Refusing to take a urine test in an Arizona state prison is treated as disobeying a direct order, which makes it a major violation. The classification is intentional. Without the ability to enforce orders, staff lose control of the facility, so the punishment is designed to be severe enough to discourage anyone else from trying the same thing.
The first consequence is placement in Disciplinary Segregation, which goes by several names: the SHU, the Special Housing Unit, solitary confinement, or just the hole. In segregation, he will be in his cell 24 hours a day, with two exceptions. He gets one hour for a shower three times a week, and two hours of recreation per week. That recreation is not what most people picture. It is a cage-like enclosure on asphalt, sometimes with dip bars, nothing else. Fresh air and a few pull-downs, that's it.
How long he stays there depends on the write-up. It could be days, weeks, or months. The officer writing the incident report has significant influence over the outcome, and if there were any aggravating factors surrounding the refusal, the punishment can stack. He could lose visitation, phone access, and commissary privileges on top of the isolation.
In the worst case, after serving six to twelve months in segregation, he could be transferred to a higher-custody facility for the remainder of his sentence. That is not guaranteed, but it is on the table when the violation is serious enough.
The short version: UA refusal is not a minor inconvenience in Arizona. It is treated as a challenge to the entire order of the facility, and the system responds accordingly.