Nuclear Fission: Uncovering the Basics
What is Nuclear Fission?
Nuclear fission is a nuclear reaction that involves the splitting of heavy atomic nuclei into lighter fragments, releasing a significant amount of energy in the process. This phenomenon is a powerful source of energy that powers nuclear reactors and has become a crucial component in today’s energy landscape. However, before delving deeper into the details, let’s first define nuclear fission and explore its components.
Key Components
Nuclear fission takes place when an atomic nucleus, typically consisting of six or more protons and an equal number of neutrons, is subjected to high levels of energy or radiation. This causes the nucleus to split or breakup into two or more fragments, releasing energy and newly formed neutrons.
Some of the key components necessary for nuclear fission are:
• Neutrons: Neutrons are essential for triggering and sustaining nuclear fission reactions. They are bombarded onto the target nucleus to initiate the fission reaction.
• Atomic Energy: High levels of atomic energy are required to exceed the binding energy holding the nucleus together, leading to fission.
• Fissionable Material: Fissionable material contains heavy atoms with atomic nuclei that can be split.
Types of Fission
There are several types of fission reactions that occur depending on the input energy and the structure of the target nucleus.
- **Neutron-induced Fission**: This type occurs when neutrons interact with the target nucleus to release energy and produce fission.
- **High-Speed Particle-induced Fission**: This type occurs when energetic particles such as electrons, protons, or cosmic rays interact with the nucleus to release energy.
- **Radioactive Fission**: This type occurs spontaneously as unstable nuclides undergo fission without external input energy.
The Fission Reaction
The fission process begins when a high-speed neutron collides with an atomic nucleus. If the nucleus absorbs the neutron, a new, excited state may be formed. If enough energy is available, this excited state will release some of its energy through photon emission (gamma decay).
If the nucleus contains one or more neutrons which are in the ground or excited state, then beta decay can occur, ultimately leading to a buildup of free neutrons within the nucleus. As these neutron accumulate, they become densely packed, and this situation can lead to:
Table 1: Energy Yields from Fission (approximate)
| isotope | Fission Q-value (MeV/nucleon) | Enrichment | Description |
|---|---|---|---|
| U-235 | 175 MeV | 0.70% | The fissile isotope of Uranium used in most power generation. |
| Pu-239 | 195.4 MeV | Less than 0.002% | A key nuclide produced during a non-proliferative burning process. |
Signs of Fission
• Heat and Radioactive Waste: The by-products of fission can undergo radioactive decay, generating large amounts of heat. Waste products also need special long-term storage due to extremely long half-lives (> 10,000 yrs).
• Sound Damping: When materials go through a nuclear explosion-like fission reaction, strong pressure waves produce infrasonic and ultrasonic energy releases. These pressures distort even extremely heavy and extremely tight objects.
Reproduction of Fission Chain-Reaction
Fission yields free neutrons as additional fission-inducing nucleons. To trigger reproduction of fission reactions within other nucleic (especially nearby) a minimal chain effect must occur:
Chain-Reaction Initiation
The chain reaction initiation consists of
- One free neutron entering a target nucleus; at least 2–neutrons (two).
- If successful, each target yields neutron pairs.
Dangers and Consequences**
Nuclear fission may lead to unintended dangers through improper storage or nuclear safety mishaps.
* High radiation levels from fuel degradation, contamination, and power plants’ release due.
* The fission-based weapons could release substantial neutrons that lead the reactions, making more destruction follow.
**Nuclear fission’s Current Application**
In addition to their immediate potential, these resources must be utilized sustainably alongside alternative sources, taking utmost care for our natural preservation and ensuring an uninterrupted sustainable supply of the precious atom energy.
