My brother and his wife are getting divorced and she is refusing visitation. Her reasoning are for things like she hasn't seen his new apartment and she is claiming he has an alcohol problem. He has no record of any alcohol offenses or any other offenses. He did have one DUI 11 years ago before they were together or had any kids. These are frivolous claims she is using to keep the kids away. He still pays for half of the mortgage and half of all the bills plus what the kids need. He just wants to be able to see the kids. He is not looking for full custody. There is no divorce judgement set yet, as this is a recent breakup. What are his rights to see the kids immediately.

He has no rights unless she gives them to him. Yes, as the father he has the same rights the mother has but the mother appears to have custody and control over the children so she's calling the shots.

Paying half of the mortgage, half of the bills and "what the kids need" doesn't qualify as spousal support OR child support so he should get to an Attorney and get support/spousal maintenance/VISITATION OR CUSTODY order by the Court.

It appears that he moved out? That could be a problem concerning abandonment of the marriage.

When they go to Court the Court will review the situation and could order an evaluation of both parties in order to determine what is in the best interest of the children.

He should not waste time.

He needs to file for custody or visits in court, he of course has equal rights with the wife to custody of the children, assuming he is on the birth certificate. And of course if he moved out, he could have taken the kids also.

But at this point she has the kids, and there is nothing he can do without going to court to see them.
He does need to document each time he tries, and she refuses to use against her in court.