Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NUEN 302 > EXAM 3 > Flashcards

EXAM 3 Flashcards

1
Q

Charged particles

A

directly ionizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Neutral particles

A

indirectly ionizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

true for transmutation

A

can occur through nuclear reactions (in which an outside particle reacts with a nucleus)

can occur through radioactive decay (where no outside particle is needed).

atoms of one element can be changed into atoms of another element

the conversion of one chemical element or isotope into another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Beta particles being light, charged particles lose energy by

A

electron excitation

emitting photons as they are deflected around nuclei.
ionization.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Gamma rays may interact with matter through

A

pair production
photoelectric absorption
Compton scattering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pair production requires that the gamma ray have at least 0.511 MeV energy.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A gamma ray gains energy when it undergoes Compton scattering.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Photoelectrons have the same kinetic energy as that of the gamma ray that produced them.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The higher the value of the linear attenuation coefficient, the smaller the average depth of penetration of gamma rays.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do ionization chambers detect radiation?

A

Radiation ionizes atoms of a gas. The ions and electrons are collected at electrodes held at a high potential, and the resulting current is measured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name neutron classification by energy. (Several answers possible, check all that a re related to the question)

A

intermediate
fast
slow (thermal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

check all that’s applied for prompt neutrons

A

constitute over 99% of fission neutrons

emitted at the time of fission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the spent fuel?

A

Fuel assemblies that are discharged from reactors during refueling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is fuel burnup? What are the units of fuel burnup?

A

The energy produced per unit mass of the fuel.

MWdt/Tonne U

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Reactivity can be positive, zero or negative

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the other use of the water in LWR except for coolant and moderator?

A

Reflector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Name all components of the 6-factor formula. Write the meaning of each of them.

A

PFNL is the fast non-leakage probability
PTNL is the thermal non-leakage probability
E is the fast-fission factor
p is the resonance escape probability (the probability for a neutron to escape resonance capture)
f is the thermal utilization factor
n is the number of fission neutrons produced per neutron absorbed in the fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

k- effective =1

A

the reactor is Critical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

k- effective>1

A

the reactor is Supercritical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

k- effective <1

A

reactor is Subcritical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Check all that apply to delayed neutrons

A

constitute only less than 1% of all fission neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

takes into account geometry of the reactor core

A

k- effective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

characterizes the multiplication properties of material in the reactor

A

k- infinite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why the Doppler feedback is strongly negative in the thermal reactor systems?

A

because their effective fissile content (U-235) is low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Compare k-infinite and k-effective

A

k-infinite > k-effective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

a positive temperature - power reactivity feedback cycle would reduce the reactivity and tend to stabilize the system

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Increased reactivity leads to a greater rate of power increase.
Increased power raises core temperatures.
Higher temperatures increase reactivity.
Is this example of a positive temperature - power reactivity feedback or negative?

A

a positive temperature - power reactivity feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Why Soluble poison can be added and dissolved in the coolant in the form of boric acid Only into the coolant of PWR, but not in BWR? Check all that is true

A

Plating can affect heat transfer as well as reactivity
Boiling can result in boron plating out on the fuel rods.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Doppler effect is positive for

A

fissile fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Doppler effect is negative for

A

fertile fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Why do we have burnable and soluble poisons? Check all that are true

A

To lower the initial reactivity
They gradually burn out as the U burns out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Name the PWR auxiliary system that is used for adding soluble boron the reactor coolant system in the form of boric acid.

A

Chemical Volume Control System (CVCS). Or Chemical Shim

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Positive reactivity feedback

A

enhances the condition that produced it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Negative reactivity feedback

A

decreases the condition that produced it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

DEFINE a Burnable poison

A

Burnable poison is used to lower the initial reactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the Non-burnable poison

A

Material that maintains a constant negative reactivity worth over the life of the core

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

DEFINE the Chemical shim

A

Adding the Burnable soluble poison in the coolant by an auxiliary system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Fixed burnable poisons have advantages over chemical shim because
-Fixed burnable poisons do not make the moderator temperature reactivity coefficient less negative as chemical shim does.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Do we use fixed non-burnable poisons in the reactor core?

A

Yes, to prevent excessive flux and power peaking near moderator regions of the reactor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is fission product poisoning?

