Question

Why is a "Breeder Reactor" called so?

• A. It generates very high amount of energy
• B. It generates nuclear fuel which can be used for fission chain reaction
• C. It is a fusion reactor
• D. It doesn't consume any nuclear fuel

Answer 1

The correct option is B It generates nuclear fuel which can be used for fission chain reaction

A breeder reactor is the one in which with the energy generation another nuclear fuel is also created at the same time.
That’s why the name Breeder.
We have talked about Uranium as the nuclear fuel so far, specially its isotope U-235.
There is another very useful nuclear fuel Plutonium. And Pu-239 has properties very similar to U-235.
An isotope of Plutonium Pu-240 is highly unstable so Pu-239 on absorbing a neutron becomes Pu-240 and hence is highly fissionable.
In a breeder reactor Pu-239 is produced which is obviously a nuclear fuel as we discussed above. The process is shown here:
${}_{92}^{238}U+n{\to }_{92}^{239}U\stackrel{{\beta }^{-}}{\to }{}_{93}^{239}Np\stackrel{{\beta }^{-}}{\to }{}_{94}^{239}Pu$

Suppose used Uranium rods which contain only U-238 are kept in or around a Uranium-reactor core. Also suppose the geometry is such that out of the average 2.5 neutrons produced in a fission, one neutron is absorbed by a U-238 nucleus in these rods resulting in Pu-239. Then we produce as much nuclear fuel in the form of Pu-239 as we consume in the form of U-235. If more than one neutron can be absorbed by these U-238 rods per fission then we produce more fuel than what we consume.
Hence we have a breeder reactor which generates nuclear fuel.