High-level nuclear waste consists largely of spent fuel from nuclear reactors. Although it represents only a small proportion of the overall volumes of waste, it represents most of the radioactivity. According to some, this most powerful form of nuclear waste must be stored safely for up to a million years. Yes, 1 million years – in other words, a period of time much longer than the period since the appearance of the Neanderthals. This is an estimate of the time required to ensure radioactive decay.

Yet existing and planned nuclear waste sites operate for much shorter periods: often 10,000 or 100,000 years. These are still durations so unimaginable that the regulatory authorities decide them, in part, on the basis of how long are ice ages expected to last. To some extent, all of these numbers are little better than educated guesses.

These are also such long periods that in 1981, the US Department of Energy established the Human Interference Task Force to devise ways to warn future generations of the dangerous contents of nuclear repositories. It was a difficult task at the time, and nuclear semiotics remains the business of science fiction. Written language has only existed for about 5,500 years, so there is no guarantee that the inhabitants of Earth, tens of thousands of years from now, would understand any of the writing systems currently in use. The the meanings of the visual signs also drift over time. The most fanciful “Ray cat solution”, of cats genetically modified to glow in the presence of radioactive material, is even less reliable.

Even shutting down nuclear operations is necessarily a long-term process. Dismantling of a single nuclear reactor usually takes around 20 years. Most countries dealing with nuclear waste plan at least 40 to 60 years old just for implement their repository programs.

After brief flirtations with bad funny ideas, including throwing nuclear waste into space, the consensus among nuclear scientists is that the best option for dealing with high-level nuclear waste is deep geological disposal. One of the agencies of the International Atomic Energy Agency conditions for such a geological site is a low groundwater content, stable for at least tens of thousands of years, and geological stability, on millions of years. Thus, Japan, with its seismic instability, is unlikely to have suitable candidates for deep geological disposal.

Like many countries, Japan is banking on the interim storage of high-level waste while hoping that longer-term solutions will emerge in the long term. In fact, no country even has an operational deep geological repository for used nuclear fuel. (The United States has a deep repository in New Mexico for “transuranic” nuclear weapon wastes, which are long-lived and intermediate-level waste whose elements have higher numbers than uranium in the periodic table.)

It is difficult to find a site that ticks all the geological boxes (including a relatively impermeable material with little risk of water infiltration), and which is not politically controversial. To take two notable examples, the communities of Nevada, United States and Bure, France, have strongly opposed plans to create repositories. Given the history of environmental justice on a global scale, it is likely that all future approved locations for nuclear waste landfills will be in poor areas.

Only one country, Finland, is even in the process of building a permanent spent fuel repository. Even in Finland, however, it is estimated that a license will not be issued until 2024. Similar licenses for other European countries seeking possible locations would likely not be available until 2050 in Germany and 2065 in the Czech Republic. And those countries outnumber those that don’t even have an estimated timeframe for licensing because they’re so far in the process of finding a site.

The strategies remain worrying in the short term, at the nuclear level. The destroyed Chernobyl reactor no. 4, for example, was locked in July 2019 in a huge steel “sarcophagus” it will only last 100 years. Not only will containers like this fail to meet the deadlines necessary for sufficient storage, but no country has allocated enough funds to cover nuclear waste disposal. In France and the United States, according to the recent published report World Nuclear Waste Report, the funding allocation covers only one third of the estimated costs. And the cost estimates that do exist rarely extend beyond several decades.

Basically, we hope that things will work out once future generations develop better technologies and find more funds to manage nuclear waste. This is one of the most striking examples of the dangers of short-term thinking.