Permissives

Reactor Trip

Both Reactor Trip and bypass breaker open

•Turbine Trip

•FWIS if low TAVG (564°F)

•Blocks automatic SIS

•Arms steam dumps

•Allows reset of SIS @ 60 seconds

Source Range trip block

1/2 IR > 10^-10 amps

Allows blocking the SR high flux trip

Low power trip block

P-10 or P-13 > 10% power

Enables the following Reactor Trips:

•Low PZR Pressure

•High PZR Water Level

•RCS loop low flow (2 loops)

•RCP Bus Undervoltage

•RCP Bus Underfrequency

Single RCS low flow block

2/4 PR < 48% power

No Reactor Trip on Single RCS low flow

Turbine Low Power

2/4 PR > 49% power

Enables Reactor Trip on turbine trip

Nuclear at-power

2/4 PR > 10% power

Allows blocking of:

•IR high Reactor trip (25%)

•PR low setpoint Reactor Trip (25%)

•C-1 rod stop (20%)

Pressurizer low pressure

2/3 PZR Pressure < 1970#

Allows blocking of low PZR pressure SIS

Allows blocking of low MS pressure SIS

•Toggles MSIS to rate setpoint

Lo-Lo T_AVG

2/4 TAVG < 550°F

Closes all Steam Dumps

Turbine at-power

Turbine >10% power

Feeds P-7

Hi-Hi SG level

2/4 SG level > 78%

Turbine trip, Trips both MFPs & FWIS