Material Characterization and Material Requirement of the High-temperature Components of the High-temperature Gas-cooled Reactor

Abstract

The design temperature of the high-temperature gas-cooled nuclear reactor (abbr. as HTR) system is as high as 950°C. Because 950°C is the highest of the design temperatures for the various nuclear reactors, it was expected that various new material behaviors may be encountered. These phenomena should be considered in the design of the high-temperature components of the HTR.

During the development of the helium heat exchanger for the HTR direct steel making system, the following material properties were considered to be important R&D items at the high operating temperature:

• (1) Creep—environment interaction under cyclic loading;

• (2) tribology problem at the metal-to-metal interface;

• (3) high hydrogen permeability.

In order to overcome these problems in the HTR design, material characterization was performed at the level of laboratory experiments, and inputs from the experience of designing intermediate heat exchangers were also considered.