LCO 3.7

Question 1

3.7.1
Main Steam Safety Valves (MSSVs)

Bases?

Answer 1

Limits 2 MSSV to 110% of design by passing 100% flow

2 MSSV limiting event - full power loss of vacuum
1 MSSV limiting event - full power FWLB in CTMT

1 - 1250#
2 - 1290#
3,4,5 - 1315#

Question 2

3.7.2
Main Steam Isolation Valves (MSIVs)

Modes?
MSIV Operability Requirements?
Actions?

Answer 2

Mode 1, Mode 2-4 (Except when all MSIVs Closed/Deactivated)

4 MSIVs AND Actuators
Isolation times in limited (<4.6 Sec?)
Close on MSIS
Fast Closure Available
Greater than or equal to 5000# Accumulator
Air Reservoir - Adequate Press (74# - Seis Alarm)

1 MSIV Actuator - 7 days
2 MSIV (1 ACT Inop/ Diff Trains) - 72 hrs
2 MSIV (1 ACT/ Same Train) - 48 hrs
1 MSIV (Both Act) - Declare MSIV INOP
3 Actuators - Declare MSIV INOP
1 MSIV INOP - Restore 4 hrs

Question 3

3.7.3
Main Feedwater Isolation Valves (MFIVs)

Modes?
Requirements?
Actions?
Notes?

Answer 3

Mode 1-4 (Except when MFIV Closed/Deactivated OR Isolated by MOV)

4 Economizer MFWs and 4 Downcomer MFIVs

Separate Entry allowed for each penetration

Isolation times in Limits

Auto Close on MSIS

Question 4

3.7.4
Atmospheric Dump Valves (ADVs)

Modes?
Requirements?
Bases?
Actions?

Answer 4

Modes 1-4 when S/Gs required for DHR

1 INOP on One/Both S/Gs - 7 Days
2 INOP on One/Both S/Gs - 24 hours

Bases:
C/D during SGTR
Remote OPS Required
13.3 hrs operations (4 hrs Mode 3/9.3 hrs to Mode 5)

Question 5

3.7.5

Answer 5

Auxiliary Feedwater (AFW) System

Question 6

3.7.6

Answer 6

Condensate Storage Tank (CST)

Question 7

3.7.7
Essential Cooling Water (EW) System

Modes?
Actions?
Bases?
Component Isolation?

Answer 7

Modes 1-4 (72 hr LCO)
Mode 4 INOP- SDC INOP (3.0.6 N/A)

Cools CS for S/D and Loop
Cools Sump Fluid (LOCA)
Cools SDC (<350 F Tc to M5)

Isolate:
  SDC HX (Both SDC and EW INOP)
  Cross Tie to NC Priority Loads = EW INOP

Question 8

3.7.8

Answer 8

Essential Spray Pond System (ESPS)

Question 9

3.7.9

Answer 9

Ultimate Heat Sink (UHS)

Question 10

3.7.10
Essential Chilled Water (EC) System

Modes?
Actions?
Component Isolation?

Answer 10

Modes 1-4 (72 Hr LCO)

Isolate One CLR - OK
Isolate greater or equal to 2 CLR - EC Operability depends on engineering evaluation

Question 11

3.7.11

Answer 11

Control Room Essential Filtration System (CREFS)

Question 12

3.7.12

Answer 12

Control Room Emergency Air Temperature Control System (CREATCS)

Question 13

3.7.13

Answer 13

Engineered Safety Feature (ESF) Pump Room Exhaust Air Cleanup System (PREACS)

Question 14

3.7.14

Answer 14

Fuel Storage Pool Water Level

Question 15

3.7.15

Answer 15

Fuel Storage Pool Boron Concentration

Question 16

3.7.16
Secondary Specific Activity

Modes?
Limit?
Bases?
Actions?

Answer 16

Mode 1-4 (Less than or equal to 0.1 mCi/gm Dose Equivalent I-131)

Mode 3 in 6 hours/ Mode 5 in 36 hours

Assumption in MSLB analysis
Small fraction of offsite dose limits (10 CFR 100)

Question 17

3.7.17

Answer 17

Spent Fuel Assembly Storage

Question 18

3.7.1
Main Steam Safety Valves (MSSVs)

Modes?
Requirements?
Actions?

Answer 18

Modes 1-3
Modes 1-2 = 10 per S/G Required (ALL)
Mode 3 = 2 per S/G Required

Modes 1-2
Up to 4 INOP per S/G - Reduce Power 4 hrs AND Reduce VOPT 36 hrs
>4 INOP per S/G - Mode 3 in 6 hours

> 8 per S/G INOP - Go to Mode 4

Question 19

3.7.2
Main Steam Isolation Valves (MSIVs)

Bases (Safety Analysis)?
Limiting Accidents?

Answer 19

SLB in CTMT
Limiting Case - HZP (Most mass in S/G)
Loop/1 MSIV Fails Open

SLB in MSSS (Upstream MSIV)
Off-Site Dose Limiting (10CFR100)

SGTR
Limits Off-Site Dose
Isolates S/G for press control

Maintain SDM (Excessive C/D)

Question 20

3.7.3
Main Feedwater Isolation Valves (MFIVs)

BASES? (Safety Analysis)

Answer 20

Large SLB/FWLB

Prevent water in steam lines (Hi Level)

Prevents excessive FW to Mo Minimize RCS Cooldown