The 20,000-hr compatibility tests using WESF /sup 90/SrF/sub 2/ have been completed. The test capsules were shipped to Oak Ridge National Laboratory (ORNL) and metallographic examination of the test specimens is now underway. Work continues on the final design of the prototype outer capsule. Efforts are underway to obtain the Hastelloy S and Hastelloy C-4 to be used in fabricating the prototype outer capsules. Puncture testing of the stand-in steel outer capsule was carried out without damage to the capsule. Effort continued on impact testing of the stand-in capsule. Tests to measure the oxidation rates of Hastelloy S and Hastelloy C-4 in air at 600 to 800/sup 0/C are continuing. Short-term test data for up to 2500-hr exposure indicated that oxidation of the two alloys adhered to parabolic rate relationships. Specimens oxidized for 5000 hr and 7500 hr exhibited erratic oxidation behavior, and the average oxidation rates were less than predicted by parabolic rate equations developed from the short-term rate data. Room-temperature tension testing of specimens oxidized in air at 600 to 800/sup 0/C for up to 7500 hr indicated that oxidation had no significant effect upon the room-temperature tensile properties of the two alloys.