RCS

Question 1

What is the Normal RCS pressure?

Design pressure?

Safety Limit?

Answer 1

2250 psia

2500 psia

2750 psia

Question 2

What is normal Rated Thermal Power (MWth)?

Answer 2

3990 MWth

Question 3

What RCP components does NC cool?

Answer 3

Motor Air Cooler
Motor lube oil cooler
thrust bearing lube oil cooler
seal cooler

Question 4

What inputs does the reactor vessel level monitoring system (RVLMS) provide to QSPDS?

Answer 4

Inadequate Core Cooling (ICC) instrumentation

for determining approach to the ICC when the core is uncovered

Question 5

When does the TRM require a reactor trip for SPS pressurizer pressure?

Answer 5

> 2409 psia

Question 6

What is the trip logic of the RTSG breakers?

Answer 6

2/4

at least one on each power supply flow path (1 from A/C and 1 from B/D)

Question 7

During a reactor startup, how is heat added to the system initially?

Answer 7

starting RCPs

Question 8

What is the purpose of the RCP flywheel?

Answer 8

Raises pump coast down time and reduces the rate of decay of coolant flow when electrical power to the motor is lost

Question 9

What is the purpose of the RCP Anti-rotation device?

Answer 9

Withstand reverse power leads and accident conditions

Has both a rotating and stationary member with sprags in between them that engage through friction during reverse rotation

Question 10

What is the allowable number of running RCP combinations when the RCS is </= 200*F?

</= 500*F?

Why is this limitation in place?

Answer 10

no more than 2

no more than 3

prevent core lift due to high density of water at lower temperatures

Question 11

Describe the flow path, flow rates, and pressure changes of the RCP seals.

Answer 11

6.6 gpm from charging enters the high-pressure piping
Seal water flows through the jet pump and mixes with approx 16 gpm from journal bearing cavity (22.6 gpm)

combined flow goes through the high-pressure seal cooler

3 seals with pressure drops of 42%, 42%, and 16% across each seal, respectfully. with each seal able to provide 100% pressure drop in the case of failure of previous seal

20 gpm goes back to RCS, 2.6 gpm goes through seals, back to VCT (per RCP)

Question 12

What is the interlock between the RCPs and the seal bleedoff isolation valves?

Answer 12

valve will not close if the RCP breaker is closed

Question 13

What happens to the seals if we lose seal injection?

Answer 13

reduced seal life due to intro of contaminants from RCS water

Question 14

What are the RCP pre-start permissives?

Answer 14

Bone

Bleedoff valve fully open
Oil flow sufficient
NC flow sufficient
No Electrical/motor faults

Question 15

How does the RCP Lift Oil pump act in regard to RCP operation?

Answer 15

Before RCP started, lift oil pump manually started to lift thrust bearing pads

When RCP is started a time delay is started, lift oil pump should secure automatically within 2 minutes

If lift oil pump is required to be operating when the RCP is in service, you have to hold the handswitch to start.

After RCP stops, lift oil pump auto starts and runs until manually secured

Question 16

Can you secure an RCP without a lift oil pump available?

Answer 16

yes

may shorten the life of rotating equipment but not cause catastrophic failure

Question 17

What are the starting requirements for RCP’s to minimize potential for lifting of an LTOP relief valve?

Answer 17

Level of pressurizer </= to 33%, the 1st RCP may be started only if SG temperature does not exceed any RCS cold leg temperature by 20 degrees F. After starting first RCP pressurizer level may be raised.

Level of pressurizer > 33% or in a water solid condition, the 1st RCP shouldn’t be started if SG temp is greater than any RCS cold leg temperature.

Question 18

What is the purpose of the pressurizer?

Answer 18

Maintains RCS in subcooled condition

Surge volume to minimize pressure changes during transients

Ensures primary system integrity by preventing over pressurization

Surge line (12” line connects the pressurizer to the Loop 1 hot leg

Question 19

How is pressurizer level maintained?

Answer 19

by PLCS as a function of Tavg

Level is kept with the normal band to ensure Pressurizer heaters remain covered and level is raised as Tave rises to accommodate a larger out-surge on a post trip cooldown.

Heaters covered and space for spray (pressure control)

Question 20

What is the purpose of maintaining a small amount of continuous spray flow in the pressurizer?

Answer 20

Maintain constant temperature in the surge and spray lines to prevent thermal shock

Limit thermal stratification in the horizontal piping runs

Help to circulate the pressurizer water with the reactor coolant loops to maintain uniform water chemistry and temperature in the pressurizer

Question 21

What provides the motive force for pressurizer main spray?

When do they spray valves start opening?

When are they fully open?

Answer 21

DP across the Reactor provided by the RCPs

2275 psia

2300 psia

Question 22

What is the purpose of the pressurizer safety valves?

When do they lift?

Answer 22

Overpressure protection for RCS
Limit RCS to less than T.S. limit of 2750 psia

2475 psig

Question 23

where do they pressurizer safety valves relieve to?

Answer 23

RDT

Question 24

How is pressurizer safety valve status monitored?

How do the B04 lights illuminate based on valve position?

Answer 24

acoustic monitoring (NNN-D11)

Green - 0% - Closed
Red - 9% - Valve >9% open
Red - 100% - Valve fully open

Question 25

What are the pressurizer Heaters rated at?

How many individual heaters are there?

Answer 25

50 kW each

36

Question 26

How are the pressurizer heaters grouped together?

Answer 26

8 banks
- 2 banks of proportional heaters (P1, P2)
– 3 heaters in each bank (150kW per bank)
- 6 banks of backup heaters
– Backup banks (B1-B6), B1 and B2 are identical to P1 and P2 (class powered)
–Banks B3-B6 have 6 heaters each (300 kW per bank)

Question 27

Where do the pressurizer heaters get power from?

Answer 27

B1 and B2 - PGA and PGB
all others from NG

Question 28

When do the class powered pressurizer heaters trip?

Answer 28

SIAS

can be overridden

Question 29

What can happen if an RCP is started when any DG is paralleled to the same startup transformer?

Answer 29

damage to the DG

Question 30

Why should you not start an RCP for the first time, post-outage, if it is suspected that there is a pocket of dilute water in the RCS?

Answer 30

could dilute the entire RCS

approval from OPS management required

Question 31

What is the normal power alignment of the RCP High pressure seal cooler inlet/outlet isolation valves?

Answer 31

open with power removed