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Chapter 38: Problem 11

Is \(^{238} \mathrm{U}\) fissionable? Is it fissile? Explain the distinction.

Short Answer

Expert verified
\(^{238} \mathrm{U}\) is fissionable but not fissile. Fissionable materials can undergo fission with fast moving neutrons, while fissile materials can undergo fission with slow, or 'thermal', neutrons.

Step by step solution

01

Understanding \(^{238} \mathrm{U}\)

\(^{238} \mathrm{U}\) is an isotope of uranium, meaning it is an atom of uranium, but with a different number of neutrons. This isotope is especially important for nuclear power reactors.
02

Is \(^{238} \mathrm{U}\) fissionable?

\(^{238} \mathrm{U}\) is indeed fissionable. When a neutron, no matter its speed, hits a \(^{238} \mathrm{U}\) nucleus, it can cause the nucleus to split, releasing a large amount of energy. This is the fundamental process that occurs in nuclear fission reactors.
03

Is \(^{238} \mathrm{U}\) fissile?

In contrast, \(^{238} \mathrm{U}\) is not fissile. This is because it does not readily undergo fission when hit by a slow, or 'thermal', neutron. To cause fission in \(^{238} \mathrm{U}\), the neutron must be moving at a higher speed.
04

Understanding the Distinction Term

The main distinction between fissionable and fissile materials is the speed of the neutron that can induce fission. Fissile materials can undergo fission with slow neutrinos, while fissionable materials require these particles to be fast-moving.

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