So if the Xeon was discharged with only 9.2 days half life (is that correct?), how far can it travel distance wise?
I think the reference here is to Xenon-135. It is a decay product of the U-235 decay chain which produces Tellurium-135 and then Iodine-135 and then Xenon-135. Xenon-135 produces a daughter Beta isotope of Cesium-135.
The half life is ~ = 0.693/ Decay Constant Lambda is ~ = 0.693/0.0753/hour, or a half-life of approx. 9.2 hours. Some sources quote a half-life of from 9.14 hours to 9.2 hours.
For a 60 mph wind, an original isotope of Xenon-135 would travel about 552 miles to its Half-Life point, or about 2500 miles before it was almost non-detectable.
The distance from Taishan to San Francisco is approx. 6,066 miles.