science

[niyati790]

which of the following rods are used to control the chain reactions in atomic reactors?aluminium ,cadmium,carbon ,steel

[BenDToy]

Carbon

[paulgallwey]

Control rods are normally made from cadmium, which absorbs neutrons. When the control rods are fully inserted into the reactor, the nuclear reaction will stop. Carbon, in the form of graphite, is used as a moderater. The moderator slows down fast neutrons, released by the splitting of uranium or plutonium atoms, so allowing the nuclear reaction to continue. Heavy water (D20) can also be used as a moderator.

[lucifer6642]

I did a project at school on fission reactors and got a lot of information from Scottish Nuclear and BNFL. Some reactors in the UK use carbon rods, others boron. Or at least in the 90's they did :) Also, here's a link on control rod materials http://www.tpub.com/content/doe/h1017v2/css/h1017v2_75.htm