高温高圧水ループによる原子炉材料の腐食の研究, (II)

ループの水化学

抄録

The study was carried out at 260° and 280°C, using an out-of pile stainless-steel water loop. Emphasis of the study was placed on the effect of dissolved oxygen on the formation of soluble corrosion product and insoluble crud in the water. The concentrations of both soluble corrosion product and insoluble crud increased with the dissolved oxygen concentration.
The particles of the insoluble crud caught in a 320-mesh filter in the loop purification system were blackish-brown platelets 50 to 100μ across. They were separated into magnetic and nonmagnetic fractions; through X-ray diffraction, the former was found to be mainly Fe₃O₄ and the latter ZrO₂.
It was observed that there was little relation between the composition of the crud and that of the main materials constituting the loop. The insoluble crud deposited more readily on 18-8 stainless-steel than on Zr alloy test specimens. The ionic forms of the elements in the soluble corrosion product were estimated from chemical analysis of the ion-exchange resin discarded from the loop water purification system.