Comparison of X-ray CT measurement for large size iron artifact

In this study, the corrosion amount of archaeological iron artifact that had been buried in the soil for a long-term is investigated, as natural analogues concerning the long-term corrosion behavior of the overpack in the bentonite. As a result, high reliable long-term corrosion model will be established, and assumed basic grounds of design and safety assessment. Many corrosion data is necessary to guarantee the validity of the long-term behavior assessment. Corrosion analysis had carried out on forty archaeological iron artifacts, which had been dug out at seventeen relics in Japan. Although JAEA estimated the corrosion depth of the carbon steel to be 31 mm for 1000 years by the second progress Report (H12), corrosion analysis results clarified the corrosion depth of the archaeological iron artifact was lower than 31 mm. Many of archaeological iron artifacts for this analysis had been buried in a oxidizing environment. Because the disposal environment is expected to be reducing condition, the corrosion data in conditions relevant for geological disposal are desirable. This study investigated the corrosion of the plow with soil excavated from the Oda castle. We examine use of medical X-ray CT owned in the JAEA for this purpose. The plow was measured by high energy industry machine for industry and medical X-ray tomography. And the applicability of medical X-ray CT, owned in the JAEA, for metal natural analogue study was evaluated by the comparison of each measurement. (author)