UN chief concerned nuclear 'coffin' leaking in Pacific

Sounds scary, but...
All of those tests (well, most) were done in the open air, with no containment other than a maritime exclusion zone. Whatever mess we made there has been in the environment for over 60 years.
Not to say it isn't a mess that we are responsible for, just saying that this genie is well out of the bottle.
Which leaves us with only one realistic possibility about the designs and motives here: money grab. He's really out there to talk about how the oceans will swamp the Marshall Islands someday and clutch his pearls about it, but since no one cares about that, gotta make news somehow.
Perhaps the UN will go after the Russians for the damages dealt to Scandinavians when they were testing in Novoya Zemlya or the Kazakhs for testing in their back yard? LOL, nope.
Perhaps the UN will go after the Chinese for damages dealt to Uighurs in Sinkiang from their tests? LOL, nope.
So this then is a targeted money grab, politically aimed at bleeding hearts in France and America.
OK, UN guy. Better hope that someone who isn't Trump nor designated trillions to be spent on Green New Deal/ Medicare for All/ Universal Basic Income/ Reparations wins... wait. That leaves nobody?
Oh.
Well, jog off then UN guy.

From Runit Island entry in Wikipedia. "In 1982, a US government task force raised concern about a probable breach if a severe typhoon were to hit the island.[4] In 2013, a report by the US Department of Energy[5] found that the concrete dome had weathered with minor cracking of the structure.[6] However, the soil around the dome was found to be more contaminated than its contents, so a breach could not increase the radiation levels by any means. Because the cleaning operation in the 1970s only removed an estimated 0.8 percent of the total transuranic waste in the Enewetak atoll, the soil and the lagoon water surrounding the structure now contains a higher level of radioactivity than the debris of the dome itself, so even in the event of a total collapse, the radiation dose delivered to the local resident population or marine environment should not change significantly. Concern primarily lies in the rapid tidal response to the height of the water beneath the debris pile, with the potential for contamination of the ground-water supply with radionuclides. One particular concern is that, in order to save costs, the original plan to line the porous bottom crater with concrete was abandoned.[1] Since the bottom of the crater consists of permeable soil, seawater is inside the dome.[1] However as the DoE report stated, the released radionuclides will be very rapidly diluted and should not cause any elevated radioactive risk for the marine environment, compared to what is already experienced.[5] Leaking and breaching of the dome could however disperse plutonium, a radioactive element that is also a very toxic heavy metal.[7]"

I say that the UN is a day late and a dollar short and appears to be in collusion with the radicals of the Democratic Party (AKA supporters of the Green New Deal and the Democratic Socialist).

Here is the 2015 RP discussion thread on issues in the Marshall Islands - https://www.rallypoint.com/shared-links/did-you-know-once-a-nuclear-test-site-group-of-pacific-islands-face-oblivion-again?loc=similar_main&pos=1&type=qrc
And the associated Stars & Stripes article - https://www.stripes.com/news/pacific/once-a-nuclear-test-site-group-of-pacific-islands-face-oblivion-again-1.380964