Why doesn't uranium ore spontaneously undergo a chain reaction?
A)Uranium ore must be "weapons' grade" in order for it to undergo chain reaction.
B)Uranium ore is mostly non-fissionable isotope U-238 and undergoes a chain reaction only if mixed with a moderator to slow down the neutrons.
C)Uranium ore does spontaneously undergo slow chain reaction over time finally resulting in it becoming lead.
D)Uranium ore,mostly U-235,must be enriched with U-238 in order for it to undergo a chain reaction.

Question

Quizplus · Accepted Answer

Uranium ore is mostly made up of the non-fissionable isotope U-238. In order for a chain reaction to occur, the U-238 must be mixed with a moderator to slow down the neutrons so that they can be readily absorbed by the fissionable isotope U-235. Additionally, other factors such as critical mass and containment must also be in place for a sustained chain reaction to occur.

Why Doesn't Uranium Ore Spontaneously Undergo a Chain Reaction