Dixie Lee Ray was Governor of Washington, a professor in Washington state with a PhD in biology, was quite in touch with marine biology. She was in charge of the AEC for a time. The reason she recommended the ocean is because of the extremely vast amounts of water in the oceans VS the rather small % of nuclear waste. + the fact that the glass encasement would not degenerate for eons and if any nuclear waste were to escape, would have zilch of any effect after being disbursed by the vast amount of oceanic water...to say nothing it would be maybe a half mile or so in the mud at the bottom of the abyss.
She wrote a book that discusses this along with a number of other things debunking a number of Green Weenie myths. Trashing the Planet