Writing paragraphs

Exercise 12

In the following article on Nuclear Hazards, the signalling words and phrases are missing. Replace them and check your answers.

There are three separate sources of hazard related to the use of nuclear reactions to supply us with energy. _Firstly, the radioactive material must travel from its place of manufacture to the power station. Even though the power stations themselves are solidly built, the containers used for the transport of the material are not. However, there are normally only two methods of transport available, just as road or rail, and both of these involve close contact with the general public, whereas the routes are bound to pass near, or even through, heavily populated areas. Secondly, there is the problem of waste. All nuclear power stations produce wastes which in most cases will remain radioactive for thousands of years. It is impossible to de-activate these wastes, and so they must be stored in one of the ingenious but cumbersome ways that scientists have invented. Therefore, they may be buried under the ground dropped into disused mineshafts or sunk in the sea. Even so, these methods do not solve the problem; they merely store it, so an earthquake could crack open the containers like nuts. Finally, there is the problem of accidental exposure due to a leak or an explosion at the power station. As with the other two hazards, this is extremely unlikely and does not provide a serious objection to the nuclear programme, in spite of the fact it can happen, as the inhabitants of Harrisburg will tell you. Separately, and during short periods, these three types of risk are no great cause for concern. Taken together, However, and especially over much longer periods, the probability of a disaster is extremely high.