LIST OP ILLUSTRATIONS 1. Factors affecting choice of an engineering Material 12 2. Factors affecting corrosion resistance of a metal 3. Service range of materials in acid chloride environments 4. Attack on steel at 310°C (590°F) by water of varying degrees of acidity and alkalinity 5. Effect of pH on the corrosion rate of 1010 wild steel ..... 21 6. Anticipated performance of unalloyed titanium in chloride brines and under NaCl or SH CI deposits 7. Planned interval test 8. Potential-current diagram for steel in an acid chloride solution. . LIST OF TABLES 1. Corrosion-resistant materials x 2. Factors influencing the survival of a spent-fuel storage canister in a brine environment 3 3. Morphology of corrosion attack in concentrated brines 11 4. Metals and alloys resistant to chloride corrosion IS 5. Anticipated performance of metals in halite brines 16 v ABSTRACT Spent fuel canisters stored in halite (NaCl) deposits (salt beds) are subject to a severely corrosive environment when the hot brine inclusions, rich in calcium and magnesium chlorides, migrate to the canister. Since no data base exists on corrosion in halite brines, a survey was made of the corrosion resistance of potential canister materials in other concentrated brine environments. Corrosion-resistant metals include Ta r Ti Code 12, TiPd Alloy, Inconel 625, Hastelloy C-276, and Fe-base 29-4 Alloy. Although carbon steels have cost and availability advantages, they suffer from excessive corrosion rates in brines. Corrosion-resistant nonmetals include carbon. Teflon-type fluorocarbons, epoxide coatings, and polymer cements. While these materials are not suitable for constructing the canister, they could be used as a protective coating on a carbon steel canister. On the basis of this survey, we recommend a coated carbon steel canister, used with cathodic protection. It is important to start a test program to gather a data base on the corrosion of materials in halite brines and to verify the suitability of canister materials. vii A. Environment: Canister internal environment: Physical and chemical form of waste Radiation flux Thermal flux Canister external environment: Bulk composition