The three completed stages of an alloy development program aimed at defining a nickel chromium-based alloy resistant to carburization in simulated high-temperature gas-cooled reactor (HTGR) helium with high-temperature strength similar to alloy Inconel-617 show that alloys based on nickel and 10% chromium with 10 to 16% tungsten and 1.1 to 3.2% titanium exhibit good corrosion resistance in dry simulated HTGR helium and have short-time creep properties similar to Inconel-617. The alloys are readily hot and cold workable and show potentially good structural stability.