Shield Cooling Flashcards Preview

Systems > Shield Cooling > Flashcards

Flashcards in Shield Cooling Deck (21):
1

Is the shield cooling system safety related and what is its purpose?

Not safety related.

Closed loop cooling system

Removes heat from the biological shield surrounding the reactor vessel thereby limiting stresses in the structural concrete.

2

What is the design function of the shield cooling system?

Maintains structural concrete temperature less than 165°F

Maximum normal heat load on the system at full power is 120,000 BTU/hr.

  • Each coil set is capable of removing 180,000 BTU/hr
  • Heat Exchanger is capable of removing 200,000 BTU/hr
  • Each pump is capable of handling 100% of the required cooling water flow for removing 180,000 BTU/hr.

 

3

P-77A/B, Shield Cooling Pumps

P-77A/B, Shield Cooling Pumps

Capacity - 180 gpm each (100%)

Discharge Pressure –approximately 61 psig 

P-77A from MCC 2

P-77B from MCC 1

4

P-77A/B auto starts how?

Pump control switch in "Pull to Standby"

PS-0935 at 35 psig starts pump 

  • Brings in EK-1302

5

E-64, Shield Cooling Heat Exchanger

E-64, Shield Cooling Heat Exchanger

Heat Removal - 200,000 BTU/hr

Shell - CCW

  • Normal Flow 126 GPM
  • CHP - 0 GPM

Tube - Shield Cooling Water

HX outlet butterfly valve (MV-CC106) is manually throttled to control system temperature.

6

Shield Wall Cooling Coils

Shield Wall Cooling Coils

Two sets of coils with 3 coil sections in each set

Design Pressure – 75 psig

Design Temperature – 200°F

Normal flow rate is 38 to 43 gpm per coil section and 134 to 154 gpm per coil set (wall section + slab section = coil set).

7

CV-0932 & CV-0934, Coil Inlet Supply Valves

CV-0932 & CV-0934, Coil Inlet Supply Valves

Air operated, fail open diaphragm valves

C-08/03

  • Two position OPEN-CLOSE key operated switch
  • Red and Green position indicating lights

Interlocked with associated flow alarm so that when valve is closed, low flow alarm is bypassed

8

What does the shild wall coil relieve at?

Each wall coil has a relief valve for overpressure protection due to thermal expansion (100 psig)

9

What are the flow indications for wall coils?

FI-0928, FI-0929, FI-0931 for A Coil

FI-0934, FI-0935, FI-0936 for B Coil

10

What temperature indications are there in the control room?

TE-0931 (TE-0933) – provides control room indication

High temperature alarm at 120°F via TIA-0931 (TIA-0933)

 

11

What alarms on low flow?

FS-0932 (FS-2104) – provides control room alarm when in-service coil flow decreases to  ≤ 80 gpm

Alarm bypassed when inlet supply valve CV-0932 (CV-0934) is closed.

12

What is the design of the Floor Slab Coils?

Two sets of coils with each having 1 section

Design Pressure – 75 psig

Design Temperature – 200°F

Normal flow rate through floor coil is 20 to 25 gpm

Local flow and temperature indication

  • FI-2110 (FI-2111)
  • TI-2110 (TI-2111)

 

13

T-62, Shield Cooling Surge Tank

T-62, Shield Cooling Surge Tank

  • Capacity - 1,700 gallons
  • Design Pressure - 50 psig
  • Design Temperature - 200°F

Maintains positive suction head on Shield Cooling Pumps.

Provides surge volume for Shield Cooling Water expansion and contraction.

Provides a point for the addition, recirculation and sampling of chemicals for the system.

14

CV-0927 Shield Cooling Surge Tank Makeup Valve

CV-0927 Shield Cooling Surge Tank Makeup Valve

Air operated diaphragm valve – fails closed

Level Switch (LS-0927) controls tank level

  • Opens valve at 23% (34”) and closes valve at 86% (74”)

Makeup supplied from T-81, Primary System Makeup Water Tank

15

CV-0939 Containment Isolation

CV-0939 Containment Isolation

C-13 by two-position OPEN-CLOSE control switch

Automatically closes on Containment High Pressure (CHP) or Containment High Rad actuation (CHR)

16

EK-1303, “REACTOR SHIELD CLG LO FLOW”

EK-1303, “REACTOR SHIELD CLG LO FLOW”

  • Actuated by FS-0932 (FS-2104) at 80 gpm
  • Check one pump running
  • Shift in-service coils
  • If necessary, start standby pump

17

EK-1302, “REACTOR SHIELD CLG PUMPS DISCH LOW PRESS

EK-1302, “REACTOR SHIELD CLG PUMPS DISCH LOW PRESS

  • Actuate by PS-0935 at 35 psig
  • Standby pump starts on low pressure
  • Verify standby pump starts - align switches
  • Check surge tank level normal
  • If low pressure is due to leakage then shift in-service coils

18

EK-1301, “SHIELD CLG PUMPS TRIP

EK-1301, “SHIELD CLG PUMPS TRIP

  • Actuated by “b” contact in breaker
  • Standby pump starts at 35 psig lowering
  • Verify standby pump starts – align switches
  • If both pumps tripped or cannot be started, then initiate plant shutdown

19

EK-1304, “REACTOR SHIELD CLG HI TEMP”

EK-1304, “REACTOR SHIELD CLG HI TEMP”

  • Actuated by TIA-0931 (TIA-0933) at 120°F
  • Check coil outlet temperature
  • Check CCW to CNTMT normal
  • Start standby pump
  • Place standby coil in service
  • If flow cannot be restored and Shield Cooling Return temperature rises to greater than 165°F, then initiate plant S/D

20

EK-1305, “SHIELD CLG SURGE TANK T-62 HI LO LEVEL”

EK-1305, “SHIELD CLG SURGE TANK T-62 HI LO LEVEL”

  • Actuated by LIA-0927, High – 95%, Low – 4.5%
  • CV-0927, Surge Tank Makeup Control Valve opens at 23%, closes at 86%
  • If high level, then close CV-0939, Shield Cooling Surge Tank Inlet Isolation until level returns to normal
  • If low level, then check open CV-0939, Shield Cooling Surge Tank Inlet Isolation and one P 79, Primary System M/U Transfer Pump running
  • If necessary, then bypass CV-0927, Surge Tank Makeup Control Valve using MV CD148, Shield Cooling Makeup CV Bypass
  • If level remains high, then direct Chemistry Department to check for CCW in-leakage
  • If level remains low, then check for leakage by shifting in-service coils

21

SOP-29 Requirements

SOP-29 Requirements

Shield Cooling System shall be in operation prior to PCS temperature exceeding 165°F

Minimum flow

  • Shield wall coil 30 gpm
  • Floor slab coil 20 gpm

Maximum system flow

  • 154 gpm; limited by heat exchanger.

Flow Balancing

  • Minimum ratio – 5 (wall coil) to 1 (floor coil)