ML16120A597

Final Safety Analysis Report Update, Revision 32, Chapter 9 - Auxiliary Systems - Sections

ML16120A597
Person / Time
Site:	Palisades
Issue date:	04/18/2016
From:	Entergy Nuclear Operations
To:	Office of Nuclear Reactor Regulation
Shared Package
ML16120A302	List: ML16120A321 ML16120A325 ML16120A326 ML16120A327 ML16120A344 ML16120A345 ML16120A347 ML16120A359 ML16120A360 ML16120A361 ML16120A362 ML16120A379 ML16120A380 ML16120A381 ML16120A382 ML16120A415 ML16120A416 ML16120A417 ML16120A419 ML16120A420 ML16120A421 ML16120A571 ML16120A573 ML16120A574 ML16120A575 ML16120A588 ML16120A589 ML16120A590 ML16120A591 ML16120A596 ML16120A597 ML16120A598 ML16120A599 ML16120A602 ML16120A603 ML16120A604 ML16120A608 ML16120A609 ML16120A610 ML16123A314 ML16123A315 ML16123A316 ML16123A320 ML16123A321 ML16123A326 ML16123A328 ML16123A329 ML16126A109 PNP 2016-015, Final Safety Analysis Report Update, Revision 32, Table of Contents
References
PNP 2016-015
Download: ML16120A597 (127)

Text

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 25SECTION 9.9Page 9.9-1 of 9.9-2 9.9SAMPLING SYSTEM 9.9.1DESIGN BASISThe sampling systems are designed to permit liquid and gaseous samplingfor analysis and chemistry control of the Plant primary and secondary fluids.Samples are used to determine if chemical and radiochemical concentrationsare within the prescribed operating limits.

9.9.2SYSTEM DESCRIPTION AND OPERATIONThe sampling system is a collection of smaller subsystems which aredesigned to sample various Plant fluids. These subsystems are designatedby the Plant systems or fluid sampled. Table 9-16 lists each subsystem.The NSSS Sampling Station is located in the auxiliary building sample room.High-temperature, high-pressure fluid samples taken from the PrimaryCoolant System are first passed through a delay coil to permit decay ofshort-lived radioactivity and then through a cooler, pressure reducing coil,flow controller and finally an analyzer or grab sample valve. All grab samplesand bomb samples are taken to the chemistry lab for analysis.Block and bleed valves, located on the reactor coolant and LPSI pumpsuction sample lines, provide the opportunity to backflush these lines throughthe sample coolers to reduce the dose rate and potential equipmentcontamination. The block valve is also controlled to shut on high temperatureat the sample cooler outlet.In lieu of the Post Accident Sampling and Monitoring panel (C-103), postaccident fuel damage is assessed using a PCS hot leg sample line dose ratecorrelation to % fuel damage. Contingency plans also exist for obtainingcontainment air, PCS liquid, and containment sump samples that may need tobe obtained to assess the extent of an accident, long after the accident hadoccurred. Offsite iodine monitoring is also maintained in this circumstances.The containment hydrogen monitoring system (Figure 9-16) consists ofredundant monitors designed to continuously monitor the containmenthydrogen concentration during post-accident conditions. Each monitor contains a sample pump, temperature, pressure and flow controllers, and athermal conductivity cell. Piping from the containment to the H 2 analyzerpanels are heat-traced and maintained at approximately 285°F to preventcondensation in the sample stream.A change to 10 CFR 50.44 for combustible gas control (Reference 56)changed the classification of the containment hydrogen monitoring system tonon-safety related, Regulatory Guide 1.97 Category 3.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 25SECTION 9.9Page 9.9-2 of 9.9-2During normal Plant operation, the system is maintained at standbyconditions permitting rapid start-up.Following initial start-up and calibration, system operation may be initiatedlocally at the panel or remotely from the control room. Once initiated,operation is automatic.The Turbine Plant Analyzer Station is located in the turbine building. Thisstation contains sample pressure reducing and cooling equipment includingvalves, pressure regulators, pressure indicators, flow regulators, piping grabsample sinks and continuous analyzers for various parameters such asconductivity, dissolved oxygen, sodium, hydrazine, and pH. A dataacquisition system, indicators and an annunciator, to alarm abnormalconditions, are located at the Turbine Plant Analyzer Station.At the Turbine Plant Analyzer Station, sample streams are sent throughcontinuous analyzers. These analyzers transmit their signals to indicators forcontinuous display on the local analyzer panel. A data acquisition systemalso receives the signals from the analyzers.The Radwaste Sample Station (Figure 9-17), located in the auxiliary buildingsample room, provides sample streams for grab sampling or collection insample bombs. The sample streams are radioactive or potentially radioactivefluids.The Radwaste Addition Sample Station, located in the new radwaste buildingsample room, provides sample streams for grab sampling or collection insample bombs. The sample streams are radioactive or potentially radioactivefluids.Table 9-17 is a summary of sample points.

9.9.3SYSTEM EVALUATIONThe sampling system obtains a maximum of information from a number ofseparately located sample points and stations. All of the continuous sampleanalysis equipment is located near its sample conditioning equipment whichpermits rapid detection of deteriorating conditions of either the samples or thesampling equipment.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-1 of 9.10-13 9.10CHEMICAL AND VOLUME CONTROL SYSTEM9.10.1 DESIGN BASISThe Chemical and Volume Control System (CVC), a CP Co Design Class 3system, is designed to:

