Status of U.S./Japan collaborative program phase II HFIR target capsules

The objective of this program is to determine the response of various U.S. Japanese austenitic and ferritic stainless steels with different pretreatments and alloy compositions to the combined effects of displacement damage and helium generation at temperatures in the range of 300 to 600 C and doses of 18 to 70 dpa. A complete description and details of the design, construction, and installation of capsules JP-9 through JP-16 has been previously reported. The capsules were installed in the High Flux Isotope Reactor (HFIR) target July 20, 1990, for irradiation beginning with HFIR fuel cycle 189. The capsules were removed and stored in the reactor pool during HFIR cycle 292 (11/25/90 - 12/10/90) to provide room for required isotope production. They were reinstalled for HFIR cycle 293 for continued irradiation. Of these eight target capsules, JP-10, 11, 13, and 16 completed their scheduled number of cycles (11) and were removed from the reactor in September 1991. These four experiments were successfully disassembled in January 1992. Three new capsules in this series, JP-20, 21, and 22, are presently being designed. These capsules were added to the program in order to complete the experimental matrix included in the JP-9 through 16 capsules. The new capsules will contain transmission electron microscope (TEM) disks and SS-3 flat tensile specimens at 300-600 C and will achieve doses of 8, 18, and 40 dpa, respectively