Question
In a version of RBMK reactors, these objects counterintuitively added reactivity when they were used for scramming. For 10 points each:
[10m] Name these objects in nuclear reactors whose height is adjusted in a negative feedback loop that can feature graphite displacer and boron carbide neutron absorber portions.
ANSWER: control rods
[10h] Control rods and neutron poisons are used for their high values of the “neutron absorbing” form of this quantity. This quantity for two particles is the area of the region within which they must meet in order to scatter.
ANSWER: cross section [prompt on sigma; reject “cross sectional area”]
[10e] Absorption of neutrons helps to control the rate of the chain reaction of this nuclear reaction that is central to the activity of nuclear reactors.
ANSWER: nuclear fission
<Lalit Maharjan, Science - Physics> ~20711~ <Editor: David Bass>