1.Maintain the required volume of water in the Primary Coolant Systemover the range of full to zero reactor power without requiring makeup 2.Maintain the chemistry and purity of the primary coolant 3.Maintain the desired boric acid concentration in the Primary CoolantSystem 4.Pressure test the Primary Coolant SystemThe design parameters for the Chemical and Volume Control System andcomponents are listed in Table 9-18.The portions of the system utilized for Primary Coolant System isolation andfor Containment isolation are CPCo Class 1.9.10.2 SYSTEM DESCRIPTION AND OPERATION9.10.2.1 GeneralThe Chemical and Volume Control System is shown in Figure 9-18. Theletdown coolant from the cold leg of the Primary Coolant System passesthrough the tube side of the regenerative heat exchanger and is partiallycooled. The cooled fluid is then partially depressurized as it passes throughthe letdown stop valves and orifices. The temperature and pressure of theletdown coolant are finally reduced to the operating requirements of thepurification system by the letdown heat exchanger and back pressure valve,respectively. The coolant then passes through an ion exchanger and a filterand is sprayed into the volume control tank. The charging pumps remove thecoolant from the volume control tank and return it to the Primary CoolantSystem by way of the shell side of the regenerative heat exchanger. Theheat exchanger transfers heat from the letdown coolant to the chargingcoolant before the charging coolant is returned to the Primary CoolantSystem.When the level in the volume control tank reaches the high level set point, theletdown flow is automatically diverted to the liquid radwaste system. Whenthe level in the volume control tank reaches the low-level set point, makeupwater, borated to the existing concentration of the Primary Coolant System,may be manually supplied to the suction of the charging pumps.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-2 of 9.10-13The volume control tank is designed and sized with a large enough capacitythat with the level in the normal control band, the tank can accommodate azero to full power increase or a full to zero power decrease.The boric acid concentration and chemistry of the primary coolant aremaintained by the Chemical and Volume Control System. Concentrated boricacid solution is prepared in a batching tank and is stored in two concentratedboric acid storage tanks. Two pumps are provided to transfer concentratedboric acid to a blender where the boric acid is mixed with primary makeupwater in a predetermined ratio. The solution is introduced to the PrimaryCoolant System by the charging pumps. Boric acid can also be gravity feddirectly from the concentrated boric acid storage tanks to the suction of thecharging pumps.Chemicals are introduced to the Primary Coolant System by means of ametering pump which pumps the chemical solution from a chemical additiontank and introduces it to the charging pump suction header.Depleted zinc ions are introduced to the PCS via the Zinc Addition System forreduction of dose to personnel through the removal of radioactive cobalt ionsfrom the inner walls of PCS piping.The Primary Coolant System may be pressure tested for leaks by means ofthe variable speed charging pump. The system is also provided withconnections for installing a hydrostatic test pump.9.10.2.2 Volume ControlThe CVC automatically adjusts the volume of water in the Primary CoolantSystem using a signal from the level instrumentation located on thepressurizer. The system reduces the amount of fluid that must be transferredbetween the Primary Coolant System and the CVC during power changes byemploying a programmed pressurizer level set point which varies with reactorpower level. The set point varies linearly with reactor power, defined for thispurpose as the average primary coolant temperature measured across asteam generator. This linear relationship is shown in Figure 4-9. The controlsystem compares the programmed level set point with the measuredpressurizer water level. The resulting error signal is used to control theoperation of the charging pumps and the letdown valves as described below.The pressurizer level control program is shown in Table 4-9.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-3 of 9.10-13The pressurizer level control program adjusts the charging rate of the variablecapacity charging pump, normally in operation, to obtain a flow equal to theletdown flow through one letdown stop valve and orifice plus the total primarycoolant pump seal bleedoff flow. If power changes or abnormal operationscause a large drop in the pressurizer level, one or both of the constantcapacity charging pumps start to return the level to the normal control band.If conditions cause a large rise in the pressurizer level, additional letdownstop valves open to lower pressurizer level.Since the normal letdown flow plus the primary coolant pump controlledbleedoff flow slightly exceeds the capacity of one constant capacity chargingpump, one of two method of maintaining pressurizer level is used when thevariable capacity charging pump is removed from service.One method places one constant capacity charging pump in manual andallows the pressurizer level control program to cycle the second constantcapacity charging pump on and off automatically to maintain level. One of theletdown orifice stop valves may be closed to reduce the cycling of the letdownorifice stop valves during this method. The second method places bothconstant capacity charging pumps in manual and allows the pressurizer levelcontrol program to maintain level by cycling the letdown stop valves.The volume control tank level may be automatically controlled. When thelevel in the tank reaches a high-level set point, the letdown flow isautomatically diverted to the liquid waste disposal system. When the level inthe tank reaches the low-level set point, makeup water is manually suppliedto the charging pumps. When the level in the tank reaches a low-low setpoint, the system automatically closes the outlet valve on the volume controltank and switches the suction of the charging pumps to the safety injectionand refueling water tank.The volume control tank can store enough coolant below its normal operatinglevel to compensate for a full to zero power decrease in the primary coolantvolume without requiring makeup. The tank is supplied with hydrogen andnitrogen gas. Gases may be vented to the waste gas surge tank.9.10.2.3 Chemical ControlThe CVC purifies and conditions the primary coolant by means of ionexchangers, filters and chemical additives.The purification demineralizers contain a mixed bed resin which removessoluble nuclides by ion exchange and insoluble nuclides by impaction of theparticles on the surface of the resin beads. A demineralizer post-filter islocated downstream of the purification demineralizers to filter out resinmaterial that may be carried over from the demineralizers. In addition, thefilter may be operated as either a prefilter or a post-filter.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-4 of 9.10-13The primary coolant is chemically conditioned to the typical conditions shownin Table 4-16 by:

1.Hydrazine scavenging to remove oxygen during start-up 2.Maintaining excess hydrogen concentration to control oxygenconcentration during operation 3.Chemical additives to control pH during operationThe chemical addition tank and metering pump are used to feed chemicals tothe charging pumps which inject the additives into the Primary CoolantSystem. The concentration of hydrogen in the primary coolant is controlledby maintaining a hydrogen atmosphere in the volume control tank.The chemical control system is designed to prevent the activity of the primarycoolant from exceeding approximately 292Ci/cc with failed fuel elements.9.10.2.4 Reactivity ControlThe boron concentration of the primary coolant is controlled by the CVC to:

1.Optimize the position of the control rods.

2.Compensate for reactivity changes in the temperature of the coolant,burnup of the core and variations in the concentration of xenon in thecore (see Figure 9-19).3.Provide a margin of shutdown for maintenance and refueling.The system includes a batching tank for preparing the boric acid solution, twotanks for storing the solution and two pumps for supplying boric acid solutionto the makeup system.Normally, the system adjusts the boron concentration of the primary coolantby "feed" and "bleed." To change concentration, the makeup (feed) systemsupplies either water or concentrated boric acid to the charging pumps, andthe letdown (bleed) stream is diverted to the waste disposal system. Towardthe end of a core cycle, the quantities of waste produced due to the "feed"and "bleed" operations become excessive. Then, the deboratingdemineralizer is used to reduce the boron concentration.The system adds boron to the primary coolant and thereby decreasesreactivity at a sufficient rate to override the maximum increase in reactivitydue to cooldown and the decay of xenon in the reactor.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-5 of 9.10-13The control rods can decrease reactivity far more rapidly than the boronremoval system can increase reactivity. The maximum equivalent reactivityinsertion rate of the rods is 143 ppm/min; whereas the maximum boronreduction rate is only 3 ppm/min.9.10.2.5 Pressure-Leakage Test SystemThe Primary Coolant System can be tested for leaks while the Plant is atpower by monitoring pressurizer level and charging rate. The chargingpumps may also be used to hydrostatically test the primary system at designpressure when the Plant is shut down.9.10.2.6 Component Functional DescriptionThe major components of the Chemical and Volume Control System performthe following functions:1.Regenerative Heat ExchangerThe regenerative heat exchanger transfers heat from the letdownstream to the charging stream. Materials of construction are primarilyaustenitic stainless steel.

2.Letdown Heat ExchangerThe letdown heat exchanger cools the letdown stream from the tubeside of the regenerative heat exchanger to a temperature suitable forentry into the purification demineralizer. Component Cooling Systemfluid is the cooling medium on the shell side of the letdown heatexchanger, with the letdown stream passing through the tube side.Materials of construction are primarily austenitic stainless steel.

