The Storage of Nuclear Waste

The short answer is scientifically and technologically it is very well understood, but the societal aspects are seemingly intractable, particularly with respect to the higher activity, more hazardous wastes. Even in the few countries which have managed to find solutions for the Storage of Nuclear Waste, it has taken decades to get to that position, but there is still no deep geological disposal facility in operation.

Whether you are in favour or against nuclear power, the simple fact is that radioactive waste exists! Even if the nuclear industry closed down tomorrow, radioactive waste will continue to be generated for many years to come and provide long-term careers for many disciplines. The flip-side is that it is a recognised international requirement that there is a need for a nation to have a solution at hand to deal with radioactive waste before it embarks on a new nuclear programme.

So where does the waste come from? In summary, from nuclear power plants and associated facilities, research and development activities, and industrial and medical uses of radioactive material. Nuclear power is, of course, the biggest contributor and this is the area we will concentrate on.

There are about 440 commercial nuclear power reactors in operation around the world. A further 154 are shut down and undergoing decommissioning, and about 70 new reactors are under construction, with several more being planned. In addition there are numerous research reactors, and nuclear powered ships and submarines. As well as generating electricity, enabling nuclear research and medical isotope production, and providing marine propulsion, they all have one thing in common: they produce liquid, gaseous and solid radioactive wastes.

If we look at the solid radioactive wastes, in broad terms these can be classed as either lower or higher activity. Again in broad terms, when it comes to disposing of suitably conditioned radioactive waste, the lower activity wastes can be emplaced in “near-surface” repositories and higher activity wastes in deep geological disposal facilities. By “near-surface” we usually mean engineered facilities at or near the surface, or at most a few tens of metres below the surface, and there are many examples of such repositories in operation around the world. In general terms, the radioactivity levels in these facilities will decay to normal background levels in about 300 years.

Deep geological disposal means putting the waste, usually the longer lived variety in the form of spent nuclear fuel, vitrified high level waste, long-lived wastes (with half-lives greater than 30 years), several hundred metres underground. But why “disposal”? Why not long-term storage, disposing at sea, firing it into space, or disposing it in ice-caps? Can it be “dumped” on so-called poorer nations, or sent to Antarctica? The list of options goes on and in the next article we will look at these options in more detail and show why all countries which have looked at the options in detail conclude that geological disposal is the right answer.