FOR LOW-LEVEL WASTE DISPOSAL-

LOW-LEVEL RADIOACTIVE WAST HAS TRADITIONALLY BEEN DISCARDED IN SHALLOW LAND TRENCHES. THERE IS A STRONG DEMAND FOR THE DEVELOPMENT, VALIDATION, AND IMPLE- MENTATION OF ALTERNATIVE TECHNOLOGIES TO SHALLOW LAND BURIAL, IN WHICH THE DEGREE OF PROTECTION OF THE PUBLIC IS SIGNIFICANTLY INCREASED FOR BOTH THE NEAR TERM AND THE LONG TERM (MANY HUNDREDS OF YEARS). THIS PROJECT WILL IDENTIFY A CONCEPTUAL DESIGN OF AN UNDERGROUND ASPHALT VAULT FACILITY FOR DISPOSING OF LOW-LEVEL, RADIOACTIVE WASTE. THE OPTIMAL ASPHALT TYPE AND ADMIX COMPOSITION WILL BE DETERMINED EXPERIMENTALLY. BENCH- SCALE PHYSICAL MODEL TESTS WILL BE PERFORMED ON A SIMULATED SHALLOW LAND-BURIAL TRENCH, A CONCRETE UNDER- GROUND VAULT, AND AN ASPHALT UNDERGROUND VAULT. HIGH- PRESSURE DIFFERENTIAL LOADING TESTS, WATER INFILTRATION, AND CONTAMINANT-LEACHING TESTS WILL BE PERFORMED ON THE BENCH-SCALE MODELS. PERFORMANCE ASSESSMENT COMPUTER ANALYSIS OF THE EXPERIMENTAL TESTS AND OF EXTRAPOLATED FIELD FACILITIES ALSO WILL BE PERFORMED. THE FEASIBILITY STUDY WILL PROVIDE RELATIVE PERFORMANCE MEASURES FOR THE CONCRETE AND ASPHALT UNDERGROUND VAULT TECHNOLOGIES AND COMPARISONS WITH THE PRESENT SHALLOW LAND-BURIAL TECHNOLOGY. THESE DATA WILL BE USED TO DEVELOP A CON- CEPTUAL DESIGN AND COST ANALYSIS FOR AN ASPHALT UNDER- GROUND VAULT FACILITY AND WILL IDENTIFY THE POTENTIAL FOR A COMMERCIAL FACILITY OF THIS TYPE.