3.Purification DemineralizersThe two purification demineralizers provide a means of removingundesired ionic species such as activation/fission products and lithiumfrom the primary coolant system. They are configured in one of twoways: 1)One vessel is loaded with mixed bed resin in the borate/lithiumform and the other vessel loaded with cation only resin in thehydrogen form. The borate/lithium demineralizer is used duringnormal operation to remove ionic specie without removinglithium. The cation demineralizer is placed in serviceperiodically to remove the natural build in of PCS lithium.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-6 of 9.10-13 2)One vessel is loaded with mixed bed resin in the borate/lithiumform and the other vessel loaded with mixed bed resin in theborate/hydrogen form. In this configuration the borate/lithiumform demineralizer is used during normal operation to removeionic specie without removing lithium. The borate/hydrogenform demineralizer is placed in service periodically to removethe natural build in of PCS lithium. During PCS source termevolutions the borate/hydrogen form demineralizer is placed inservice.Each unit is designed to handle maximum letdown flow of 120 gpm.The vessels and retention screens are constructed of austeniticstainless steel.

4.Deborating DemineralizerThe deborating demineralizer may be used to remove boron from theprimary coolant when this mode of operation is preferable to a feedand bleed operation, or may be used as a purification demineralizer.The anion resin used for deborating is initially in the hydroxyl form andis converted to a borated form during boron removal. The unit isdesigned for the maximum letdown flow of 120 gpm, and the quantityof resin is sufficient to remove the equivalent of 50 ppm of boron fromthe entire Primary Coolant System. The vessel and retention screensare of austenitic stainless steel construction.

5.Purification FiltersThe purification filters collect resin fines and insoluble particulates fromthe primary coolant. The filters will accommodate maximum letdownflow of 120 gpm. The filter housing is austenitic stainless steel.

6.Volume Control TankThe volume control tank accumulates water from the Primary CoolantSystem. The tank has enough capacity to accommodate the variationin water inventory of the Primary Coolant System due to power levelchanges in excess of that accommodated by the pressurizer. The tankprovides a gas space where hydrogen atmosphere is maintained tocontrol the hydrogen concentration in the primary coolant. A vent towaste processing system permits removal of gaseous fission productsreleased from solution in the volume control tank. The tank is ofaustenitic stainless steel construction and provided with overpressureprotection. Level controls release coolant to the waste processingsystem on high level or notify the operator of the need to supplymakeup water.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-7 of 9.10-13 7.Charging PumpsThree charging pumps supply makeup water to the Primary CoolantSystem. The pumps return coolant to the Primary Coolant System at arate equal to the purification flow rate and the bleedoff rate. Thecharging pumps automatically start upon a safety injection signal anddischarge concentrated boric acid into the Primary Coolant System.P-55B and P-55C automatically start upon low pressurizer level. Thepumps are of the positive displacement type. All wetted parts, exceptseals, are of austenitic stainless steel. Two of the pumps are fixedcapacity pumps while one (P-55A) is a variable capacity pump. Anytwo of the three pumps are capable of providing an output of 68 gpm,with a single pump providing a minimum of 33 gpm. The normalpurification flow rate is specified in Table 9-18. Accumulators arelocated on the suction and discharge of each pump to reduce pumpinduced vibrations.

8.Chemical Addition TankThe chemical addition tank is used to prepare chemicals for primarycoolant pH control, oxygen control, and source term reductionevolutions. These chemicals are added to the suction of the chargingpumps with the metering pump. The tank is austenitic stainless steel.

9.Metering PumpThe metering pump is an air operated double diaphragm pump withwetted parts of austenitic stainless steel. The pump is used to inject acontrolled amount of chemicals into the suction of the charging pumps.10. Concentrated Boric Acid Storage TanksEach of the two concentrated boric acid tanks stores enoughconcentrated boric acid solution to bring the reactor to a cold shutdowncondition at any time during the core lifetime. The combined capacityof the tanks will also be sufficient to bring the primary coolant torefueling concentration. The tanks are heated to maintain atemperature above the saturation temperature of the concentratedsolution, and sampling connections are used to verify that properconcentration is maintained. The tanks are constructed of stainless steel.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-8 of 9.10-1311. Boric Acid PumpsThe two boric acid pumps supply boric acid solution at the desiredconcentration to the charging pumps through the blender. Upon asafety injection signal, these pumps line up with the charging pumps topermit direct introduction of concentrated boric acid into the PrimaryCoolant System. Each is capable of supplying boric acid at themaximum demand conditions. Each pump is capable of providing aminimum flow of 68 gpm. Wetted parts of the pumps are stainless steel.12. Process Radiation MonitorThe process radiation monitor monitors the fluid from the primarycoolant loop for high levels of activity which would provide an indicationof failed fuel.9.10.3 OPERATIONS9.10.3.1 Start-UpDuring start-up, the reactor is brought from cold shutdown to hot standby atnormal operating pressure, zero power temperature, with the reactor critical ata low power level. While the primary coolant is being heated, and until thepressurizer steam bubble is established, the charging pumps in combinationwith the backpressure regulating valves in the CVCS system maintainpressure in the primary system. During the heatup and after the steambubble is established, the operator adjusts the pressurizer water levelmanually, with the intermediate pressure letdown control valves, the letdownorifice bypass control valves and/or the letdown orifices. The level controls ofthe volume control tank automatically divert the letdown flow to the wastedisposal system.If the residual activity in the core is insufficient to reduce the oxygen in theprimary coolant by recombining it with excess hydrogen prior to start-up,hydrazine is used to scavenge the oxygen. If required, chemicals are addedto control the pH of the coolant.The volume control tank is initially vented to the radioactive waste treatmentsystem. After the tank is purged with nitrogen, a hydrogen atmosphere isestablished and the vent is secured.Throughout start-up, one purification filter is in service to reduce the activity ofwastes entering the radioactive waste treatment system. When the PrimaryCoolant System reaches hot standby temperature and pressure, one or bothpurification ion exchangers are put into service.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-9 of 9.10-13Depending on limitations placed on the shutdown margin, the boric acidconcentration may be reduced during heatup. The operator may inject apredetermined amount of primary makeup water by operating the system inthe dilute mode. The concentration of boric acid in the primary coolant ismeasured by analyzing samples.9.10.3.2 Normal OperationsNormal operation includes operating the reactor at hot standby and when it isgenerating power, with the Primary Coolant System at normal operatingpressure and temperature.During normal operation:

1.Level instrumentation on the pressurizer automatically controls thevolume of water in the primary system by adjusting the charging rate ofthe variable capacity charging pump.

2.Instrumentation on the volume control tank automatically controls thelevel of water in the tank as described in Subsection 9.10.2.

3.The operator controls the hydrogen concentration and pH of thecoolant as described in Subsection 9.10.2.3.

