Question

A reactor operating at 1 MW is scrammed by instantaneous insertion of $5.00 of negative reactivity. Approximately how long does it take the power to drop to 1 milliwatt?

Answer 1

time is 3333.33 min or 55.55 hr

Step-by-step explanation:

given data

reactor operating = 1 MW

negative reactivity = $5

power = 1 miliwatt

to find out

how long does it take

solution

we know here power coefficient that is

power coefficient =
`(10^(6) )/(10^(6) )`

power coefficient = 1

so time required to reach power is

power = reactivity × time / power coefficient + reactor operating

1 ×
`10^(-3)` = -5 t / 1 + 1 ×
`10^(6)`

5t =
`10^(6)` -
`10^(-3)`

t = 199999.99 sec

so time is 3333.33 min or 55.55 hr