LR-N17-0034, Salem Generating Station, Units 1 & 2, Revision 29 to Updated Final Safety Analysis Report, Section 9.3, Process Auxiliaries
Text
9.3 PROCESS AUXILIARIES 9.3.1 Compressed Air System The Compressed Air System provides the station with a reliable supply of clean, oil free air which is directed to various locations for services as required. The system is illustrated on Plant Drawings 205217 and 205317. 9.3.1.1 Design Bases The system provides a reliable supply of clean, oil free, dry air at temperatures and pressures suitable for use as control air and for containment penetration cooling, as well as for miscellaneous services and maintenance. The Compressed Air System is designed such that any single failure will not result in loss of function. 9.3.1.2 System Description 9.3.1.2.1 General The Compressed Air System is supplied by three motor-driven, oil free, centrifugal compressors which draw air from the atmosphere. The intakes of the air compressors are located to avoid drawing in toxic or corrosive gases. Each compressor has a capacity of 3300 scfm at 120 psig discharge pressure. One compressor is typically running to satisfy the normal requirements of station air and control air for both units as well as to supply containment penetration cooling air for both units. A second compressor serves as standby. A third compressor is available when required. Each compressor is furnished with a 800-hp motor, intake filter-silencer, blow-off silencer and digital pressure controls only, intercoolers, aftercooler, and moisture separator. The compressors discharge into two independent service air headers, with an air receiver tied to each header. 9.3-1 SGS-UFSAR Revision 27 November 25, 2013 The station air header for each unit is supplied from either of the two service air headers. This station air header provides operating and service requirements at various locations. The containment penetration cooling system for each unit is furnished with two supply lines. The normal supply is taken from the station air header and the backup supply from either of the two service air headers. 9.3.1.2.2 Control Air The Control Air System for each unit consists of a dual header arrangement as shown on Plant Drawings 205247 and 205347. This control air for each unit is supplied through two distinct parallel paths. One path is supplied from the Unit 1 Station Air System and the other is supplied from the Unit 2 Station Air System. Control air for the safety-related portions is automatically backed up by an emergency control air compressor. Control air is fed from the Station Air System through heatless, desiccant-type air dryers. The dual station service air headers are fed by three 100-percent capacity air compressors, any one of which can supply the total service and control air requirements for both units. In addition to the normal air supply from the service air headers, each system has an emergency control air compressor complete with its own dryer and accessories to supply the safety-related headers. The emergency control air for either system may be directed to supply air for the opposite system through a valved connection. Each emergency control air compressor motor is energized from the standby ac power supply. The Emergency Control Air System is designated Class I (seismic) and is located in a Class I (seismic) structure. Each emergency control air compressor has a capacity of 500 scfm at 110 psig and is driven by a 125-hp motor. Accessory equipment includes an independent heatless desiccant-type air dryer, intake filter, silencer, intercooler, aftercooler, moisture separator, inlet control valve, relief valve and automatic condensate trap and drain. The emergency control air compressors with Teflon piston rings and stainless steel cylinder liners. Cooling of the emergency control air compressors is provided from the safety-related Chilled Water System. In the event that the Chilled Water System is not available, the Service Water System (SWS) serves as a backup. Operational or test data that verify the functional reliability of the emergency control air compressors were not initially available although stress analysis calculations by the manufacturer indicated that the compressor could withstand both operational and seismic loadings simultaneously. 9.3-2 SGS-UFSAR Revision 27 November 25, 2013 The parallel control air headers for each unit include air receivers of sufficient capacity to dampen pressure surges and act as a momentary reservoir of air to permit switching of air supply sources without cycling the system. The Compressed Air System is also backed up by the Station Blackout ( SBO) emergency diesel driven air compressor through a connection to Header 2A as illustrated in Plant Drawing 604495. This SBO air compressor is designed to be manually started in the event of a loss of offsite power coincident with the failure of either the "C" emergency diesel generator or the emergency air compressor in the non-blacked out unit. The SBO Air Compressor may also be used to supply limited control air in the event of a complete loss of control air due to reasons other than a SBO event. The SBO air compressor, located in the Station Blackout Compressor Building, draws in outside air through louvers built into the building wall. The supply air passes through a filter and then through a regulating inlet valve. After the air has been compressed, it passes through an air/oil separator where the oil is removed and reused for compressor lubrication. The air is then passed through an aftercooler where it is cooled. The excess water is removed by a centrifugal separator and a moisture trap at the aftercooler outlet. A coalescing filter is used to meet the hydrocarbon content requirements by removing oil droplets and particulates to well within the required limits. The air is passed through a heatless desiccant air dryer to lower the moisture content of the compressed air. An additional filter is added onto the outlet of the air dryer to remove any desiccant fines that may be entrained when passing through the dryer. The compressed air is supplied to the emergency control air header via yard access valve 2CA584 which provides air to all required safety related controls. 9.3.1.3 Design Evaluation Reserve air storage of sufficient capacity to minimize pressure fluctuation is provided by means of air receivers in each control air header. The Control Air System is designed to supply the required air during normal and abnormal conditions. Any single component failure will not result in a loss of function. A total loss of control air to all systems and equipment is therefore not considered credible. Redundant safety-related air users are provided with independent single air supplies from the control air header system. The redundant system instruments have control air supplied from independent air headers. 9.3-3 SGS-UFSAR Revision 27 November 25, 2013 Separate and redundant headers, backed up by emergency control air compressors energized from the Standby Power System and preservation of header independence, assure that air is available during normal as well as abnormal plant conditions. A single failure within the system would not result in total loss of air supply to redundant equipment. The following are failures considered and the resultant action: Failure Loss of a station air compressor Loss of all station air compressors Loss of offsite power and emergency compressor fails to start Action The spare air compressor automatically supplies the total requirements for both units. Each emergency control air compressor, energized from its standby ac power supply, will supply all control air requirements for its safety related headers. Emergency air receivers on each control air header supply enough capacity to maintain header pressure. The second emergency second emergency air compressor can provide the safety-related control air requirements for both units. Toe SBO Emergency Compressed Air System is physically isolated and independent of the plant safety related components and system. As a result, during normal and abnormal plant operation or during accident conditions, the systems, structures, and components required to mitigate the consequences of all analyzed events will remain unaffected due to failures of this system. The SBO Emergency Compressed Air System is manually started within one hour following a SBO event. If any abnormality occurs in the starting of the system during an event, appropriate measures will be taken to start the system with replacement spare parts available in stock. Therefore, redundancy and diversity in the system are neither required, nor provided. The SBO Air Compressor may also be used to supply limited control air in the event of a complete loss of control air due to reasons other than a SBO event. 9.3.1.4 Tests and Inspections Prior to plant operation, the Compressed Air System was inspected and tested to verify correct installation and operation. During plant operation, the system is in operation on a continuous basis, except for the emergency control air compressors which can be tested to verify automatic starting and operability. The maintenance and surveillance on the SBO emergency diesel driven air compressor unit will be performed in accordance with the manufacturer's recommendations. 9.3-4 SGS-UFSAR Revision 20 May 6, 2003 9.3.1.5 Instrumentation and Control 9.3.1.5.1 Station Air Compressors The compressor control circuits are designed to protect the compressor against the following hazards: 1. Low oil pressure 2. High air temperature 3. Low/High oil temperature 4. Low cooling water pressure 5. Excessive vibration 9.3.1.5.2 Control Air The emergency control air compressors may be operated in three modes: 1. Remote manual operation from the Control Room 2. Local manual operation from the "Hot Shutdown panel or 3. Automatic start-stop operation Normally, the emergency air compressors are in the automatic mode. The compressor motors are started by either tripping of all three station air compressors or decay of control air header pressure below 85 psig, as sensed by a pressure switch in the respective control air header. The SBO air compressor is designed to be manually started in the event of a loss of offsite power coincident with the failure of either the "C" emergency diesel generator or the emergency air compressor in the non-blacked out unit. The SBO Air Compressor may also be used to supply limited control air in the event of a complete loss of control air due to reasons other than a SBO event. The compressor will trip automatically if any of the operating parameters (engine oil pressure, discharge air temperature, and engine water temperature) exceed their design limits. SGS-UFSAR Revision 20 May 6, 2003 9.3.2 Sampling System 9.3.2.1 Design Bases The Sampling System provides a means for obtaining fluid and gas samples for laboratory analysis of chemistry and radiochemistry conditions of the Reactor Coolant System (RCS) and other systems. The system is designed to permit the taking of samples during reactor operations, during cooldown, and following an accident without requiring access to the containment. The system has no emergency function, nor is it required to take action to prevent an emergency condition. In the event of a loss-of-coolant accident (LOCA), the system is isolated at the containment boundary. Sampling following a LOCA would occur when conditions would allow use of the sample lines. Sampling system discharge flows are limited under normal and anticipated fault conditions (malfunctions or failure) to preclude any fission product release beyond the 1 OCFR2 0 limit. Adequate safety features are provided to protect laboratory personnel and prevent the spread of contamination from the Sampling Room when samples are being drawn. Each unit has an identical sampling system and only the boron analyzer is shared between units. herein is equally applicable to either unit. The description contained System component code requirements are given in Table 9.3-1. 