Also maybe you misunderstood the post because dumping in the ocean wasn't a real proposal. The point is that containment is solved, and indeed solved by very smart people. It's politics and general ignorance that has hampered nuclear power, not technology.
There is plenty of evidence of the opposite in fact and is not difficult to find at all. We can choose to close the eyes to not see it, but the truth is stubborn:
Techa river (Russia): Used as dumpster from dismantled nuclear submarines until 2004. 25 times more probable than normal of having limb and organ malformation in newborn babies from people living there, plus a bonus 40% increase of probability of having cancer. This is the harvest of just 50 years of activity. What would you call that?
Time to just get rid of the mess hiding it under the rug and saying that "There is not our fault, it was yet like that when we arrived and now is somebody else's problem" has passed.
We deserve better, much more honest and much more smart people this time.