ML16054A425
| ML16054A425 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 01/26/2016 |
| From: | Northern States Power Co, Xcel Energy |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML16054A376 | List:
|
| References | |
| L-MT-16-004 | |
| Download: ML16054A425 (28) | |
Text
SECTION 11
SECTION 1111.1
SECTION 1111.211.2.111.2.2
11.2.311.2.4
SECTION 1111.311.3.1
11.3.2
SECTION 1111.411.4.111.4.2
11.4.3 SECTION 1111.511.5.111.5.2
11.5.3
Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 4SECTION 11PLANT POWER CONVERSION SYSTEMSI/cah11.6Cooling Tower System11.6.1Design BasisThe cooling tower system is designed to remove the heat rejected to thecirculating water system over the range of expected operating loads and to provide sufficient operating flexibility to return either part or all of the cooled water to the circulating water pump basin for recirculation or to return either part or all of the cooled water directly to the river via the discharge canal.11.6.2DescriptionCirculating water from the main condenser and the plant's service water heatexchangers flows through parallel chambers at the discharge structure where itis directed by vaned scoops to the suction of two parallel half-capacity cooling tower pumps.The two cooling tower pumps are each rated 145,000 gpm (circulating waterplus service water) at 57.5 feet TDH, and driven by 2,500 hp synchronous motors, as noted in Table 11.6-1. The pump motor is designed for a maximumreverse speed of 150% rated speed for protection in the event that a trippedpump has an open discharge valve when the other pump continues to run. Each pump discharges through a 66 inch diameter motor-operated butterfly valve with a 20-second operating time. Opening (and closing) of the valve is automatically synchronized with pump start (or trip) as described in Section 7.9.A single underground steel pipe conveys the water from both pumps to twocooling towers. The pipe is 108 inches in diameter and approximately 200 feetlong to the first tower, and 78 inches in diameter and 300 feet long from the firstto the second tower. Each tower has two 60-inch diameter risers with a manually operated butterfly valve at grade.As indicated in Table 11.6-2 each tower is a 9-cell, induced-draft, cross-flowtower with one 26 foot diameter fan per cell. The fans are driven by 200 hp, 1,800 rpm motors. Control equipment for the fans is located in a small fancontrol house adjacent to each tower and there is a hand switch in the maincontrol room to shut down the fans.Water flows by gravity from each tower basin through an 84 inch diameter steelpipe with a motor-operated control gate. The lines combine in a single 108 inch diameter pipe for conveying water to the intake structure where the flow diverges to parallel circulating water pump basins. The distance from the far tower to theintake structure is approximately 1,150 feet.Two 14,000 gpm make-up pumps located at the intake structure are arranged fordischarging make-up water to the circulating water pump basins as required during cooling tower operation.
Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 4I/cahBlowdown and overflow from the tower basins flows across a series of parallelweirs to the inlet of corrugated metal pipes for conveyance to the dischargecanal leading to the river. The weirs permit measurement of the rate of overflow.Discharge at the canal is through a structure designed to prevent erosion of the canal banks. A final overflow weir structure is located at the end of the discharge canal. The weir structure permits the normal outflow of cooling water while preventing fish from entering the canal. The weir is an earth fill dike with avertical sheet-pile overflow. Provision is also made for draining the tower basinsthrough these discharge lines by manual operation of a tower gate.Concrete isolation gates permit continued operation if one cooling tower pump isout of service for repairs.11.6.3Performance AnalysisAt a design wet bulb temperature of 73°F, each tower is rated to reduce the temperature of 145,000 gpm of water from an inlet temperature of 116.9°F to anoutlet temperature of 90°F.Closed cycle operation with full cooling tower capacity is required only duringconditions of low river flow and/or high river temperature. For this condition, theriver is isolated by closing control gates at the inlet and discharge structures, andthe control gates in the recirculation lines from the cooling tower basins are open. Flow through the system is stabilized by operating one circulating water pump with one cooling tower pump or both pairs of pumps. For interlocks between the pumps, refer to Section 7.9.During periods when the river flow is insufficient for compliance withgovernmental restrictions, it may be necessary to operate the cooling towers in order to meet thermal restrictions on river use. In this case, the system is operated on helper cycle by closing the recirculation gates and returning water from the cooling tower basins directly to the river via the basin overflow weirs.In the event of low river flow and a cooling tower discharge temperature higherthan the upstream river temperature, the recirculation gates may be partially opened to allow only enough recirculation to satisfy the appropriate requirement.
Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 4I/cahTable 11.6-1 Cooling Tower PumpNumber of units2PumpTypeDry pit, mixed flowRated flow and head145,000 gpm at 57.5 feet TDHRated Speed277 rpm Bhp at rating2,340 bhp Shut-off head97.5 feetShut-off load2,720 bhpMotorTypeGE type TS-V brushless synchronousVoltage, phase, and cycles4,000 v, 3-phase, 60 HzRated continuous load2,500 hpRated speed277 rpmPower factor1.0 Service factor1.0 Starting torque40% rated Pull-in torque120% ratedPull-out torque150% ratedMaximum speed (reverse)150% rated Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 4 of 4I/cahTable 11.6-2 Cooling TowerNumber of towers2TypeCrossflowCells per tower9Tower size, L x W x H overall270 ft x 59 ft x 61 ftHeight, curb to stack/stack47 ft/14 ftStatic pumping head above curb42.7 ftRated performanceWater flow, total for two towers290,000 gpmWater temperature, entering/leaving116.9°F/90°FHeat transfer3,900 x 106 Btu/hrWet bulb temperature73°FFansNumber per cell1Number of blades/diameter9/26 ftFan speed/TIP speed146 rpm/11,925 fpmCapacity per fan1,316,939 SCFMFan bhp193.5 bhpMotor hp/speed200 hp/1,800 rpmFan blade materialFiberglass reinforced,vinyl ester resin011007370110073701100737 Revision 28USAR 11.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 2SECTION 11PLANT POWER CONVERSION SYSTEMSI/arb11.7Condensate Demineralizer System11.7.1Design BasisThe design basis of the condensate demineralizer system is as follows:a.To remove dissolved and suspended solids from the reactor feedwater tomaintain a high reactor feedwater quality. High quality water minimizesthe possibility of scaling deposits and solids buildup in the reactor whichcould affect fuel performance and accessibility to reactor primary system components, and reduces the capacity required for the reactor cleanup demineralizer system.b.To protect the reactor water-steam system from entry of foreign materials,such as could occur due to main condenser leaks.c.To provide final polishing of make-up water entering the reactor feedwaterloop.d.To maintain high water-purity water rejected to condensate storage andtransfer system.11.7.2DescriptionThe condensate system pumps take suction from the main condenser hotwell and discharge through the steam jet air ejector condensers and gland seal steam condenser to the full flow condensate demineralizer system to insure a supply of high purity water to the reactor. The condensate demineralizer P&ID is shown in Drawings NH-36038 and NH-36038-2, Section 15.The condensate demineralizer system consists of five demineralizer vesselsoperating in parallel and sized for full condensate flow at reactor ratedconditions. In addition to demineralizer vessels, the condensate demineralizer system includes the associated piping, valving, instrumentation and controls for proper operation and protection against malfunction. Instrumentation includes automatic flow balancing control to maintain equal flow through each on-streamunit.The condensate demineralizer system is controlled from local panels anddesigned for computer based control initiation. Valves, pumps, and instrumentation are remotely operated. Integrated flow and conductivity monitors are provided for each demineralizer to indicate when a unit isexhausted. Suitable alarms are provided.The demineralizer vessels are located in shielded cells. Wastes from anexhausted unit are transferred to the radwaste system for disposal.01234902 Revision 28USAR 11.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 2I/arbA bypass line, with an automatic flow control valve around the demineralizer, isprovided to maintain system flow in case the demineralizers in service areinsufficient to maintain the required flow. The condensate demineralizer systempressure drop controls the system bypass valve. The effluent is monitored to assure that water quality is within acceptable limits. When the limiting conductivity is approached, an alarm is actuated to alert the operator to take appropriate action.11.7.3Performance AnalysisThe condensate demineralizer system is sized to process the peak condensate impurity concentrations, which may occur for periods up to about a week during plant startup, as well as handle lower concentrations during extended full power operation. Radioactive impurities in the condensate requiring removal occur from:a.Corrosion products from main steam line, turbine, main condenser,condensate and feedwater systems and the steam side of feedwaterheaters;b.Corrosion product and solid fission product carry-over from the reactor inthe steam;c.Fission products occurring in the condensate as volatized iodine andradioactive daughters of fission gases, if fuel leaks are present.While the radioactivity effects from the above sources do not measurably affect the capacity of the resins, concentration of radioactive material requires shieldingwhich is provided for the condensate demineralizer equipment.
