[Jabbles]

It's been done before.

https://en.wikipedia.org/wiki/Ocean_disposal_of_radioactive_...

It wouldn't be negligible. Dumping all our HWL waste (250,000 tons) would increase background radiation of the oceans by 10% if completely mixed, but of course oceans are not. We would simply end up with highly radioactive areas of ocean if and when the containment failed.

[belorn]

Just a throwaway idea, but instead of radiating the whole ocean evenly, why not dump it in the already highly radiated nuclear weapon test zone? The US blow around 100 nukes and I wonder if a few thousands of tons would actually do much worse compared to what already down there.