What do you mean by this time? Nuclear waste has already been dumped in the oceans before (prior to new regulations). 8 nuclear submarines have been lost and there's no environmental impact detected.
This has been well studied by several groups including the US Navy, which is one of the biggest nuclear operators with over 80 reactors currently in warships. In the event of catastrophic loss, the plan is to just leave it because the oceans already have billions of tons of radioactive material and infinite capacity to absorb more.
Also nuclear reactors have occurred naturally [1] and without any serious fallout or contamination risks, showing that containment is really not that challenging. Most people think nuclear is scary because of popular science and culture, and they lack the knowledge and understanding to know any different. It's similar to people not trusting vaccines because they don't understand medical science.
Absence of evidence is not evidence of absence. Deep sea ecosystems are extremely fragile and we need to leave them as is if we want to feed people
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.
There is plenty of evidence - of no impact. As I said this has been extensively studied and there's so much radioactive material in the ocean that it makes no difference.
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?
This is the things that make me cringe when I see this people saying again "This time will be different, we promise".
Look mum, radioactive tornadoes coming from the ocean...