The Nuclear Industry worldwide is generating an appalling legacy of radioactive wastes. The properties of those wastes vary enormously, but many are highly radioactive and toxic, and many will remain radioactive for hundreds of thousands of years.

Nuclear waste embraces a great range of material, from lightly contaminated overalls, to uranium mill tailings, to the fiercely radioactive liquid high level waste that is produced by reprocessing.

By the turn of the century, the worldwide inventory of high-level wastes is projected to reach 150,000 million curies.

The production wastes starts at the first stage of the nuclear fuel cycle - with the minig of uranium. In the USA it has been calculated that radon emissions from mill tailings could cause 4,000 cancer deaths a year.

Mill tailings apart, the amount of radioactive wastes produced by a nuclear power programme depends critically on whether reprocessing or long term storage is practiced.

A large pressurized water reactor (PWR) produced 11 cubic metres of irradiated fuel per gigawatt per year. If stored, this is the only volume to be dealt with. If reprocessed, 6.25 cubic metres high-level waste, 40 metres of intermediate-level waste and 600 cubic metres of lowlevel waste are produced from the original 11 cubic metres of spent fuel.

At the end of the first year after extraction from the reactor, the irradiated fuel still contains, in highly concentrated form, 270,000 times more radioactivity than the ore from which it was derived. Even after 10,000 years, one kilogram would contain, gram for gram, 18 million times more radioactivity than the lambs that Britons were forbidden to eat as a result of Chernoybl.

High-level wastes are generally stored in stainless steel tanks, constantly cooled. In the USA the main storage center is Hanford, a site that has a notorious record for accidents involving waste. Between 1945 and 1973, some 422,000 gallons liquid waste containing 500,000 curies of radioactivity had leaked out of the tanks. Tritium and ruthenium have been detected in the groundwater; strontium-90 and iodine-131 in the Columbia River; and plutonium-239 in the soil. The levels of plutonum were 5,000 times the permissible level.

In the UK, high level wastes are stored at Sellafield. Ultimately, the aim is to solidify the waste in glass through a process known as vitrification. The process is intended to reduce the volume of waste and to make it easier to handle.
A pilot vitrification plant is now in operation at Marcoule in France, but it has only vitrified waste with a radioactivity no higher than 10 curies per cubic metre: once fully operational, it must contend with wastes with a radioactivity up to 300 curies per cubic metre.

Several US and Austrailian researchers are strongly critical of vitrification. The danger is that the glass blocks will disintegrate at some time in the future.
Even assuming vitrification works, the problem of a long-term repository for high-level wastes remains unresolved - and, many would claim, insoluable. In both Europe and the USA, the nuclear industry talks of burying waste in deep underground sites, but the search for stable geological sites has proved fruitless. Indeed, uncertainities of geological faults, the ability to predict future geological movement, and the possibility of earthquakes, make it possible to guarantee the integrity of any site for the length of time that the waste must be kept isolated.

In the USA, three out of six sites have been closed down due to contamination problems or breeches in transportation regulations. The West Valley Site in New York State was closed after tritium contaminated local ground water, and the Maxley Flats dump in Kentucky after plutonium was fond to have migrated three-forths of a mile off site within three years of the site opening. At Bernwell, South Dakota - one of the three sites still operating - movement of both cobalt-60 and tritium have been detected.

The only available dump site in Britian for disposing of solid low-level waste is at Drigg, adjacent to Sellafield. The site, which is almost full, is designed to allow its wastes to drain into the Irish Sea, on the grounds that they will be rendered harmless through "dilution and dispersal."

...Discharges of low-level nuclear waste into the sea from land (as opposed to dumping from ships) escape the LDC moratorium, and such waste is still discharged by both Sellafield and Cap de la Hague.

The failure to find a suitable land-disposal site for intermediate and low-level wastes in Britian has again focused on the sea, one proposal being to bury the waste under the seabed, with access via tunnels from the land...

WestGermany's nuclear industry seeks to dispose of waste in China's Gobi Desert. Germany's biggest nuclear company - Kraftwerke Union - announced that deal with China would be taken in exchange for nuclear technology.

Radiation and Health