On the thermochemical hydrogen release rate and activity transport in a supercritical water‐cooled reactor

Abstract

Hydrogen evolution and activity release rates for stainless steel SS316 and nickel-based Alloy 800H at the supercritical water-cooled reactor (SCWR) conditions were estimated, together with amount of oxygen absorbed into the passivation oxide layers formed on both materials. Hydrogen evolution from an oxidized SS316 surface was found to be about six times larger than from Alloy 800H at constant temperature and pressure of 650 8C and 25 MPa. The largest 60 Co activity release rate due to corrosion was estimated to be for SS316 at 650 8C and at pH10. Because of a single loop design, the radioactive corrosion products of in-core surfaces of the SCWR are expected to be carried out-of-core with the supercritical coolant.

Hydrogen evolution and corrosion behavior of zirconium tubing in sub‐ and supercritical water

“…From this perspective, it would be advantageous to be able to conduct hydrogen evolution studies and corrosion testing in a more controlled environment, without the need to interrupt the experiment and remove the corrosion coupons. Recently, a continuous flow‐through reactor with tubular test section was employed for online monitoring of hydrogen evolution rates and apparent corrosion rates of Fe–Cr–Ni alloys . This investigation aims at the study of Zr corrosion and hydrogen evolution under high‐temperature and pressure flow conditions.…”