Unescorted Access Denial because of previous unallowed Control Room visits?!

[nuclearjunky]

Hello, I am new to the forum. I, female, 25 years old, am studying mechanical engineering and technology management.
Since my high school, I am fascinated by nuclear power. This led me to visit a nuclear power plant close to my home town in 2007. As I had a private contact to a manager, a technician allowed me to visit the turbine hall and the reactor area after filling out a form. This was a tour that was also offered to media at that time. Later, in 2010, I asked for a control room visit to get a clue about the operator jobs that exist there. Sure, they had a simulator on site, but I wanted "the real thing". As they told me at the site, the control room was not to be allowed to be visited by public, because it was "too dangerous". At this plant, staff had the instruction that only own staff with unescorted access authorization were allowed to the control room and only if they had a work task there. This was also told by the plants general manager who told that he expects all employees to stick to that rule. Shortly thereafter, I had a talk with the plants chief security officer, who asked me to provide some enrollment and address data. He then made some inquiries about my person -not an official background check for UA (unescorted access) permit. Then he invited my to the plant and asked me onsite why I am interested in the control room. After that, he surprisingly guided me (as a single private visitor from public) around in the control room and I was allowed to ask questions about operator's positions. They also allowed me to go directly up to the reactor controls etc.
After that, I decided to add a university course, nuclear engineering, to my other course from mid-2011 on. For this course, I needed a field-related internship of 8 weeks that needed to be completed before the university course was supposed to start. I applyed at this plant's operating company and got a contract for an internship position in which I was supposed to work at this plant (in the production department) and another plant (in the workshop) of the same operating company.
In spring 2011, I had interviews with the engineers who I was supposed to work for. For the interview in the first plant, I again as authorized to the control room as I was supposed to work for the shift supervisor. The shift supervisor was nice and offered me to simply pass by if I had other questions. Still, I did not have UA permit for that plant- but for another I now had. Then, 5 days before my internship was supposed to start, the chief security officer- who prevously guided me to the control room- denied access to the plant for me; they denied to tell me any reason for it. The only thing I found out was, that the HR employee told me: "There are safety concerns with you". This would not be the case with other interns. Consequently, I could not do an internship in this or the other plant of the operating company. Thus, I could not begin the study course. When I asked public authority later on, they told me that my background check is completly OK (what has also been confirmed by the plant when the public authority clerk talked to its staff) and that the plant who denied my access does not need to tell the reason for my denied access.

Is it possible that you could get UA access denial if an employee had violated a plant's rule to give you access to a certain area before? If yes, for how long you would be denied unescorted access to that facility? As I plan to work for a supplier in the nuclear field: Do I need to indicate this access denial in the form if I am supposed to get UA access to other nuclear plants?
As I mentioned: My background check is completly OK and I got to get UA access permit at a research reactor in 2012 without problems.

[Content1]

Short of you bursting into the control room unannounced and unapproved, it sounds like all your actions were reasonable as a student trying to learn your eventual career position. Now somebody goofed up and gave you access and then they got in trouble and possibly lied about your access, you may have no choice but to take action against utility denying you access and the provide the reasons for doing so. One of the grounds for slander is false statements involving your career. This is a serious matter involving your career because one of the first questions they ask and security checks is if you've ever been denied access to a nuclear facility. Borrow money if you have to from family or friends to hire an attorney to handle your case. Since a career you have invested time and money and will go to waste, you must have the "take no prisoners" attitude against those who have harmed you.

[UncaBuffalo]

UA questions are tricky. I'd wait until Graphic, the SME, replies before you act on any answers you get in this thread.

Good luck! 

[nuclearjunky]

@Content1

The authority told me my background check is fine. Besides this, I now remember that I got a letter from the plant's operating company in which was written something like  "our safety concerns do not base on your background check".

[Content1]

Then you have a right to know what they base their safety concerns on.  Some disgruntled enemy who is making trouble for you without a basis?  Someone doesn't like your political views?  It could be for a false or forbidden reasons and if  your livilihood is dependent on access, your fight is still there.