The location[]
A unidentified top-secret nuclear fuel plant in Tennessee.
1979 accident[]
A unquantified amount of highly enriched uranium spewed out of a top-secret nuclear fuel plant in Tennessee. This lead to 1,000 people getting up to 500% as much radiation as they would normally have had in a year.
It dose not officially have a INES ratting, but probably was a Level 5 INES Scale event.
Also see[]
Link[]
http://www.cbsnews.com/htdocs/nuclear_disasters/framesource_timeline.html