Useful Notes: Nuclear Energy YKTTW Discussion
|Useful Notes: Nuclear Energy|
This (very first draft) article covers nuclear reactions, basic reactor design, and types of radiation. The Four fundamental forces of nature: Gravity - The weakest of the four forces. Because it has unlimited range, can not be blocked, and effects all matter is the most noticeable on large scales. Force carrying particle - Graviton (has not been confirmed) Electromagnetism - affects anything that has a charge. Strength drops by the cube of the distance from the source. Plays a big role in nuclear fission and fusion. Force Carrying Particle- Photon (light) Weak Nuclear Force - Allows the transmutation of one particle in to another. Force Carrying Particle - Bosons Strong Nuclear Force - All baryonic matter is affected by the Strong Nuclear Force. It only effects neutrons and protons that are right next to each other. For atoms smaller than uranium the binding energy of the strong nuclear force over comes the repulsion of the positively charged protons. Structure of an atom: Nucleus: Composed of Neutrons and Protons. Electron Shell: For every proton in the nucleus, there is a corresponding electron orbiting the nucleus. Elementary particles: Neutron - Large neutrally charged particle. Resides in the nucleus. Proton - Large positively charged particle. Resides in the nucleus. Electron - Really small negatively charged particle. Resides in the electron shell. There are four types of nuclear reactions: Fission: A heavy nucleus absorbs a neutron, cause it to split into two or more daughter nuclei (generally releasing energy). Fusion: Two light nuclei collide and form a heavier nucleus (generally releasing energy). Spallation: A nucleus is hit by a sufficiently energetic particle to cause it to release additional particles and/or fragments. Induced gamma emission: Isotopes in a stable excited state lose that state when exposed to high energy photons, releasing even more energetic photons. Basic Reactor Design All power plants in the United States, and most of the world use the same basic principle. The reactor vessel house fuel, a moderator, and coolant. The moderator increases the chance that neutrons emitted by the fuel collide with the atoms of the coolant generating heat. The coolant moves that heat to a steam turbine that powers an electrical generator. Any excess heat is removed from the coolant via a heat exchanger in to the environment. Types of Radiation Alpha Radiation: Ionized helium atoms released from heavy isotopes. It is the easiest type of radiation to shield against (your skin is sufficient to stall all of it), but is biologically the most damaging. Beta Radiation: electrons released from the decay of unstable isotopes. Second easiest type to shield against (aluminum foil does the trick). Gamma Radiation: Gamma rays are released by either excited nuclei moving down to more stable energy states, or the decay of heavy isotopes. Second hardest to shield against (about a foot of lead to cut exposure by half). Neutron Radiation: Neutron Radiation is the release of neutrons from the fissioning of heavy isotopes. The hardest to shield against (several feet of concrete or water are needed to reduce exposure by half).