Assertion: plutonium | /r/HasAspect | half-life of 24,100 years
Facets:
value: after 20 half-lives
type: TEMPORAL
Source sentences:
text: Plutonium, specifically PU-239, has a half-life of 24,100 years and”only after 20 half-lives (482,000 years) can be said to be harmless to the environment”, according to the group of scientific and technical ecologists for a non-nuclear future.