Usually radioactive wastes are disposed by deep well injection method and land fill method.These method involve storing waste in area below porous materials but sometimes these may interact with water table or ground water *REMEMBER GROUND WATER DIFFERS FROM WATER TABLE*Remember gamma rays may release which penetrate deeper but gamma rays can't reflected as they are electromagnetic waves.But theory say Alpha and beta can reflected as alpha is positive whereas beta is negative.

Nice question buddy.Keep your curiosity.