9.3.2.2 System Description 9.3.2.2.1 General The Sampling System, shown on Plant Drawings 205244 and 205344, provides the representative samples for laboratory analysis. Analysis results provide guidance in the operation of the RCS, Residual Heat Removal (RHR), Component Cooling, Chemical and Volume Control (CVCS), Main Steam, and Steam Generator Blowdown (SGB) Systems. Analysis shows both chemical and radiochemical conditions. Typical information obtained includes reactor coolant boron and chloride concentrations, fission product radioactivity level, 9.3-6 SGS-UFSAR Revision 27 November 25, 2013 hydrogen, oxygen, and fission gas content, conductivity, pH, corrosion product concentration, and chemical additive concentration. The information is used in regulating boron concentration adjustments, evaluating fuel element integrity and mixed bed demineralizer performance, and regulating additions of corrosion controlling chemicals to the systems. The Sampling System is designed to be operated manually, on an intermittent basis, except for Steam Generator Blowdown which is continuously analyzed. Samples can be withdrawn under conditions ranging from full power to cold shutdown. Samples are drawn from the following locations. Inside Containment 1. The pressurizer steam space 2. The pressurizer liquid space 3. Hot legs of reactor coolant loops 1 and 3 4. The Safety Injection System (SIS) accumulators 5. Steam generator blowdown Outside Containment 1. The mixed bed demineralizer inlet header 2. The mixed bed demineralizer outlet header 3. Each RHR System heat exchanger outlet 4. The volume control tank gas space 5. Main Steam 9.3-7 SGS-UFSAR Revision 6 February 15, 1987 Local sample connections are provided at various locations outside the containment. These connections are shown on the respective flow diagrams and are not considered part of the Sampling System. Samples originating from locations within the containment flow through lines to the Sampling Room in the Auxiliary Building. Each line is equipped with a manual isolation valve close to the source; a remote, air-operated valve immediately downstream of the isolation valve; containment boundary isolation/trip valves located inside and outside the containment, except for blowdown sample lines which have an isolation/ trip valve outside the containment only. Manual valves are located inside the Sampling Room for component isolation, sample flow control and routing. High temperature sample lines also contain a sample heat exchanger. In addition, the high pressure reactor coolant sample line contains sufficient length to provide at least a 60-second sample transit time within the containment. An additional 20-second transit time from the reactor containment to the sampling hood is provided by the sampling line. This allows for decay of the short-lived isotope, N-16, to a level that permits normal access to the Sampling Room. All sample lines, whether originating from locations outside the containment or inside, are provided with manual isolation valves. The RHRS also has a remote, air-operated sampling valve. Samples are drawn in an enclosed room with controlled ventilation and drainage to confine the spillage of radioactivity. The sample flows are limited to preclude the release of radioactivity above IOCFR20 limits in the event of a system failure. 9.3-8 SGS-UFSAR Revision 6 February 15, 1987 9.3.2.2.2 Operation Sampling System equipment is located inside the Auxiliary Building with most of it in the Sampling Room. remotely operable valves. All sample lines from inside the containment have Reactor coolant loop liquid, pressurizer liquid, pressurizer steam and steam generator blowdown samples originate inside the containment and flow through separate sample lines to the sampling room. A delay is provided by the length of the reactor coolant sample lines to provide sufficient elapsed time for N-16 decay. The samples pass through the containment to the Auxiliary Building, and into the Sampling Room, where they are cooled (pressurizer steam samples condensed and cooled) in the sample heat exchangers. The sample stream pressure is reduced by a manual throttling valve located downstream of each sample pressure vessel. The sample stream is purged to the volume control tank in the eves until sufficient volume has passed to permit collection of a representative sample. After sufficient purging, the sample pressure vessel is isolated tor laboratory analysis of the contents or degassed, depending on the analysis required. Alternately, these liquid samples may be collected by bypassing the sample pressure vessels. After sufficient volume has passed to the volume control tank to permit collection of a representative sample, a portion of the sample flow is diverted to the sample sink where the sample is collected. Samples from the accumulators in the SIS pass through the containment, to the Auxiliary Building, and into the Sampling Room. The sample stream is purged until sufficient volume has passed to permit collection of a representative sample. After sufficient purging, samples are obtained at the sample sink. The reactor coolant samples originating from the RHRS have remote operated, normally closed air-operated sampling valves located 9.3-9 SGS-UFSAR Revision 17 October 16, 1998 olose to the sample sources. The sample lines from these sources are connected to the sample lines coming from the reactor coolant loops at a point upstream of the sample heat exchanger. Samples from this source can be collected either in the sample pressure vessel or at the sample sink as with reactor coolant loop samples. Liquid samples originating at the eves letdown line at the mixed bed demineralizer inlet and outlet headers are purged directly to the volume control tank. Samples are obtained by diverting a portion of the flow to the sample sink. If the pressure is low in the letdown line, the purge flow is directed to the Waste Disposal System (WDS). The sample line from the gas space of the volume control tank delivers gas samples to the volume control tank sample pressure vessel in the Sampling Room. Purge flow for these samples is discharged to the vent header in the WDS. The steam generator blowdown samples originate from locations inside the containment, flowing through lines to the sampling area in the Auxiliary Building. Each line is equipped with a manual valve close to the source, a remote air-operated valve downstream of the manual valve, an automatic containment boundary isolation valve located outside the containment and manual valves located inside the sampling area for component isolation, flow control and routing. These sample lines also contain a sample heat exchanger for cooling. A blowdown sample from each steam generator is reduced in pressure and is continuously monitored for radioactivity level, pH, and conductivity. The steam generator samples originate from locations outside the containment, flowing through lines to the sampling area in the Auxiliary Building. Each line is provided with a manual valve close to the source and manual valves located inside the sampling area for component isolation and flow control. These sample lines also contain a sample heat exchanger for condensing and cooling. 9.3-10 . SGS-UFSAR Revision 6 February 15, 1987 --
The sample sink, which is located in the Sampling Room, contains a drain line to the WDS. 9.3.2.2.3 Components A summary of principal component data is given in Table 9. 3-2. Sample Heat Exchangers Eleven sample heat exchangers are installed in the system. Each heat exchanger is designed to cool the sample flow to a maximum of 127°F before the sample reaches the sample vessel or sample sink. The sample heat exchangers are of the shell and coil tube type. Sample flow circulates through the tube side, while component cooling water circulates through the shell. The tubes and other surfaces in contact with sample flow are austenitic stainless steel while the shell is carbon steel. The inlet and outlet tube sides have socket-welded joints for connections to the high pressure sample lines. Sample Pressure Vessel The sample vessel is designed to receive liquid or gas samples at RCS design pressure and temperature. The sample vessel is sized to contain sufficient gas to perform a radiochemical analysis on the volume control tank gas space constituents or sufficient reactor coolant for dissolved hydrogen and fission gas analyses. Integral isolation valves are furnished with the sample vessel. Sample Sink The sample sink is located in a hooded enclosure which is equipped with an exhaust ventilator. The work area around the sink and the enclosure is large enough for sample collection and storage for radiation monitoring equipment. The sink perimeter has a raised 9.3-11 SGS-UFSAR Revision 6 February 15, 1987 edge to contain any spilled liquid. The enclosure is penetrated by sample lines and by a demineralized water line, all of which discharge into the sink. Piping and Fittings All liquid and gas sample lines are austenitic stainless steel tubing and are designed for high pressure service. Lines are so located as to protect them from accidental damage during routine operation and maintenance. Valves Stop valves within the containment are remotely operated from the Sampling Room. They are used to isolate all sampling points and to route sample fluid flow. The remotely operated isolation valve used for sampling from the RHRS is provided so that the operator does not have to enter a possibly high radiation area following a LOCA. Stop valves are provided for component isolation and flow path control at all Sampling System locations which are normally accessible. A check valve in the sample line prevents accidental overpressurization of the RHRS by preventing back flow from the RCS, should both the air-operated sample valves be open. Two isolation valves are provided, one inside and one outside the containment on all sample lines leaving the containment except for the steam generator blowdown lines which have one isolation valve outside the containment on each line. The valve trip closes upon actuation of the containment isolation signal. All valves in the system are constructed of austenitic stainless steel or equivalent corrosion-resistant material. 9.3-12 SGS-UFSAR Revision 6 February 15, 1987 9.3.2.3 System Evaluation The Sampling system is not required to function during an emergency, nor is it required to take action to prevent any emergency condition. Samples are collected under a hood provided with a vent to the building Exhaust Ventilation System. Liquid leakage in the sample sink is collected in the sink and drained to the WDS. Any leakage from the system inside of the containment (i.e., valve stem leakage) is collected in the containment sump. The Sampling Room and the sample hood are ventilated to reduce the potential for airborne radioactive exposure of operating personnel. Sufficient length is provided in the reactor coolant sample line to reduce personnel exposure from short-lived radionuclides. Shielding is provided as necessary to reduce personnel exposures. The operating procedures will specify the precautions to be observed when purging and drawing samples. The system is designed to be operated on an intermittent basis under administrative control except for steam generator blowdown sampling which is a continuous operation. The system is normally closed with no flow, except for the steam generator blowdown samples. Sample lines penetrating the containment are equipped with remote-operated isolation valves which close on receipt of a containment isolation signal. In the event of a LOCA, the malfunctions or failures presented in Table 9.3-3 could occur without loss of integrity of the containment. 9.3-13 SGS-UFSAR Revision 6 February 15, 1987 9.3.2.4 Tests and Inspection System operation is verified by normal, periodic collection of samples. 