4.The operator may compensate for changes in the reactivity of the coreby controlling the concentration of boric acid in the primary coolant. Hemay operate in three modes.

a.In the dilute mode, the operator preselects a quantity of primarymakeup water and introduces it into the charging pump suctionat a preset rate. When the selected quantity of makeup waterhas been added, the flow is secured upon signal from theprimary makeup water batch controller.

b.In the borate mode, the operator preselects a quantity ofconcentrated boric acid and introduces it as a preset rate asdescribed in a. above.

c.In the blend mode, the operator presets the flow rates of theprimary makeup water and concentrated boric acid for anyblend between primary makeup water and concentrated boricacid. This mode is primarily used to supply makeup to thesafety injection and refueling water tank.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-10 of 9.10-139.10.3.3 ShutdownPlant shutdown is a series of operations which bring the reactor plant from ahot standby condition at normal operating pressure and zero powertemperature to a cold shutdown.Before the plant is cooled down, the volume control tank is vented to thegaseous Radwaste System to reduce the activity and hydrogen concentrationin the Primary Coolant System. The operator may also increase the letdownflow rate to accelerate degasification, ion exchange, and filtration of theprimary coolant.Before the plant is cooled down, the operator increases the concentration ofboric acid in the primary coolant to the value required for cold shutdown. Thisis done to assure that the reactor has an adequate shutdown marginthroughout its period of cooldown.During cooldown, the operator uses the charging pumps to adjust andmaintain the level of water in the pressurizer. The operator can introduce acalculated combination of concentrated boric acid and primary makeup waterthrough the blender into the charging pumps' suction. The flow ratio for eachaddition is manually selected and provided by the blender inlet valves andcontrollers. The operator may switch the suction of the charging pumps to thesafety injection and refueling water tank (SIRW). A portion of the chargingflow may be used as an auxiliary spray to cool the pressurizer, when thepressure of the primary system is below that required to operate the primarycoolant pumps.In the event that the SIRW tank is unavailable, borated water from the SpentFuel Pool (SFP) may be gravity fed to the charging pumps suction header.The flow path is via a firehose connected between the discharge of the SFPCooling System and the charging pump suction header (see Section 1.8.5).

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-11 of 9.10-139.10.3.4 Emergency OperationsPresently the CVCS is not credited in the Chapter 14 accident analyses withany mitigating actions. However, the system responds to Safety InjectionActuation Signal and the charging pumps inject concentrated boric acid intothe Primary Coolant System. Either the pressurizer level control or the safetyinjection signal will automatically start all charging pumps, with the exceptionthat the pressurizer level control does not start P-55A, which is assumed tobe operating during normal conditions. The safety injection signal will alsocause the charging pump suction to be switched from the volume control tankto the discharge of the boric acid pump. If the boric acid supply from the boricacid pump is not available, boric acid from the concentrated boric acid tankswill be gravity fed into the charging line. If the charging line inside the reactorcontainment building is inoperative, the line may be isolated outside thereactor containment, and the Safety Injection System may be used to injectconcentrated boric acid into the Primary Coolant System.9.10.4 DESIGN ANALYSIS 1.System ReliabilityThe CVC is designed for reliability by the provision of redundantcomponents. Redundancy is provided as follows: Component RedundancyPurification DemineralizerParallel Standby UnitPurification FiltersParallel Standby UnitCharging PumpTwo Parallel Standby UnitsLetdown Flow ControlTwo Parallel Standby Orifices and ValvesBoric Acid Pump and TankParallel Standby UnitThe charging and boric acid pumps are powered by the diesel generatorsunder emergency conditions. One diesel generator supplies ChargingPumps A and B and Boric Acid Pump A. The other diesel generator suppliesCharging Pump C and Boric Acid Pump B. Additionally, Charging Pumps Band C can be powered from an alternate power supply (480 volt, Bus 13).Charging Pump B can be powered from the Charging Pump C power supplydue to a change made in October 1989 (refer to Section 7.4 for details).Standby start features are provided so that at least one charging pump isrunning. The boric acid pumps and the charging pumps may be controlledlocally at their switchgear.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-12 of 9.10-13The boric acid solution is stored in heated tanks and piped in heat-tracedlines to preclude precipitation of the boric acid. Two independent heatingsystems are provided for the boric acid tanks and lines. Low temperaturealarms and automatic temperature controls are included in the heatingsystems. If the boric acid pumps are not available, boric acid from theconcentrated boric acid tanks may be gravity fed into the charging line. If thecharging line inside the reactor containment building is inoperative, thecharging pump discharge may be routed via the Safety Injection System toinject concentrated boric acid into the Primary Coolant System.9.10.5 TESTING AND INSPECTIONThe operability of the system can be demonstrated by the periodic testing ofactive components and the cycling of all valves. Pump and valve operabilitytests are conducted in accordance with the ASME OM Code.9.10.6 REGENERATIVE HEAT EXCHANGERThe Regenerative Heat Exchanger (RHX) is CP Co Design Class 1 and wasdesigned according to the ASME Boiler and Pressure Vessel Code,Section III, Class C (ASME B&PV Code,Section III, Class C) vessel. Thereare two principal reasons for this:

1.A reliable charging path was the principal reason for originallyconsidering Class A for this component. As the detailed design of thePalisades Plant evolved, it was found desirable to add a two-inch,high-pressure line from the charging pumps through one of thehigh-pressure safety injection headers and to the primary loop throughthe four safety injection headers. Thus, an alternate charging path wasavailable. Also, it was felt desirable to have the ability to isolate theRHX by remote manual means. Therefore, isolation valves are locatedon the inlet and outlet lines of both the shell and tube sides of the RHXas shown on Figure 9-18. These valves can be operated from thecontrol room.

2.The manufacturer of the Palisades RHX was unable to obtain approvalfrom the ASME Code "N" stamp committee to produce ASME B&PVCode,Section III, Class A components. Combustion Engineering (CE)knew of no manufacturer of such heat exchangers who had met therequirements of the "N" stamp committee. CE and the vendor agreedto additional quality control inspections, to be provided by CE, asdetailed in subsequent paragraphs.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-13 of 9.10-13Combustion Engineering assured that the following requirements were met,which were in addition to those required for a Class C vessel, and whichwould normally have been performed for a Class A vessel.

1.A fatigue analysis equivalent to the requirements of a Class A vesselwas performed by the manufacturer or his consultant. This analysiswas reviewed under the direction of a licensed professional engineer atCE to assure its accuracy.

