Control Rod Drive (RDS) Flashcards
What are the Power Supplies for the RDS pumps?
P1A - SWG14
P1B - SWG15
What is Control Power to the RDS Pumps?
Batt B
What CRDM Hydraulic Control Unit pressure does an alarm come in?
1025 psig
What is T.S. pressure for the CRDM Hydraulic Control Units (HCUs)
940 psig
How is a CRDM hydraulically disarmed?
Close 103 & 105 to hydraulically disarm. (Rod must be full in)
What keeps the drive water stable in the RDS system?
Stabilizing valves (Stab valves)
What is flow through the directional control valves and stab valves on a control rod insert?
4 gpm through control valves
2 gpm through stab valves
What is flow through the directional control valves and stab valves on a control rod withdraw?
2 gpm through control valves
4 gpm through stab valves
What causes a SCRAM from the SCRAM Discharge Volume (SDV)
46.5”
What is the normal position of the SDV vent valves and how do they fail?
- Normally Open
- Fail Closed
How do the FCVs (FV6A/B) fail on a loss of IAS?
Fail Closed
Where is FE107 location in relation to the Charging Water Header?
Before the Charging Water Header
On a SCRAM what position will FV6A/B indicate and what will flow indicate and why?
They will indicate shut and flow will indicate upscale because all flow is being diverted to recharge the HCUs.
What are Backup SCRAM valves powered by?
Divisional DC
Are backup SCRAM valves energized or deenergized to function?
Energized (ONLY NEED 1)
What are RDS pump trips?
- Low suction pressure (25”Hg for 3.5sec)
- Motor Fault
What are the RDS auto starts?
There are no auto starts!!!!
What do the SCRAM air header vents do for ARI, Backup RPS & RPS…Energize or Deenergize?
- ARI - Energize
- B/U RPS - Energize
- RPS - Deenergize
When is a Control Rod considered INOP from SCRAM Time Testing
> 7 sec SCRAM time
How many HCUs can be isolated at one time?
no more than 80 HCUs can be isolated at one time.
What is Cooling Water D/P MAX?
35 psid
What is MAX insert pressure for adjusting drivewater D/P
400#
What is MAX withdraw pressure for adjusting drivewater D/P
600#
What is MAX pressure for a rod in a cell with a bowed fuel channel?
Shal Not Exceed 430#
What is MAX Drivewater pressure?
1510 psig
What does the velocity limiter do?
Slows control rod in a rod drop accident, .280 cal/gm
What is the purpose of the Buffer Orifices?
Slow down a rod on a SCRAM
What happens with a stuck collet finger?
Rod drifts out
What is required when withdrawing to position 48?
Coupling check
What must be done on a Control Rod High Temp Alarm?
Insert Rod 1 notch (position 46) OP-30, H.14
Where are the Position indicating switched located?
Position Indicating Probe
What indication(s) does the Position Indicating Probe provide?
Position AND Temperature
What does Position 50 provide indication for in regard to Control Rods?
- Uncoupled
- Over Travel
- Blank Position indication on display
What provides input to the Blue SCRAM lights on the full core display?
V126 & 127
What happens with a withdraw line break?
- Rod Drifts in
- Can still SCRAM
What happens with an insert line break?
- Ball checks against Rx pressure.
- Can still SCRAM
What happens with bad seal for CRDMs?
Slow SCRAM
