Dear Doc Zoomie, what’s this stuff I saw about France trying to recover a quarter million barrels of radioactive waste they dumped in the ocean a lifetime ago? How could that have ever been a thing? Is this for real?
Ah – deep-sea disposal! And, yeah – that was a thing for a while…close to a half-century. I know it sounds sorta crazy, but at the time it actually made a lot of sense. And, to be honest, it’s still got a few things going for it.
One thing to remember is that, back in the 1940s and for a few decades that followed, nobody gave much thought to dumping pretty much anything into the oceans – waste had been dumped into the ocean for centuries; it’s just the way things were done. So we dumped just about everything into the sea – sewage, garbage, old chemical weapons, aged warships, radioactive waste, and anything else society just didn’t need or want and that might pose a risk to people living near the landfills they might be put into. But we weren’t much nicer to the land – I remember reading some older Department of Energy documents that referred to “soil column cleanup” for liquid wastes contaminated with radioactivity or any of a number of chemicals. Part of it was a lack of imagination – the inability to imagine we could ruin something as big as a planet and its oceans.
With radioactive waste, disposal depended on the type of waste. Liquids were frequently simply dumped into the water – preferably far from land. Solids were often put into metal drums and dumped off a ship, to sink into the deep ocean and thence into the seafloor’s muck. Which turns out not to be as dreadful place to put it as one might think because that muck is loaded with clay, and clay minerals do a great job of absorbing and immobilizing contaminants. So it turns out that, of the waste put into barrels and dumped into the deep sea, almost all of it has stayed put, trapped in the sediments into which it fell. But we see the same near the sunken nuclear submarines – there might be traces of radioactivity in the vicinity of the submarines, but nothing that’s at any great distance.
What’s interesting about the deep sea is that the water is cold and it doesn’t contain much oxygen, so metals don’t corrode very readily. That’s why, for example, the Titanic is still recognizably a ship instead of a pile of rust on the seafloor. So metal drums have a longer life than we’d expect of something submerged in saltwater.
And then there’s the sediments. At the risk of geeking out a little, clay minerals are a group of minerals called phyllosilicates, with the “phyllo” meaning more or less the same thing as in phyllo dough – the thin layers of dough that back to form the multiple thin layers of pastry that tasks so good in baklava, strudel, and other baked goodness. Phyllosilicates tend to have a lot of surface area, and to have a very slight electrical charge on their surface layers – this means that they glom onto anything that comes in contact with them that has an opposite electrical charge, which turns out to be a lot of things. Contaminants that attach to the surface of the clay minerals are locked into place and are more or less removed from the environment. On top of that, like baklava, phyllosilicates are layered and, in some of them, ions can squeeze in between the layers and be trapped in the interlayer space. This is another way for the clay minerals that comprise a large fraction of many soils and even more of the deep-sea sediments to latch onto contaminants, including radioactive waste, and keep them from spreading through the environment.
The bottom line is that, by today’s standards, dumping radioactive waste into the ocean is a bad idea – but t it made sense at the time and, even if the folks who started dumping it weren’t aware of it, there was actually some justification for thinking it to be not a horrible idea.
The article you linked to mentions that the French are trying to locate and recover over 200,000 barrels of radioactive waste from France and a number of other European nations that’s lying on the bottom in water more than 2 ½ miles deep off the coast of France. But a lot of nations disposed of radioactive waste at sea: Russia, the UK, Switzerland, Belgium, the Netherlands, the US, Japan, Sweden, Germany, South Korea, Italy, and even the environmentally minded New Zealand. The Soviet Union and the UK were responsible for more than anyone – over 74,000 TBq (2million Ci) of radioactivity left in the Atlantic and Arctic oceans, the Sea of Japan, and nearly 20 other locations, mostly off the British coast. And that’s not counting the nuclear reactors, sunken nuclear submarines, and other radioactive things that decorate our oceans’ floors.
For a while there were suggestions that the waste be placed into containers designed to penetrate into the deep-sea sediments and bury themselves in the seafloor. Another suggestion was to dump the waste in subduction zones – places where one of the Earth’s tectonic plates is being subsumed beneath another, ultimately to melt and mix with the other rocks of the Earth’s mantle. The problem with this approach is that tectonic plates move at about the velocity of growing fingernails – waiting for so slow a process to sequester wastes deep within the Earth requires more patience than most people possess.
Seafloor burial of waste was outlawed by the London Convention in the 1970s and deep-sea disposal of radioactive waste more or less stopped by 1994. Now, it’s up to nations like France to find and (if possible) recover what was left there in less-informed times.
Image Credits/Citations
1. Header Image
- File name: Fûts de déchets faiblement radioactifs en Atlantique Nord-Est (Ifremer 00539-65072 – 9585).jpg
- Description: Photograph of a container (metal drum) of low-level radioactive waste in the North-East Atlantic dumping zone (depth 4,500–4,700 m). Taken during the EPICEA 1 campaign in May 1984 by Ifremer’s unmanned submersible EPAULARD aboard N/O Le Suroît.
- Source: Wikimedia Commons — File page
- License: Creative Commons Attribution 4.0 International (CC BY 4.0)
2. Main Body Image
- File name: Fûts de déchets faiblement radioactifs en Atlantique Nord-Est (Ifremer 00539-65072 – 9586).jpg
- Caption used in article:
“A barrel of low-level radioactive waste resting on the seabed in the North-East Atlantic dumping zone (depth ~4,500–4,700 m), photographed by Ifremer’s unmanned submersible EPAULARD during the EPICEA 1 campaign in 1984.” - Source: Wikimedia Commons — File page
- License: Creative Commons Attribution 4.0 International (CC BY 4.0)
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