CTS and H2 Recombiners

Question 1

What is the purpose of the CTS system?

Answer 1

• Limits post-accident containment pressure and temperature to less than design values of 12#
• Removes radioactive elemental iodine from the containment atmosphere in the event of a DBA.

Question 2

What is the purpose of the H2 Recombiner?

Answer 2

• Recombines H2 and O2 to form steam

Question 3

What is the purpose of DIS?

Answer 3

• The DIS eliminates hydrogen in the containment following a LOCA to prevent a detonation by period ignition of h2 mixtures

Question 4

What are the CTS pump starts?

Answer 4

• Load Shed (W/ Phase B)
• Phase B
• Manual

Question 5

What are the CTS pump Trips?

Answer 5

• Load Shed
• Overload/Overcurrent
• Manual

Question 6

What causes a CTS signal?

Answer 6

• 2.8# (2/4)

Question 7

What happens on a SAT low-low lvl?

Answer 7

• SAT outlet valves close and eductor suction valves should have closed prior to the SAT Low Low lvl alarm

Question 8

What is the CTS flow to upper ctmnt spray header?

Answer 8

• 2000gpm

Question 9

What is the CTS flow to lower ctmnt spray header?

Answer 9

• 1200gpm

Question 10

Which CTS header does RHR feed and how much flow?

Answer 10

• Upper ctmnt spray header only, and 2000gpm

Question 11

What is the intended pH of the recirc sump due to CTS?

Answer 11

• 7-10 pH

- want 8.5 pH to keep iodine in solution

Question 12

What is added to the SAT to help remove radioactive iodine?

Answer 12

• Sodium Hydroxide

Question 13

What do we use in the SAT to minimize moisture?

Answer 13

• Nitrogen overpressure

Question 14

Can the H2 Recombiners be started in modes 1-4?

Answer 14

• Yes, but you have to declare the EDGs inoperable because it will over load the EDGs in the event of an SI with LOOP

Question 15

What powers the H2 recombiners?

Answer 15

• 11/21 B

- 11/21 C

Question 16

Will the CTS pump auto start on a Containment Spray Signal?

Answer 16

• No

Question 17

Main Steam Isolation comes from with Ctmnt iso phase?

Answer 17

• Phase B (Auto only)

Question 18

What will 2.8# in ctmnt cause?

Answer 18

• Phase B
• Ctmnt Spray Actuation
• Steam Line Iso (auto only)

Question 19

What are the auto actions of a Ctmnt Spray Actuation?

Answer 19

• CTS pump disch valves open
• SAT outlet valves open
• CTS Hx ESW outlet OPEN w/ recirc sump valves (ICM-305/306) open

Question 20

What are the H2 production sources?

Answer 20

• Zirc (Clad) H20 reaction
• Radiolytic decomp of H20
• Corrosion of metals inside containment

Question 21

What is the purpose of the Spray Add educator?

Answer 21

• Draws the NaOH solution from the SAT and mixes it with a portion of the CTS pump discharge flow

Question 22

What must be closed before you can open ICM-305 and 306?

Answer 22

• IMO-310/320 closed

- IMO215/225 closed

Question 23

When do the ESW to CTS Hx outlet valves throttle open and to what flow?

Answer 23

• Throttle open on a CTS Signal and ICM 305/306 open to 2400gpm

Question 24

What do the manual phase B switches actuate

Answer 24

• Train specific phase B containment isolation
• Train specific CTS
• Train specific CVI
• Starts CTS pump

Question 25

What does maintaining a pH of less than 10 prevent

Answer 25

Chloride and caustic stress corrosion cracking

Question 26

What are the capacity and NaOH concentration requirements for the SAT

Answer 26

- 4000-4600 gal | - 30%-34% NaOH

Question 27

What temperature do the H2 Recombiners operate at

Answer 27

1200 deg F

Question 28

What temperature does DIS operate at

Answer 28

1700 deg F

Question 29

Explain the interlock associated with the CTS pump suction valves from the RWST

Answer 29

- Normally open, interlocked with recirc sump suction valves so that only one source can be aligned at a time

Question 30

Explain the interlock associated with the CTS pump discharge valves

Answer 30

- Normally closed, open automatically on a CTS signal

Question 31

Explain the interlocks associated with the SAT valves

Answer 31

- SAT Isolation valves normally close, open on CTS signal - Eductor supply valves normally open - SAT Isolation AND educator supply valves auto close on lo-lo level in SAT

Question 32

Explain the interlock associated with the CTS Hx ESW outlet valves

Answer 32

- Normally closed, open on CTS signal combined w/ recirc sump suction valves open - Must be opened manually if CTS signal is reset before recirc sump valves are opened.