9.3.2.5 Instrumentation and Control Local instrumentation is provided to permit manual control of sampling operations and to ensure that the samples are at sui table temperatures and pressures before diverting flow to the sample sink. 9.3.3 Equipment and Floor Drainage System 9.3.3.1 Design Bases Equipment and floor drains are provided to drain radioactively contaminated water into sumps for transfer to the Liquid Waste Disposal System (See Section 11.2) . In many cases equipment drainage is provided by permanently installed lines which eliminate (or reduce) surface and airborne contamination. Permanently piped equipment vents are also provided to enable various mechanical components to be vented to the respective building Ventilation System to preclude the direct release of potentially radioactive gases to the building atmosphere. 9.3.3.2 System Description The contaminated floor drains and equipment vents and drains flow diagrams are shown on Plant Drawings 205227, 205327, 205226 and 205326. All liquid drains originating in the Containment and Auxiliary Buildings are considered potentially radioactive and are therefore drained to the Liquid Waste Disposal System. The drain connections on nearly all components within these areas are permanently piped to the equipment drain system. Exceptions include some room cooler condensate drain piping, the Component Cooling System and certain portions of the 9.3-14 SGS-UFSAR Revision 27 November 25, 2013 eves containing 12 percent boric acid. Hose connections are provided where it is impractical to have a permanently piped drain in which case equipment drains can be temporarily connected by hose to a local floor drain. These provisions eliminate or reduce the possibility of inadvertently allowing radioactive drains to contaminate concrete floor areas and the building atmosphere. Condensate drain piping from room cooler drip pans is extended to the floor for free discharge to the nearest existing floor drains. In the Auxiliary Building the floor drains at Elevations 84 feet, 100 feet and 122 feet are piped to the waste holdup tanks. Elevation 64 foot drains are piped to the waste holdup tanks via the Auxiliary Building sump tanks and sump tank pumps. All drains below the elevation of the Auxiliary Building sump tank drain to the waste holdup tank via the Auxiliary Building sump and the Auxiliary Building sump pump. A floor drain, 4 inches in diameter, in the immediate vicinity of each charcoal filter bank, directs the drainage or deluge water to the waste holdup tanks, either directly or via sump pumps. In the Containment Building, all equipment drains to the WDS from the containment sump. In the Fuel Handling Building, the equipment drains are piped to the WDS via a fuel handling area sump. With the exception of Nuclear Steam Supply System (NSSS) tanks that are blanketed with nitrogen, all tanks containing potentially contaminated waste are permanently vented to the suction side of the Auxiliary Building exhaust fans. This ensures that the tanks are maintained at a slight negative pressure to eliminate the possibility of introducing airborne contamination to the Auxiliary Building atmosphere. 9.3-15 SGS-UFSAR Revision 18 April 26, 2000 9.3.3.3 System Design The contaminated floor and equipment drain piping was originally designed to ASME/ANSI B31.1, while material selection, fabrication, inspection, testing, installation and quality controls were in accordance with ASME/ANSI B31.7. The original design classification of the system was based on early interpretation of the Regulatory Guides during the construction period, and the system was classified to be non-safety related, Nuclear Class III and non-seismic. Based on the current revisions of the Regulatory Guides and ANSI standards, the system has been reclassified to be non-safety related, non-Nuclear (Quality Group 0) and non-seismic. Supplemental quality* assurance requirements (Augmented D) have been incorporated to the applicable piping specification section to maintain the quality level recommended by Regulatory Guide 1.143. 9.3-lSa SGS-UFSAR Revision 13 June 12, 1994 THIS PAGE INTENTIONALLY LEFT BLANK 9.3-lSb SGS-UFSA.R Revision 13 June 12, 1994 9.3.4 Chemical and Volume Control System The eves is used to 1} adjust the concentration of boric acid, i.e., the chemical neutron absorber for reactivity control, 2) maintain the proper water inventory in the RCS, 3} provide the required seal water flow for the reactor coolant pump shaft seals, 4) process reactor coolant letdown for reuse of boric acid and reactor makeup water, 5) maintain the proper concentration of corrosion-inhibiting chemicals in the reactor coolant, 6) maintain the reactor coolant activities to within design limits, and 7) provide borated water for safety injection. The system is also used to fill and hydrostatically test the ReS. In addition, the system is used to provide reactivity management, normal RCS make-up, and RCP seal injection flow through the cross-tied portions to support a safe shutdown of the opposite unit if it loses its charging capability due to a fire. During normal operation, this system also has provisions for supplying the following chemicals: 1. Regenerant chemicals to the evaporator condensate and deborating demineralizers 2. Hydrogen to the volume control tank 3. Nitrogen as required for purging the volume control tank 4. Hydrazine hydrogen peroxide and lithium hydroxide as required via the chemical mixing tank to the charging pumps suction 9.3.4.1 Design Bases 9.3.4.1.1 Redundancy of Reactivity Control Systems Two independent Reactivity Control Systems, preferably of different principles, shall be provided. In addition tG the reactivity control achieved by the rod cluster control assemblies (RCCA) as detailed in Sections 7 and 4, reactivity control is provided by the eves which regulates the concentration of boric acid solution neutron absorber in the RCS. 9.3-16 SGS-UFSAR Revision 20 May 6, 2003 9.3.4.1.2 Reactivity Hold-Down Capability The Reactivity Control Systems provided shall be capable of making the core subcritical under credible accident conditions with appropriate margins for contingencies and limiting any subsequent return to power such that there will be no undue risk to the health and safety of the public. Normal reactivity shutdown capability is provided by control rods with boric acid injection used to compensate for the long-term xenon decay transient and for plant cooldown. Any time that the plant is at power, the quantity of boric acid retained in the boric acid tanks and ready for injection always exceeds that quantity required for the normal cold shutdown. This quantity always exceeds the quantity of boric acid required to bring the reactor to hot shutdown and to compensate for subsequent xenon decay. The system is designed to allow for concurrent mixing and subsequent injection of boric acid solution. Thus the CVCS provides extended reactivity hold-down capability. 9.3.4.1.3 Reactivity Hot Shutdown Capability The Reactivity Control Systems provided shall be capable of making and holding the core subcritical from any hot standby or hot operating condition. The Reactivity Control Systems provided are capable of making and holding the core subcritical for any hot standby or hot operating condition, including those resulting from power changes. The chemical shim control serves to provide hot shutdown for the reactor as backup to the RCCAs. 9. 3-17 SGS-UFSAR Revision 6 February 15, 1987 9.3.4.1.4 Reactivity Shutdown Capability The Reactivity Control Systems provided shall be capable of making the core subcritical under credible accident conditions with appropriate margins for contingencies and limiting any subsequent return to power such that there will be no undue risk to the health and safety of the public. The sizing of the CVCS components and redundancy of its components and flow paths determines the eves reactor shutdown capability. The boric acid solution is transferred from the boric acid tanks by boric acid transfer pumps to the suction of the charging pumps which inject boric acid into the RCS. Any charging pump and any boric acid transfer pump can be operated from diesel generator power on loss of primary power. On the basis of the above, the injection of boric acid is shown to afford backup shutdown reactivity capability, independent of control rod clusters which normally serve this function in the short-term situation. Shutdown for long terms and reduced temperature conditions can be accomplished with boric acid injection using redundant components. 9.3.4.1.5 Codes and Classifications All pressure retaining components (or compartments of components) of the CVCS which are exposed to reactor coolant comply with the following codes: 1. System pressure vessels ASME Boiler and Pressure Vessel Code,Section III, Class C. 2. System valves, fittings and piping -ANSI B3I.l (for design). For piping not supplied by the NSSS supplier, material inspections, fabrication and quality control conform to ANSI B31. 7. Where not possible to comply 9.3-18 SGS-UFSAR Revision 6 February IS, 1987 with ANSI B31.7, the requirements of ASME III-1971, which incorporated ANSI B31.7,. were adhered to. System integrity is assured by conformance to applicable codes listed in Table 9. 3-4, and by the use of austenitic stainless steel or other corrosion-resistant materials in contact with both reactor coolant and boric acid solutions. The regenerative heat exchanger and the tube side of the excess letdown heat exchanger are designed as ASME III, Class C. following considerations: This designation is based on the 1. Each exchanger can be isolated from the RCS. 2. Each is located inside the reactor containment, and 3. Both exchangers are protected by a missile barrier. Accordingly, the designation of "Class C" for these exchangers is justifiable and does not lead to any public hazard. 9.3.4.2 System Design and Operation The CVCS shown on Plant Drawings 205228, 205328, 205229, 205329, 205230 and 205330 provides a means for injection of soluble neutron adsorber in the form of boric acid solution, chemical additions for corrosion control and reactor coolant cleanup and degasification. This system also provides a means to add makeup water to the RCS, reprocesses water letdown from the RCS, provides seal water injection to the reactor coolant pump seals, and fills and hydrostatically tests the RCS. In addition, the system is used to provide reactivity management, normal RCS make-up, and RCP seal injection flow through the cross-tied portions to support a safe shutdown of the opposite unit if it loses its normal charging capability due to a fire. The CVCS system is capable of supporting safe power operation and, at the same time, supporting the opposite unit's safe shutdown. System components whose design pressure and temperature are less than the RCS design limits are provided with overpressure protective devices. 9.3-19 SGS-UFSAR Revision 27 November 25, 2013 System discharge from overpressure protective devices and system leakages are directed to closed systems. Effluents removed from such closed systems are monitored and discharged under controlled conditions. System design enables post-operational hydrostatic testing to test pressure required by the codes listed in Table 9.3-4. 