Systems Exam 2 - Containment Systems

Question 1

Max Containment Pressure and Temp

Answer 1

→max design pressure: 50 psig
→max design temp: 280°F
(applies to the structure, not the inside atmosphere)

Question 2

Basis for Max Containment Pressure and Temp

Answer 2

1. Serve as the outermost barrier in preventing the release of radionuclides to the environment, in the event of an accident.
2. Protect the NSSS and its auxiliaries from outside hazards.
3. Serve as a support structure for various components.
4. Act as part of the CPSES Biological Shielding.
5. Meeting design temperature and pressure ensures CTMT does not exceed allowable leakage

Question 3

Purpose of Charcoal Filters

Answer 3

Charcoal filters are used to remove iodine from CTMT atmosphere

Question 4

Purpose of Particulate filters

Answer 4

Particulate filters remove aerosols

Question 5

Design criteria for Containment Ventilation Isolation valves

Answer 5

Containment Ventilation Isolation valves must be capable of being closed during reduced inventory in case RHR cooling is lost

Question 6

10CFR100 Criteria

Answer 6

1. Exclusion area (2 hours):
   < 25 R whole body
   < 300 R thyroid
2. Low Population Zone (duration of accident):
   < 25 R whole body
   < 300 R thyroid

Question 7

Hydrogen Generation Aluminum and Zinc Corrosion

Answer 7

The use of aluminum inside the containment is limited, but zinc can be found in both the paint used in containment and also the galvanizing process used in the duct work. The hydrogen generated from zinc is completed during the first day after the accident.

Question 8

Containment Leakage Detection

Answer 8

CNTMT Sumps provide CNTMT SUMP FILL RATE INCREASE alarm if level increases by 5/8” over preset time, fill rate and total flow required by TS

Question 9

Describe the response of the Containment Sumps to a Phase A signal

Answer 9

The containment isolation valves will close on a Phase A signal. Valve closure results in a pump trip.

Question 10

CNTMT PRESS HI 1 alarm

Answer 10

→3.2 psig (1/3)
→2/3 channels provides SI (Channels 2-4)

Question 11

CNTMT PRESS HI 2 alarm

Answer 11

→6.2 psig (1/3)
→2/3 generates MSL Isolation (Channels 2-4)

Question 12

CNTMT PRESS HI 3 alarm

Answer 12

→18.2 psig (1/4)
→2/4 generates Containment Spray Actuation (Channels 1-4)
→requires relays to energize to actuate; loss of power will not cause CS actuation

Question 13

Containment Atmosphere Hydrogen Analyzers

Answer 13

→continuously monitor the hydrogen content of the containment atmosphere during normal plant operation →shall be operational within 30 minutes following a LOCA

Question 14

Containment Pressure IR Channels

Answer 14

Channel 1 - 937
Channel 2 - 936
Channel 3 - 935
Channel 4 - 934

Question 15

TS 3.6.3 CIV notes

Answer 15

→separate condition entry is allowed for each penetration flow path.
→during fuel movement containment penetrations are required to be isolated or tracked by a LCOAR or fuel movement must be suspended

Question 16

TS 3.6.4 CTNMT Pressure

Answer 16

→ctnmt pressure must be maintained ≥-0.3 psig and ≤1.3 psig
→use pressure relief system to maintain

Question 17

TS 3.6.5 CTNMT Temperature

Answer 17

→ctnmt average temp must be ≤120°F
→start additional CACRS to maintain

Question 18

Which accidents is containment designed to protect against?

Answer 18

→large break LOCA (i.e. double ended pipe shear)
→faulted S/G (a.k.a. major steam pipe rupture)

Question 19

How are the valves that close on Phase A different than the valves that close on Phase B?

Answer 19

Phase B valves are MOVs because Instrument Air to Containment is isolated on Phase A.

Question 20

What do the black labels under MCB instruments mean?

Answer 20

used for Post Accident Monitoring (PAM) - they’re rated for use in adverse conditions inside Containment after an accident

Question 21

What is the range of the Containment pressure indicator on the MCB?

Answer 21

-2.5 to 2.5 psig