Status of U.S./Japan collaborative program phase II HFIR target and RB{sup *} capsules

Capsules HFIR-MFE-JP9 through 16 were installed in the High Flux Isotope Reactor (HFIR) target July 20, 1990 for irradiation beginning with HFIR fuel cycle 289. Of these eight target capsules, JP10, 11, 13, 16 accumulated 18 dpa and were removed from the reactor in September 1991. JP14 was removed from the reactor at the end of cycle 310 (September 1992) after achieving a peak dose of 34 dpa. Capsules JP9, 12, and 15 completed 35 cycles on April 1, 1994 and were removed from the target region. Each capsule had accumulated a peak dose of approximately 57 dpa. Three new capsules, HFIR-MFE-JP20, 21, and 22, have been designed to complete the original experiment matrix of the JP9 through JP16 series capsules. Irradiation began in December 1993 with the start of cycle 322. As of April 1, 1994 (end of cycle 324), each capsule had achieved approximately 4.9 dpa. The RB* experiments are the continuation of the ORR spectrally tailored experiments. In this stage, a hafnium liner is used to modify the spectrum to simulate fusion helium to displacements per atom (He/dpa) ratio in the austenitic steel specimens. Of the four capsules in this set, two (60J-1 and 330J-1) were disassembledmore » during this reporting period after accumulating a peak dose in HFIR of 11 dpa. Two capsules (200J-1 and 400J-1) are in the reactor and have achieved a dose of 5.5 dpa.« less