9.3.4.2.1 System Description During plant operation, reactor coolant flows through the letdown line from one of the reactor coolant loop cold legs on the suction side of the reactor coolant pump and is returned through the charging line to the cold leg of another loop. An alternate return path is provided to the cold leg of a different loop (see Plant Drawings 205228 and 205328). An excess letdown line is also provided as an alternate in case the normal letdown circuit is inoperative or it can be used to supplement maximum letdown during final stages of heatup. Each of the eves connections to the Res has an isolation valve. In addition, a check valve is located downstream of each charging line isolation valve. Reactor coolant entering the eves flows through the shell side of the regenerative heat exchanger where its temperature is reduced. The coolant then flows through a letdown orifice which reduces the coolant pressure. The cooled, low pressure water leaves the reactor containment and enters the Auxiliary Building where it undergoes a second temperature reduction in the tube side of the letdown heat exchanger followed by a second pressure reduction by the low pressure letdown valve. After passing through one of the demineralizers, where ionic impurities are removed, coolant flows through the reactor coolant filter and enters the volume control tank through a spray nozzle. Hydrogen is automatically supplied, as determined by pressure control, to the vapor space in the volume control tank, which is 9.3-20 SGS-UFSAR Revision 27 November 25, 2013 predominantly filled with hydrogen and water vapor. The hydrogen within the tank is, in turn, the supply source to the reactor coolant. Fission gases are removed from the system by venting the volume control tank to the WDS prior to '-a cold or refueling shutdown. During plant shutdown, dissolved hydrogen in the RCS must be removed prior to opening the RCS for maintenance or refueling. Hydrogen removal can be performed in either or a combination of the following methods: 1 l The VCT level can be raised and lowered repeatedly to "burp" the hydrogen-rich VCT gas space to the WDS. When the level is lowered, fresh nitrogen is admitted to the gas space. 2) Hydrogen peroxide is added to the RCS to react with the dissolved hydrogen to form water. If there is uncertainty concerning the removal of hydrogen, then additional monitoring, actions, and precautions will be performed during opening of the component for refueling or maintenance to ensure safe conditions are established. To enter the RCS the coolant flows from the volume control tank to the charging pumps which raise the pressure above that in the RCS. The coolant then enters the containment, passes through the tube side of the regenerative heat exchangers, and returns to the RCS. A portion of the high pressure charging flow is filtered and injected into the reactor coolant pumps between the pump impeller and the shaft seal so that the seals are not exposed to particulate matter in the reactor coolant. Part of the flow cools the lower radial bearing and enters the RCS through a labyrinth seal on the pump's shaft. The remainder, which is the shaft seal leakage flow, is filtered, cooled in the seal water heat exchanger and returned to the suction of the charging pumps. An alternate path provides means for returning seal water to the volume control tank. Coolant ected through the reactor coolant pump seals joins with the reactor coolant. An equal amount of reactor coolant returns to the volume control tank by the normal letdown flow path through the regenerative heat exchanger. When the normal letdown route is not in this reactor coolant letdown returns to the suction of the charging pumps through the excess letdown and seal water heat exchangers. 9.3-21 SGS-UFSAR Revision 19 November 19, 2001 The* cation bed demineralizer, located downstream of the mixed bed demineralizers, may be used intermittently to control cesium in the coolant and also to remove excess lithium which is formed from the s10 (n, <<) . 7 . Ll react1.on. Boric acid is dissolved in water in the batching tank to a concentration between 3. 75 to 4. 0 weight percent. The batching tank is jacketed to permit heating of the hatching tank solution with low pressure* steam. One of two boric acid transfer pumps is used to transfer the batch to the boric acid tanks. Small quantities of boric acid solution are metered from the discharge of an operating boric acid transfer pump for blending with the water supplied to makeup for normal leakage, or for increasing the reactor coolant boron concentration during normal operation. Electric immersion heaters maintain the temperature of the solution in the boric acid tanks high enough to prevent precipitation. During plant startup, normal operation, load reductions and shutdowns, liquid effluents containing acid flow from the RCS through the letdown line and are collected in the holdup tanks or the volume control tank. As liquid enters the holdup tanks, the nitrogen cover gas is displaced to the gas decay tanks in the WDS through the waste vent header. The concentration of boric acid in the holdup tanks varies throughout core life from the refueling concentration to essentially zero at the end of the core cycle. A recirculation pump is provided to recirculate and transfer liquid from one holdup tank to another. Liquid effluent the holdup tanks is through a processing This liquid is pumped by the gas stripper feed pumps through the evaporator feed ion exchangers which primarily remove lithium and long-lived cesium. Additional ion exchange resin may be used to enhance removal if isotopes such as cobalt. The liquid then flows through the ion exchanger filter, and into the gas stripper section of the combined boric acid evaporator gas stripper package where dissolved gases are removed from the liquid. These gases are vented to the Gaseous Waste Disposal System. The liquid effluent from the gas stripper section enters the boric evaporator. The vapor produced in the boric acid evaporator leaves the evaporator condenser and is pumped through a condensate cooler where the distillate is cooled to the operating temperature of the evaporator distillate demineralizers. After non-volatile 9.3-22 SGS-UFSAR Revision 21 December 6, 2004 * * *
- *
- evaporator carryover is removed by one of the two evaporator distillate demineralizers 1 the distillate then flows through the distillate filter and accumulates in one of the two monitor tanks. The evaporator bottoms left behind in the boric acid evaporator are concentrated to approximately 12 weight percent boric acid. Subsequent handling of the condensate is dependent on the results of sample analysis of the monitor tank contents. Discharge from the monitor tanks may be pumped by either of the two monitor tank drain pumps to the primary water storage tank, recycled through the evaporator distillate demineralizers, returned to the holdup tanks for reprocessing in the evaporator train or, if the sample analysis of the monitor tank contents indicates sufficiently low levels, the contents may be discharged to the environment via the WDS (Section 11). Boric acid evaporator bottoms are discharged through a concentrates filter to the concentrates holding tank to the Boric Acid Storage Tanks or the hold-up tanks, depending on sample analysis and plant requirements. The concentrated solution can also be pumped from the evaporator to the WDS portable demineralizer or waste evaporator for additional reprocessing before being placed in containers. These containers can then be stored at the station site for ultimate shipment offsite for disposal . The eves demineralizers can be used intermittently to remove boron from the coolant near the end of core life when boron concentration is low. When the deborating demineralizers are in operation, the letdown stream passes through the mixed bed demineralizers and then through the deborating demineralizers and into the volume control tank after passing through the reactor coblant filter. During shutdown, hydrogen peroxide is added to the RCS via the Chemical Mixing Tank to dissolve radionuclides and non-radioactive metals from piping and equipment to allow their removal by the eves demineralizers. Duri,ng plant cooldown when the residual heat removal loop is operating and the letdown orifices are not in service, a flow path is provided to remove fission products, corrosion products and other impurities. A portion of the flow leaving the residual heat exchangers passes through the letdown heat exchanger, ... ,: ........ '-"'"-;::;, reactor coolant filter and volume control tank. The fluid is then pumped via the charging pump through the tube side of the regenerative exchanger into the RCS . .SGS-UFSAR 9.3-23 Revision 21 December 6, 2004 During normal operation, the isolation valves on the charging. and BAST cross-ties between the units are kept shut to maintain between units . The cross-ties enhance plant safety by allowing the eves in one unit to be an alternate source of high pressure, borated water to the opposite unit. This alloy.,s, even with a total loss of its own charging pumps, for a unit to be safely shutdown. This charging flow satisfies reactivity management, normal ReS inake-up, and RCP seal injection. Furthermore, the design provides the capability for separation of the C/SI pump and PO pump flow paths for cooldown and boration from the BAST to achieve cold shutdown of the opposite Separation of the PO pump allows for a unit to continue safe power operation using its C/SI pumps with the PO pump used to achieve cold shutdown o.f the opposite unit. When separated, the C/SI pumps are aligned to the VCT to provide normal charging, while the PO pump takes suction from either the RWST or the BAST thus providing charging to the opposite unit via the cross-tie, The charging line to the opposite unit is normally isolated by a check valve and normally shut MOV. The MOV can be operated from the control room to minimize any delay in starting charging to the opposite unit. The BAST cross-tie between units allows the BAST from the unit being shutdown to the source of borated water to the PD pump to minimize the impact on the RWST*. The operation of the cross-tied boration system and charging system is controlled manually as necessary in accordance with station procedures. 9.3.4.2.2 Expected Operating Conditions Tables 9. 3-5 and 9. 3-6 list the system performance requirements and data for system components 9.3.4.2.3 Reactor Coolant Activity Concentration The parameters used in the calculation of the reactor coolant fission invehtory, including the expected coolant cleanup flow rate and the demineralizer effectiveness, are presented with the results of the calculations in Appendix I. In these calculations the defective fuel rods are assumed to be present at core loading uniformly distributed throughout the core. The fission prod]Jct . escape rate coefficients are therefore based upon an average fuel tempf:!rature. 9.3-24 SGS-UFSAR Revision 21 December 6, 2004 * *
- Tritium is produced in the reactor from ternary fission in the fuel, irradiation of boron in the burnable poison rods (during initial fuel cycle only), irradiation of boron in the control rods, and irradiation of boron, lithium and deuterium in the coolant. 9.3.4.2.4 Reactor Makeup Control Modes The reactor makeup control is designed to operate 'from the Control Room by manually preselecting makeup composition to the charging pump suction header or the volume control tank in order to maintain the desired operating fluid inventory in the volume control tank and to adjust the reactor coolant boron concentration for reactivity control. The operator can stop the makeup operation at any time in any operating mode by remotely closing the makeup stop valves or depressing the makeup mode selector stop pushbutton. Makeup water to the RCS is provided by the eves from the following sources: 1. The primary water storage tank, which provides water for dilution when the reactor coolant boron concentration is to be reduced. 2. The boric acid tanks, which supply concentrated boric acid solution when the reactor coolant boron concentration is to be increased. 3. The refueling water storage tank which supplies borated water for emergency makeup. 4. The chemical mixing tank, which is used to inject small quantities of solution when additions of hydrazine hydrogen peroxide or pH control chemical (Li70H) are necessary. Makeup for normal plant leakage is regulated by the reactor makeup control which is set by the operator to blend water from the primary water storage tank with concentrated boric acid to match the reactor coolant boron concentration. Makeup is added automatically if the volume control tank level falls below a preset point. Automatic Makeup The "automatic makeup" mode of operation of the reactor primary water makeup control provides boric acid solution present to match the boron concentration in the RCS. The "automatic makeup" compensates for minor leakage of reactor coolant without causing 9.3-25 SGS-UFSAR Revision 20 May 6, 2003 significant changes in the coolant boron concentration. The operator sets the following equipment in the automatic position: 1. Either primary water makeup pump 2. Either boric acid transfer pump 3. Boric acid flow control valve 4. Primary water flow control valve 5. Charging suction makeup valve 6. Makeup mode selector By depressing the start pushbutton of the makeup mode selector, the following actions occur when a low level signal is received from the volume control tank: 1. The boric acid transfer pump is switched to high speed and the primary water makeup pump is switched on. 2. The boric acid flow control valve is switched to its respective flow controller. 3. The primary water flow control valve is unblocked. 4. The charging suction makeup valve is open. The flow controllers then blend the makeup stream according to the present concentration. Makeup addition to either the charging pump suction header or the spray line to the volume control tank causes the water level in the volume control tank to rise. After the level in the volume control tank is restored, the primary water flow control valve closes, the boric acid transfer pump is 9.3-26 SGS-UFSAR Revision 6 February 15, 1987 *-
