Question 1

In the normal operation of a nuclear reactor:

Accepted Answer

A) control rods are adjusted so the reactor is subcritical 
B) control rods are adjusted so the reactor is critical 
C) the moderating fluid is drained 
D) the moderating fluid is continually recycled 
E) none of the above 
A) control rods are adjusted so the reactor is subcritical 
B) control rods are adjusted so the reactor is critical 
C) the moderating fluid is drained 
D) the moderating fluid is continually recycled 
E) none of the above B

Question 2

Which one of the following is NOT needed in a nuclear fission reactor?

Accepted Answer

A) Moderator 
B) Fuel 
C) Coolant 
D) Control device 
E) Accelerator 
A) Moderator 
B) Fuel 
C) Coolant 
D) Control device 
E) Accelerator E

Question 3

Most magnetic confinement projects attempt:

Accepted Answer

A) proton-proton fusion 
B) proton-deuteron fusion 
C) deuteron-deuteron fusion 
D) deuteron-triton fusion 
E) triton-triton fusion 
A) proton-proton fusion 
B) proton-deuteron fusion 
C) deuteron-deuteron fusion 
D) deuteron-triton fusion 
E) triton-triton fusion C

Question 4

The Sun has enough hydrogen in its core to continue fusing hydrogen to helium for about another:

Accepted Answer

A) million years 
B) five million years 
C) five billion years 
D) five trillion years 
E) The Sun can continue to fuse hydrogen to helium indefinitely. 
A) million years 
B) five million years 
C) five billion years 
D) five trillion years 
E) The Sun can continue to fuse hydrogen to helium indefinitely.

Question 5

The table lists properties of several heavy nuclei when they are struck by thermal neutrons; En is the excitation energy and Eb is the energy barrier.Which quantity, or combination of quantities, represents the energy put into the oscillation of the resulting compound nucleus?

Accepted Answer

A) En 
B) Eb 
C) En - Eb 
D) Eb - En 
E) Mass of the target nuclide + Eb 
A) En 
B) Eb 
C) En - Eb 
D) Eb - En 
E) Mass of the target nuclide + Eb

Question 6

235U is readily made fissionable by a thermal neutron but 238U is not because:

Accepted Answer

A) the neutron has a smaller binding energy in 236U 
B) the neutron has a smaller excitation energy in 236U 
C) the potential barrier for the fragments is less in 239U 
D) the neutron binding energy is greater than the barrier height for 236U and less than the barrier height for 239U 
E) the neutron binding energy is less than the barrier height for 236U and greater than the barrier height for 239U 
A) the neutron has a smaller binding energy in 236U 
B) the neutron has a smaller excitation energy in 236U 
C) the potential barrier for the fragments is less in 239U 
D) the neutron binding energy is greater than the barrier height for 236U and less than the barrier height for 239U 
E) the neutron binding energy is less than the barrier height for 236U and greater than the barrier height for 239U

Question 7

If the nucleus of a lead atom were broken into two identical nuclei, the total mass of the result would be:

Accepted Answer

A) the same as before 
B) greater than before 
C) less than before 
D) converted into radiation 
E) converted into kinetic energy 
A) the same as before 
B) greater than before 
C) less than before 
D) converted into radiation 
E) converted into kinetic energy

Question 8

Which one of the following represents a fusion reaction that would yield large amounts of energy?

Accepted Answer

A) "238U92 + 1n0 $\rightarrow$90Kr36 + 146Cs55 + 2H1 + 1n0" 
B) "239Pu92 + 1n0 $\rightarrow$96Sr38 + 141Ba56 + 31n0" 
C) "238U92$\rightarrow$ 234Th90 + 4He2" 
D) "3H1 + 2H1 $\rightarrow$4He2 + 1n0" 
E) "107Ag47 + 1n0$\rightarrow$108Ag47 $\rightarrow$108Cd48 + 0e-1" 
A) "238U92 + 1n0 $\rightarrow$90Kr36 + 146Cs55 + 2H1 + 1n0" 
B) "239Pu92 + 1n0 $\rightarrow$96Sr38 + 141Ba56 + 31n0" 
C) "238U92$\rightarrow$ 234Th90 + 4He2" 
D) "3H1 + 2H1 $\rightarrow$4He2 + 1n0" 
E) "107Ag47 + 1n0$\rightarrow$108Ag47 $\rightarrow$108Cd48 + 0e-1"