A

Accumulation of fission products with significant absorption cross-section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

DESCRIBE how equilibrium samarium-149 concentration varies with a reactor power level

A

Equilibrium concentration of Sm-149 is independent of neutron flux and power level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

The equilibrium concentration and the poisoning effect build to an equilibrium value during reactor operation for Sm is reached in approximately at what time?

A

20 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

DESCRIBE how samarium-149 concentration changes following a reactor startup

A

Samarium-149 does not peak as Xenon-135 does, but increases slowly to a maximum value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Helium- 3 does not have a significant effect on the reactivity of a reactor

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

How samarium-149 is produced during reactor operation?

A

Sm-149 is in the decay chain of the fission product neodymium 149

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

DESCRIBE how xenon-135 concentration changes following a reactor shutdown from steady-state conditions.

A

The Xe concentration peaks at about 10-11.6 h and then decreases for the next 30-40h

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

DESCRIBE how equilibrium xenon-135 concentration varies with reactor power level.

A

The equilibrium value for Xe135 increases as power increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

The higher the power of the R before the shutdown, the higher concentration of Xe

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q
A
50
Q

STATE the approximate time following a reactor shutdown at which the reactor can be considered “xenon free.”

A

40 h

51
Q

LIST two methods of production for xenon-135 during reactor operation

A

-It is produced directly by some fission
-It is produced by tellurium-135 decay chain

52
Q

Chose what is true for production of Xe

A

Tellurium-135 decay chain can be ignored in production of Xe

53
Q

DESCRIBE how xenon-135 concentration changes following a reactor shutdown from steady-state conditions.

A

The Xe concentration peaks at about 10-11.6 h and then decreases for the next 30-40h

54
Q

What information does the fission product yield curve provide?

A

-The probability of production of a fission product with a given mass number.
-That the most likely fission products are those with mass numbers between89 and 101 and between 133 and 144 for thermal fission of 235U
-That symmetric fission is less likely than asymmetric fission

(ALL OF THE ABOVE)

55
Q

The amount of energy released during fission is equivalent to the

A

difference between the binding energy of the compound nucleus and the sum of the binding energies of the fission product nuclei.

56
Q

Why is 235U a good reactor fuel?

A

It can fission with thermal neutrons

57
Q

Fission products are a major concern in nuclear power technology because

A

ALL OF THE ABOVE

58
Q

Fission products undergo β− decays usually followed by the release of gamma rays

A

Delayed Stage

59
Q

Fission fragments are formed

A

Prompt Stage

60
Q

Most of the energy of fission is released

A

Prompt Stage

61
Q

Lasts a fraction of a second

A

Prompt Stage

62
Q

May last thousands of years

A

Delayed Stage

63
Q

Neutrons are always released in every fission event.

A

Prompt Stage

64
Q

Gamma rays can be released.

A

Both prompt and delayed stages

65
Q

If a 236U compound nucleus fissions emitting two neutrons, which of the following examples are the most probable masses of the two fragments?

A

94 and 130

66
Q

Which of the following statements about fission is true?

A

More neutrons are released during the delayed stage than the prompt stage

67
Q

Which of the following contribute(s) to cause fission?

A

ALL

-Coulombic repulsion
-Overcoming the nuclear force
-Kinetic energy of incident neutron
-Binding energy of incident neutron

68
Q

If a = 14 % of the fissions in a reactor occur in 239Pu and the rest in 235U, what is the overall value of the delayed neutron fraction, β?
β235 = 0.0065
β239 = 0.0021

A

0.00588

69
Q

If a = 7 % of the fissions in a reactor occur in 239Pu and the rest in 235U, what is the overall value of the delayed neutron fraction, β?
β235 = 0.0065
β239 = 0.0021

A

0.0062

70
Q

The average prompt neutron yield for thermal fission of 235U is very nearly equal to

A

2.42

71
Q

Delayed neutrons are delayed because

A

they are emitted by the excited daughter products of certain fission products following b- (-) decay

72
Q

Which of the following isotopes does NOT fission with thermal neutrons?

A

U238

73
Q

Which of the following isotopes is (are) fissile?

A

-U 233
-Pu 241

74
Q

What is the minimum threshold energy required for an isotope to fission?

A

Critical energy

75
Q

Why are delayed neutrons important in reactor operation?

