LOT 201.27 Containment Combustible Gas Flashcards
- LOT 201.27 Containment Combustible Gas*
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What provides power for the H2 recombiners and the H2 monitors?
- H2 Recombiners:*
- *MCCs E1B4/E1C2**
- Not safety related*
- H2 Monitors:*
- *DP001/DP002**
- H2 Monitor Blowers:*
- *MCCs E1A4/E1C4**
- LOT 201.27 Containment Combustible Gas*
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How is H2 lowered during a DBA LOCA?
- *One Recombiner in Service**
- ↓ H2 < 4%*
- Place in-service at 3.5%*
- *Purge containment through supplementary containment purge subsystem**
- ↓ H2 < LCL*
- Available once containment pressure ≈ atmospheric*
H2 Recombiner controlled from CP002
Containment Supplementary Purge is controlled from CP022
- LOT 201.27 Containment Combustible Gas*
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What provides adequate mixing of the containment atmosphere during a DBA LOCA?
RCFC’s
Containment Spray
- LOT 201.27 Containment Combustible Gas*
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What are the sources of H2 during a LOCA?
- Major Source:*
- *Radiolytic decomposition of water ****
Other Sources:
Zirc water reaction **
H2 from the RCS
Max is 1190 scf
Corrosion of metals and paint in containment
Zinc-based paints & galvanized steel
Aluminum
Less of a source than zinc
- Note:*
- Radiolytic decomposition of water and Zirc water reaction are variable and will increase with fuel damage*
- LOT 201.27 Containment Combustible Gas*
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The operation of the H2 analyzers are based on what principle?
- *Thermal Conductivity ∝ ∆ in gas concentration**
- Thermal Conductivity of H2 7x greater than other gasses*
- LOT 201.27 Containment Combustible Gas*
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What are the sample points for the H2 monitors?
Top of Containment Dome
Above S/Gs (S/G C/D)
Inside S/G Compartment (S/G C/D)
Inside Primary Shield (S/G A/B)
Controlled from CP002
- Note:*
- H2 monitor “B” penetrations used by PASS*
- LOT 201.27 Containment Combustible Gas*
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How do the containment recombiners work?
Flowpath is through natural convection
Heater section (1225 ˚F - 1450 ˚F) causes recombination
- LOT 201.27 Containment Combustible Gas*
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Where are the Containment H2 monitors physically located?
60 ‘ MAB west of CCW surge tank