returned to low speed operation, the boric acid flow control valve returns to the full open position, and the charging suction makeup valve closes. Dilution The "dilute" mode of operation permits the addition of a preselected quantity of reactor primary water makeup at a preselected flow rate to . the RCS. The operator sets the following equipment in the automatic position: l. Either primary water makeup pump 2. The primary water flow control valve 3. The volume control tank makeup valve He then selects the setpoint for the primary water makeup flow rate and the total quantity of makeup water desired on the primary water flow register. By depressing the "dilute" and start pushbuttons on the makeup mode selector, the following actions are initiated: l. The primary water makeup pump is switched on. 2. The primary water flow control valve is unblocked. 3. The boric acid flow control valve is closed if it is in the automatic position. 4. The volume control tank makeup valve is opened. This provides a regulated supply of unborated primary water to the volume control tank which subsequently goes to the charging pump suction header. 'When the preset quantity of primary water makeup has been added, the primary water flow register causes the primary 9.3-27 SGS-UFSAR Revision 6 February 15, 1987 water makeup pump to stop, the primary water flow control valve to close, and the volume control tank makeup valve to close. The volume control tank level is controlled by a three-waY. valve which normally modulates flow between the volume control tank and the holdup tanks with a level controller.* In the event the level becomes abnormally high, the entire flow is diverted to the holdup tanks. Alternate Dilution The "alternate dilute" mode of operation provides a more rapid reduction of boric acid concentration than the "dilute" mode. This is accomplished by opening both the charging suction makeup valve and the volume control tank makeup valve. The operation is the same as described for the "dilute" mode except the operator must have the charging suction makeup valve in the automatic position in addition to the equipment listed for the "dilute" mode, and he must depress the "alternate dilute" pushbutton of the makeup mode selector instead of the "dilute" pushbutton. To provide a more rapid boron reduction rate, the operator can take manual control and close valve CV181 thereby directing all dilution flow to the charging pump suction. Boration The "borate" mode of operation permits the addition of a preselected quantity of concentrated boric acid solution at a preselected flow rate to the RCS. The operator sets the following equipment in the automatic position: 1. Either boric acid transfer pump 2. The charging suction makeup valve 3. The boric acid control valve He then selects the set:point for the concentrated boric acid flow rate and the total quantity of concentrated boric acid desired on the boric acid flow register. By depressing the "borate" and 9.3-28 SGS-UFSAR Revision 13 June 12, 1994 start pushbuttons of the makeup mode selector the following actions are initiated: 1. The boric acid transfer pump is switched to high speed. 2. The boric acid flow control valve is switched to its respective flow controller. 3. The charging suction makeup valve is opened. This provides a regulated supply of 3. 7 5 to 4. 0 weight percent boric acid solution to the charging pump suction header. The total quantity added in most cases will be so small that it will have only a minor effect on the volume control tank level. When the preset quantity of concentrated boric acid solution has been added, the boric acid flow register causes the boric acid transfer pump to return to low speed operation and closes the charging suction makeup valve and returns the boric acid flow control valve to the full open In the event of a volume control tank low-low level signal, the suction of the charging pumps is automatically aligned to take suction from the refueling water storage tank. The maximum rate of boration with the two centrifugal charging pumps delivering water from the refueling water storage tank at a concentration of 2000 ppm boron is 9 ppm per minute. This compensates for a cooldown rate of 2°F per minute at the end of core life when the moderator temperature coefficient is most By comparison, normal cooldown rates are about 0.8°F per minute. The rate of boration of the primary system with 45 gpm from a boric acid transfer pump directed to the charging pump suction is 4. 8 ppm per minute, which is above the required value for normal cooldowns. Deviation of reactor primary water makeup flow rate from the control and deviation of concentrated boric acid flow rate from the control setpoint are alarmed on the main control board. Boration During Cooldown Boration during cooldown may be performed as an alternative to boration prior to cooldown per amendments 145/133. This methodology does not require the use of the non-safety letdown line, and it minlmizes the amount of Boric Acid Tank volume required to borate the RCS. The methodology is described in detail in Reference 2. 9.3-29 SGS-UFSAR Revision 14 December 29, 1995 If ion contraction during cooJ.down is selected, the sole source of RCS c.aoldown make-up must be undiluted boric acid until the Technical Specification BAT volume is added. Thereafter, the make-up concentration is varied depending on the desired end point concentration. To use undiluted boric acid as RCS makeup, the "automatic make-up" mode is selected as previously described except that ( 1) both primary water make-up pump$ are placed in manual and (2) the primary water flow control valve setpoint is adjusted to zero gpm. The RCS make-up system will respond to VCT level signals as described in "automatic mode" except that the PWST pump will not operate and the primary water flow control valve remain closed. Undiluted boric acid will be sent through the blender to the VCT as the RCS make-up. Opposite Unit Safe Shutdown Whenusing the cross-ties to conduct a safe shutdown of the opposite unit, the "boration during cooldown" methodology is credited with the following differences: The BAST cross-tie isolation valves are opened. The 11 (21) BAT pump, in the unit providing the PD pump, is aligned to take suction from the BAST of the unit being shutdown. The 11 (21) BAT pump discharge is then aligned to the PO pump suction through a line that discharges downstream of 1(2)CV571 the isolation valve for the PO pump suction branch line. This allows the 11 {21) BAT pump to supply concentrated boric acid to the PO pump without affecting the VCT boron concentration. The *po pump dedicated RWST suction line gate valve need not be shut since the check valve will prevent back flow to the RWST. In this line up, undiluted boric acid is charged to the opposite unit as long as the PD pump is operated within the flow capacity of the BAT pump. This may limit the cooldown rate until the required BAST volume is added. Once the BAT pump flow to the PD pump is stopped, the PD pump will draw suction from the RWST. 9.3.4.2.5 Charging Pump Control Positive Displacement Charging Pump The pump available in modes 1 -4 to support either normal charging in its unit, or safe shutdown of the opposite unit. For opposite unit use, the pump suction is first aligned to the RWST through the safety injection suction path in the short term, then aligned to the RWST or BAST through dedicated suction lines with normally closed valves. 9.3-30 SGS-UFSAR Revision 21 December 6, 2004 * * *
- *
- Since the BAST and RWST are both non-pressurized tanks vented to the atmoSphere, packing leakage should not cause an airborne concern. DurLng modes 5 and 6, the PD pump can the boration flow path for its own unit. support safe shutdown of the opposite unit. normal charging and to serve as Also, the PD pump may be used to The positive displacement charging pump has a variable speed drive and has the capability of providing normal charging to the RCS. The speed of this pump can be contro*lled manually, or automatically by pressurizer level. During load changes, the pressurizer level setpoint varies automatically with compensating partially for the expansion or contraction of reactor coolant asso,ciated with Tavg changes. Charging pump speed will not change rapidly with pressurizer level controller. If the pressurizer level increases, the speed of the pump decr.eases; conversely, if the level decreases, the increases. When using the positive displacement charging pump to charge to the opposite unit, the speed control must be set in manual. In normal operation, if flow demand exceeds the capacity of the positive displacement charging pump, it beco'mes necessary to fer operation to a C/SI pump. Transfer is achiev.ed by first running both pumps in parallel, and then the PD pump . To ensure that the charging pump flow is always sufficient to meet the seal water flow requirements of the reactor coolant pumps, the pump has a low speed stop which prevents pump flow lower than the specified minimum. Centrifugal Charging Pumps The centrifugal pumps are constant speed pumps with flow control accomplished by a modulating valve in the pump discharge line. When the positive displacement pump is in operation, this control valve is in the wide open position. A flow transmitter on the charging line upstream of the regenerative heat excqanger transmits a signal to a controller which regulates a modulating valve in the charging line to maintain a preset charging flow. A pressurizer water error the charging flow setpoint to take corrective action. The response of the charging line modulating valve to changes in the flow control signal is normally maintained slow to reduce charging flow fluctuations due to short-term pressurizer level 9.3.4.2.6 Components A summary of principal component data is given in Table 9.3-6 . 