SECTION 1111.811.8.111.8.2
11.8.3 SECTION 1111.9 Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 5SECTION 11PLANT POWER CONVERSION SYSTEMSI/jmrFIGURESFOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-11.FIGURESDoc Type:Admin Initials:Date:9703 Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 5I/jmrFigure 11.5-2a Cooling Tower Open Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 5I/jmrFigure 11.5-2b Cooling Tower Closed Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 4 of 5I/jmrFigure 11.5-2c Cooling Tower Helper Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 5 of 5I/jmrFigure 11.5-2d Cooling Tower Partial Closed Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY SECTION 11
SECTION 1111.1
SECTION 1111.211.2.111.2.2
11.2.311.2.4
SECTION 1111.311.3.1
11.3.2
SECTION 1111.411.4.111.4.2
11.4.3 SECTION 1111.511.5.111.5.2
11.5.3
Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 4SECTION 11PLANT POWER CONVERSION SYSTEMSI/cah11.6Cooling Tower System11.6.1Design BasisThe cooling tower system is designed to remove the heat rejected to thecirculating water system over the range of expected operating loads and to provide sufficient operating flexibility to return either part or all of the cooled water to the circulating water pump basin for recirculation or to return either part or all of the cooled water directly to the river via the discharge canal.11.6.2DescriptionCirculating water from the main condenser and the plant's service water heatexchangers flows through parallel chambers at the discharge structure where itis directed by vaned scoops to the suction of two parallel half-capacity cooling tower pumps.The two cooling tower pumps are each rated 145,000 gpm (circulating waterplus service water) at 57.5 feet TDH, and driven by 2,500 hp synchronous motors, as noted in Table 11.6-1. The pump motor is designed for a maximumreverse speed of 150% rated speed for protection in the event that a trippedpump has an open discharge valve when the other pump continues to run. Each pump discharges through a 66 inch diameter motor-operated butterfly valve with a 20-second operating time. Opening (and closing) of the valve is automatically synchronized with pump start (or trip) as described in Section 7.9.A single underground steel pipe conveys the water from both pumps to twocooling towers. The pipe is 108 inches in diameter and approximately 200 feetlong to the first tower, and 78 inches in diameter and 300 feet long from the firstto the second tower. Each tower has two 60-inch diameter risers with a manually operated butterfly valve at grade.As indicated in Table 11.6-2 each tower is a 9-cell, induced-draft, cross-flowtower with one 26 foot diameter fan per cell. The fans are driven by 200 hp, 1,800 rpm motors. Control equipment for the fans is located in a small fancontrol house adjacent to each tower and there is a hand switch in the maincontrol room to shut down the fans.Water flows by gravity from each tower basin through an 84 inch diameter steelpipe with a motor-operated control gate. The lines combine in a single 108 inch diameter pipe for conveying water to the intake structure where the flow diverges to parallel circulating water pump basins. The distance from the far tower to theintake structure is approximately 1,150 feet.Two 14,000 gpm make-up pumps located at the intake structure are arranged fordischarging make-up water to the circulating water pump basins as required during cooling tower operation.
Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 4I/cahBlowdown and overflow from the tower basins flows across a series of parallelweirs to the inlet of corrugated metal pipes for conveyance to the dischargecanal leading to the river. The weirs permit measurement of the rate of overflow.Discharge at the canal is through a structure designed to prevent erosion of the canal banks. A final overflow weir structure is located at the end of the discharge canal. The weir structure permits the normal outflow of cooling water while preventing fish from entering the canal. The weir is an earth fill dike with avertical sheet-pile overflow. Provision is also made for draining the tower basinsthrough these discharge lines by manual operation of a tower gate.Concrete isolation gates permit continued operation if one cooling tower pump isout of service for repairs.11.6.3Performance AnalysisAt a design wet bulb temperature of 73°F, each tower is rated to reduce the temperature of 145,000 gpm of water from an inlet temperature of 116.9°F to anoutlet temperature of 90°F.Closed cycle operation with full cooling tower capacity is required only duringconditions of low river flow and/or high river temperature. For this condition, theriver is isolated by closing control gates at the inlet and discharge structures, andthe control gates in the recirculation lines from the cooling tower basins are open. Flow through the system is stabilized by operating one circulating water pump with one cooling tower pump or both pairs of pumps. For interlocks between the pumps, refer to Section 7.9.During periods when the river flow is insufficient for compliance withgovernmental restrictions, it may be necessary to operate the cooling towers in order to meet thermal restrictions on river use. In this case, the system is operated on helper cycle by closing the recirculation gates and returning water from the cooling tower basins directly to the river via the basin overflow weirs.In the event of low river flow and a cooling tower discharge temperature higherthan the upstream river temperature, the recirculation gates may be partially opened to allow only enough recirculation to satisfy the appropriate requirement.
Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 4I/cahTable 11.6-1 Cooling Tower PumpNumber of units2PumpTypeDry pit, mixed flowRated flow and head145,000 gpm at 57.5 feet TDHRated Speed277 rpm Bhp at rating2,340 bhp Shut-off head97.5 feetShut-off load2,720 bhpMotorTypeGE type TS-V brushless synchronousVoltage, phase, and cycles4,000 v, 3-phase, 60 HzRated continuous load2,500 hpRated speed277 rpmPower factor1.0 Service factor1.0 Starting torque40% rated Pull-in torque120% ratedPull-out torque150% ratedMaximum speed (reverse)150% rated Revision 24USAR 11.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 4 of 4I/cahTable 11.6-2 Cooling TowerNumber of towers2TypeCrossflowCells per tower9Tower size, L x W x H overall270 ft x 59 ft x 61 ftHeight, curb to stack/stack47 ft/14 ftStatic pumping head above curb42.7 ftRated performanceWater flow, total for two towers290,000 gpmWater temperature, entering/leaving116.9°F/90°FHeat transfer3,900 x 106 Btu/hrWet bulb temperature73°FFansNumber per cell1Number of blades/diameter9/26 ftFan speed/TIP speed146 rpm/11,925 fpmCapacity per fan1,316,939 SCFMFan bhp193.5 bhpMotor hp/speed200 hp/1,800 rpmFan blade materialFiberglass reinforced,vinyl ester resin011007370110073701100737 Revision 28USAR 11.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 2SECTION 11PLANT POWER CONVERSION SYSTEMSI/arb11.7Condensate Demineralizer System11.7.1Design BasisThe design basis of the condensate demineralizer system is as follows:a.To remove dissolved and suspended solids from the reactor feedwater tomaintain a high reactor feedwater quality. High quality water minimizesthe possibility of scaling deposits and solids buildup in the reactor whichcould affect fuel performance and accessibility to reactor primary system components, and reduces the capacity required for the reactor cleanup demineralizer system.b.To protect the reactor water-steam system from entry of foreign materials,such as could occur due to main condenser leaks.c.To provide final polishing of make-up water entering the reactor feedwaterloop.d.To maintain high water-purity water rejected to condensate storage andtransfer system.11.7.2DescriptionThe condensate system pumps take suction from the main condenser hotwell and discharge through the steam jet air ejector condensers and gland seal steam condenser to the full flow condensate demineralizer system to insure a supply of high purity water to the reactor. The condensate demineralizer P&ID is shown in Drawings NH-36038 and NH-36038-2, Section 15.The condensate demineralizer system consists of five demineralizer vesselsoperating in parallel and sized for full condensate flow at reactor ratedconditions. In addition to demineralizer vessels, the condensate demineralizer system includes the associated piping, valving, instrumentation and controls for proper operation and protection against malfunction. Instrumentation includes automatic flow balancing control to maintain equal flow through each on-streamunit.The condensate demineralizer system is controlled from local panels anddesigned for computer based control initiation. Valves, pumps, and instrumentation are remotely operated. Integrated flow and conductivity monitors are provided for each demineralizer to indicate when a unit isexhausted. Suitable alarms are provided.The demineralizer vessels are located in shielded cells. Wastes from anexhausted unit are transferred to the radwaste system for disposal.01234902 Revision 28USAR 11.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 2I/arbA bypass line, with an automatic flow control valve around the demineralizer, isprovided to maintain system flow in case the demineralizers in service areinsufficient to maintain the required flow. The condensate demineralizer systempressure drop controls the system bypass valve. The effluent is monitored to assure that water quality is within acceptable limits. When the limiting conductivity is approached, an alarm is actuated to alert the operator to take appropriate action.11.7.3Performance AnalysisThe condensate demineralizer system is sized to process the peak condensate impurity concentrations, which may occur for periods up to about a week during plant startup, as well as handle lower concentrations during extended full power operation. Radioactive impurities in the condensate requiring removal occur from:a.Corrosion products from main steam line, turbine, main condenser,condensate and feedwater systems and the steam side of feedwaterheaters;b.Corrosion product and solid fission product carry-over from the reactor inthe steam;c.Fission products occurring in the condensate as volatized iodine andradioactive daughters of fission gases, if fuel leaks are present.While the radioactivity effects from the above sources do not measurably affect the capacity of the resins, concentration of radioactive material requires shieldingwhich is provided for the condensate demineralizer equipment.
SECTION 1111.811.8.111.8.2
11.8.3 SECTION 1111.9 Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 5SECTION 11PLANT POWER CONVERSION SYSTEMSI/jmrFIGURESFOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-11.FIGURESDoc Type:Admin Initials:Date:9703 Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 5I/jmrFigure 11.5-2a Cooling Tower Open Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 5I/jmrFigure 11.5-2b Cooling Tower Closed Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 4 of 5I/jmrFigure 11.5-2c Cooling Tower Helper Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY Revision 22USAR 11.FIGURESMONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 5 of 5I/jmrFigure 11.5-2d Cooling Tower Partial Closed Cycle Operating DiagramCOOLINGTOWER BCOOLINGTOWER ADISCHARGEMISSISSIPPI RIVERBALPHPHPLPMAINCONDENSERSTURBINEBUILDINGREACTORBUILDINGAUXILIARYSYSTEMSXYZRSTSTRUCTUREINTAKE STRUCTUREABABMAKEUPPUMPSCIRCPUMPSWATERCOOLING TOWERPUMPSPUMPSSERVICE WATERRADWASTESYSTEMSFACILITY