Question: What tributary enters the Clinch near the former site which goes by the codename given it by the Manhattan Project during World War II for the project to produce enriched uranium for atomic bombs using the gaseous diffusion method?
Sentence (from "K-25"): When it was built in 1944, the four-story K-25 gaseous diffusion plant was the world's largest building, with over 1640000 sqft of floor space and a volume of 97500000 cuft .
Relevant evidence: No