12][13][14][15], often allowing the observation of the lower swelling temperature limit at much lower dpa levels. This increase in swelling arises primarily from a decrease in the duration of the transient regime of swelling at lower dpa rates.…”

“…Recently, it was shown that the Soviet analog of AISI 316, when irradiated as a hexagonal blanket assembly at relatively low dpa rates (on the order of 10 À8 dpa/s) in BN-350 also exhibits swelling at unexpectedly low levels, with voids seen as low as 281°C and only 1.3 dpa [14].…”

Evolution of Microstructure and Microchemistry in Cold-worked 316 Stainless Steels under PWR Irradiation

“…To compare the present results with other irradiation conditions, the size and number density of cavities are plotted in Fig. 12, together with the literature data in which irradiation temperature was below 623 K. 8,11,[21][22][23][24][25][26][27] A high density of fine bubbles similar to the present study was reported in HFIR and ATR irradiations. 22,23) In these data the diameter and number density were <3 nm and in the order of 10 23 m À3 , respectively.…”

“…Such high helium generation rate is likely to be the origin of fine bubble formation. On the other hand, void formation with a size of 7-8 nm and a density of less than 10 22 m À3 was reported in PWR-irradiated stainless steel bolts to doses up to 10 dpa at temperatures higher than 593 K. 8,11) Such low-density void formation was also reported in Russian stainless steels irradiated in fast reactors at temperatures 562-613 K. [24][25][26][27] The notable difference in cavity structure between the high He/dpa data and the others indicates that evolution of bubbles and voids is sensitive to He/dpa ratio, as well as temperature and dose rate which were previously emphasized. 21,22) Although the present study demonstrated that the fine helium bubble structure was stable up to 73 dpa at temperatures less than 595 K, further studies are needed to precisely predict cavity evolution and swelling at different irradiation conditions such as lower dose rates and higher temperatures.…”