A reactivity coefficient measures a/an ________________ change in reactivity while a reactivity defect measures a _________________ change in reactivity due to a change in the measured parameter.
A. integrated; total
B. integrated; differential
C. unit; total
D. unit; differential
ANSWER: C.
Comment: The question is technically incorrect because neither the reactivity coefficient nor the reactivity defect "measure" anything; they are a "measure of" something. A reactivity coefficient is not a measure of a "unit" change in reactivity. A reactivity coefficient is a measure of the reactivity change associated with a unit increase in a given parameter. However, note the rare instance where both the reactivity coefficient and the reactivity defect are correctly referred to in terms of a "change in reactivity."
QID: P352 (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters, select the final reactor coolant boron concentration required to decrease average coolant temperature by 4 F. (Assume no change in rod position or reactor/turbine power).
Initial reactor coolant system boron concentration = 600 ppm
Moderator temperature coefficient = -0.015% delta-K/K per degree F
Differential boron worth = -0.010% delta-K/K per ppm
Inverse boron worth = -100 ppm/% delta-K/K
A. 606 ppm
B. 603 ppm
C. 597 ppm
D. 594 ppm
ANSWER: A.
Comment: The question is technically incorrect because the moderator temperature coefficient is incorrectly indicated to represent reactivity per degree F, the differential boron worth is incorrectly indicated to represent reactivity per ppm, and the inverse boron worth is expressed incorrectly as reactivity.
QID: P852 (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters, select the final reactor coolant boron concentration required to increase average coolant temperature by 6 F. (Assume no change in rod position or reactor/turbine power.)
Initial boron concentration = 500 ppm
Moderator temperature coefficient = -0.012% delta-K/K per degree F
Differential boron worth = -0.008% delta-K/K per ppm
Inverse boron worth = -125 ppm/% delta-K/K
A. 491 ppm
B. 496 ppm
C. 504 ppm
D. 509 ppm
ANSWER: A.
Comment: The question suffers the same defect as P352. Parameters are incorrectly represented.
QID: P953 (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters:
Total power coefficient = -0.016% delta-K/K/%
Boron worth = -0.010% delta-K/K/ppm
Rod worth = -0.030% delta-K/K/inch inserted
Initial reactor coolant system
(RCS) boron concentration = 500 ppm
Which one of the following is the final RCS boron concentration required to support increasing plant power from 30% to 80% by boration/dilution with 10 inches of outward control rod motion. (Assume no change in xenon reactivity.)
A. 390 ppm
B. 420 ppm
C. 450 ppm
D. 470 ppm
ANSWER: C.
Comment: The question suffers the same defect as P352. Parameters are incorrectly represented, in this case total power coefficient, boron worth, and rod worth. In addition, xenon does not possess "reactivity."
QID: P1553 (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters, select the final reactor coolant boron concentration required to decrease average coolant temperature by 6 F. (Assume no change in rod position or reactor/turbine power.)
Initial boron concentration = 500 ppm
Moderator temperature coefficient = -0.012% delta-K/K per degree F
Differential boron worth = -0.008% delta-K/K per ppm
Inverse boron worth = -125 ppm/% delta-K/K
A. 509 ppm
B. 504 ppm
C. 496 ppm
D. 491 ppm
ANSWER: A.
Comment: The question suffers the same defect as P352. Parameters are incorrectly represented, in this case moderator temperature coefficient, differential boron worth, and inverse boron worth.
QID: P1753 (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters:
Total power coefficient = -0.020% delta-K/K/%
Boron worth = -0.010% delta-K/K/ppm
Rod worth = -0.025% delta-K/K/inch inserted
Initial reactor coolant system
(RCS) boron concentration = 500 ppm
Which one of the following is the final RCS boron concentration required to support increasing plant power from 30% to 80% by boration/dilution with 10 inches of outward control rod motion? (Assume no change in xenon reactivity.)
A. 425 ppm
B. 450 ppm
C. 550 ppm
D. 575 ppm
ANSWER: A.
Comment: The question suffers the same defect as P352. Parameters are incorrectly represented, in this case total power coefficient, boron worth, and rod worth. In addition, xenon does not possess "reactivity."