2.The Quality Control requirements of ASME B&PV Code,Section III,Appendix IX, 1965, W67a were met except that shop inspectionpersonnel, although experienced in inspection techniques, did notmeet in all respects the qualifications of the applicable standards.Inspections were performed in accordance with written procedureswhich had been reviewed by CE Quality Assurance (QA) personnel. Inaddition, CE QA personnel witnessed certain predeterminedinspections and also conducted random periodic surveillanceinspections. Inspection records were kept at the manufacturer's officeand also at Combustion Engineering. Certification of inspectioncompliance was transmitted to Consumers Power Company.In addition to the above, nondestructive testing was witnessed by CE QApersonnel who were qualified to ASME B&PV Code,Section III, Appendix IX,1965, W67a procedures. All nondestructive test procedures were reviewedby CE QA personnel and were deemed acceptable and in accordance withASME B&PV Code,Section III, Appendix IX, 1965, W67a.With the aforementioned changes in Plant design, additional analyses andquality control, we believe that Class C vessel classification of theregenerative heat exchanger was justified.During operations the RHX primary side shell to tube-sheet welds and theprimary head are periodically inspected per ASME Code requirements.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 25SECTION 9.9Page 9.9-1 of 9.9-2 9.9SAMPLING SYSTEM 9.9.1DESIGN BASISThe sampling systems are designed to permit liquid and gaseous samplingfor analysis and chemistry control of the Plant primary and secondary fluids.Samples are used to determine if chemical and radiochemical concentrationsare within the prescribed operating limits.

9.9.2SYSTEM DESCRIPTION AND OPERATIONThe sampling system is a collection of smaller subsystems which aredesigned to sample various Plant fluids. These subsystems are designatedby the Plant systems or fluid sampled. Table 9-16 lists each subsystem.The NSSS Sampling Station is located in the auxiliary building sample room.High-temperature, high-pressure fluid samples taken from the PrimaryCoolant System are first passed through a delay coil to permit decay ofshort-lived radioactivity and then through a cooler, pressure reducing coil,flow controller and finally an analyzer or grab sample valve. All grab samplesand bomb samples are taken to the chemistry lab for analysis.Block and bleed valves, located on the reactor coolant and LPSI pumpsuction sample lines, provide the opportunity to backflush these lines throughthe sample coolers to reduce the dose rate and potential equipmentcontamination. The block valve is also controlled to shut on high temperatureat the sample cooler outlet.In lieu of the Post Accident Sampling and Monitoring panel (C-103), postaccident fuel damage is assessed using a PCS hot leg sample line dose ratecorrelation to % fuel damage. Contingency plans also exist for obtainingcontainment air, PCS liquid, and containment sump samples that may need tobe obtained to assess the extent of an accident, long after the accident hadoccurred. Offsite iodine monitoring is also maintained in this circumstances.The containment hydrogen monitoring system (Figure 9-16) consists ofredundant monitors designed to continuously monitor the containmenthydrogen concentration during post-accident conditions. Each monitor contains a sample pump, temperature, pressure and flow controllers, and athermal conductivity cell. Piping from the containment to the H 2 analyzerpanels are heat-traced and maintained at approximately 285°F to preventcondensation in the sample stream.A change to 10 CFR 50.44 for combustible gas control (Reference 56)changed the classification of the containment hydrogen monitoring system tonon-safety related, Regulatory Guide 1.97 Category 3.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 25SECTION 9.9Page 9.9-2 of 9.9-2During normal Plant operation, the system is maintained at standbyconditions permitting rapid start-up.Following initial start-up and calibration, system operation may be initiatedlocally at the panel or remotely from the control room. Once initiated,operation is automatic.The Turbine Plant Analyzer Station is located in the turbine building. Thisstation contains sample pressure reducing and cooling equipment includingvalves, pressure regulators, pressure indicators, flow regulators, piping grabsample sinks and continuous analyzers for various parameters such asconductivity, dissolved oxygen, sodium, hydrazine, and pH. A dataacquisition system, indicators and an annunciator, to alarm abnormalconditions, are located at the Turbine Plant Analyzer Station.At the Turbine Plant Analyzer Station, sample streams are sent throughcontinuous analyzers. These analyzers transmit their signals to indicators forcontinuous display on the local analyzer panel. A data acquisition systemalso receives the signals from the analyzers.The Radwaste Sample Station (Figure 9-17), located in the auxiliary buildingsample room, provides sample streams for grab sampling or collection insample bombs. The sample streams are radioactive or potentially radioactivefluids.The Radwaste Addition Sample Station, located in the new radwaste buildingsample room, provides sample streams for grab sampling or collection insample bombs. The sample streams are radioactive or potentially radioactivefluids.Table 9-17 is a summary of sample points.

9.9.3SYSTEM EVALUATIONThe sampling system obtains a maximum of information from a number ofseparately located sample points and stations. All of the continuous sampleanalysis equipment is located near its sample conditioning equipment whichpermits rapid detection of deteriorating conditions of either the samples or thesampling equipment.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-1 of 9.10-13 9.10CHEMICAL AND VOLUME CONTROL SYSTEM9.10.1 DESIGN BASISThe Chemical and Volume Control System (CVC), a CP Co Design Class 3system, is designed to:

