I don't know that the good people over at Infowars actually got this story correct. My father has been a professor in the ASE department at UT for his entire career. His building and department predates the building of the LBJ library by 20+ years and is located a solid block and a half away. I don't think you can build a nuclear reactor without someone that close noticing it, especially if you are trying to built under the library of the biggest ASE supporting president (arguably) in US history with a department full of the guys that helped put a man on the moon within a good stones throw. I think maybe the guys at Infowars need to do a little fact checking.
No, to answer your question, I don't expect this is likely to create a downward pressure on Austin real estate values. At least I am not planning to sell any of my property in Austin just yet.