Nuclear Boiler Instrumentation - .5

Question 1

Describe Narrow Range Level Detectors

Answer 1

1) 0” to +60”
2) Calibrated hot at 1000#, 135°F in Drywell, and 75°F in Rx building.
3) If indicated level is steady, actual level goes down with Rx pressure going up.

Question 2

Describe Wide Range Level Detectors

Answer 2

1) -150” to +60”
2) Calibrated hot at 1000#, 135°F in drywell, and 75°F in Rx building.
3) ECCS initiation goes off of wide range instruments.
4) Largest disparity between indicated and actual level occurs when cooling down

Question 3

Describe Upset Range Level Detectors

Answer 3

1) 0” to +180”
2) Calibrated hot at 1000#, 135°F drywell, and 75°F Rx Building
3) Indicates higher when cooling down

Question 4

Describe Shutdown Range Level Detectors

Answer 4

1) 0” to 400”
2) Calibrated cold at 0#, 120°F Water, 80°F drywell, and 75°F Rx building.
3) Indicates lower when cooling down because it is calibrated colder, more dense, higher D/P.

Question 5

Describe Fuel Range Level Detectors

Answer 5

1) -311” to -111”
2) Calibrated for accident: no jet pump flow, 0# in vessel and drywell, saturated steam water mixture, and 75°F in Rx building.
3) When in refueling, the absence of the Fuel Pool Low Level Alarm indicates that level is >22’ 5” above the RPV flange.

Question 6

Wide Range Pressure Detectors

Answer 6

0-1200# OR 0-1500#

Question 7

Narrow Range Pressure Detectors

Answer 7

850-1050#

Question 8

Low Range Pressure Detectors

Answer 8

0-50#

Question 9

Describe PAMS Recorders

Answer 9

1) Channels A&B - They have the shortest vertical run of piping in the drywell and are less affected by accident conditions. Preferred instrument during accident. (See EOP Caution 1)
2) Shifts to fast speed on Level 3 (12.5” OR 1037#). Can return to slow speed by pressing button next to recorder when above 12.5” or below 1037#.

Question 10

Level 8

Answer 10

+54”
(4 turbine trips)
-Main Turbine trip (NR)
-RFP Turbines trip (NR)
-HPCI Turbine trip (WR)
-RCIC “Trip” (WR). (F045 shuts => secures steam)

Question 11

Level 7

Answer 11

+39”
-Hi Level Alarm (NR)

Question 12

Level 5/6

Answer 12

+35”
-Normal Operating Level

Question 13

Level 4

Answer 13

+30”
-Low Level Alarm
-Interim (45%) Recirc Runback (IF concurrent w/ a RFP trip)

Question 14

Level 3

Answer 14

+12.5”
-Rx Scram
-Lowers FWLC setpoint set down (14”)(.5 sec TD)*
-Full recirc runback
-ADS Confirmatory signal
-RHR sample and discharge to RW isolation

Question 15

Why is the FWLC setpoint lowered during Level 3?

Answer 15

Prevent over feeding on a scram/low level.

Question 16

Level 2

Answer 16

-38”
-RCIC & HPCI initiate.
-RRCS Input: ARI, RPT (9 sec TD), start 3.9 minute SLC timer.
-A&B SACS pumps start
-RBVS isolates, supply and exhaust fans trip.
-FRVS fans start
-Radwaste supply and exhaust fans trip
-EIAC trips
-PCIS isolations
-NSSSS Isolations: RWCU F001/F004, Recirc sample 4310/4311, TIPS retract and isolate.

Question 17

What are the PCIS Isolations for Level 2?

Answer 17

-RC boundary leak detection system
-H2/O2 analyzers
-CPCS/N2ME/DW purge valves
-H2 recombiner
-TWCU
PCIG (minor)
-Drywell floor and equipment drains

Question 18

Level 1

Answer 18

-129”
-CS & LPCI initiate
-Signal to ADS Logic
-CRD trips
-A-D EDG, SACS, and SSW start.
-PCIG trips
-FPC, PCIG, TACS SACS cross ties close
-RACS pumps A&B Trip, SSW to RACS Isol.
-RACS to Turb and Aux bldgs isolates
-TSC Chillers Start
-CREF aligns and both loops start
-Non 1E MCCs Trips
DW Coolers Trip
MT LO Pumps and Lift Pumps Trip
RFP LO Pumps Trip
-NSSSS Isolations
MSIVs and MSIV Drains (F016 & F019)
-PCIS Isolations
Chilled Water to DW
RACS to Recirc Pump Pedestal
CRD to Recirc Seal Purge

Question 19

What happens if drywell temp is hotter than vessel temp?

Answer 19

Indicated water level will indicate higher due to boiling in the reference leg.

Question 20

Rx Flange level

Answer 20

+217.5”

Question 21

Steam Lines Level

Answer 21

+118”

Question 22

Top of Moisture Separators level

Answer 22

+80”

Question 23

TAF Level

Answer 23

-161”

Question 24

Level Zero

Answer 24

-211”

Question 25

BAF

Answer 25

-311.5”

Question 26

The pressure drop across the steam dryers can cause…

Answer 26

A 7” level difference inside core shroud-downcomer.

Question 27

A-E SRVs Pressure setpoint

Answer 27

1130

Question 28

G, J, L, R, and P SRVs Pressure setpoint

Answer 28

1120

Question 29

F, H, K, and M SRVs Pressure setpoint

Answer 29

1108

Question 30

RRCS Hi Pressure (ATWS) Pressure setpoint

Answer 30

1071

Question 31

Lo-Lo Set Actuation (Lo-Lo Set Armed, SRV P Open) Pressure setpoint

Answer 31

1047

Question 32

SCRAM Pressure setpoint

Answer 32

1037

Question 33

Hi Pressure alarm

Answer 33

1022.4

Question 34

Lo-Lo set H opens Pressure setpoint

Answer 34

1017

Question 35

Lo-Lo Set P closes Pressure setpoint

Answer 35

935

Question 36

Lo-Lo set H closes Pressure setpoint

Answer 36

905

Question 37

MSIVs close w/ Mode switch in run (NSSSS)

Answer 37

756

Question 38

Core Spray Injection Permissive Pressure setpoint

Answer 38

461

Question 39

LPCI Injection Permissive Pressure setpoint

Answer 39

450

Question 40

HPCI Isolation Pressure setpoint

Answer 40

100

Question 41

RHR SDC High Pressure Isolation setpoint

Answer 41

82

Question 42

RCIC Isolation Pressure setpoint

Answer 42

64.5