Nowadays, during the era of the highly developed technologies, a nuclear reactor seems to be an invention from the past. In this paper we are going to discuss the general characteristics of a nuclear reactor, the way it operates, the breeder reactors and its advantages and disadvantages.
The short definition of a nuclear reactor can be formulated as following “a nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate, as opposed to a nuclear bomb, in which the chain reaction occurs in a fraction of a second and is uncontrolled causing an explosion”ť (Adams, 12).Usually, nuclear reactors are applied as energy sources for electrical power and for ships’ power. The central method of power generation is the usage of the heat of the nuclear reaction through power steam turbines.
The process of operation of a reactor consists of absorption of neutron by the nucleus of uranium ”“ 235 atoms, which are later on divided into fast-moving light elements, i.e. the fission products and free neutrons (Adams, 33). Most of other thermal power stations generate electricity from the thermal energy, appearing after fossil fuels are burnt. Actually the same is the principle of thermal energy generation by nuclear power plants, i.e. from nuclear fissions. The main task of the reactor in this case is the transformation of the nuclear or “atomic”ť energy into heat.
There are several general types of nuclear reactors, one of them is breeder reactor. This is “a nuclear reactor that generates new fissile or fissionable material at a greater rate than it consumes such material”ť (Yamashita, 111). From the very beginning this type of reactors was singled out from the others, first of all because it was considered to be more economical than others. Normal reactors could consume only around 1 % of the natural uranium, whereas a breeder was able to use much greater amount. Besides, a breeder reactor could re-process the initial fissionable material. Important is also the fact, that breeder reactors can operate with thorium, which is much easier to find than uranium. At the moment, breeder reactors are again in the process of thorough investigation and studies, because they consume less natural uranium and produce less waste, at the same time producing the same amount of energy as for example conventional light-water reactors.
Among the major disadvantages of breeder reactors is the necessity of cooling with liquid sodium and the fact, that this type of reactors is more sophisticated and certainly more expensive than usual reactors. The potential of the breeder reactors for misuse of plutonium is a controversial issue. Although it is considered to be possible, there is an opinion, that in reality this is very difficult to use plutonium for creating an atomic bomb, even if applying rather difficult techniques. Most researchers still agree, that the application of breeder reactors should be only under severe control and management, in order to avoid the problems with possible nuclear weapons and their further misuse.
Overall, we have studied briefly the definitions of nuclear reactors, their structure, usual scheme of work and areas of application; with more details we considered the special type of nuclear reactors ”“ breeders. Breeder reactors stand out for their economy and less wasteful application, at the same time they are characterized as expensive and potentially dangerous if misused for creation of nuclear weapon.