| Abstract: | The Japan Atomic Energy Research Institute (JAERI) has carried out a series of research and development work related to the high temperature gas-cooled reactor (HTGR) and, accordingly the high temperature engineering test reactor (HTTR) will be constructed in the near future. As the reactor pressure vessel (RPV) material,
Mo steel will be used. Material characterization tests have been carried out to evaluate the applicability of the
Mo steel for the RPV and to prepare for the licensing. The present paper summarizes the fracture toughness behavior including KId and KIa, irradiation embrittlement susceptibility and degradation of steel due to the long term aging at high temperature of the forged low
Mo steel. These tests reveal good fracture toughness which well meets the requirements of the ASME Code, low neutron irradiation embrittlement susceptibility, little embrittlement by long term aging and so on. The present test results demonstrate good applicability of forged low
Mo steel to the RPV of HTGR. |
