CBA

Question 1

State how Control Room pressure is maintained

Answer 1

CBA-DP-28 modulates to maintain CR pressure

The Controller output is clipped at 9% to prevent fan trip

Question 2

State inlock for CBA-FN-15

Answer 2

Supply fan FN-27A/B must be running for FN-15 to start
DP-28 must be open for fan to start
Closure of DP-28 will cause FN-15 to stop

Question 3

Discuss supply fan discharge dampers on CRFRM

Answer 3

Supply dampers 53A/B are cross train powered to ensure that both FN-27A/B are stopped on single train actuation

Question 4

State how CBA responds on LOP

Answer 4

DP-27A/B fail open on LOP. When FN-16A/B is reenergized it will see DP-27A/B not full closed and start the CR in CRFRM

Question 5

State the CRFRM actuation signals

Answer 5

• Hi rad in either intake in either train Rad Monitor, both channels in either train of Rad monitor
• Manually starting CBA-FN-16A/B or CRFRM
• LOP due to DP-27A/B failing open
• Any SI due to DP-27A/B opening

Question 6

State how to recover from CRFRM

Answer 6

• Remove CRFRM signal (SI, Hi rad, Switch back to Auto)

- Stop FN-16A/B

Question 7

State how Discharge dampers are arranged by train

Answer 7

DP-28 is dual trained
DP-1058 is only B train
So…either train CRFRM will close 28, 1058 will only close on B

Question 8

State the response of the Safety Related CBA chillers on LOP

Answer 8

Since the NNS chillers are powered from bus 1

the Safety related chillers will start when their E-bus is repowered and then load at step 5

Question 9

State what needs happed if 1 train of CBA rad monitoring is OOS (T.S. 3.3.3.1)

Answer 9

Within 1 hour initiate and maintain CRFRM

Question 10

State what must be done if the CRE is inoperable (T.S. 3.7.6.1)

Answer 10

Immediately initiate action to implement mitigating actions or be in at least HOT STANDBY within the next 6 hours

Question 11

State what must be done if both trains of CRFRM are inoperable

Answer 11

enter T.S. 3.0.3