SG Blowdown

Question 0

What ESFAS signals will cause the two automatic containment isolation valves on the blowdown lines to isolate the blowdown system?

Answer 0

AFAS, MSIS, SIAS

Question 1

What is the purpose of the SG blowdown system?

Answer 1

Compensate for impurity concentration

Also maintains the SG in wet layup by providing the capability to adequately mix, sample and add chemicals to the SG

Question 2

What are the possible possible flow paths for SG bd?

Answer 2

BFT, Cond, downcomer bd connection (primary)

Manually selected.

Question 3

What system provides cooling for the bdhx?

Answer 3

Condensate CD

Question 4

Where is the BFT liquid outlet routed?

Answer 4

3 LP FW heater

Question 5

Where is the condensate cooling water discharged to after it has gone through the BDHX?

Answer 5

Discharge of the ED pumps just prior to the suction of the main FW pumps.

Question 6

Where are the blowdown flow control valves physically located?

Answer 6

100’ turbine building west side

Question 7

How are the bd flow control valves operated and what is their fail position?

Answer 7

Air operated. Fail closed.

Question 8

How are the flow control valves operated?

Answer 8

Manually controlled inlet and outlet valves must be operated by an AO.

Question 9

Where is SG blowdown controlled from and how?

Answer 9

From control room

Via isolation and stop valve control switches.

Question 10

How many BFTs are there for both SGs?

Answer 10

One BFT for both SGs.

Question 11

Where does the BFT discharge to?

Answer 11

Bdhx or the #3 LP FW heater.

Question 12

How are the blowdown pressure regulating valves operated and how do they fail?

Answer 12

Air operated

Fail open

Question 13

What is the purpose of the blowdown pressure regulating valves?

Answer 13

Maintain BFT pressure which can be adjusted by AO at the local pressure controller.

Question 14

Describe the blowdown demineralizer package.

Answer 14

2 mixed bed, regen resin type units operated in series.

Question 15

Where are the blowdown demineralizers located?

Answer 15

North yard of the turbine building

Question 16

What happens to the bd demins if a high sodium level is detected?

Answer 16

The vessels will be removed from service IF the switch is in AUTO STOP mode.

Question 17

What happens to the bd demins if a high dP is detected while in AUTO STOP mode?

Answer 17

The vessel will be removed from service for regen

Question 18

Where is the bdhx located?

Answer 18

If the yard area on the plant south side of the bd demins

Question 19

Where do the wet layup recirc pumps normally take suction from and discharge to?

Answer 19

Normally a pump from SG 1
B pump from SG 2

Can be aligned to take and discharge to either SG.

Question 20

Where are the wet layup recirc pump switches located?

Answer 20

Ctmt next to the pumps on the 70’

Question 21

Where are the 480 Vac MCC breakers that supply power to the wet layup recirc pumps located?

Answer 21

Aux building 120’

Question 22

On loss of IA how does the bd to flash tank control valve fail?

Answer 22

Closed

Question 23

On loss of IA how do the bd to cond control valves fail?

Answer 23

Closed stopping blowdown

Question 24

How does the flash tank condensate level control valve to FW heater fail?

Answer 24

Closed

Question 25

How do the blowdown flash tank pressure control valve to HDT and BFT pressure control valves to cond fail?

Answer 25

Open

Question 26

Where does wet layup recirc water enter the tube bundle area of the SG?

Answer 26

Through the recirc lines

Question 27

What is the disadvantage of downcomer blowdown?

Answer 27

Advantage- highest levels of impurities 3-10*

Disadvantage- has no cleaning effect on the tube sheet sludge pile.