1.Maintain the required volume of water in the Primary Coolant Systemover the range of full to zero reactor power without requiring makeup 2.Maintain the chemistry and purity of the primary coolant 3.Maintain the desired boric acid concentration in the Primary CoolantSystem 4.Pressure test the Primary Coolant SystemThe design parameters for the Chemical and Volume Control System andcomponents are listed in Table 9-18.The portions of the system utilized for Primary Coolant System isolation andfor Containment isolation are CPCo Class 1.9.10.2 SYSTEM DESCRIPTION AND OPERATION9.10.2.1 GeneralThe Chemical and Volume Control System is shown in Figure 9-18. Theletdown coolant from the cold leg of the Primary Coolant System passesthrough the tube side of the regenerative heat exchanger and is partiallycooled. The cooled fluid is then partially depressurized as it passes throughthe letdown stop valves and orifices. The temperature and pressure of theletdown coolant are finally reduced to the operating requirements of thepurification system by the letdown heat exchanger and back pressure valve,respectively. The coolant then passes through an ion exchanger and a filterand is sprayed into the volume control tank. The charging pumps remove thecoolant from the volume control tank and return it to the Primary CoolantSystem by way of the shell side of the regenerative heat exchanger. Theheat exchanger transfers heat from the letdown coolant to the chargingcoolant before the charging coolant is returned to the Primary CoolantSystem.When the level in the volume control tank reaches the high level set point, theletdown flow is automatically diverted to the liquid radwaste system. Whenthe level in the volume control tank reaches the low-level set point, makeupwater, borated to the existing concentration of the Primary Coolant System,may be manually supplied to the suction of the charging pumps.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-2 of 9.10-13The volume control tank is designed and sized with a large enough capacitythat with the level in the normal control band, the tank can accommodate azero to full power increase or a full to zero power decrease.The boric acid concentration and chemistry of the primary coolant aremaintained by the Chemical and Volume Control System. Concentrated boricacid solution is prepared in a batching tank and is stored in two concentratedboric acid storage tanks. Two pumps are provided to transfer concentratedboric acid to a blender where the boric acid is mixed with primary makeupwater in a predetermined ratio. The solution is introduced to the PrimaryCoolant System by the charging pumps. Boric acid can also be gravity feddirectly from the concentrated boric acid storage tanks to the suction of thecharging pumps.Chemicals are introduced to the Primary Coolant System by means of ametering pump which pumps the chemical solution from a chemical additiontank and introduces it to the charging pump suction header.Depleted zinc ions are introduced to the PCS via the Zinc Addition System forreduction of dose to personnel through the removal of radioactive cobalt ionsfrom the inner walls of PCS piping.The Primary Coolant System may be pressure tested for leaks by means ofthe variable speed charging pump. The system is also provided withconnections for installing a hydrostatic test pump.9.10.2.2 Volume ControlThe CVC automatically adjusts the volume of water in the Primary CoolantSystem using a signal from the level instrumentation located on thepressurizer. The system reduces the amount of fluid that must be transferredbetween the Primary Coolant System and the CVC during power changes byemploying a programmed pressurizer level set point which varies with reactorpower level. The set point varies linearly with reactor power, defined for thispurpose as the average primary coolant temperature measured across asteam generator. This linear relationship is shown in Figure 4-9. The controlsystem compares the programmed level set point with the measuredpressurizer water level. The resulting error signal is used to control theoperation of the charging pumps and the letdown valves as described below.The pressurizer level control program is shown in Table 4-9.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-3 of 9.10-13The pressurizer level control program adjusts the charging rate of the variablecapacity charging pump, normally in operation, to obtain a flow equal to theletdown flow through one letdown stop valve and orifice plus the total primarycoolant pump seal bleedoff flow. If power changes or abnormal operationscause a large drop in the pressurizer level, one or both of the constantcapacity charging pumps start to return the level to the normal control band.If conditions cause a large rise in the pressurizer level, additional letdownstop valves open to lower pressurizer level.Since the normal letdown flow plus the primary coolant pump controlledbleedoff flow slightly exceeds the capacity of one constant capacity chargingpump, one of two method of maintaining pressurizer level is used when thevariable capacity charging pump is removed from service.One method places one constant capacity charging pump in manual andallows the pressurizer level control program to cycle the second constantcapacity charging pump on and off automatically to maintain level. One of theletdown orifice stop valves may be closed to reduce the cycling of the letdownorifice stop valves during this method. The second method places bothconstant capacity charging pumps in manual and allows the pressurizer levelcontrol program to maintain level by cycling the letdown stop valves.The volume control tank level may be automatically controlled. When thelevel in the tank reaches a high-level set point, the letdown flow isautomatically diverted to the liquid waste disposal system. When the level inthe tank reaches the low-level set point, makeup water is manually suppliedto the charging pumps. When the level in the tank reaches a low-low setpoint, the system automatically closes the outlet valve on the volume controltank and switches the suction of the charging pumps to the safety injectionand refueling water tank.The volume control tank can store enough coolant below its normal operatinglevel to compensate for a full to zero power decrease in the primary coolantvolume without requiring makeup. The tank is supplied with hydrogen andnitrogen gas. Gases may be vented to the waste gas surge tank.9.10.2.3 Chemical ControlThe CVC purifies and conditions the primary coolant by means of ionexchangers, filters and chemical additives.The purification demineralizers contain a mixed bed resin which removessoluble nuclides by ion exchange and insoluble nuclides by impaction of theparticles on the surface of the resin beads. A demineralizer post-filter islocated downstream of the purification demineralizers to filter out resinmaterial that may be carried over from the demineralizers. In addition, thefilter may be operated as either a prefilter or a post-filter.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-4 of 9.10-13The primary coolant is chemically conditioned to the typical conditions shownin Table 4-16 by:

1.Hydrazine scavenging to remove oxygen during start-up 2.Maintaining excess hydrogen concentration to control oxygenconcentration during operation 3.Chemical additives to control pH during operationThe chemical addition tank and metering pump are used to feed chemicals tothe charging pumps which inject the additives into the Primary CoolantSystem. The concentration of hydrogen in the primary coolant is controlledby maintaining a hydrogen atmosphere in the volume control tank.The chemical control system is designed to prevent the activity of the primarycoolant from exceeding approximately 292Ci/cc with failed fuel elements.9.10.2.4 Reactivity ControlThe boron concentration of the primary coolant is controlled by the CVC to:

1.Optimize the position of the control rods.

2.Compensate for reactivity changes in the temperature of the coolant,burnup of the core and variations in the concentration of xenon in thecore (see Figure 9-19).3.Provide a margin of shutdown for maintenance and refueling.The system includes a batching tank for preparing the boric acid solution, twotanks for storing the solution and two pumps for supplying boric acid solutionto the makeup system.Normally, the system adjusts the boron concentration of the primary coolantby "feed" and "bleed." To change concentration, the makeup (feed) systemsupplies either water or concentrated boric acid to the charging pumps, andthe letdown (bleed) stream is diverted to the waste disposal system. Towardthe end of a core cycle, the quantities of waste produced due to the "feed"and "bleed" operations become excessive. Then, the deboratingdemineralizer is used to reduce the boron concentration.The system adds boron to the primary coolant and thereby decreasesreactivity at a sufficient rate to override the maximum increase in reactivitydue to cooldown and the decay of xenon in the reactor.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-5 of 9.10-13The control rods can decrease reactivity far more rapidly than the boronremoval system can increase reactivity. The maximum equivalent reactivityinsertion rate of the rods is 143 ppm/min; whereas the maximum boronreduction rate is only 3 ppm/min.9.10.2.5 Pressure-Leakage Test SystemThe Primary Coolant System can be tested for leaks while the Plant is atpower by monitoring pressurizer level and charging rate. The chargingpumps may also be used to hydrostatically test the primary system at designpressure when the Plant is shut down.9.10.2.6 Component Functional DescriptionThe major components of the Chemical and Volume Control System performthe following functions:1.Regenerative Heat ExchangerThe regenerative heat exchanger transfers heat from the letdownstream to the charging stream. Materials of construction are primarilyaustenitic stainless steel.

2.Letdown Heat ExchangerThe letdown heat exchanger cools the letdown stream from the tubeside of the regenerative heat exchanger to a temperature suitable forentry into the purification demineralizer. Component Cooling Systemfluid is the cooling medium on the shell side of the letdown heatexchanger, with the letdown stream passing through the tube side.Materials of construction are primarily austenitic stainless steel.

3.Purification DemineralizersThe two purification demineralizers provide a means of removingundesired ionic species such as activation/fission products and lithiumfrom the primary coolant system. They are configured in one of twoways: 1)One vessel is loaded with mixed bed resin in the borate/lithiumform and the other vessel loaded with cation only resin in thehydrogen form. The borate/lithium demineralizer is used duringnormal operation to remove ionic specie without removinglithium. The cation demineralizer is placed in serviceperiodically to remove the natural build in of PCS lithium.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-6 of 9.10-13 2)One vessel is loaded with mixed bed resin in the borate/lithiumform and the other vessel loaded with mixed bed resin in theborate/hydrogen form. In this configuration the borate/lithiumform demineralizer is used during normal operation to removeionic specie without removing lithium. The borate/hydrogenform demineralizer is placed in service periodically to removethe natural build in of PCS lithium. During PCS source termevolutions the borate/hydrogen form demineralizer is placed inservice.Each unit is designed to handle maximum letdown flow of 120 gpm.The vessels and retention screens are constructed of austeniticstainless steel.