9.3-31 SGS-UFSAR Revision 21 December 6, 2004 Regenerative Heat Exchanger The regenerative heat exchanger is designed to recover heat from the letdown flow by reheating the charging flow, to eliminate reactivity effects due to insertion of cold water, and to reduce thermal shock on the charging penetrations into the reactor coolant loop piping. The design also considers the limit of difference in temperature which occurs during periods when letdown flow exceeds charging flow by a greater margin than at normal letdown conditions. The letdown stream flows through the shell of the regenerative heat exchanger and the charging stream flows through the tubes. The unit is made of austenitic stainless steel, and is of all welded construction. It is a multi-shell U-tube type heat exchanger using three shells. Letdown Orifices One of the three letdown orifices controls flow of the letdown stream during normal operation and reduces the pressure to a value compatible with the letdown heat exchanger design. Two of the letdown orifices are designed to pass normal letdown flow. The third orifice is designed to be used in conjunction with one normal letdown flow orifice to maintain maximum purification flow at normal RCS operating pressure. The orifices are placed in and taken out of service by remote manual operation of their respective isolation valves. The standby orifice may be used in parallel with the normally operating orifice in order to increase letdown flow when the RCS pressure is below normal. This arrangement provides a full standby capacity for control of letdown flow. Each orifice is an austenitic pipe containing a bored corrosion-and erosion-resistant insert. Letdown Heat Exchanger The letdown heat exchanger cools the letdown stream to the operating temperature of the mixed bed demineralizers. Reactor coolant flows through the tube side of the exchanger while component cooling water flows through the shell. The letdown stream outlet temperature is automatically controlled by a temperature control valve in the component cooling water outlet stream. The unit is a multiple-tube-pass heat exchanger. All surfaces in contact with the reactor coolant are austenitic stainless steel, and the shell is carbon steel. Mixed Bed Demineralizers Two flushable mixed bed demineralizers assist in maintaining reactor coolant purity. A cation resin (Lithium or hydrogen form) and a hydroxyl form anion resin may be used in the demineralizers. Both forms of resin remove fission and corrosion products. The resin is designed to reduce concentration of ionic isotopes in the purification stream except for cesium, yttrium and molybdenum, by 9.3-32 SGS-UFSAR Revision 20 May 6, 2003
- *
- a minimum factor of 10 power operation. The anion resin rapidly converts to a borate form and thereafter does not remove boron from the reactor coolant . Each demineralizer is to the maximum letdown flow. Alternately, approved, application-specific resins capable of enhanced particle removal, layered atop either an anion or mixed bed resin underlay, may be used. The demineralizer Vessels are provided with suitable connections to facilitate resin replacement when required. The vessels are equipped with a resin screen. Each demineralizer has sufficient capacity for approximately one core cycle with one percent defective fuel rods. Catton Bed Demineralizer A flushable cation bed demineralizer is located downstream of the mixed bed demineralizers and may be used Li 7 which builds up in the coolant demineralizer also has su£ficient the coolant below from the capacity 1.0 f.J.C/cc to control the 810 (n, a) Li7 to maintain with 1 percent concentration of reaction. The the cesium-137 defective fuel. The demineralizer MAY BE used intermittently to control cesium. The demineralizer vessel is provided with suitable connections to facilitate resin replacement when required. The vessel is equipped with resin retention screens. The cation bed demineralizer has sufficient capacity for approximately one core cycle with 1 percent defective fuel rods. Resin Fill Tank The resin fill tank is mobile and is used to charge fresh resin to the . demine.talizers. The line from the conical bottom of the tank is fitted with a valve and a flexible hose spool piece that maybe connected to any one of the demi'neralizer fill lines. The 9.3-33 SGS-UFSAR Revision 21 December 6, 2004 demineralizer water and resin slurry can then be sliced into the demineralizer by the valve. Reactor Coolant Filter The filter collects resin fines and particulates from the letdown stream. The vessel is provided with connections for draining and venting. The nominal flow capacity of the filter is equal to the maximum purification flow rate. Disposable synthetic filter elements in a cage assembly are used. The volume control tank is an operating surge volume compensating in part for reactor coolant releases from the RCS as a result of level changes. The volume control tank also acts as a head tank for the charging pumps and a reservoir for the leakage from the reactor coolant pump controlled leakage seal. Overpressure of hydrogen gas is maintained in the volume control tank to control the hydrogen concentration in the reactor coolant at 25 to 50 cc per kg of water (STP) . Hydrogen concentration may be reduced to l5 cc/kg 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to a A spray nozzle is located inside the tank on the inlet line frcm the reactor coolant filter. This spray nozzle provides intimate contact to equilibrate the gas and liquid phases. A remotely operated vent valve discharging to the WDS permits removal of gaseous fission products which are stripped from the reactor coolant and collected in the tank. Three charging pumps are provided for injection coolant into the RCS. Two are pumps and the third is a variable speed drive. All parts in contact fabricated of austenitic stainless steel or pump equipped with with the reactor coolant are other material of adequate corrosion resistance. The centrifugal pump packing glands and positive 9.3-34 SGS-UFSAR Revision 25 October 26, 2010
- *
- disp;lacement pump stuffing box are provided with lc_'akoffs to collect reactor cool,ant. Pump leakage piped to the drain header for The pump design prevents lubricating oil from contaminating the charging flow. The discharge *valves on the positive displacement pump act as check The positive displacement pump is designed to provide the full charging flow and the reactor coolant pump seal water supply. The centrifugal pumps have a higher flow capacity that is capable of matching maximum letdown or purification flows. Each pump is designed to provide rated flow against a pressure equal to the sum of the RCS normal maximum pressure (existing when the zer power operated relief valve is operating) and the piping, valve, and equipment pressure losses at the design charging flows. A suction stabilizer and pulsation dampener are provided on the suction and discharge, resp'ectively, of the positive displacement pump to attenuate the inherent pressure pulsations that are caused by the reciprocating actions of the pump. The positive displacement charging pump is used to hydrotest the RCS. Unde.r normal conditions, either the positive displacement charging pump or a centrifugal charging pump will take suction from the volume control tank and discharge to the normal charging and reactor coolant pump seal water injection paths. Flow control for the positive displacement pump is accomplished by varying the pump speed. If the positive displacement pump is not used, one of the . centrifugal charging pumps is operated. The flow paths remain the same, but flow control is accomplished by a modulating valve on the discharge side of the . centrifugal pumps. A centrifugal charging pump is operated to provide charging when maximum letdown or is The. centrifugal chai:ging pumps also serve as safety injection pumps in the Emergency Core Cooling System (Section 6) . 9. 3,...)5 SGS-,UFSAR Revision 21 December 6, 2004 Chemical Mixing Tank The primary use of the chemical mixing tank is for the injection of various chemicals for RCS water control. These include the injection of caustic solutions for ph control, hydrazine for oxygen scavenging and hydrogen peroxide for chemical degassing and corrosion product solubilization. The capacity of the chemical mixing tank is determined by the quantity of 35 percent hydrazine solution necessary to increase the hydrazine concentration in the reactor coolant by 10 ppm. This capacity is more than sufficient to prepare solution of pH control chemical for the RCS. The excess letdown heat exchanger cools an amount of reactor coolant letdown equal to the nominal injection rate through the reactor coolant pump labyrinth seal, if letdown through the normal letdown path is not usable. The unit is designed to reduce the letdown stream temperature from the cold leg temperature to 195°F. The letdown stream flows through the tube side and component cooling water is circulated through the shell side. All surfaces in contact with the reactor coolant are austenitic stainless steel and the shell is carbon steel. All tube joints are welded. The seal water heat exchanger removes heat from several sources: the reactor coolant pump seal water to the volume control tank, the reactor coolant discharge from the excess letdown heat exchanger and the centrifugal charging pump bypass flow. Reactor coolant flows through the tubes and component cooling water is circulated through the shell side. The tubes are welded to the tube sheet to prevent leakage in either direction and undesirable contamination of the reactor coolant or component cooling water. All surfaces in contact with reactor coolant are austenitic stainless steel and the shell is carbon steel. 9.3-36 SGS-UFSAR Revision 18 April 26, 2000 The unit is designed to cool the excess letdown flow, the pump seal water flow and the centrifugal charging pump bypass flow to the temperature normally maintained in the volume control tank. Seal Water Filter This filter collects particulates from the reactor coolant pump seal water return and from the excess letdown heat exchanger flow. The filter is designed to pass the sum of the excess letdown flow and the maximum design leakage from the reactor coolant pump seals. The vessel is provided with connections for draining and venting. Disposable synthetic filter elements in a cage assembly are used. The filter collects particulates from the reactor coolant pump seal water inlet. Two filters are provided in parallel, each sized for the maximum design pump seal flow rate. The vessel is provided with connections for draining and venting. Disposable synthetic filter elements in a cage assembly are used. Boric Acid Filter The boric acid filter collects particulates from the boric acid solution being pumped to the charging pump suction line or boric acid blender. The filter is designed to pass the design flow of two boric acid transfer pumps operating simultaneously. The filter elements are disposable synthetic cartridges in a cage assembly. Provisions are included for venting and draining the filter. Boric Acid Tanks Each tank holds 8,000 gallons of boric acid 9.3-37 SGS-UFSAR Revision 14 December 29, 1995 solution at a concentration of 3.75 to 4.0 percent by weight (6560 ppm to 6990 ppm). The volume required to meet cold shutdown requirements with the most reactive RCCA not inserted are in accordance with Technical Specification Figure 3.1-2 for Salem Unit 1 and Figure 3.1-2 for Salem Unit 2. The Technical Specifications state the minimum amount of boric acid required to be available. It is likely that additional boric acid solution would be prepared following
either of these evolutions (cold shutdown or refueling shutdown.
Periodic manual sampling and corrective action, if necessary, ensures that these limits are maintained. As a consequence, measured amounts of boric acid solution can be delivered to the reactor coolant to control the chemical poison concentration. The combination overflow and breather vent connection has a
water loop seal to minimize vapor discharge during storage of the solution.
Batching Tank The batching tank is sized to hold makeup supply of boric acid solution for transfer to the boric acid tanks. The tank may also be used for solution
storage.
A local sampling point is provided for verifying the solution concentration prior to transferring it to the boric acid tank or for draining the tank. The tank is provided with an agitator to improve mixing during batching operations.
The tank is provided with a steam jacket for heating the boric acid solution to
>80 F to facilitate mixing.
