Medical Dictionary. brachial plexus. noun. Medical Definition of brachial plexus. : a complex network of nerves that is formed chiefly by the lower four cervical nerves and the first thoracic nerve, lies partly within the axilla, and supplies nerves to the chest, shoulder, and arm.
Nonrenewable Sources of Energy. Most of the energy we use comes from fossil fuels, such as coal, natural gas and petroleum. Uranium is another nonrenewable source, but it is not a fossil fuel.Uranium is converted to a fuel and used in nuclear power plants.Once these natural resources are used up, they are gone forever.nergy is the power we use for transportation, for heat and light in our homes and for the manufacture of all kinds of products. There are two sources of energy: renewable and nonrenewable energy.
Types of Nuclear Fuel. The different nuclear processes will use different types of fuel. In general terms: 1  Fission reactions will use fissile heavy elements.2  Fusion will use fusible light elements.he most often used fuels are Uranium-235 and Plutonium-239; they become instable when bombarded by slow (also known as âthermalâ) neutrons. They are not easy to find or produce materials, and the process to generate them is usually the most expensive part in the creation of a nuclear bomb.