Reactor Theory Review-Neutrons

Question 1

What charge do neutrons have?

Answer 1

None.

Question 2

Where is the neutron located in an atom?

Answer 2

In the nucleus.

Question 3

What charge does an Electron have?

Answer 3

Negative

Question 4

What charge does a proton have?

Answer 4

Positive

Question 5

What is the location of the electron in an atom?

Answer 5

Orbiting the nucleus.

Question 6

What is the location of a proton in an atom?

Answer 6

In the nucleus.

Question 7

What is a fast neutron?

Answer 7

A neutron that has a charge greater than 0.1MeV

Question 8

What is a prompt neutron?

Answer 8

A neutron born before 10 to the minus 14sec

Question 9

What is Atomic Mass Number?

Answer 9

The number of protons and neutrons.

Question 10

What is the atomic number?

Answer 10

The number of protons.

Question 11

What is the mass of a proton?

Answer 11

1.00727 amu.

Question 12

What is the mass of a neutron?

Answer 12

1.00866 amu

Question 13

What is the mass of an electron?

Answer 13

0.00055 amu

Question 14

What are the neutron interactions for scattering?

Answer 14

elastic

inelastic.

Question 15

What are the neutron interactions for Absorbtion?

Answer 15

Fission,

Radiative capture.

Question 16

If you have 12 electrons in an stable atom how many protons would you have?

Answer 16

12

Question 17

What determines what element an atom is?

Answer 17

The number of protons.

Question 18

If you have the same number of protons but different number of neutrons then you have a different what?

Answer 18

Isotope

Question 19

What are the types of naturally accruing neutrons?

Answer 19

Photo

Alpha

Question 20

What is the difference between elastic scattering and inelastic scattering?

Answer 20

Elastic scattering the neutron just bounces off the target nucleus.
Inelastic scattering the neutron joins the target nucleus for a short time then a neutron exits the target nucleus.

Question 21

What is the difference between Radiative capture and Fission?

Answer 21

Radiative capture the neutron enters the target nucleus and stays there no fission.
Fission is when a Neutron enters the target nucleus and then the nucleus becomes unstable and breaks into two fission fragments and also gives off extra neutrons.

Question 22

What is a thermal neutron?

Answer 22

A neutron that is at equilibrium with my surroundings.

Question 23

All fission neutrons are slow or fast?

Answer 23

Fast

Question 24

What is the difference between Prompt and Delayed neutrons?

Answer 24

Prompt neutrons are neutrons that are produced before 10 to the negative 14th seconds.
Any neutrons that are produced after are delayed neutrons.

Question 25

Why is water a good moderator?

Answer 25

Cost effective. Abundant. It has similar mass.

Question 26

What are the two types of neutron reactions?

Answer 26

Scatter | Absorbtion

Question 27

When an neutron collides with a target nucleus what 4 things can happen?

Answer 27

Elastic scattering Inelastic scattering Radiative capture Fission

Question 28

What neutrons are fast neutrons prompt or delayed?

Answer 28

Both.

Question 29

What percent of neutrons are prompt and delayed?

Answer 29

99% prompt | 1% delayed

Question 30

What would be the effect of using only prompt neutrons?

Answer 30

Power changes would happen to fast you would not be able to control the reactor. That's why you need delayed neutrons.

Question 31

What is Keff?

Answer 31

The number of neutrons in this generation compared to the number in the last generation.

Question 32

Keff = 1

Answer 32

Stable the number of neutrons this generation is the same a the number of neutrons in the last generation. (Critical)

Question 33

Keff = >1

Answer 33

The number of neutrons in this generation is greater than the number of neutrons in the last generation. (Super critical).

Question 34

Keff = <1

Answer 34

The number of neutrons in this generation is less than the number of neutrons in the last generation. (Sub critical).

Question 35

What are the two factors in the neutron life cycle that are positives?

Answer 35

Fast fission factor. | Reproduction factor.

Question 36

What is Neutron Flux?

Answer 36

The amount of neutrons in a square centimeter per sec

Question 37

What are the two major way that we change reactivity?

Answer 37

Resonance losses - we change RCS temperature. | Thermal neutrons absorbed - we use control rods and boron concentration.