201.20 SSPS Flashcards Preview

Systems 2 > 201.20 SSPS > Flashcards

Flashcards in 201.20 SSPS Deck (32):
1

201.20 SSPS


Functions of SSPS

Monitors parameters and initiates protective function to ensure w/in Tech Spec limits

Maintains fuel clad integrity via Rx Trip for Condition I and II events

Actuates ESF Systems to mitigate Condition III and IV events to ensure offsite dose w/in 10CRF50.67 limit

2

201.20 SSPS


ANS Classification of Accidents

Condition I - normal ops and operational transients

no clad damage

Condition II - faults of moderate frequency

no clad failure or fuel melting, rad release < 10CFR20, at worst trip with return to power

Condition III - infrequent faults

small amount of fuel damage, rad release small fraction of 10CFR50.67, considerable outage time

Condition IV - limiting faults

rad release < 10CFR50.67

3

201.20 SSPS


Acutation Train Urgent Alarm

Causes

Loss of power (Slave Relay Cabinet or Test Cabinet)

Actuation train in test

Test Cabinet in test

4

201.20 SSPS


Logic Cabinet Urgent Alarm

Causes

Loose or removed circuit card

“Respective” Actuation Train Urgent

Associated Rx Trip Bypass Breaker racked in and closed

 

Test Switches:

Input Error in INHIBIT

Logic Test Switch A in other than OFF

Permissive Test Switch in other than OFF

Memory Test Switch in other than OFF

 

A image thumb
5

201.20 SSPS


SSPS Trouble Alarm Train R and S

Causes

Loss of any 15 VDC or 48 VDC

Any Actuation Train in test

Any Actuation Train loss of power

MRDS Switch in other than NORMAL

Multiplexer Test Switch in INHIBIT

6

201.20 SSPS


Reactor Protection Channel Bypassed Alarm

Causes

Any protection channel bypassed in the 7300 process cabinets.

Specific channel determined by bistable indications.

7

201.20 SSPS


3 "systems" that should NOT be tested concurrently

1.Reactor Trip System (RTBs)

2.Reactor Protection System (Instruments, 7300 and Rx Trip part of Logic Cabinets)

3.Solid State Protection System (Rest of the Logic and Actuation Cabinets)

 

Work on any 1 is fine

Work on 2 parts or 2 channels / trains needs thought:

Will this cause a trip or actuation?

Will this place the plant in an unanalyzed condition?  (LCO 3.0.3)

8

201.20 SSPS


First Out Annunciator Panels

Indicate cause of Rx Trip, SI,  or Turbine Trip on CP-005, CP-006

Basic Operation:

Initially all trip signals currently in will flash rapidly

Main Panel reset causes all but initiating signal to go solid

Depressing first out reset clears all windows

Manual trip signal may be delayed and look like a Turbine Trip.

9

201.20 SSPS


Generic SSPS Tech Spec Information

If OOS may be left as is or bypassed for 72 hours

If OOS for 72 hours must be placed in tripped condition

Permissives verified in proper state within 1 hour (if less than minimum channels operable)

Containment Spray receives special treatment – placed in BYPASS because it is energize to trip

10

P-4

Rx Trip Breakers are Open

Setpoint - both Rx Trip and Bypass bkrs open for that train 2/2

 

What it does:

Turbine Trip

Allows FWI on Low Tavg (574°F)

Allows manual block and reset of SI

Closes SB isolations if SR Flux Trip blocked

 

Why - Reactor Protection

 

11

P-6

Setpoint

What it does

Why

Source Range Trip Block Permissive

Setpoint - 10-10 amps IR power (1/2)

What - Block of SR High Flux Trip, removes power from SR detectors

 

Why - Ensures IR overlap prior to power ascension

Protects SR detectors from excessive flux while energized

12

P-7

Setpoint

What does it allow?

Why?

At-Power Permissive

Setpoint - P-10 OR P-13

 

What - At power Rx Trips:

PZR low press / high level

RCS low flow (2/4 loops)

RCP UV / UF

 

Why - Allow normal plant shutdown / cooldown without tripping shutdown banks

13

P-8

Single Loop Loss of Flow Permissive

Setpoint - 40% on PR NIs (2/4)

What - Rx Trip on low flow in one loop

(if not true, requires 2 loops low flow to trip)

Why - prevents DNB conditions

14

P-9

Turbine Trip / Reactor Trip Permissive

Setpoint - 50% on PR NIs (2/4)

What - C-8 to cause Rx Trip

Why - Rods can reduce power 10% step load change; Steam dumps can handle a 40% load rejection.

