Suppose Alice wins the Nobel Prize and $1 million. Does the prize money go entirely to personal matters, or is she likely to use some (most/all?) of it for academic pursuits? If the latter, how does she go about it? Does she just "award herself" a grant similar to grants that academics apply for?

I'm particularly curious about the Fields Medal since it has a stated purpose to encourage awardees for further achievement, which can be interpreted as saying that awardees should use the prize money for academic purposes.