Question 9

Tokamaks confine deuteron plasmas using:

Accepted Answer

A) thick steel walls 
B) magnetic fields 
C) laser beams 
D) vacuum tubes 
E) electric fields 
A) thick steel walls 
B) magnetic fields 
C) laser beams 
D) vacuum tubes 
E) electric fields

Question 10

When uranium undergoes fission as a result of neutron bombardment, the energy released is due to:

Accepted Answer

A) oxidation of the uranium 
B) kinetic energy of the bombarding neutrons 
C) radioactivity of the uranium nucleus 
D) radioactivity of the fission products 
E) a reduction in binding energy 
A) oxidation of the uranium 
B) kinetic energy of the bombarding neutrons 
C) radioactivity of the uranium nucleus 
D) radioactivity of the fission products 
E) a reduction in binding energy

Question 11

The purpose of a moderator in a nuclear reactor is to:

Accepted Answer

A) provide neutrons for the fission process 
B) slow down fast neutrons to increase the probability of capture by uranium 
C) absorb dangerous gamma radiation 
D) shield the reactor operator from dangerous radiation 
E) none of the above 
A) provide neutrons for the fission process 
B) slow down fast neutrons to increase the probability of capture by uranium 
C) absorb dangerous gamma radiation 
D) shield the reactor operator from dangerous radiation 
E) none of the above

Question 12

The binding energy per nucleon:

Accepted Answer

A) increases from all fusion events 
B) increases for some, but not all, fusion events 
C) remains the same for some fusion events 
D) decreases for all fusion events 
E) decreases for some, but not all, fusion events 
A) increases from all fusion events 
B) increases for some, but not all, fusion events 
C) remains the same for some fusion events 
D) decreases for all fusion events 
E) decreases for some, but not all, fusion events

Question 13

The first step of the proton-proton cycle is:

Accepted Answer

A) "1H + 1H $\rightarrow$2H" 
B) "1H + 1H $\rightarrow$ 2H + e+ + $\nu$" 
C) "1H + 1H$\rightarrow$ 2H + e- + $\nu$" 
D) "1H + 1H $\rightarrow$2H + $\gamma$" 
E) "1H + 1H $\rightarrow$3H + e- + $\nu$" 
A) "1H + 1H $\rightarrow$2H" 
B) "1H + 1H $\rightarrow$ 2H + e+ + $\nu$" 
C) "1H + 1H$\rightarrow$ 2H + e- + $\nu$" 
D) "1H + 1H $\rightarrow$2H + $\gamma$" 
E) "1H + 1H $\rightarrow$3H + e- + $\nu$"

Question 14

In a nuclear power plant, the power discharged to the environment:

Accepted Answer

A) can be made zero by proper design 
B) must be less than the electrical power generated 
C) must be greater than the electrical power generated 
D) can be entirely recycled to produce an equal amount of electrical power 
E) is none of the above 
A) can be made zero by proper design 
B) must be less than the electrical power generated 
C) must be greater than the electrical power generated 
D) can be entirely recycled to produce an equal amount of electrical power 
E) is none of the above

Question 15

The approximate amount of energy emitted in the fission of a nucleus such as 235U is:

Accepted Answer

A) 200 eV 
B) 7.6 MeV 
C) 200 MeV 
D) 760 MeV 
E) 200 GeV 
A) 200 eV 
B) 7.6 MeV 
C) 200 MeV 
D) 760 MeV 
E) 200 GeV

Question 16

If a control rod is pulled rapidly out of a nuclear reactor core, what controls the response time (how fast the power level increases)?

Accepted Answer

A) the speed at which the rod can be removed 
B) the speed at which neutrons are captured 
C) the rate at which delayed neutrons from beta decay of fission fragments are emitted 
D) the rate at which the coolant circulates in the core 
E) the time between when a neutron is captured and when the nucleus actually fissions 
A) the speed at which the rod can be removed 
B) the speed at which neutrons are captured 
C) the rate at which delayed neutrons from beta decay of fission fragments are emitted 
D) the rate at which the coolant circulates in the core 
E) the time between when a neutron is captured and when the nucleus actually fissions

Question 17

What was the most convincing evidence that a natural nuclear reactor formed two billion years ago in a uranium deposit in Africa?

