PLCS

Question 1

What is a potential concern when working on PLCS

Answer 1

A potential to initiate a unit trip

Question 2

What input does PLCS receive from RRS

Answer 2

Tave

Question 3

What are the Pzr LT power supplies

Answer 3

110x - PNA-D25

110y - PNB-D26

Question 4

What is the power supply FROM LT-110x/y to PLCS

Answer 4

110x - NNN-D12

110y - NNN-D11

Question 5

What automatic actions will PLCS provide to PPCS

Answer 5

• actual level +3.0% above setpoint will cause htrs to
  energize in anticipation of an out surge
• Level <25% trips all htrs off

Question 6

Where are LT 110x/y signal sent?

Answer 6

110y - RSP, Hi/Lo alarms, Hi/Lo deviation alarms

110x - Same, and PAM recorder

Question 7

What is the purpose of the PLCS Function Generator

Answer 7

Calculates a PZR level set point based on Tave from RRS

Question 8

Describe how PZR level is controlled in relation to Tave, and power

Answer 8

• Tave band 568-586*F equates to 15-100% power
• PZR level increases Linearly from 15-100% power
• PZR min set point level (15%) - 33%
• PZR max set point level (100%) -52.6%

Question 9

What is the purpose/reasoning behind the PZR min/max levels

Answer 9

Insurge will not reach nozzles

Outsurge will not drain PZR on a trip

Question 10

What is the proper way to shift RCN-LIC-110 PZR level controller from R/A to L/A

Answer 10

• Adjust L/A setpoint to match remote setpoint
• Press Manual button
• Place R/L switch to Local
• Press the Auto button

Be in Manual when shifting R/L

Question 11

What are the different pointers on RCN-LIC-110 for

Answer 11

Red - Actuall PZR level
Black/White - Remote setpoint
Black - Local setpoint from thumb wheel

Question 12

What is required to make the PZR “Operable”

LCO 3.4.9

Answer 12

Pressurizer SHALL be Operable

• Water level ≥27% and ≤56%
• 2 groups of HTRS ≥125kw each

Mode 1-3
N/A transient levels

Question 13

What interlock is there between RRS and PLCS

Answer 13

RRS cannot be taken to test with RCN-LIC-110 in R/A

Question 14

What are the Letdown flow limits when RCN-LIC-110 is in Automatic

Answer 14

30-135 gpm

30 - adequate CH flow preheat to minimize stress on
CH nozzle
135 - prevent exceeding max LD flow

Lag feature used to minimize sudden flow changes

Question 15

What are the letdown flow limits when RCN-LIC-110 is in manual

Answer 15

0-150 gpm

Lag feature disabled

Question 16

When should the LD selector switch be in P/Q or Both

Answer 16

• 1 LD control valve should be used above 1000psia
  increasing
• 2 LD control valves can be in service below 1050 psia
  decreasing
  -2 LD control vlvs >1200 could exceed relief capacity

Question 17

How does PLCS control the always running CH pump

Answer 17

Always running, PLCS does not control

Question 18

How does PLCS control the Normally running CH pump

Answer 18

• Normally running
• +15% increasing of setpoint pump STOPS
• +14% decreasing pump restarts

Must be in Auto After Stop

Question 19

How does PLCS control the STBY CH pump

Answer 19

• Normally not running
• -23% of setpoint Starts STBY pump
• -14% of setpoint Stops STBY pump

Question 20

When do the PZR Hi/Lo level alarms come in

Answer 20

60%

25% - resets at 27%

Question 21

When do the PZR level Error alarms come in

Answer 21

+8.5% resets at 8.2%

-3.5% resets at -2.7%

Question 22

List PZR pressure settings and event

Answer 22

2750 psia - RCS Safety Limit
2500 psia - RCS Design Press.
2475 psia - PZR safeties open
2409 psia - SPLA HP B/U trip
2383 psia - HP Rx trip
2300 psia - Spray Full open
2295 psia - DNB LCO
2285 psia - PZR Hi press alarm/ cutout
2275 psia - Spray vlv begin to open
2250 psia - NOP
2225 psia - Prop htrs max, low press. reset
2200 psia - All htrs on, Low press. stpt. 
                     override blocked
2160 psia - Low Press alarm
1837 psia - LP Rx trip, SIAS, CIAS

Question 23

What are the CH pump different flag indications and how are controls different for each

Answer 23

Red Flag - Run; no PLCS control

Green Flag - Auto after Stop; PLCS controls