Advanced irradiation-resistant materials

In our research toward an advanced irradiation-resistant material, we firstly started by eliminating structurally hardened materials with high doses of Ti and A1 for the following reasons ... 

Advanced irradiation-resistant materials for Generation IV nuclear reactors... 

Identification of potential advanced irradiation-resistant materials... 

It seems that, beyond the progresses realized from the first 300-series steels to the present reference materials (15-15Ti and D9 derivatives), it would be possible to find an ultimate upgrade in the family of irradiation-resistant austenitic steels using a CW 12-15/15-25 Ti + Nb stabilized and P-doped matrix, but further work has yet to be done to specify the content of other alloying elements (Mo, Mn, C, Si, N, B) and to adjust the fabrication route to optimize the in-pile behavior of such advanced austenitic material for high-dose applications. 

A second major shortcoming of these advanced materials is that their anticipated superior irradiation resistance has not been experimentally confirmed over a suitable range of neutron irradiation temperatures and doses. The most extensive irradiation studies have been performed on MAX phase ceramics, and even in this case it is largely limited to ion irradiation studies [32,33,165,166] with only two recently published low-dose (0.1—4 dpa) neutron irradiation studies [34,167]. A variety of neutron and ion irradiation experiments are in preparation for the next-generation steels some exploratory ion... 

Table 7 shows the results of electrical resistivity measurements for five insulator materials irradiated heavily at 325 K in the Advanced Test Reactor [65]. Irradiation conditions were the same as those for mechanical tests mentioned in the preceding section. The remarkable decreases of resistivity were observed in both G-10 and G-ll CR which were made with E-glass cloth. The other three specimens containing S-glass cloth showed fairly good tolerance of electrical resistivity to radiation. 

An example system is PVC and polyethylene wire and cabling irradiated to improve stresscracking resistance, abrasion resistance, high-temperature properties and flame retardance, via controlled electron-beam crosslinking (Loan, 1977). Additionally electron-beam crosslinking is utilized to impart memory into a polymer system, such as crosslinked PE materials for heat-shrinkable films and pipe applications (Baird, 1977). The control of electron-beam processing has advanced the quality of cell size and shape of PE foams via control of crosslink distribution (Paterson, 1984). 

Both kinds of nuclear plants have experienced SCC problems of neutron-irradiated material in the core, and some of the most ambitious corrosion research of the past two decades has dealt with the resulting blend of material property alteration, microstructure, and SCC behavior using advances in modeling and characterization. As a result of experimentation and basic research, material life can be predicted more accurately, and recommendations exist for new alloys with enhanced resistance to this specialized form of SCC. The ultimate goal is quantitative prediction of life once the corrosion and degradation mechanisms have been frilly understood. 

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