4.Deborating DemineralizerThe deborating demineralizer may be used to remove boron from theprimary coolant when this mode of operation is preferable to a feedand bleed operation, or may be used as a purification demineralizer.The anion resin used for deborating is initially in the hydroxyl form andis converted to a borated form during boron removal. The unit isdesigned for the maximum letdown flow of 120 gpm, and the quantityof resin is sufficient to remove the equivalent of 50 ppm of boron fromthe entire Primary Coolant System. The vessel and retention screensare of austenitic stainless steel construction.

5.Purification FiltersThe purification filters collect resin fines and insoluble particulates fromthe primary coolant. The filters will accommodate maximum letdownflow of 120 gpm. The filter housing is austenitic stainless steel.

6.Volume Control TankThe volume control tank accumulates water from the Primary CoolantSystem. The tank has enough capacity to accommodate the variationin water inventory of the Primary Coolant System due to power levelchanges in excess of that accommodated by the pressurizer. The tankprovides a gas space where hydrogen atmosphere is maintained tocontrol the hydrogen concentration in the primary coolant. A vent towaste processing system permits removal of gaseous fission productsreleased from solution in the volume control tank. The tank is ofaustenitic stainless steel construction and provided with overpressureprotection. Level controls release coolant to the waste processingsystem on high level or notify the operator of the need to supplymakeup water.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-7 of 9.10-13 7.Charging PumpsThree charging pumps supply makeup water to the Primary CoolantSystem. The pumps return coolant to the Primary Coolant System at arate equal to the purification flow rate and the bleedoff rate. Thecharging pumps automatically start upon a safety injection signal anddischarge concentrated boric acid into the Primary Coolant System.P-55B and P-55C automatically start upon low pressurizer level. Thepumps are of the positive displacement type. All wetted parts, exceptseals, are of austenitic stainless steel. Two of the pumps are fixedcapacity pumps while one (P-55A) is a variable capacity pump. Anytwo of the three pumps are capable of providing an output of 68 gpm,with a single pump providing a minimum of 33 gpm. The normalpurification flow rate is specified in Table 9-18. Accumulators arelocated on the suction and discharge of each pump to reduce pumpinduced vibrations.

8.Chemical Addition TankThe chemical addition tank is used to prepare chemicals for primarycoolant pH control, oxygen control, and source term reductionevolutions. These chemicals are added to the suction of the chargingpumps with the metering pump. The tank is austenitic stainless steel.

9.Metering PumpThe metering pump is an air operated double diaphragm pump withwetted parts of austenitic stainless steel. The pump is used to inject acontrolled amount of chemicals into the suction of the charging pumps.10. Concentrated Boric Acid Storage TanksEach of the two concentrated boric acid tanks stores enoughconcentrated boric acid solution to bring the reactor to a cold shutdowncondition at any time during the core lifetime. The combined capacityof the tanks will also be sufficient to bring the primary coolant torefueling concentration. The tanks are heated to maintain atemperature above the saturation temperature of the concentratedsolution, and sampling connections are used to verify that properconcentration is maintained. The tanks are constructed of stainless steel.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-8 of 9.10-1311. Boric Acid PumpsThe two boric acid pumps supply boric acid solution at the desiredconcentration to the charging pumps through the blender. Upon asafety injection signal, these pumps line up with the charging pumps topermit direct introduction of concentrated boric acid into the PrimaryCoolant System. Each is capable of supplying boric acid at themaximum demand conditions. Each pump is capable of providing aminimum flow of 68 gpm. Wetted parts of the pumps are stainless steel.12. Process Radiation MonitorThe process radiation monitor monitors the fluid from the primarycoolant loop for high levels of activity which would provide an indicationof failed fuel.9.10.3 OPERATIONS9.10.3.1 Start-UpDuring start-up, the reactor is brought from cold shutdown to hot standby atnormal operating pressure, zero power temperature, with the reactor critical ata low power level. While the primary coolant is being heated, and until thepressurizer steam bubble is established, the charging pumps in combinationwith the backpressure regulating valves in the CVCS system maintainpressure in the primary system. During the heatup and after the steambubble is established, the operator adjusts the pressurizer water levelmanually, with the intermediate pressure letdown control valves, the letdownorifice bypass control valves and/or the letdown orifices. The level controls ofthe volume control tank automatically divert the letdown flow to the wastedisposal system.If the residual activity in the core is insufficient to reduce the oxygen in theprimary coolant by recombining it with excess hydrogen prior to start-up,hydrazine is used to scavenge the oxygen. If required, chemicals are addedto control the pH of the coolant.The volume control tank is initially vented to the radioactive waste treatmentsystem. After the tank is purged with nitrogen, a hydrogen atmosphere isestablished and the vent is secured.Throughout start-up, one purification filter is in service to reduce the activity ofwastes entering the radioactive waste treatment system. When the PrimaryCoolant System reaches hot standby temperature and pressure, one or bothpurification ion exchangers are put into service.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-9 of 9.10-13Depending on limitations placed on the shutdown margin, the boric acidconcentration may be reduced during heatup. The operator may inject apredetermined amount of primary makeup water by operating the system inthe dilute mode. The concentration of boric acid in the primary coolant ismeasured by analyzing samples.9.10.3.2 Normal OperationsNormal operation includes operating the reactor at hot standby and when it isgenerating power, with the Primary Coolant System at normal operatingpressure and temperature.During normal operation:

1.Level instrumentation on the pressurizer automatically controls thevolume of water in the primary system by adjusting the charging rate ofthe variable capacity charging pump.

2.Instrumentation on the volume control tank automatically controls thelevel of water in the tank as described in Subsection 9.10.2.

3.The operator controls the hydrogen concentration and pH of thecoolant as described in Subsection 9.10.2.3.