Accepted Answer

A) the relative depletion of 235U in the deposit 
B) the relative depletion of 238U in the deposit 
C) the relative abundance of lead in the deposit 
D) the isotopic distribution of neodymium in the deposit 
E) the appearance of radiation damage in the surrounding rock 
A) the relative depletion of 235U in the deposit 
B) the relative depletion of 238U in the deposit 
C) the relative abundance of lead in the deposit 
D) the isotopic distribution of neodymium in the deposit 
E) the appearance of radiation damage in the surrounding rock

Question 18

Consider the following energies:   Rank them in order of increasing value.

Accepted Answer

A) 1, 2, 3, 4 
B) 3, 4, 2, 1 
C) 1, 2, 4, 3 
D) 2, 1, 4, 3 
E) 2, 4, 1, 3 
A) 1, 2, 3, 4 
B) 3, 4, 2, 1 
C) 1, 2, 4, 3 
D) 2, 1, 4, 3 
E) 2, 4, 1, 3

Question 19

Two billion years ago, a natural nuclear reactor formed in a uranium deposit in Africa.Why is it not possible for such a natural reactor to form somewhere on Earth today?

Accepted Answer

A) It is in fact possible for this to occur. 
B) Too much uranium has already been mined for this to occur. 
C) Too much 235U has now decayed for a critical mass to form naturally. 
D) The remaining uranium deposits are too far underground for this to occur. 
E) Uranium in the remaining deposits is mixed with too many other elements for this to occur. 
A) It is in fact possible for this to occur. 
B) Too much uranium has already been mined for this to occur. 
C) Too much 235U has now decayed for a critical mass to form naturally. 
D) The remaining uranium deposits are too far underground for this to occur. 
E) Uranium in the remaining deposits is mixed with too many other elements for this to occur.

Question 20

In a neutron-induced fission process, delayed neutrons come from:

Accepted Answer

A) the fission products 
B) the original nucleus just before it absorbs the neutron 
C) the original nucleus just after it absorbs the neutron 
D) the moderator material 
E) the control rods 
A) the fission products 
B) the original nucleus just before it absorbs the neutron 
C) the original nucleus just after it absorbs the neutron 
D) the moderator material 
E) the control rods

Exam 43: Energy From the Nucleus

In the normal operation of a nuclear reactor:

Which one of the following is NOT needed in a nuclear fission reactor?

Most magnetic confinement projects attempt:

The Sun has enough hydrogen in its core to continue fusing hydrogen to helium for about another:

The table lists properties of several heavy nuclei when they are struck by thermal neutrons; En is the excitation energy and Eb is the energy barrier.Which quantity, or combination of quantities, represents the energy put into the oscillation of the resulting compound nucleus?

235U is readily made fissionable by a thermal neutron but 238U is not because:

If the nucleus of a lead atom were broken into two identical nuclei, the total mass of the result would be:

Which one of the following represents a fusion reaction that would yield large amounts of energy?

Tokamaks confine deuteron plasmas using:

When uranium undergoes fission as a result of neutron bombardment, the energy released is due to:

The purpose of a moderator in a nuclear reactor is to:

The binding energy per nucleon:

The first step of the proton-proton cycle is:

In a nuclear power plant, the power discharged to the environment:

The approximate amount of energy emitted in the fission of a nucleus such as 235U is:

If a control rod is pulled rapidly out of a nuclear reactor core, what controls the response time (how fast the power level increases)?

What was the most convincing evidence that a natural nuclear reactor formed two billion years ago in a uranium deposit in Africa?

Consider the following energies: Rank them in order of increasing value.

Two billion years ago, a natural nuclear reactor formed in a uranium deposit in Africa.Why is it not possible for such a natural reactor to form somewhere on Earth today?

In a neutron-induced fission process, delayed neutrons come from:

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The table lists properties of several heavy nuclei when they are struck by thermal neutrons; E_n is the excitation energy and E_b is the energy barrier.Which quantity, or combination of quantities, represents the energy put into the oscillation of the resulting compound nucleus?

²³⁵U is readily made fissionable by a thermal neutron but ²³⁸U is not because:

The approximate amount of energy emitted in the fission of a nucleus such as ²³⁵U is: