This has been thrown around quite a bit for the last 6-8 years here in East Tennessee. I managed to talk with a raceshop owner that runs GT3 that has been trying to get the motion going for this track. I believe politics has held it back for the most part.
The house owners that decided to build/buy houses near a nuclear facility are complaining that'll polute the area............. K-25 as some of you may know was a big factor in the Manhattan project.
The location makes sense. It's had traffic coming in and out of it for a LONG time. Its basically desolate nowadays. A big industrial area is begging for a motorsports theme, lol. Lots of traffic comes thru Knoxville and is sort of centrally located for the south east.
The track looks stupid fast, a 4000+ft back straight. Your run-off space is the creek! It'd still be fun, different variations of the course will sure to be put into to place, but this is just a "it may look like this" type of deal.
Talk of Road Atlanta not doing so well in the past has lead to making this a Petit Le Mans track.
The current word is that K-25 will either be made into this motorsports park or a historical park. I hope that the track will happen, we need more tracks on the east coast!