Containment Systems Block Prior Systems Review Questions

Question 1

What are the power supplies for the Circulating Water pumps?

Answer 1

N71-C001A 4160v Bus A

N71-C001B 4160v Bus B

Question 2

What causes Condenser Room Flooding logic to initiate? What actions happen as a result of this?

Answer 2

3” water above the floor

• DIRECT Trip of Circ Water Pumps
• CW Pump trip causes Pump Disch vlvs to close.
• Water Box In and Out Vlvs close.
• 4160V Bus 2A and 2B norm & alt supply brkrs trip OPEN
• Breakers opening cause Recirc Pumps to trip on undervoltage. (Comply with Tech Specs with no forced circulation in the Rx.)
• PSW Turb Bldg Isol Valves F316A-D (F310A-D) will close (CANNOT BE OVERRIDDEN)
• Main Turb trips in a few sec due to low vac. Causes a Rx Scram due to a turbine trip with Rx power greater than 27.6%.

Question 3

What is the time delay associated with restarting Circ Water pumps after a trip? What happens when the pump starts?

Answer 3

Pump cannot be restarted until 90s TDR has timed out after pump trip. (Disch valve does not have to be closed to restart pump, just need 90-sec TDR timed out)

When the pump is restarted, the pump discharge valve will OPEN.

Question 4

What are the T.S. safety limits? What actions are required if they are violated?

Answer 4

• W/ Rx steam dome pressure <685 psig or core flow <10% rated core flow:
  THERMAL POWER shall be ≤24% RTP.
• W/ Rx steam dome pressure ≥685 psig and core flow ≥10% rated core flow:
  MCPR shall be ≥1.07
• RPV water level shall be >top of active irradiated fuel TOF (-155”)
• Reactor steam dome pressure shall be ≤1325 psig.

If any violated:
2 hr, restore compliance with all SLs
AND
Insert all insertable control rods.

Question 5

What are the various Modes for Rx operations, and what are the switch/temperature/head bolt requirements of each?

Answer 5

1 - Power Operation - Mode switch: Run - Temp: N/A

2 - Startup - Mode switch: Refuel(a) or Startup/Hot
Standby - Temp: N/A

3 - Hot Shutdown(a) - Mode switch: Shutdown - Temp: > 212

4 - Cold Shutdown(a) - Mode switch: Shutdown - Temp: ≤ 212

5 - Refueling(b) - Mode switch: Shutdown or Refuel - Temp: N/A

(a) - All reactor vessel head closure bolts fully tensioned.
(b) - One or more reactor vessel head closure bolts less than fully tensioned.

Question 6

What are the requirements for LLS to be armed?

Answer 6

• Rx press ≥1074
  AND
• Tailpipe pressure 85 psig
  CONCURRENTLY

Question 7

Which valves are LLS valves for Unit 2/Unit 1? When do they open/close to control pressure?

Answer 7

Unit 2: (B)e (G)ood (F)or (D)ad - BGFD

	   OPEN 	    CLOSE  (15,15,9)
	B	997 	851
	G	1012 	866 
	F	1027 	881 
	D	1036 	890 

Unit 1: (H)ave (A) (G)ood (C)hristmas - HAGC

             OPEN        CLOSE (15,15,10)
	H	993 	847
	A	1008 	862 
	G	1023 	877 
	C	1033 	887

Question 8

What are the power supplies for ADS logic “A” and “B”? Which valves on each unit are ADS valves?

Answer 8

ADS Logic “A”
NORM - 125VDC “A” R25-S001
ALT - NONE

ADS Logic “B”
NORM - 125VDC “A” R25-S001
ALT - 125VDC “B” R25-S002

U2: MACK/HEL

U1: KLFD/JEB

Question 9

What signals are required for ADS to blow down?

Answer 9

DRAW the logic, ADS will not blowdown unless Rx water level is less the -101 (right leg of logic will prevent)

• CS 152#, RHR >127#]
(timer still times w/o this)

Question 10

What are all of the SRV electrical/mechanical lift setpoints? Which ones have controls at the RSDP? What is lost if control is transferred to RSDP?

Answer 10

SRVs-U2
•	B,G,F,D	        1120psig
•	MACK	        1130psig
•	HEL	                1140psig
•	Mech OP	1150psig

SRVs-U1
•	H,A,G,C	        1120psig
•	KLFD	        1130psig
•	JEB	                1140psig
•	Mech OP	1150psig

B & F (C & G) have controls on RSDP – LLS logic disabled.