Final answer:
The approval authority for firing depleted uranium munitions in training usually lies with the military chain of command. Decision to use such munitions is based on factors like training objectives, training ranges, and compliance with regulations.
Step-by-step explanation:
The approval authority for the firing of depleted uranium munitions in training typically lies with the military chain of command. The specific approval process may vary depending on the country and military branch involved. For example, in the United States, the authority to approve the use of depleted uranium munitions in training exercises generally rests with the commanding officer of the unit conducting the training.
However, it's important to note that the use of depleted uranium munitions in training exercises is strictly regulated due to their potential environmental and health risks. The decision to use such munitions is typically based on careful consideration of factors like the intended training objectives, the availability of suitable training ranges, and compliance with relevant environmental and safety regulations.