A

They make it possible to control power increases in a reactor

76
Q

Conversion of 238U to 241Pu is an example of

A

a breeding reaction.

77
Q

Fission products most often decay by

A

Beta (-) decay followed by gamma ray emission

78
Q

Weight fraction changes in the fuel are so small (only a few percent) that they have no consequence on the operation or safety of the reactor

A

False

79
Q

Decay heat is generated by the radioactive decay of fission products

A

True

80
Q

Decay heat is generated only after a reactor is shut down and not while it is operating

A

False

81
Q

More prompt neutrons result from thermal fission of 239Pu than from thermal fission of 235U

A

True

82
Q

Nuclear reactor shielding problems are concerned mainly with

A

Gamma-rays, neutrons

83
Q

studies have shown that alpha and neutron radiation cause greater biological damage for a given energy deposition per kg of tissues than gamma radiation does

A

True

84
Q

Alpha particles have

A

HIGH-LET

85
Q

protons have

A

HIGH-LET

86
Q

neutrons have

A

HIGH-LET

87
Q

gamma rays have

A

LOW-LET

88
Q

give 3 parameters that buildup factors depend on

A
  • radiation type
  • particle energy
  • medium
  • distanced traveled
  • response type
89
Q

Radiation counters

A

the rate of generation of radiation-induced pulses can be used to measure the rate at which radiation particles traverse to

90
Q

energy spectrometers

A

by measuring both the number of pulses and the distribution of pulse

91
Q

dosimeters

A

the average current can be used as a measure of the amount of ionization or energy deposition

92
Q

photons of what energies are important in radiation shielding design and analysis?

A

10eV- 20MeV

93
Q

List at least 5 gamma rays sources

A

radioactive decay, neutron capture reactions, inelastic neutron scattering reactions, fission, fusion, spallation, annihilation

94
Q

Prompt fission neutrons

A

Neutrons which are omitted within milliseconds of the fission event

95
Q

Photoneutrons

A

neutrons which results from the absorption of a gamma ray reaction

96
Q

delayed fission neutrons

A

neutrons which are released during the decay of certain fission product

97
Q

From what shell the electron- ejection during fluorescent radiation will produce enough energy to produce X-ray that we concern with

A

K-shell

98
Q

Prompt fission gammas

A

emitted during the fission process

99
Q

fission product gammas

A

emitted by the decay of fission product

100
Q

capture gammas

A

emitted immediately after the capture of a neutron reaction

101
Q

activation gammas

A

emitted during the radioactive decay of an isotope form from a neutron capture

102
Q

Inelastic gammas

A

emitted by nuclei which has been excited by inelastic collision with fast neutrons

103
Q

For want incident particles and what material bremsstrahlung is important?

A

High Z material, small mass incident particles

104
Q

what is the inelastic scattering threshold?

A

The minimum energy that an incident particle must have to induce an inelastic scattering reaction

105
Q

roentgen

A

the amount of x or gamma radiation which produces carrying one electrostatic unit (esu) of 1 change in cubic centimeter

106
Q

REM

A

A biological dose unit take in account the relative biological effect of the various type of radiation

107
Q

The RBE

A

The biological damage from one rad of Y compared with the biological damage from one rad of gamma

108
Q

By what bonding the biological tissue is characterized?

A

Covalent bond

109
Q

a dose of radiation

A

The total quantity of radiation received

110
Q

the dose rate

A

The quantity of radiation being received per unit time

111
Q

equivalent dose

A

a dose quantity calculated for individual organs

112
Q

The radiation weighting factor

A

A dimensionless factor used to determine the equivalent dose from the absorbed dose average over a tissue or an organ

113
Q

KERMA

A

Kinetic Engergy of Radiation produced per unite MAss in matter

114
Q

Radiation doses received at high dose rate are less significance than the same doses received at a low high dose rate (T/F)

A

False

115
Q

Atomic Radiation

A

The emission of particle or X-ray from an atomic source

115
Q

medical radiation protection

A

The protection of patients

115
Q

occupational radiation protection

A

The protection of worker

115
Q

In radiation protection, there are three ways how to protect people from identified external radiation sources. Name them.

A

Limiting time, Distance, Shielding

116
Q

public radiation protection

A

The protection of individual

116
Q

Contamination

A

Bits of radioactive material in the air or water or in any surface

NUEN 302 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions