Term
| Function of RHR Service Water |
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Definition
| "Supply strained river water to the RHR heat exchangers which remove heat rejected by the RHR system during normal reactor shutdown cooling, during reactor isolation or accident conditions, and during the time when the fuel pool has an emergency heat load from spent fuel. Also, the system can provide an inexhaustible supply of cooling water to the core by pumping river water through LPCI lines." |
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Term
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Definition
| Two separate, redundant loops, each capable of providing the cooling requirements for a DBA LOCA (and the less demanding reactor S/D cooling mode). |
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Term
| Purpose of RHRSW basket strainers |
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Definition
| Reduce the possibility of plugging the heat exchangers. |
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Term
| Indication of RHRSW strainer plugging |
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Definition
| 5 psid as indicated by alarm in control room. |
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Term
| Minimum flow required to prevent RHR motor thrust bearing from overheating. |
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Definition
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Term
| Various sources of seal water to RHRSW pump. |
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Definition
| When shutdown: seal water system; when operating: self-sealed |
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Term
| Connection between RHRSW and Service Water system |
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Definition
| Service Water system provides RHRSW keep-fill to maintain discharge header pressurized and full of water under normal conditions. |
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Term
| Through which loop can RHRSW provide emergency makeup to the vessel? |
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Definition
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Term
| Where does RHRSW enter the Reactor building? |
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Definition
| NE corner above ground floor. |
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Term
| Connection between RHRSW and Demin Water system |
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Definition
| Demin can be used to flush the heat exchangers. |
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Term
| Where does RHRSW discharge? |
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Definition
| Into a common discharge line for all the Service Water Systems in the Reactor Building which eventually meets up with the Circulating water system discharge line (upstream of the radiation monitor). |
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Term
| Discuss the differential pressure between RHRSW and RHR in the heat exchanger. |
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Definition
| "Differential control valve, normally manually operated, maintains RHRSW discharge pressure from HX at least 20 psid above RHR inlet to HX pressure. Acceptance criteria for minimum RHRSW dP is such that under worst case conditions and 1 RHRSW pump in service, the RHRSW system will maintain at least 20 psi above the max RHR pressure expected at the HX." |
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Term
| Why is RHR HX dP maintained the way it is? |
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Definition
| It is maintained such that RHRSW is at least 20 psi greater than RHR pressure at the HX to prevent the possibility of radioactive water (in the event of a tube leak) being discharged to the river. |
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Term
| Normal shutdown cooling range |
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Definition
| From 281 degrees F and 50 psia (steam supply pressure insufficient to maintain turbine shaft seals and vacuum in the main condenser cannot be maintained) to 125 degrees F in 24 hours. |
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Term
| When is torus cooling placed in service? |
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Definition
Following RCIC operation or testing of HPCI, OR whenever suppression pool water approaches 90 degrees F. NOTE: minimum torus temperature is 65 degrees F. |
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Term
| Discuss RHRSW operation upon ECCS initiation signal from LPCI Control system (normal power available). |
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Definition
| RHRSW pumps will be tripped if they are running. Pumps can not be re-started unless ECCS signal clears or the keylocked bypass switch is operated. |
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Term
| Discuss RHRSW operation upon ECCS initiation signal from LPCI Control system (coincident with loss of off-site power). |
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Definition
| Initiation of automatic loading sequence, combined with the ECCS initiation signal, will automatically trip and lock out the RHRSW pumps. Lock-out will remain until: ECCS initiation signals from core spray and LPCI control systems are terminated or bypassed and an RHR pump is stopped; Normal power is restored to the essential bus and the ECCS initiation signal from LPCI is terminated or bypassed; OR Keylock bypass switch is taken to Manual Override. |
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Term
| "Under conditions of DBA, how many RHR pumps in LPCI mode are required to restore reactor water level? How many are then required to maintain greater than two-thirds core height?" |
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Definition
| Two are required to restore level. One is required to maintain greater than 2/3 core height. |
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Term
| Interlock between RHRSW HX discharge valve and RHRSW pump. |
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Definition
| RHRSW HX disch valve is interlocked to close whenever the RHRSW pumps are tripped or stopped. |
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Term
| Normal air supply to RHR valves; Supply on loss of normal air. |
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Definition
| "Normal: Instrument air; Upon loss of plant air, air is supplied by aux air compressors to hold valves closed or modulate them." |
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Term
| Purpose of main service water discharge header radiation monitoring |
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Definition
| Warn operators of a system leak that could cause radioactive water to be discharged to the river. |
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Term
| Operating requirement regarding RHRSW heaters on pump motors |
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Definition
| Should remain in service continuously when the pumps are on standby duty. |
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Term
| Operating requirement regarding RHRSW loop A and B X-tie |
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Definition
| Must be maintained closed in the standby condition. |
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Term
| RHRSW strainer dP that should not be exceeded |
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Definition
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Term
| RHRSW Pump start limitations |
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Definition
| Two successive motor starts from ambient or one start from rated temperature are allowed. For subsequent starts allow 30 minutes running time at full speed or 60 minutes idle time. |
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Term
| Minimum and Maximum flow limits for RHRSW pumps |
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Definition
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Term
| Emergency or abnormal RHRSW pump flow limit |
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Definition
| 6000 gpm (runout may occur beyond this limit) |
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Term
| RHR temperature at HX where RHRSW loop SHALL remain in operation. Why? |
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Definition
| Greater than 200 degrees F RHR temperature at HX inlet to ensure voiding of RHRSW does not occur within the HX or piping. |
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Term
| Discuss excessive RHRSW pump packing leakage (briefly). |
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Definition
| Excessive pump packing leakage or loss of seal water to the RHRSW pumps will NOT prevent the pumps from performing their safety function. |
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Term
| Briefly discuss the issue of dead heading RHRSW pumps. |
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Definition
| Do not dead head pumps for more than 7 minutes. Vortexing is not a concern and NPSH does not become a factor until approximately 7 minutes after dead head (due to rise in temperature). |
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Term
| Connection between RHRSW and Service Water system |
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Definition
| Service Water system, through cross-ties to each division of RHRSW, keeps RHRSW piping full of water when in a standby condition at a minimum of 6 psig. HOWEVER, this pressure is not required for operability." |
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Term
| Discuss the concern when physically removing an RHRSW pump. |
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Definition
| Adversely affects the seismic qualification of the associated division and appropriate tech spec must be entered. |
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Term
| Concern with placing RHRSW PMP LPCI/ECCS LOAD SHED OVERRIDE switch in manual override when neither a valid ECCS nor LPCI initiation signal is present. |
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Definition
| Results in inoperability of 2R and 1R Transformers because the AC Load study assumes all RHRSW pumps are off prior to the ECCS load sequencing. The bypass of any of the RHRSW load sheds while a pump is operating puts the associated normal off-site power supply in an unanalyzed condition. |
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Term
| #11 RHRSW Pump Motor power supply |
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Definition
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Term
| #13 RHRSW Pump Motor power supply |
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Definition
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Term
| #14 RHRSW Pump Motor power supply |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| #11 RHR Aux Air Compressor power supply |
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Definition
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Term
| #12 RHR Aux Air Compressor power supply |
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Definition
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