Topic: Letter of The Law / Second Chance Act

I am writing to inquire about prolonged isolation for inmates. My son is incarcerated at the Hughes Unit in Gatesville. He is in a high security area based on his line class. He has stated many times that he does not get out of his cell for weeks at a time with no outside time at all. Is this normal? I worry about long term affects in isolation. I need to learn what the procedures are for this type of punishment.