Paul Kwan at New England Medical Center has

>>just received an estimate for disposing 1,000 mL of 5% uranyl acetate: 
$7,000. The solidified waste will be embedded in concrete and buried 
somewhere in Florida.<<

I'd suggest precipitating it as sodium uranyl sulfate, which is crystalline 
and insoluble. Put the dried precipitate in a jar with a tight cap on it. 
Choose a big enough jar that it won't be filled until the day after you 
retire!

Bob Richmond
Samurai Pathologist