If that number is correct, the half life works out to 7.5 seconds. Even
if the moon were 10,000 years old, there would be no U-236.
In trying to backout a source for U-236, I found myself wandering around
progressively larger transuranic elements of progressively short half
lives. There seems to be no good explanation for U-236 appearing at all.
One might question to source of this information.