Nuclear Instrumention system

Question 1

N-31/32 are what kind of detector?

Answer 1

Proportional Counter, filled with BF3 gas. Has a pulse dampner in it to ignore Nuetrons pulses on the the detector and only sense the gamma.

Question 2

N-31/32 has what trip? What is before this?

Answer 2

Source Range HIgh Flux
(High flux source range alarm which also causes CV evacuation alarm)

Question 3

What effect does loosing Instrument power have on Source and Intermediate Range NI’s?

Answer 3

A lost of instrument power with cause a reactor trip unless the bypass switch is closed. (Always before P-6/10 is blocked)

Question 4

What effect does loosing control power have on Source and Intermediate Range NI’s?

Answer 4

Causes Reactor Trip unless above P-6/10

Question 5

If High Flux at shutdown switch is blocked, will the Shutdown alarm and CV horn sound?

Answer 5

NO, if in block neither the alarm or horn will sound

Question 6

N-35/36 is what kind of detector?

Answer 6

Can in a Can. Both the inner and outer surgaces of the outside chamber is coated with Boron-10.
Over compensated reads low
Under compensated reads high

Question 7

Over Power Rod Stop bistable is what conicident?

Answer 7

1/4 at 103%
Any Power Range NI will stop rods

Question 8

P-6 has a premissive Defeat (2/2 pushbuttons) when can it be used?

Answer 8

Only operable below P-10
If NI-51A/B are indicating <10^3cps and NI-35/36 are not reading below 10^-10amps

Question 9

N-35/36 rod stop set point and conicident?

Answer 9

20% CE 1/2

Question 10

Remember OPdelatT…..?

Answer 10

Does not have pressure fed into it.

Question 11

N-44 does not feed into what?

Answer 11

OT Delta T
OP Delta T

Question 12

APP

IR HI Level ROd Stop
Setpoint and conicident

Answer 12

20% CE
1/2 IR Detectors

Question 13

APP

PR Dropped rod setpoint?

Answer 13

5% power change in 5 seconds

Question 14

APP

PR overpower rod stop
setpoint conicident?

Answer 14

103% on 1/4 PR detectors

Question 15

NI-51/52 we need because of what OE?

Answer 15

Three mile island

Question 16

Axial Flux Difference tech spec is applicabile when? What is the required action, and completion time?

Answer 16

Mode 1 with THERMAL power >= 50%
Reduce THERMAL power <50%
Within 30 minutes

Remember greater than or equal too

Question 17

Two source range neutron flux channels inoperable below P-6

Answer 17

Open Reactor Trip breakers immediatley

Question 18

If one channel is inoperable (SR/IR/PR)

Answer 18

Verify interlock is in required state for existing unit conditions (1 hour)

Question 19

If in mode 6, two SR instruments shall be operable.

Answer 19

If one is inoperable, Verify one PAM source range neutron flux monitior provides indication in the CR (15mins)
AND
Log PAM source range count rate (30mins, and then once 30mins thereafter)

Question 20

PR detectors provide signals to:

Answer 20

OP Delta T/ OT Delta T
Current comparator Drawer (QPTR alarms)
ERFIS (AFD alarms)

Question 21

If two PR detectors are inoperable, what does this do to SR?

Answer 21

Creates a false P-10 signal that prevents the operation of the SR instruments

Question 22

When a SR or IR detector looses Istrument power what are your indications on the Drawer?

Answer 22

Indication falls to zero, lights light up

Question 23

When a SR or IR etector looses Control Power what are you indications on the drawer?

Answer 23

Indication stays on needle, lights go out