Assertion: neptunium's mass | /r/CapableOf | range in high fifties
Facets:
value: from kilogram weights
type: OTHER
value: to low sixties
type: OTHER
Source sentences:
text: In September 2002, researchers at the Los Alamos National Laboratory briefly created the first known nuclear critical mass using neptunium in combination with shells of enriched uranium (uranium-235), discovering that the critical mass of a bare sphere of neptunium-237 "ranges from kilogram weights in the high fifties to low sixties," showing that it "is about as good a bomb material as [uranium-235]." The United States Federal government made plans in March 2004 to move America's supply of separated neptunium to a nuclear-waste disposal site in Nevada.