Control Interlocks

Question 1

C-1

Answer 1

IR Hi Flux Rod Stop
IR NIS > 20%

1/2

Stops ALL Rod OUT Motion (Blocked by (P-10))

Question 2

C-2

Answer 2

PR Hi Flux Rod Stop
PR NIS > 103%
1/4

Stops ALL Rod OUT Motion

Question 3

C-3

Answer 3

OTΔT Rod Stop

114% (± Penalties)

Inputs:
PR NIS (∆I > +8%) / Tave / Pzr Pressure 
< 1.5% of Setpoint

2/4

Stops ALL Rod OUT Motion

Question 4

C-4

Answer 4

OPΔT Rod Stop

∆T < 100% ∆T ( 1.08 -0.02/◦F(T rate) - 0.002 (T-592 ◦F) - ∆I

∆I set to zero

STPT 108%

< 1.5% of Setpoint

2/4

Stops ALL Rod OUT Motion

Question 5

C-5

Answer 5

Low Turbine Impulse Pressure Rod Stop

Impulse Pressure (PT-505) / Inlet Press*
< 15%

1/1

*UNIT 1 ONLY Uses average of
PT-505/506 OR average of
PT-7483/7484 as selected

Question 6

C-7

Answer 6

Steam Dump Load Rejection

Impulse Pressure (PT-506) / Inlet Press*

> 10% Step Load Loss
OR
5%/min Load Loss

1/1

Arms Steam Dumps in Load Reject Mode with (C-9) Tave Mode with Variable Setpoint for Load

*UNIT 1 ONLY uses average of PT-7483/7484

Question 7

C-8

Answer 7

Turbine Trip

EH Pressure < 1245.8 psig
(2/3)

OR

TV Valves Closed
(2/4)

Rx Trip (P-9 is True)
Main Generator Trip
Arm Steam Dumps in Trip Mode
Tave Mode with Setpoint of No Load: 567 F

Question 8

C-9

Answer 8

Condenser Available for Steam Dumps

Condenser Vacuum > 22” Hg
(2/3)

AND

> 1 CW Brkr Closed

Allows Steam Dump Operations

Question 9

C-11

Answer 9

Top Rod Stop

CR Bank D

> 248 Steps

Stops AUTO Rod OUT Motion

Question 10

C-17

Answer 10

Stop Turbine Loading

Lo-Tave < Tref (>17*F)

OR

Tave <563*F

Blocks Raising Turbine Load

Question 11

C-20

Answer 11

AMSAC Armed

Impulse Pressure >30%
2/2
Arms AMSAC