Most industries produce waste products which can be difficult or dangerous to dispose of. Coal and oil fired power stations produce enormous amounts of waste. A large coal power station will send 17 million
tons of flue gas out of its chimney each year.
It will also make around 2 million tons of ash, a fine white powder which is difficult to dispose of.
Nuclear power stations also produce waste. The problem is that this waste is radioactive, and is dangerous unless kept safely away from living creatures.
High-level waste is the radioactive ‘ash’ from used nuclear fuel. This
waste must be prevented from mixing with the environment until the
radioactivity has decayed to safe levels.
Radioactivity, unlike other poisons which are with us forever, disappears with time. So the highly radioactive ‘ash’ begins to lose its activity as soon as it is taken out of the reactor. It is normally kept at the bottom of a deep tank of water at the power station for several months. At the end of a year 90 per cent of the radioactivity is gone.
At the end of 10 years 99 per cent would have ceased to exist. But what’s left of this high-level waste is still very dangerous and will go on being so for thousands of years. However, the volume is not great, which makes storage comparatively simple. The total amount produced for the entire nuclear programme since 1956 would take up about the space of a pair of semi-detached houses – less than 1,500 cubic metres.
Intermediate-level wastes are far less radioactive. Currently, they are contained in solid concrete stores. The quantities involved are larger – about 2,500 cubic metres each year. There are no technical or safety-related advantages in storing these wastes for long periods. Plans are being developed to dispose of these wastes either deep underground or deep under the seabed.
In the meantime, they will be specially encapsulated in cement to make them easier to store and handle.
Low-level wastes consist of gases and liquids as well as solid laboratory refuse – protective clothing, gloves, used syringes and tissues. Much of the radioactive waste from hospitals and industry is low-level. The gases and liquids can, with government authorisation, be released directly into the environment, where they quickly become diluted to a level that presents no appreciable risk.
At present, the low-level solid wastes are disposed of in a shallow disposal site at Drigg, Cumbria. In the longer term they can be put in the same repository as the intermediate-level wastes – either deep
underground or under the seabed. Our only ‘vested interest’ in nuclear waste is to dispose of it without harm to the public.
Surely the most balanced approach you could wish for.