9.3-38 SGS-UFSAR Revision 29 January 30, 2017
The limit for 4.0 weight boric acid is reached at a temperature of 58°F. This temperature is sufficiently low that the normally expected ambient temperatures within the auxiliary building will maintain boric acid solubility. Heaters remain in place for manual or automatic operation in the event auxiliary building ambient temperature falls below the Technical Specification requirement. Two horizontal, pumps with mechanical seals are supplied. Normally, one pump is aligned with one boric acid tank and runs continuously at low speed to provide recirculation of the Boric Acid System and boric acid tank. The second pump is aligned with the second boric acid tank and is then considered as a standby pump, with service being transferred as operation requires. This second pump also intermittently circulates fluid through the second tank. Manual or automatic initiation of the Reactor Coolant Makeup System will activate the running pump to the to provide normal makeup of boric acid solution as For emergency boration, supplying of boric acid solution to the suction of the charging pump can be accomplished by manually choosing either fast or slow speed and actuating either or both pumps. The transfer pumps also function to transfer boric acid solution from the batching tank to the boric acid tanks. The original pump rated flow was 75 gpm. This value was significantly above the value required for normal operations and by the safety requirements. Due to the severe service requirement associated with pumping boric acid, the Inservice program tests these pumps to ensure a minimum flow of 45 per minute at rated pump head. The safety requirements can be met with a flow of 33 gpm of 3.75 to 4.0 weight percent boric acid. This corresponds to a boration rate of 132 ppm/hour. This requirement is based on GDC 26 which requires a 9.3-39 SGS-UFSAR Revision 25 October 26, 2010 second reactivity system "capable of controlling the rate of reactivity changes resulting from planned normal power outages (including Xenon burnout) to assure acceptable fuel limits are not exceeded. One of the systems shall be capable of holding the reactor subcritical under cold conditions." Westinghouse has established the maximum Xenon burnout rate as 132 ppm per hour. The maximum required RCS make-up rate during normal operation is 120 gpm. This can be met without resorting to taking a suction on the RWST. One boric acid transfer pump at 45 gpm supplying 3. 75 to 4.0 weight percent boric acid (6560 ppm to 6990 ppm boron) to the boric acid blender can, in conjunction with the primary water make up pumps, provide 120 gpm of make-up water well in excess of 2518 ppm to the RCS. The boric acid transfer pump design discharge pressure is sufficient to overcome any pressures which may exist in the suction manifold of the charging pumps (volume control tank relief valve setting). In addition to the automatic actuation by the Makeup Control System and manual actuation from the main control board, these pumps also may be controlled locally. 9.3-39a SGS-UFSAR Revision 14 December 29, 1995 THIS PAGE INTENTIONALLY LEFT BLANK 9.3-39b SGS-UFSAR Revision 12 July 22, 1992 All parts in contact with the solution are of austenitic stainless steel. Connections are provided to enable the use of these pumps to flush the equipment and piping with primary water. Each boric acid transfer pump is powered by a separate 460 V vital bus which is capable of being supplied by the associated diesel generator in the event of loss of offsite power. Each boric acid transfer pump can pump from either boric acid tank. Operator action to place the plant in a cold shutdown condition with one boric acid tank unavailable would consist merely of using the other tank. Boric Acid Blender The boric acid blender promotes thorough mixing of boric acid solution and primary water makeup for the reactor coolant makeup circuit. The blender consists of a conventional pipe tee. Holdup Tanks Three holdup tanks contain radioactive liquid which enters the tanks from the letdown line. The liquid is released from the RCS during startup, shutdowns, load changes and from boron dilution to compensate for burnup. The contents of -one tank are normally being processed by the gas stripper boric acid evaporator packages while another tank is being filled. The third tank is available for storage as required. Unit No. 1 has only two eves holdup tanks. The No. 12 tank has been abandoned in place. The total liquid storage capacity of the three holdup tanks is equal to two RCS volumes. The tanks are constructed of austenitic stainless steel. The cover gas used in these tanks is nitrogen. 9.3-40 SGS-UFSAR Revision 14 December 29, 1995 Holdup Tank Recirculation Pump The recirculation pump is used to mix the contents of a holdup tank for sampling or to transfer the contents of a holdup tank to another holdup tank. The wetted surface of this pump is constructed of austenitic stainless steel. Gas Stripper Feed Pumps The two gas stripper feed pumps supply feed to the gas stripper-boric acid evaporator train from the holdup tanks. The capacity of each pump is equal to the capacity of a gas stripper-evaporator. The nonoperating pump is a standby and is available for operation in the event the operating pump malfunctions. These canned centrifugal pumps are constructed of austenitic stainless steel. Evaporator Feed Ion Exchangers Four flushable evaporator feed ion exchangers remove cations (primarily cesium and lithium) from the holdup tank effluent. Additional ion exchange resin may be used to enhance removal of isotopes such as cobalt. The design flow rate is equal to the gas stripper-boric acid evaporator processing rate. The demineralizer vessels are constructed of austenitic stainless steel and are provided with suitable connections to facilitate resin replacement when required. The vessels are equipped with resin retention screens. Ion Exchanger Filters These filters collect resin fines and particulates from the evaporator feed ion exchangers. The vessels are made of austenitic stainless steel and are provided with connections for draining and venting. Disposable synthetic filter elements in a cage assembly are used. The maximum design flow capacity is equal to the boric acid evaporator flow rate. 9.3-41 SGS-UFSAR Revision 20 May 6, 2003 Gas Stripper -Boric Acid Evaporator Package One gas stripper-boric acid evaporator package is provided. The package will process 30 gpm of dilute radioactive boric acid and produce distillate and approximately 12 weight percent of concentrated boric acid, both stripped of the radioactive gases. Radioactive gas stripping is achieved by passing heated feed through packed towers employing stripping steam which removes nitrogen, hydrogen and fission gases from the feed and is designed to reduce the influent gas concentration by a factor of 105. After stripping, the feed enters the evaporator where it is evaporated by a submerged steam tube bundle. The vapors leaving the boiling pool are stripped of entrained liquid and volatile boron by passing through an absorption tower. Pure vapors are then condensed in the condenser section and pumped from the system. When the desired concentration is reached in the boiling pool, the concentrates are pumped from the system. The solids decontamination factor between the condensate and bottoms is approximately 106 All evaporator equipment is constructed of austenitic stainless steel. A boric acid solution is fed from the holdup tanks through the ion exchangers to the gas stripper evaporator packages at a temperature of 50 to 130°F. The feed then passes through a heat exchanger where condensing steam raises its temperature to about 215°F. The feed then passes into the top of the stripping column. Radioactive and other gases are stripped off as the feed passes over the packing in the tower. After stripping, the feed is introduced into the evaporator as makeup. Radioactive gases and other noncondensables are discharged from the system into the waste disposal vent header. Heating for the evaporator is provided by steam in a submerged tube bundle. Steam to the feed preheater is taken from the same system. A constant vapor pressure is maintained in the evaporator by a pressure control valve on the steam supply line. 9.3-42 SGS-UFSAR Revision 6 February 15, 1987 A cooling water supply for condensing the distillate is passed through a tube bundle in the condenser. Some of the distillate produced in the evaporator passes through the absorption tower. This reduces ionic carryover and volatile boron carryover to less than 10 ppm. Condensed distillate is pumped from the system by a distillate pump. Conductivity measurement causes an automatic dump system to return contaminated distillate to the evaporator. Distillate is cooled to l20°F by passing through the distillate cooler heat exchanger. The concentration of boric acid is determined by sampling and chemical analysis. The boric acid concentrates' pump continuously draws a concentrated solution from the evaporator and through use of hand valves the operator can either return the concentrates to the evaporator or pump it to the concentrates' holding tank. A concentrate sample connection is provided at the discharge of the boric acid concentrates' pump. The operating output of the system can be adjusted by manual (board mounted control) positioning of the distillate condenser flow control valve. Adjustment of cooling water flow controls the temperature/pressure of condensing distillate in the vapor section of the evaporator. Vapor temperature automatically controls steam input to the submerged tube heating bundle. Thus when the operator manually increases cooling water flow, the vapor temperature is lowered and the steam flow control valve automatically opens to compensate and maintain vapor temperature at the setpoint. When equilibrium is again reached, the overall operating output of the system is increased. Other control circuits such as concentrate level, feed temperature, distillate level, etc., will automatically follow the system conditions and maintain their setpoint. In case of a low evaporator level caused by feed failure, etc. an alarm will sound; the operator can open a manual distillate return valve which will return all distillate produced to the evaporator. 9.3-43 SGS-UFSAR Revision 6 February 15, 1987 This coupled with manual return of the blowdown will stop any loss of liquid or vapor from the system until level is returned to normal. A low temperature in the evaporator, caused by failure of the automatic steam control valve, etc., would sound an alarm on the panel and the operator can open a manual steam bypass valve to raise the temperature. All lines and miscellaneous equipment in the system containing concentrated boric acid are electric heat traced to prevent boric acid precipitation at low temperatures. Plant Drawings 205229 and 205329 show two lines discharging from the Boric Acid Evaporator. The lines which are heat traced transfers the evaporator bottoms to the Concentrates Holding Tank. This line is heat traced due to high boron concentrates (21000 ppm). The line which is not heat traced is used as the stripping medium in the Gas Stripper. The line runs from the evaporator overhead (steam) and enters the bottom of the packed stripping column of the Gas Stripper. The steam contains low boron concentrates approximately 100 ppm). Heat tracing is therefore not necessary. The batching tank has a steam jacket to heat the boric acid solution. The source of steam heating for the batching tank is from the house heating boilers and/or one of the main turbines, either of which has a capacity of 140,000 lbs/hr. The batching tank steam jacket requires only 150 lbs/hr. The design, materials, testing and inspection of the batching tank are in accordance with the ASME Boiler and Pressure Vessel Code,Section VIII. Evaporator Distillate Demineralizers Two anion demineralizers remove any boric acid contained in the evaporator distillate. Hydroxyl based ion-exchange resin is used to produce evaporator distillate of high purity by releasing a hydroxyl ion when a borate ion is absorbed. Facilities are SGS-UFSAR 9.3-44 Revision 27 November 25, 2013 for of the resin. When regeneration is no longer feasible, the resin is flushed to the spent resin storage tank. Each demineralizer is sized for a flow rate equal to the evaporator flow rate. The demineralizer vessel is made of all-welded austenitic stainless steel and is equipped with a resin retention screen. The filter collects resin fines and from the boric acid evaporator condensate stream. The vessel is made of austenitic stainless steel and is with connections for draining and venting. Disposable synthetic filter elements in a cage assembly are used. The design flow capacity of the filter is equal to the total installed gas stripper-boric acid evaporator flow rate. Two monitor tanks continuous operation of the evaporator train. When one tank is filled, the contents are analyzed and either to the WDS. Each of the tanks has sufficient to hold the condensate produced during 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of operation from an evaporator at full output. The tank is vented to the Auxiliary Building atmosphere. 9.3-45 SGS-UFSAR Revision 26 May 21, 2012 Monitor 'rank Pumps Two monitor tank pumps discharge water from the monitor tanks. sized to empty a monitor tank in approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. constructed of austenitic stainless steel. Each pump is The pumps are When required, two anion demineralizers may be used to remove boric acid from the RCS fluid. The demineralizers are for use near the end of a core cycle, but can be used at any time when boron concentration is low. These deminera1izers may also be used in a fashion similar to the mixed bed demineralizers, or for lithium removal similar to the cation bed demineralizer when boric acid removal is not required. based resin is used to reduce RCS boron concentration by ion when a borate ion is absorbed. Facilities are for When the resin is flushed to the spent resin storage tank. Each demineralizer is sized to remove the quantity of boric acid that must be removed from the RCS to maintain full power operation near the end of core life should the holdup tanks be full. A disposable evaporator concentrates. cartridge-type filter removes particulates from the Design flow capacity of the filter can accommodate the total installed boric acid evaporator capacity. The vessel is provided with connections for draining and venting. elements in a cage assembly are used. The concentrates' holding tank is sized to hold concentrates from one batch from the evaporator. Disposable synthetic filter the production of The tank is supplied with an electrical heater which prevents boric acid precipitation. 