Permissives

Question 1

What are the only permissives that are “lit” at 100% power?

Answer 1

P-6 and P-10

Question 2

Which permissives don’t have a physical status light?

Answer 2

P-4 and P-14

Question 3

When is the P-6 status light lit, and what is the function?

Answer 3

ANY Intermediate Range NI greater than or equal to E-10 Amps and rising permits the MANUAL block of the SR High Flux Trip

Question 4

When does the P-6 status light go out, and what is the function?

Answer 4

When BOTH Intermediate Range NIs are < 6E-11 amps and lowering. This prevents/defeats the manual block of the SR High Flux Trip

Question 5

When does the P-10 status light get lit, and what are the functions?

Answer 5

2/4 Power Range NIs Greater than or equal to 10%. This permits the manual block of:
1. PR High Flux Trip, Low Setpoint
2. IR Trip
3. IR Rod Stop
and also:
4. Resets P-7
5. de-energizes the SR NIs (backup)

Question 6

When does the P-10 Status light go out, and what are the functions?

Answer 6

3/4 Power Range NIs < 10%. This prevents / defeats the manual blocks of:
1. PR High Flux Trip, Low Setpoint
2. IR Trip
3. IR Rod Stop
and also:
4. Inputs into P-7

Question 7

When does P-12 status light get lit, and what is function?

Answer 7

2/4 Loop Tavg less than or equal to 541 degrees F. This allows a manual block of SI due to low steam line pressure and blocks all steam dumps.

If combined with high steam flow, there will be a Main Steam Line Isolation

Question 8

When is the P-12 status light clear and what is the function?

Answer 8

3/4 Loop Tavg > 541 degrees F. This prevents / defeats the manual block of SI due to low steam line pressure

Question 9

Under what conditions is P-4 met, and what are the functions?

Answer 9

Both reactor trip breaker A and bypass Breaker A open.
OR
Both Reactor Trip Breaker B and Bypass Breaker B open.

This seals in FWI from SI / Hi-Hi SG Level and permits a manual block of auto SI signals.

If combined with Low Tavg, there will be a FWI

Question 10

When is P-4 no longer met? And what is the function?

Answer 10

Either Reactor Trip or Bypass Breaker racked in and closed. This prevents/defeats the manual block of SI

Question 11

When is the P-7 status light lit? What is the function?

Answer 11

3/4 PRs < 10% AND 2/2 Turbine 1st stage pressures < 10%

This permits the AUTO block of the 6 “at power” reactor trips

Question 12

When is the P-7 Status light not lit? What is the function?

Answer 12

2/4 PRs >10% OR 1/2 turbine 1st stage pressures > 10%

This prevents/defeats auto block of at power reactor trips, with the exception of the turbine trip

Question 13

What are the 6 at power reactor trips that are auto blocked when P-7 Status light is lit?

Answer 13

1. Pressurizer Pressure Low
2. Pressurizer Water Level High
3. RCS Loss of Flow
4. Undervoltage on RCP Buses
5. Under Frequency on RCP Buses
6. RCP Breaker Position

Question 14

When considering other Permissives, what will make P-7 status light be lit?

Answer 14

Reset of P-10 and actuation of P-13

Question 15

What makes P-8 status light get lit, and what are the functions?

Answer 15

3/4 PRs less than or equal to 29% permits the auto block of Rx Trips due to a single loop low flow trip AND Turbine Trip

Question 16

When will the P-8 status lights clear and what are the functions?

Answer 16

Clears when 2/4 PR NIs are > 29%. This prevents/defeats the auto block of the reactor trip due to a singl eloop low flow and turbine trip.

Question 17

When is P-11 status light lit, and what is the function?

Answer 17

Lit when 2/3 Pressurizer Pressures are < 1910 psig. This permits a manual block of SI on low pressurizer pressure

Question 18

When is P-11 status light clear, and what does it do?

Answer 18

Clear when 2/3 Pressurizer Pressures are greater than or equal to 1910 psig. This prevents/defeats manual block of SI on low pressurizer pressure.

Question 19

When is P-13 status light lit? And, what does it do?

Answer 19

Lit when 2/2 Turbine 1st stage pressures are < 10%. It inputs ito P-7

Question 20

When is P-13 status light clear, and what does it do?

Answer 20

Clear when 1/2 turbine 1st stage pressures >10%. Inputs into P-7

Question 21

When is P-14 met, and what does it do?

Answer 21

Met when 2/3 NR SG Levels are < 64% in ALL SGs. This permits MFW addition into the SGs

Question 22

When is P-14 not met, and what does that do?

Answer 22

Not met when 2/3 SG NR Levels >67% in at least 1 SG. This causes a FWI, trips both MFPs and trips the Main Turbine