Corrosion test of reformer tube material in the HTTR hydrogen production system. 1. Total test plan and construction of test apparatus (contract research)

In the HTTR hydrogen production system, hydrogen is produced by means of steam reforming of methane using hot secondary helium supplied from an intermediate heat exchanger. The steam reformer is one of most important equipment in this system. In the steam reformer, helium gas whose maximum temperature is at 880degC flows outside of tubes and process gas that is a mixture of hydrogen, steam, carbon mono-oxide, carbon di-oxide and residual methane flows inside. The reforming tube has to withstand against these conditions. Only Hastelloy XR, nickel based high temperature resistant alloy, can meet the design temperature of reforming tube in available materials for nuclear equipment. Database of Hastelloy XR is provided for use in helium gas so that it is required to ensure the integrity of Hastelloy XR and the applicability of existing mechanical test database such as tensile strength, fatigue life, creep life and so on in the process gas. Corrosion tests in the simulated process gas condition and the mechanical te,sts by using post corrosion specimens are planned. This report describes the test plan, corrosion test apparatus and a result of corrosion test in steam atmosphere. (author)