original_query: What was the enrichment level of uranium-235 at the Y-12 facility on 6 December 1946?
query: What was the enrichment level of uranium-235 at the Y-12 facility on December 6, 1946?
answer: On December 6, 1946, the Y-12 facility's enrichment activity was curtailed because the K-25 plant was producing a satisfactory product of 93.7 percent uranium-235.