Irradiation is just using energy to kill bacteria. In no way does it impart radioactivity to the food that's being irradiated, so it certainly poses no risk to consumers. Irradiation has been endorsed by virtually every scientific body that's ever taken the time to evaluate its safety, including the American Medical Association and the World Health Organization. The best analogy is to compare irradiation to how we use heat pasteurization for milk. We systematically treat all of the raw milk that we produce in this country with heat in order to inactivate, or destroy, harmful bacteria that might be present.
Irradiation is simply a pasteurization process.
Like pasteurizing milk, we are using energy to pasteurize meat and poultry. It systematically renders those products safe for consumers. The cost varies depending on the system employed, but at the most, it would cost just pennies per pound. It's not an expensive process. Irradiation does have a lot of uses.