4.The operator may compensate for changes in the reactivity of the coreby controlling the concentration of boric acid in the primary coolant. Hemay operate in three modes.

a.In the dilute mode, the operator preselects a quantity of primarymakeup water and introduces it into the charging pump suctionat a preset rate. When the selected quantity of makeup waterhas been added, the flow is secured upon signal from theprimary makeup water batch controller.

b.In the borate mode, the operator preselects a quantity ofconcentrated boric acid and introduces it as a preset rate asdescribed in a. above.

c.In the blend mode, the operator presets the flow rates of theprimary makeup water and concentrated boric acid for anyblend between primary makeup water and concentrated boricacid. This mode is primarily used to supply makeup to thesafety injection and refueling water tank.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-10 of 9.10-139.10.3.3 ShutdownPlant shutdown is a series of operations which bring the reactor plant from ahot standby condition at normal operating pressure and zero powertemperature to a cold shutdown.Before the plant is cooled down, the volume control tank is vented to thegaseous Radwaste System to reduce the activity and hydrogen concentrationin the Primary Coolant System. The operator may also increase the letdownflow rate to accelerate degasification, ion exchange, and filtration of theprimary coolant.Before the plant is cooled down, the operator increases the concentration ofboric acid in the primary coolant to the value required for cold shutdown. Thisis done to assure that the reactor has an adequate shutdown marginthroughout its period of cooldown.During cooldown, the operator uses the charging pumps to adjust andmaintain the level of water in the pressurizer. The operator can introduce acalculated combination of concentrated boric acid and primary makeup waterthrough the blender into the charging pumps' suction. The flow ratio for eachaddition is manually selected and provided by the blender inlet valves andcontrollers. The operator may switch the suction of the charging pumps to thesafety injection and refueling water tank (SIRW). A portion of the chargingflow may be used as an auxiliary spray to cool the pressurizer, when thepressure of the primary system is below that required to operate the primarycoolant pumps.In the event that the SIRW tank is unavailable, borated water from the SpentFuel Pool (SFP) may be gravity fed to the charging pumps suction header.The flow path is via a firehose connected between the discharge of the SFPCooling System and the charging pump suction header (see Section 1.8.5).

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-11 of 9.10-139.10.3.4 Emergency OperationsPresently the CVCS is not credited in the Chapter 14 accident analyses withany mitigating actions. However, the system responds to Safety InjectionActuation Signal and the charging pumps inject concentrated boric acid intothe Primary Coolant System. Either the pressurizer level control or the safetyinjection signal will automatically start all charging pumps, with the exceptionthat the pressurizer level control does not start P-55A, which is assumed tobe operating during normal conditions. The safety injection signal will alsocause the charging pump suction to be switched from the volume control tankto the discharge of the boric acid pump. If the boric acid supply from the boricacid pump is not available, boric acid from the concentrated boric acid tankswill be gravity fed into the charging line. If the charging line inside the reactorcontainment building is inoperative, the line may be isolated outside thereactor containment, and the Safety Injection System may be used to injectconcentrated boric acid into the Primary Coolant System.9.10.4 DESIGN ANALYSIS 1.System ReliabilityThe CVC is designed for reliability by the provision of redundantcomponents. Redundancy is provided as follows: Component RedundancyPurification DemineralizerParallel Standby UnitPurification FiltersParallel Standby UnitCharging PumpTwo Parallel Standby UnitsLetdown Flow ControlTwo Parallel Standby Orifices and ValvesBoric Acid Pump and TankParallel Standby UnitThe charging and boric acid pumps are powered by the diesel generatorsunder emergency conditions. One diesel generator supplies ChargingPumps A and B and Boric Acid Pump A. The other diesel generator suppliesCharging Pump C and Boric Acid Pump B. Additionally, Charging Pumps Band C can be powered from an alternate power supply (480 volt, Bus 13).Charging Pump B can be powered from the Charging Pump C power supplydue to a change made in October 1989 (refer to Section 7.4 for details).Standby start features are provided so that at least one charging pump isrunning. The boric acid pumps and the charging pumps may be controlledlocally at their switchgear.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-12 of 9.10-13The boric acid solution is stored in heated tanks and piped in heat-tracedlines to preclude precipitation of the boric acid. Two independent heatingsystems are provided for the boric acid tanks and lines. Low temperaturealarms and automatic temperature controls are included in the heatingsystems. If the boric acid pumps are not available, boric acid from theconcentrated boric acid tanks may be gravity fed into the charging line. If thecharging line inside the reactor containment building is inoperative, thecharging pump discharge may be routed via the Safety Injection System toinject concentrated boric acid into the Primary Coolant System.9.10.5 TESTING AND INSPECTIONThe operability of the system can be demonstrated by the periodic testing ofactive components and the cycling of all valves. Pump and valve operabilitytests are conducted in accordance with the ASME OM Code.9.10.6 REGENERATIVE HEAT EXCHANGERThe Regenerative Heat Exchanger (RHX) is CP Co Design Class 1 and wasdesigned according to the ASME Boiler and Pressure Vessel Code,Section III, Class C (ASME B&PV Code,Section III, Class C) vessel. Thereare two principal reasons for this:

1.A reliable charging path was the principal reason for originallyconsidering Class A for this component. As the detailed design of thePalisades Plant evolved, it was found desirable to add a two-inch,high-pressure line from the charging pumps through one of thehigh-pressure safety injection headers and to the primary loop throughthe four safety injection headers. Thus, an alternate charging path wasavailable. Also, it was felt desirable to have the ability to isolate theRHX by remote manual means. Therefore, isolation valves are locatedon the inlet and outlet lines of both the shell and tube sides of the RHXas shown on Figure 9-18. These valves can be operated from thecontrol room.

2.The manufacturer of the Palisades RHX was unable to obtain approvalfrom the ASME Code "N" stamp committee to produce ASME B&PVCode,Section III, Class A components. Combustion Engineering (CE)knew of no manufacturer of such heat exchangers who had met therequirements of the "N" stamp committee. CE and the vendor agreedto additional quality control inspections, to be provided by CE, asdetailed in subsequent paragraphs.

FSAR CHAPTER 9 - AUXILIARY SYSTEMSRevision 30SECTION 9.10Page 9.10-13 of 9.10-13Combustion Engineering assured that the following requirements were met,which were in addition to those required for a Class C vessel, and whichwould normally have been performed for a Class A vessel.

1.A fatigue analysis equivalent to the requirements of a Class A vesselwas performed by the manufacturer or his consultant. This analysiswas reviewed under the direction of a licensed professional engineer atCE to assure its accuracy.

2.The Quality Control requirements of ASME B&PV Code,Section III,Appendix IX, 1965, W67a were met except that shop inspectionpersonnel, although experienced in inspection techniques, did notmeet in all respects the qualifications of the applicable standards.Inspections were performed in accordance with written procedureswhich had been reviewed by CE Quality Assurance (QA) personnel. Inaddition, CE QA personnel witnessed certain predeterminedinspections and also conducted random periodic surveillanceinspections. Inspection records were kept at the manufacturer's officeand also at Combustion Engineering. Certification of inspectioncompliance was transmitted to Consumers Power Company.In addition to the above, nondestructive testing was witnessed by CE QApersonnel who were qualified to ASME B&PV Code,Section III, Appendix IX,1965, W67a procedures. All nondestructive test procedures were reviewedby CE QA personnel and were deemed acceptable and in accordance withASME B&PV Code,Section III, Appendix IX, 1965, W67a.With the aforementioned changes in Plant design, additional analyses andquality control, we believe that Class C vessel classification of theregenerative heat exchanger was justified.During operations the RHX primary side shell to tube-sheet welds and theprimary head are periodically inspected per ASME Code requirements.