Program of United States-Japan collaborative testing in HFIR and ORR

The objective of the program of US-Japan collaborative testing in HFIR and ORR is to investigate the response of austenitic stainless steels to levels of neutron radiation damage anticipated in fusion reactors. Emphasis is placed on United States and Japanese Type 316 stainless steels and prime candidate alloys (PCA), but improved alloys are also included. The program consists of eight HFIR target capsules and two ORR spectral tailoring capsules with test temperatures of 60 to 6000C and fluences of 30 to 50 dpa. Helium contents after irradiation match or exceed those produced in a fusion reactor at the same dpa level. Types of data to be obtained include tensile, fatigue, crack growth, irradiation creep, swelling, and microstructural evolution. Five HFIR capsules have been irradiated, and testing is under way. Less than 1% swelling is observed for Type 316 stainless steel and PCA alloys irradiated to about 30 dpa at 300 to 5000C. (orig.)