I think the only option is to open a science museum adjacent to the actual research facilities. It is staffed by actors playing scientists, or perhaps by second-rate scientists used as actors.
##Real Science vs. Hollywood Science
A lot of tourists would be disappointed at what they see. There are a hundreds of failures for every spectacular success. And even a successful experiment might look like a failure because it is only designed to test a specific aspect of new technology. Or there is nothing to see except for tiny wiggles on a chart.
##Unwanted Publicity
There will be foreign spies among the tourists. What will they learn from what they see? Among other things they will learn who your top researchers are and what they do.
Spies could then try to befriend the researchers in the hope of learning details. If the researches are told to be too wary about such things, the public relations effort might backfire.
##Unwanted Distractions
Will the researchers be as productive as they are now when a new tour group gawks through the window every hour? What happens if a tour group passes by and the research team has a break with coffee and donuts. The tourists would be disappointed. So the project management will pressure the researchers to schedule their breaks according to the tour schedule, not at the best time for productivity.
##No Haystack to Hide Needles
Imagine they have some research projects that really have to stay secret. Enemy agents would have to take note which buildings don't offer tours, and keep track who goes in and out.
