Nuclear fission Flashcards Preview

GCSE Physics: Topic 7 > Nuclear fission > Flashcards

Flashcards in Nuclear fission Deck (10):
1

What is nuclear fission?

Splitting of an atomic nucleus into two smaller nuclei

2

What does fission process results in the emission of?

  • Two or three high-speed neutrons
  • energy - in forms of gamma radiation and kinetic energy of the nuclei and neutrons

3

Naturally occuring uranium is mostly?

Uranium-238 which which is non-fissionable

4

What do most nuclear reactors use?

'Enriched' uranium that contains 2-3%

 uranium -235 which is fissionable

some reactors use plutonium-239

5

What is induced fission?

Occurs when a neutron absorbed by uranium-235 nucleus or plutonium-239 nucleus and nucleus splits 

6

What is spontaneous fission?

Occurs without a neutron being absorbed

7

When does a chain reaction occur?

When neutrons released from each fission event

causes further fission events to occur 

8

What is the result of nuclear reactor being controlled?

One fission neutron per fission, on average, goes on to produce further fission

9

What is function of control rods in nuclear reactor core?

Absorbs surplus neutrons

the depth of rods in the core is adjusted to maintain a steady chain reactions

10

How is moderator used in nuclear reactor?

Fast neutrons don't cause further fission so in reactor core

moderator used to slow high-speed neutrons