CBS

Question 1

State Pressure limit for Containment

Answer 1

52#

Question 2

State when CBS pumps start on LOP

Answer 2

either at SR3

Or at HR8, there is a 5 sec delay if that train of CT pump just started for Starting amps to decay

Question 3

State when CBS-V-8/14 get auto open signal

Answer 3

120,478 Gal in RWST, 2/4 logic
Interlocked with RHR loops isolation valves
Requires operator to close CBS-V-2/5 within 3 min

Question 4

State T.S. limits on RWST

Answer 4

477,00 gallons
min temp 50F
max temp 98F

Question 5

State worse case scenario for LOCA and why

Answer 5

RCS crossover leg.

• High venting rate (pipe is larger)
• path of least resistance
• after partial blowdown S/G’s become a heat source
• peak pressure 49.6#

Question 6

State two reasons why Iodine is kept in solution

Answer 6

Iodine in gaseous form leaks out of containment

Iodine is absorbed into the thyroid

Question 7

State why we use NaOH in the SAT

Answer 7

Raises pH to 8.5 - 11

Chemical reaction keeps Iodine in solution

Question 8

State setpoints and coincidences of CSAS

Answer 8

Manual, 2/2, also causes CVI and Phase B

HI-3, 18#, 2/4, also Phase B isolation

Question 9

Explain the limits on pH for CBS

Answer 9

Lower limit to keep iodine in solution

Upper limit is to prevent stress corrosion cracking

Question 10

State T.S. 3.5.4 (RWST) LCO and Actions

Answer 10

The RWST shall be operable with:
477,000 gallons
Concentration listed in COLR
min temp 50F
max temp 98F

If LCO can not be met the restore to OPERABLE within 1 hour or be in HOT STANDBY within 6 hrs and COLD SHUTDOWN within the following 30

Question 11

State plant response to a CSAS

Answer 11

CBS pumps start
CBS-V-11/17 open (Containment isolations)
CBS-V-30,31 and 33 close (recirc isolations)
CBS-V-38,43 open (SAT isolations)
Phase B isolation
Manual initiates CVI (normally done by S-signal)

Question 12

State plant response to a P signal

Answer 12

CRDM fans trip
CC-V-137 & 266, CBS HX PCCW outlets, open
CAH-FN-3-A & B, cont recirc fans, start in the RECIRC mode
PCCW containment isolations close
Requires RCP trip due to loss of cooling (loss of forced cooling)
Containment cooling fans will also trip on low CC flow

Question 13

Discuss auto swap over to containment sumps

Answer 13

Opening CBS-V-8 and 14
‘S’ signal lock in
coincident with RWST lo-lo level (2/4 @ 120,478 gal) 
Closing CBS-V-2 and 5
Manually closed by procedure (ES-1.3)
Time limit for switchover is 180 seconds

Question 14

State T.S. 3.6.1.1 for Containment Integrity LCO and Action

Answer 14

Primary CONTAINMENT INTEGRITY shall be maintained.
MODES: 1,2,3, and 4
Without primary CONTAINMENT INTEGRITY, restore CONTAINMENT INTEGRITY within 1 hr or be in atleast HOT STANDBY within the next 6 hours and in COLD SHUTDOWN within the following 30 hours.

Question 15

State T.S. 3.6.1.2 For Containment Leakage LCO and Action

Answer 15

Leakage rates shall be limited in accordance with the LLRT program
MODES: 1,2,3, and 4
With the overall integrated leakage rate exceeding 1.0 La restore CONTAINMENT INTEGRITY within 1 hr or be in atleast HOT STANDBY within the next 6 hrs and in COLD SHUTDOWN within the following 30 hours

Question 16

State T.S. for Internal Pressure LCO and Action

Answer 16

Primary containment internal pressure shall be maintained between 14.6 and 16.2 psia
MODES: 1,2,3, and 4
With the containment internal pressure outside of the limits above, restore the internal pressure to within the limits within 1 hour or b in at least HOT STANDBY within the next 6 hrs and in COLD SHUTDOWN within the following 30 hrs.