Page 46 - Dynamics and Control of Nuclear Reactors
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4.3 Maneuvers in a zero power reactor 37
4
3.5
3
P/P(0) 2.5
2
1.5
1
0 10 20 30 40 50 60 70 80 90 100
Time (s)
FIG. 4.1
Response of a zero-power reactor to a + 10 cent step reactivity perturbation.
150
P/P(0), 1 second into transient 100
125
75
50
25
0
0 1 2 3 4 5 6 7
Step reactivity magnitude × 10 −3
FIG. 4.2
Effect of step reactivity magnitude on reactor response at t ¼ 1 s, for different reactivity
values.
The reactor period is an important parameter in the operation of a reactor. A large
value of the reactor period indicates that reactor power is remaining at or near a con-
stant value. Short period indicates that a reactor excursion is under way. Reactor
period is a safety-related parameter and must be monitored so that it does not fall
below a specified value.
