RQ-C-4834 (Control Rod Theory)

Question 1

What is the change in reactivity per unit change in rod position known as

Answer 1

• Differential Rod Worth

Question 2

How and why does control rod worth change as moderator temperature is increased

Answer 2

• Moderator density lowers allowing more neutrons to be absorbed by the control rods

Question 3

How does a dropped rod effect AFD and tilt

Answer 3

• Little effect on AFD, noticeable effect on tilt depending on where in the core it is dropped

Question 4

Tavg rises 2 degrees.
Rx Power remains stable at 50% power

what is the effect on Control Rod Worth?

A. Rises
B. Remains the same
C. Lowers

Answer 4

A. Rises

Question 5

The Unit is at 50% power
The Turbine is in MW-IN.

The Crew inserts Control Rods for 5 seconds.

Reactor power will stabilize _____(1)________ the initial power level and coolant temperature will stabilize ______(2)________ the initial temperature.

A. (1) below
(2) below
B. (1) below
(2) at
C. (1) at
(2) below
D. (1) at
(2) at

Answer 5

C. (1) at
(2) below

Question 6

As the core ages, what is the effect on Control Rod Worth?

A. Rises
B. Remains the same
C. Lowers

Answer 6

A. Rises

Question 7

The purposes of using control rod bank overlap are to…

A. provide a more uniform differential rod worth and to provide a more uniform radial power distribution.
B. provide a more uniform radial power distribution and to maintain individual and group rod position indicators within allowable tolerances.
C. maintain individual and group rod position indicators within allowable tolerances and to provide a more uniform axial power distribution.
D. provide a more uniform axial power distribution and to provide a more uniform differential rod worth.

Answer 7

D. provide a more uniform axial power distribution and to provide a more uniform differential rod worth.

Question 8

What is the purpose of the Rod Insertion Limit?

RIL ensures that control rods will be more withdrawn as reactor power ____(1)______ to compensate for the change in _____(2)_______.

A. (1) rises
(2) xenon reactivity
B. (1) lowers
(2) xenon reactivity
C. (1) rises
(2) power defect
D. (1) lowers
(2) power defect

Answer 8

C. (1) rises
(2) power defect

Question 9

Differential Control Rod Worth is the change in ______(1)______ per ____(2)________ change in rod position.

A. (1) reactor power
(2) total
B. (1) reactivity
(2) unit
C. (1) reactor power
(2) unit
D. (1) reactivity
(2) total

Answer 9

B. (1) reactivity
(2) unit

Question 10

What is Rod Shadowing?

A. Integral reactivity impact when one rod bank begins moving with another
B. Reactivity worth impact one control rod has on another
C. Differential reactivity impact when one rod bank begins moving with another
D. Twilight Zone host

Answer 10

B. Reactivity worth impact one control rod has on another

Question 11

As long as core quadrant power distribution is maintained within design limits, which one of the following conditions is most likely?

A. Axial power distribution is within design limits.
B. Radial power distribution is within design limits.
C. Nuclear instrumentation is indicating within design accuracy.
D. Departure from nucleate boiling ratio is within design limits.

Answer 11

B. Radial power distribution is within design limits.

Question 12

The Unit is stable at 80% power.

The Crew withdraws Control Rods 10 steps.

Which parameter will be significantly affected?

A. Total xenon reactivity
B. Axial power distribution
C. Radial power distribution
D. Quadrant power distribution

Answer 12

B. Axial power distribution