Term
Function of Secondary containment |
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Definition
"Minimize ground level release of airborne radioactive material to environment. Controlled, elevated release from Reactor building." |
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Term
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Definition
Less than or equal to 4000 cfm (3 volume changes per day under neutral wind conditions (5 mph) and 0.25 inch vacuum) |
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Term
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Definition
"Less than or equal to 100 percent free volume per day with 0.25 inch vacuum and 40 mph wind speed. (Exfiltration is unfiltered, ground level release)." |
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Term
Maximum internal pressure for secondary containment |
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Definition
7 inches water (blow-out panels relieve at this pressure) |
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Term
Secondary Containment Isolation signals |
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Definition
High drywell pressure: 1.84 psig; Low Low Reactor Level: -47 inches; Rx Building Plenum Radiation: 26 mR/hr (1 pscale or 2 downscale); Refuel floor radiation: 50 mR/hr (1 upscale or 2 downscale)
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Term
What happens on an automatic secondary containment signal? |
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Definition
Isolates secondary containment, Initiates StandBy Gas Treatment, Initiates EFT in HIGH RAD MODE.
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Term
Explain the logic required for automatic secondary containment initiation. |
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Definition
The initiation signals come from RPS which is DE-ENERGIZE to activate (failsafe); The secondary containment logic is energize to activate. |
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Term
When is secondary containment required? |
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Definition
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Term
What must be done after experiencing Tornado or high winds? |
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Definition
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Term
Explain the operability requirements for SBGT in terms of dilution fans. |
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Definition
"V-EF-18A, stack dilution fan SHALL be operable for SBGT A train to be considered operable. Likewise, V-EF-18B SHALL be operable for SBGT B train to be considered operable." |
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Term
What does the Ops manual list as secondary containment? |
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Definition
Rx Building closed including HPCI Room roof plugs in place; Steam Chase Blowout Panels in place and not blocked; At least one door in each access opening closed; shield plugs in place or isolation dampers closed and wired shut and floor drain analyzed for acceptable SCTMT leakage; Ventilation system isolation dampers SHALL be operable or secured in the CLOSED position; Ventilation interface dampers (V-EF-26 to Plenum room) SHALL be operable or secured in the OPEN position.
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Term
Precaution associated with securing a SBGT Train. |
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Definition
Each Train should be run for about 5 minutes after the filter heaters have been placed in OFF to provide for cooldown of the filter trains. Immediate shutdown without cooldown could result in overheating of the filter heaters or other components of the filter train. |
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Term
Suggested run time to minimize the amount of moisture in HEPA filters. |
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Definition
Per Ops manual, 10 hours a month with heaters energized. |
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Term
Power supply to SBGT A (fan, damper and control power) |
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Definition
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Term
Power supply to SBGT B (fan, damper and control power) |
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Definition
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Term
Compare the failure mechanisms of SCTMT and SBGT dampers |
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Definition
SCTMT dampers fail closed on a loss of instrument air. SBGT dampers fail open on a loss of instrument air. |
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Term
Describe the Secondary containment airlocks |
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Definition
De-energize to unlatch with battery back-up |
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