Radioactive scrap metal is any metal that has become contaminated with radioactive materials. Radioactive materials are very small particles that can give off dangerous radiation that can harm people and the environment. When these materials come into contact with metal, they can stick to the surface of the metal and stay there. This means that the metal itself becomes radioactive and can harm people and the environment if it's not handled properly.
Imagine you are playing with some toys and you accidentally spill some wet paint on them. Just like how paint sticks to toys, radioactive particles can stick to metal. These particles can hang around for a very long time and continue to give off dangerous radiation. The more radioactive particles a piece of metal has on it, the more dangerous it becomes.
Even though the metal may appear to be clean and shiny, it can still be dangerous if it's radioactive. That's why it's important that people who handle scrap metal take special precautions to make sure they don't get sick or hurt. They need to wear special protective clothing, use special equipment to handle the metal, and store it in special containers to keep it away from other people and the environment.
In summary, radioactive scrap metal is metal that has been contaminated with tiny, dangerous radioactive particles, and needs to be handled carefully to protect people and the environment.