Irradiation is used as a type of pasteurization to kill bacteria that can contaminate meat.
This is especially a problem in ground meat, where a large surface area provides all the nutrients for germs to proliferate. The USDA will require irradiated meat and meat products to carry the international symbol for irradiation on labeling plus a statement that the product was treated with irradiation. For unpackaged meat products that do not have labels, the statement and symbol must be displayed at the point of sale. Irradiated meat does not become radioactive. Neither do you when you get an x-ray.