[ErnstStavroBlofeld]

The last known incident of dumping at sea by the Russian Navy occurred in 1993, when approximately 900 tons of liquid radioactive waste were dumped into the Sea of Japan.

[Does so]

I recall US sub-tenders weren't too "clean" in this regard.

:-\

I found a land-based nuclear reactor—Sellafield— along the Irish Sea with similar "easy" disposals.

http://www.corecumbria.co.uk/tour/irishsea.htm