Nuclear reactions as a source of energy
3 marks · EasyThe diagram shows a simple nuclear reactor setup:
Name one part used to slow down neutrons and one part used to absorb neutrons in a real reactor.
State the purpose of shielding.
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(a) Moderator (slows down neutrons), control rods (absorb neutrons)
(b) To protect people (and surroundings) from radiation.
Must show: marks for correct name of moderator and control rod, and purpose of shielding
Common mistakes: Saying control rods slow neutrons instead of absorb.
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Names the moderator (or gives a valid example) that slows down neutrons.
B2 (a) · 1 mark · Names control rod (or a valid substance, e.g. boron) that absorbs neutrons.
B1 (b) · 1 mark · Correctly states the purpose of shielding (protects people from radiation).
Worked solution
a) The moderator (e.g. graphite) slows down neutrons; control rods (e.g. boron) absorb neutrons. b) Shielding protects people and surroundings from radiation.