15

P-10

Power Range low FLux Trip Block Permissive

Setpoint - 10% on PR NIs (2/4)

What -

Allows block of IR flux trip and rod stops (C-1)

Allows block of PR high flux (low) trip

Backup, automatic input to SR NI blocks

Ensures SR NIs do not energize at power and trip the Rx if IR NIs fail

P-7

16

P-11

Low Pressure SI/SLI Block Permissive

Setpoint- Pressurizer Pressure < 1985 psig  (2/3)

 

What- Block of Low PZR Pressure SI AND Low Steamline Pressure SI/SLI

(When blocked, SLI protection is provided by the high negative rate signal)

Closure of SI Accumulator outlet valves

 

Why- Prevent SI actuation on normal plant cooldown

17

P-12

Low Tave Steam Dump Permissive

Setpoint - Tave < 563 F (2/4)

What - Vents air from steam dump operators

(bypass allows 3 valves to remain open)

Why - Prevent overcooling

18

P-13

Turbine At-Power Trips Permissive

Setpoint - 10% impulse pressure (1/2)

What - P-7

Why - At-power Trips apply with either nuclear or turbine power at 10%

19

P-14

S/G Hi-Hi level Trip

Setpoint - 87.5% 2/4 in any 1 S/G

What - Trips Main Turbine, SGFPs, and SUFP

FWI

Why - prevent overcooling and protect turbines from carryover

20

P-16

Rx Trip to Trip Turbine

Setpoint - P-4 OR SSPS Logic Train requests Rx Trip

What - Trips Main Turbine

Why - Prevent overcooling

Help mitigate ATWS with loss of feedwater

21

C-1

IR High Flux Rod Stop

Setpoint - IR NI current equal to 20% Rx power (1/2)

What - Stops ALL rod out motion

Why - Limits power excusion from events beginning in IR

22

C-2

23

C-3

OTΔT Rod Stop

Setpoint - PR NIs w/in 1.5% of current OTΔT setpoint (1/4)

What - stops ALL rod out motion

Why - DNB protection

24

C-4

25

C-5

Low Turbine Impulse Pressure Rod Stop

Setpoint - PT 505 pressure equivalent to 15% Turbine power

What does it do?

ONLY stops AUTO rod out motion

 Why?

Below 15%, impulse pressure is not an accurate input Tref

26

C-7

Steam Dump Load Rejection

Setpoint - >10% step load loss (PT-0506)

rate of load loss faster than 5%/min (PT-0506)

 

What - Arms the steam dumps in load reject mode

Why - Load is dropping faster than rod control can handle alone     steam dumps will be needed to prevent overheating the RCS

27

C-8

Turbine Trip

Setpoint - EH pressure <1245.8 psig (2/3) OR TVs closed (2/4)

 

What - Reactor Trip (if P-9 is true)

Main Generator Trip

Arms the steam dumps in Trip Mode

Blocks the load reject controller

Why - Prevent overheating the RCS

Prevent reverse power of Main Generator

Turbine tripped ⇉ PT-0506 is no longer a valid input.

28

C-9

Condenser Available for Steam Dumps

Setpoint - Any CW pump breaker closed AND Condenser Vacuum > 22”Hg (2/3)

What - Vents air from the steam dump operators

Why - Prevent dumping steam to a condenser that cannot support it.

29

C-11

Rods at Top Rod Stop

Setpoint - Bank D at 248 steps

What - Stops AUTO rod out motion ONLY

Why - I’m givin’ her all she’s got, cap’n!

30

C-17

Stop Turbine Loading

Setpoint - Tavg – Tref too negative (auctioneered low)

Tavg < 563 °F (auctioneered low)

What - Prevents raising turbine load

Why - prevent overcooling

31

C-20

AMSAC Armed

Setpoint - BOTH (505 and 506) turbine impulse pressure > 30% of full load pressure

What - Arms AMSAC (ATWS Mitigation System Actuation Circuitry)

Why - AMSAC is a backup to SSPS for certain trips, but is not needed < 30% power

32

201.20 SSPS


Describe controls available to operate Rx Trip Breakers

UV trip removes 48 VDC from UV coils on trip breakers

Shunt trip applies 125 VDC to shunt coil, which activates plunger to trip breaker

Auto - same train (R,S) trip bkr and opposite train bypass UV coils

same train trip bkr and bypass shunt

Manual Switches - Trip and SI control all 4 UV coils

Trip controls all 4 shunt coils