QID: P2353 (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters:
Total power coefficient = -0.020% delta-K/K/%
Boron worth = -0.010% delta-K/K/ppm
Rod worth = -0.025% delta-K/K/inch inserted
Initial reactor coolant system
(RCS) boron concentration = 500 ppm
Which one of the following is the final RCS boron concentration required to support decreasing plant power from 80% to 30% by boration/dilution with 10 inches of inward control rod motion? (Assume no change in xenon reactivity.)
A. 425 ppm
B. 475 ppm
C. 525 ppm
D. 575 ppm
ANSWER: D.
Comment: The question suffers the same defect as P352. Parameters are incorrectly represented, in this case total power coefficient, boron worth, and rod worth. In addition, xenon does not possess "reactivity."
QID: P2453 (B2453) (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters:
Total power coefficient = -0.020% delta-K/K/%
Boron worth = -0.010% delta-K/K/ppm
Rod worth = -0.025% delta-K/K/inch inserted
Initial reactor coolant system
(RCS) boron concentration = 600 ppm
Which one of the following is the final RCS boron concentration required to support increasing plant power from 40% to 80% by boration/dilution with 40 inches of outward control rod motion? (Assume no change in core xenon -135 reactivity.)
A. 420 ppm
B. 580 ppm
C. 620 ppm
D. 780 ppm
ANSWER: C.
Comment: The question suffers the same defect as P352. Parameters are incorrectly represented, in this case total power coefficient, boron worth, and rod worth. In addition, xenon does not possess "reactivity."
QID: P2553 (TOPIC: 192004 KNOWLEDGE: K1.12 [2.7/2.7])
Given the following initial parameters:
Reactor power = 100%
Total power coefficient = -0.020% delta-K/K/%
Boron worth = -0.010% delta-K/K/ppm
Rod worth = -0.025% delta-K/K/inch inserted
Initial reactor coolant system
(RCS) boron concentration = 500 ppm
Which one of the following is the final RCS boron concentration required to support decreasing plant power to 30% by boration/dilution with 20 inches of inward control rod motion? (Assume no change in xenon reactivity.)
A. 410 ppm
B. 425 ppm
C. 575 ppm
D. 590 ppm
ANSWER: D.
Comment: The question suffers the same defect as P352. Parameters are incorrectly represented, in this case total power coefficient, boron worth, and rod worth. In addition, xenon does not possess "reactivity."
QID: P2071 (B2070) (TOPIC: 192004 KNOWLEDGE: K1.13 [2.9/2.9])
Neglecting the effects of core Xe-135, which one of the following power changes requires the greatest amount of positive reactivity addition?
A. 3% power to 5% power
B. 5% power to 15% power
C. 15% power to 30% power
D. 30% power to 60% power
ANSWER: D.
Comment: The question suffers the same defect as P250. Reactivity is not added.
QID: P2169 (B2669) (TOPIC: 192004 KNOWLEDGE: K1.13 [2.9/2.9])
Neglecting the effects of core Xe-135, which one of the following power changes requires the greatest amount of positive reactivity addition?
A. 3% power to 5% power
B. 5% power to 15% power
C. 15% power to 30% power
D. 30% power to 60% power
ANSWER: A.
Comment: The question suffers the same defect as P250. Reactivity is not added.
QID: P2851 (B2470) (TOPIC: 192004 KNOWLEDGE: K1.13 [2.9/2.9])
Neglecting the effects of core Xe-135, which one of the following power changes requires the greatest amount of positive reactivity addition?
A. 3% power to 10% power
B. 10% power to 25% power
C. 25% power to 60% power
D. 60% power to 100% power
ANSWER: D.
Comment: The question suffers the same defect as P250. Reactivity is not added.
QID: P2953 (N/A) (TOPIC: 192004 KNOWLEDGE: K1.13 [2.9/2.9])
Neglecting the effects of core Xe-135, which one of the following power changes requires the greatest amount of positive reactivity addition?
A. 3% power to 10% power
B. 10% power to 25% power
C. 25% power to 65% power
D. 65% power to 100% power
ANSWER: C.
Comment: The question suffers the same defect as P250. Reactivity is not added.