Radioactive Wastes Slide 1 of 10

Go to slide: 1: Radioactive Wastes 2: Classes of Waste 3: Classes of Waste 4: High Level Waste 5: Fuel Assembly 6: Spent Fuel Storage 7: Private Fuel Storage 8: Yucca Mountain 9: Transuranic Wastes 10: Waste Isolation Pilot Plant

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Everything in the world is made up of extremely small particles called "atoms." An atom consists of a very dense nucleus with small particles orbiting around it. This atom is a normal atom of helium. The nucleus consists of two positively charged PROTONS and two neutrally charged particles called NEUTRONS. The mass of a proton is less than one billionth of a gram. To make it more convient to work with, a relative mass scale was developed where an "atomic mass unit" is equal to the mass of a proton. The neutron also weighs 1 amu. The electron weighs 1800 times less than the proton. It carries a minus one charge. Chemical properties are determined primarily by the outer shell electrons. The number of electrons will equal the number of protons in a normal atom. Atoms are identified by the number of protons in the nucleus. This is called the atomic number or "Z" number. This also identifies which element the atom is. The total number of particles in the nucleus also helps to identify the atom. We call this number the atomic mass number or "A" number. Both of these numbers are used together to identify atoms.