OK, sorry to cause a problem:
1) I was not in uniform because I am not in the military. My point was that access to Nimitz does not appear to be limited to military. When I walk into Nimitz it is obvious I am a civilian.
2) Re records: I have a particular interest in CDR. Ernest Evans. Died at the Battle of Samar in 1944; awarded the medal of honor. He looks to have lived an amazing life, but I haven't been able to find much information on him. I asked at the front desk if the USNA maintained any records on Grads like Cmdr. Evans. I was directed to the Third floor Archive where I filled out a request from to see Cmdr. Evan's file. After a short wait I was handed a fairly narrow sleeve with what I assume was public information that the USNA had archived on the man. Mostly things I already knew, but a few things I didn't, (like his son's USNA attendance and service in the USMC, and descriptions of the man in USNA yearbooks). I looked thru the file in archive reading room and was required to return it when I left. The second USNA Grad of interest was George Dewey, a family relation. Files/information you'd expect to find and access in a library archive.
My point was/is that In my experience, the Nimitz library appears to be generally open and friendly to civilian visitors. I was able to access the archive on the 3rd floor(?), I was not asked for military Id (might have been asked for my Dr Lic), or required to make any showing of authority to view these records, beyond stating my interest, and filling out a doc request form, (people seemed happy that I was interested).
I didn't know that admission/application records are stored in Nimitz..... But then how/why would I know that? The USNA doesn't hang a sign up to advertise the presence of admissions records at Nimitz: makes sense to me. It seems equally reasonable that any records containing private/confidential records on Mids are stored in secure areas of the library, whose specific locations within the building are not disclosed to the average visitor. Again, the question was "can civilian access Nimitz?" My experience has been that civilians are welcomed (pretty warmly) and allowed access to areas commonly associated with a library.