Term
| Function of recombiner system |
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Definition
| Recombine radiolytic hydrogen and oxygen normally present in the off-gas. |
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Term
| Name the three basic parts of the Gaseous rad waste system |
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Definition
| "Air Ejector Off-Gas system, gland steam packing exhauster, off-gas stack." |
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Term
| List the sources of radioactive gases |
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Definition
Main condenser air ejectors Gland steam packing exhauster MVP HPCI gland seal Standby gas treatment Dilution air
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Term
| Which sources of radioactive gases are directed to the gland steam packing exhauster holdup line (1.75 minute holdup line)? |
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Definition
Gland steam packing exhauster effluent, MVP effluent, HPCI gland seal effluent.
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Term
| List the major components of a recombiner train. |
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Definition
Preheater, recombiner Desuperheating condenser Condensate flash tank Drain cooler Pumps Hydrogen analyzer loop.
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Term
| What major recombiner components do the cooling water pumps supply? |
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Definition
| Desuperheating condenser and drain cooler. |
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Term
| What major recombiner components does main steam supply? |
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Definition
| Preheater and inlet off-gas warm-up supply. |
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Term
| Where does off-gas leaving the recombiner trains go? |
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Definition
| 42 inch diameter delay pipe |
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Term
| Which way is the 42 inch delay pipe sloped? Why? |
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Definition
| Sloped downward toward the plant so that any condensate formed in the line is gravity drained to V-810 (Drain Collecting Tank, SJAE room). |
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Term
| Purpose of recombiner preheater |
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Definition
| (Further) superheats the steam and off-gas mixture approximately 50 degrees F to improve recombination efficiency and to reduce condensation during a train startup. |
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Term
| Source of heat to recombiner preheater. Why? |
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Definition
| 260 psig saturated steam to assure that temperature of mixture exiting the preheater will not exceed 422 degrees F. This assures that post-recombination temperature of the off-gas will not exceed 850 degrees F which is safely below the hydrogen auto-ignition temperature of 1060 degrees F. |
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Term
| Source and purpose of dilution steam |
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Definition
| Source: second stage steam jet air ejectors. Purpose: supplied in such a quantity that yields a hydrogen concentration of less than 4% by volume. Also, prevents hydrogen burns between air ejectors and recombiners. Dilution steam creates an inert environment within the process piping during all operating conditions (with and without HWC). |
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Term
| Cooling supply to desuperheating condenser (tube side). |
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Definition
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Term
| Where does condensate from the desuperheating condenser go? |
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Definition
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Term
| What goes in the (recombiner system) flash tank? |
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Definition
| Desuperheating condenser condensate, condensate from preheater hotwell and various steam traps. |
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Term
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Definition
| Separate the liquid and vapor phases of the condensate it receives so that each can be returned individually to the main condenser without water hammer. |
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Term
| Purpose of recombiner drain cooler |
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Definition
| Further subcool condensate that is returning to the main condenser so that it does not flash upon entering the vacuum environment. |
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Term
| Where do non-condensable off-gases from desuperheating condenser go? |
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Definition
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Term
| Hydrogen alarm and trip setpoints |
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Definition
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Term
| What happens when train outlet valve is OPEN and 4% Hydrogen setpoint is exceeded? |
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Definition
| Off-gas compressors automatically shutdown. |
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Term
| During startup, when is a recombiner warmed and ready to receive off-gas? |
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Definition
| When the PREHEATER 11/12 OUTLET TEMP LOW alarm clears at 278 degrees F. |
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Term
| Upon the PREHEATER 11/12 OUTLET TEMP LOW clearing, how is a recombiner placed in service? |
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Definition
| Opening the air ejector suction valves. |
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Term
| List the parameters which cause AO-1085 A/B to automatically terminate off-gas flow. |
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Definition
Closes AO-1085 A/B AND AO-7557 A/B Loss of dilution steam as indicated by low pressure 110 psig at 2nd stage steam jet air ejector steam chest (5 second time delay); High off-gas radiation level at the pretreatment monitor after a 30 minute delay; Closure of MSIVs as indicated by low pressure on all four pressure switches for 5 seconds
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Term
| List the parameters which cause hydrogen analyzers to initiate an off-gas compressor auto shutdown. |
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Definition
| Outlet hydrogen concentration above 4% by volume (dry basis) as sensed by two-out-of-three analyzers in the operating train (10 second time delay); 2 out of 3 analyzers are disabled due to any of the following: low sample flow; filament failure; high cooler temperature; power failure. |
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Term
| State the major purpose of the off-gas monitoring system (off-gas pretreatment radiation monitoring systems). |
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Definition
| Provide continuous radiation monitoring of main condenser off-gas, cause an alarm and terminate off-gas flow when the gamma radiation level exceeds established limits. |
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Term
| What happens on an off-gas pretreatment Radiation monitoring system trip? |
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Definition
| AO-1085A and B, as well as AO-7557 A and B trip closed. |
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Term
| What causes an Off-gas pretreatment rad monitor trip? |
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Definition
NOTE: Trip occurs after 30 minute timer times out. |
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Term
| What protects against a failure of the (260 psig) pressure control valve? |
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Definition
| A relief valve, set at 330 psig, which discharges back to main condenser. |
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Term
| Criteria to consider Hydrogen Analyzers operable. |
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Definition
Hydrogen readings should have unsteady indication greater than or equal to -0.1 percent; Rotameter readings should be greater than 50 CCM and less than full scale; Bypass flow 1800 to 2800 CCM.
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Term
| Which areas particularly apply to the general precaution that standard NMC rad protection procedures shall be complied with prior to entry? |
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Definition
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Term
| IF a valid 4% shutdown occurs, THEN… |
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Definition
| Verify trip of both off-gas compressors. |
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Term
| Nuclear concern general precaution concerning off-gas steam flow. |
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Definition
| Off-gas steam flow is an input to the nuclear instrumentation (IRM) heat balance. Any changes to this parameter will affect calculated thermal power. |
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Term
| Power supply to #11 Recombiner Condensate pump |
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Definition
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Term
| Power supply to #12 Recombiner Condensate pump |
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Definition
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Term
| Control power for #11 Recombiner Condensate drain pump |
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Definition
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Term
| Control power for #12 Recombiner Condensate drain pump |
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Definition
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Term
| Control/Trip Logic Power to Recombiner train A |
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Definition
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Term
| Control/Trip Logic Power to Recombiner train B |
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Definition
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