Incore Instrumentation

Question 1

How many fixed, incore instrumentation assemblies are there?

Answer 1

61

Question 2

What does each ICI assembly consist of?

Answer 2

5 self-powered rhodium detectors
1 background detector
1 core exit thermocouple (CET)
1 dry, movable detector calibration tube

Question 3

How are the ICI assemblies placed on the core?

Answer 3

10, 30, 50, 70, and 90% of active core height

Question 4

What is the process range of the thermocouples?

Answer 4

200F - 2300F

Question 5

The CETs and Heated Junction Thermocouples provide direct input into what?

why?

Answer 5

QSPDS

determining an approach to inadequate core cooling during core uncovery

Question 6

The CET’s are one of the indications used to monitor what in the core by CET subcooling and delta-T between max quadrant CET temperature and T-hot?

Answer 6

natural circulation conditions

Question 7

What provides power to the incore amplifiers?

Answer 7

PN

Question 8

Fixed incore detectors provide inputs to the core operating limit supervisory system (COLSS) for what?

Answer 8

calculation of azimuthal tilt
axial peaking factor
local power density
DNB margin.

Question 9

What are the Neutron detectors?

How do they work?

Answer 9

Self-powered Rhodium detectors

they give off a Beta decay, giving the detector a signal

Question 10

Where are the CETs physically located?

Answer 10

above the fuel alignment plate in the Rx Coolant outlet plenum

allowing for an accurate measure of the coolant as it exits the fuel

Question 11

What could bring in the FIXED INCORE AMP SYS TRBL alarm?

Answer 11

Causes for this annunciator include:
* Fixed Incore Amp Trouble
* Incore Amplifier Ch (A-D) Bin Assy In Test