9.3-46 SGS-UFSAR Revision 25 October 26, 2010 Concentrates' Holding Tank Transfer Pump Two holding tank transfer pumps discharge boric acid solution from the concentrates' holding tank to the boric acid tanks. The canned centrifugal pumps are sized to approximately match the capacity of the boric acid evaporator concentrates' pumps or to pump out the contents of the tank in approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The wetted surfaces are constructed of austenitic stainless steel. Electrical Heat Tracing Boric Acid Storage system heat tracing is no longer required due to the reduction in boric acid concentration to between 3.75 and 4.0 weight percent. Boric acid evaporator and concentrates system heat trace is required since these systems will be concentrated to approximately 12 weight percent boric acid. 9.3-47 SGS-UFSAR Revision 14 December 29, 1995 Valves Valves that perform a modulating function are equipped with two sets of packing and an intermediate leakoff connection that discharge to the wos. Valves are normally installed such that, when closed, pressure is not on the packing. Basic material of construction is stainless steel for all valves. Isolation valves are provided for all connections to the RCS. Lines entering the reactor containment also have check valves inside the containment to prevent reverse flow from the containment. Relief valves are provided for lines and components that might be pressurized above design pressure by improper operation or component malfunction. Pressure relief for the tube side of the regenerative heat exchanger is provided by a locked open manual isolation valve and a 250 psi spring-loaded check valve bypassing the charging isolation valves. The Volume Control Tank relief path contains administratively controlled manual isolation valves between the relief valve and the Holdup Tanks. ASME Section III Code relief was obtained for the Volume Control Tank and regenerative heat exchanger relief systems using administrative controls per NRC approval (Section 9.7.3, Reference 3). 9.3-48 SGS-UFSAR Revision 16 January 31, 1998 -*
Piping All CVCS piping handling radioactive liquid is austenitic stainless steel. All piping joints and connections are welded, except where flanged connections are required to facilitate equipment removal for maintenance and hydrostatic testing. Primary Water Storage Tank The tank is provided with a high level alarm and the overflow line is piped to the diked area around the No. 13 chemical and volume control holdup from where any overflow can be pumped to the Liquid Waste Disposal System. The overflow line includes a collection pot which is also provided with a high level alarm. Both alarms are indicated in the Control Room. 9.3.4.3 System Design Evaluation 9.3.4.3.1 Availability and Reliability A high degree of functional reliability is assured in the eves by providing standby components where performance is vital to safety and by assuring fail-safe response to the most probable mode of failure. Special provisions include duplicate heat tracing with alarm protection of lines, valves, and components normally containing concentrated boric acid and required for boric acid control. The CVeS has three high pressure charging pumps, which are capable of supplying the required reactor coolant pump seal and makeup flow. Aside from those components that are also part of the Eecs (Section 6), the eves is not required to function during a LOCA. The generation of a safety injection signal automatically closes the motor-operated valves in the outlet line of the volume control 9.3-49 SGS-UFSAR Revision 6 February 15, 1987 tank and in the normal charging line thus isolating the eves from the safety injection path. The letdown line and reactor coolant pump seal water return line are isolated at the containment boundary by a valve which automatically closes as a result of high containment pressure caused by a LOCA. The centrifugal charging pumps are also automatically started and commence pumping into the RCS immediately. 9.3.4.3.2 Control of Tritium The eves is also used to control the concentration of tritium in the ReS. Essentially all of the tritium is in chemical combination with oxygen as a form of water. Therefore, any leakage of coolant to the containment atmosphere carries tritium in the same proportion as it exists in the coolant. Thus, the level of tritium in the containment atmosphere, when it is sealed from outside air ventilation, is a function of tritium level in the reactor coolant, the dewpoint temperature of the air, and the presence of leakage other than reactor coolant as a source of moisture in the containment air. There are two major considerations with regard to the presence of tritium in the reactor coolant: 1. Possible plant personnel hazard during access to the containment must be limited. Leakage of reactor coolant during operation with a closed containment causes an accumulation of tritium in the containment atmosphere. 2. Undue public hazard due to release of tritium to the plant environment must be avoided. Both of these criteria are met in this plant. The concentration of tritium in the reactor coolant is maintained at a level which precludes personnel hazard during access to the containment. This can be achieved by discharging part of the distillate from the primary water recovery process to the WDS (Section 11). 9.3-50 SGS-UFSAR Revision 6 February 15, 1987 Essentially all of the tritium in the reactor coolant will eventually be released via the Radwaste System (Section 11) to the plant discharge stream. In the plant discharge stream, the tritium (and other liquid radwastes) is mixed '-with the plant effluent water flow. 9.3.4.3.3 Leakage Provisions Quality control of the material and installation of the eves valves and piping which are designated for radioactive service is provided, in order to essentially eliminate leakage to the atmosphere. The components designated for radioac:ti ve service are provided with welded connections to prevent leakage to the atmosphere. However, flanged connections are provided on each charging pump suction and discharge, on each boric acid pump suction and discharge, on the relief valves' inlet and outlet, on three-way valves and on the flow meters to permit removal for maintenance. The ive displacement charging pump stuffing box is provided with a leakoff to collect reactor coolant. All valves which are larger than 2 inches and which are for radioactive service at an operating fluid temperature normally above are provided with a stuffing box and lantern leakoff connections. All control valves are either provided with stuffing box and leakoff connections or are totally enclosed. Diaphragm valves are where the operating pressure is 200 psi or below and the operating temperature is 200. F or below. 9.3-51 SGS-UFSAR Revision 19 November 19, 2001 I 9.3.4.3.4 Incident Control The letdown line and penetrate the reactor operated valves inside outside the reactor the reactor coolant pumps' seal water return line containment. The letdown line contains three air-the reactor containment and one air-operated valve containment which are automatically closed by the containment isolation signal. The reactor coolant pumps' seal water return line contains one motor-operated isolation valve outside the reactor containment and one motor-operated valve inside the containment which are automatically closed by the containment isolation signal. The four seal water injection lines to the reactor coolant pumps and the charging line are inflow lines penetrating the reactor containment. Each line contains a check valve inside the reactor containment to provide isolation of the reactor containment should a break occur in these lines outside the reactor containment. In the event of an accidental release of radioactivity in the area housing the eves, personnel safety equipment is available and will be used to protect personnel. For example, equipment such as respirators, appropriate protective clothing, and radiation survey meters would be used to guard against inhalation of possible airborne activity, contamination, and exposure to possibly high radiation levels. Immediately after the accidental release of a radioactive source, entry into the building housing the eves will be through an access control point under the supervision of health physics trained personnel. The required equipment, outlined above, will be available in the vicinity of the control point. This area also contains a monitoring and clothing change area, a personnel decontamination washroom and showers, and a first aid room. Radiation levels outside of a shielded compartment where such a release has occurred will not be severely affected. The dose rates outside the shield wall could rise from 2.5 mR/hr to approximately 4.0 mR/hr until cleanup procedures have been 9.3-52 SGS-UFSAR Revision 6 February 15, 1987
-initiated. This higher dose rate is based on a leak large enough to result in all inner compartment surfaces being covered with radioactive liquid, and that the excess liquid that drains from the surfaces runs into the floor drains. The liquid activity is assumed to be that associated with 1 percent failed fuel. If the excess liquid did not flow into the floor drains and was contained within the compartment, the dose rate outside the shield wall could rise to approximately 25 mR/hr. If a demineralizer ruptured releasing all its resin into the shielded compartment, the dose rates outside the compartment would not be significantly affected since each demineralizer tank is in a cell which is completely isolated from personnel and separated from the operating aisle by a valve gallery shield wall. Further, no credit for the thickness of the demineralizer wall was taken in the design of the concrete shield wall. 9.3.4.3.5 Malfunction Analysis To evaluate system safety, failures or malfunctions were assumed concurrent with a LOCA, and the consequences analyzed {see Table 9.3-7 and Section 15). If a rupture takes place between the reactor coolant loop and the first isolation valve or check valve, an uncontrolled loss of reactor coolant occurs. The is of the LOCA is discussed in Section 15. Should a rupture occur in the eves outside the containment, or at any the first check valve or remotely operated isolation valve, actuation of the valve would limit the release of coolant and assure continued functioning of the normal means of heat dissipation from the core. For the general case of rupture in the eves outside the containment, the largest source of radioactive gases and fluid ect to release is the contents of the volume control tank. The consequences of such a release are considered in Section 15. 9.3-53 SGS-UFSAR Revision 6 February 15, 1987 Wherl the reactor is subcritical, i.e., during cold or hot shutdown, refueling and approach to criticality, the relative reactivity status (neutron source multiplication) is continuously monitored and indicated by BF3 counters and count rate indicators. Any appreciable increase in the neutron source multiplication, including that caused by the maximum physical boron dilution is slow enough to give ample time to start corrective action (boron stop and emergency boron injection) to prevent the core from becoming critical. This cas_e is analyzed in Section 15. At least two separate indepl?ndent flow paths are available for reactor coolant boration; i.e., the charging line, or the high head safety injection, BIT cold leg flow path. The malfunction or failure of one component does not result in the inability to borate the RCS. An alternate flow path is always available for emergency boration of the reactor coolant. As backup to the Bora:tion System, the operator can align the refueling water storage tank outlet to the suction of the chargipg pumps. Boration during operation to compensate for powe;t: changes will be indicated to the operator from a combination of two sources: 1) the control rod movement and !2} the flow indicator in the boric acid transfer pump discharge line. When the emergency boration path is used, four indications to the ope;t:ator are available. The primary indication is a flow indicator in the emergency. boration line. The charging line flow indicator will indicate boric acid flow sinc*e the charging pump suction is aligned to the boric acid transfer pump suct'ion for this mode of operation. The change in boric acid tank level and contirol rod motion are other indications of boric acid injection. on loss of seal injection water to the reactor coolant pump seals, seal water flow may be re-established by starting a standby charging pump. If all the unit's charging pumps are lost, seal injection can be re-established using the cross-tie from the opposite unit. Short-term actions re-align the charging suct1ion header to the RWST in the opposite unit and the normally shut cross-tie discharge isolation valve, which is remote/manual MOV, is opened from the Control Room to minimize the time delay. 9.3-54 SGS-DFSAR Revision 21 December 6, 2004 * *
- During plant operation without seal injection flow, the thermal barrier cooler serves to cool the reactor coolant flow that passes through the thermal barrier cooler, thereby controlling the No. 1 seal leak-off temperature. However, studies have shown that with an initial seal leak-off flow <2.5 gpm, seal leak-off temperature limits could be exceeded unless seal injection is restored. In the event seal water injection flow cannot be re-established prior to the reactor coolant pump No. 1 seal leak-off temperatures exceeding the alarm setpoint, the affected reactor coolant pump will be stopped and plant will be shutdown, as required. It can be concluded that proper consideration has been given to station safety in the design of the system. 9.3.4.3.6 Galvanic Corrosion The only types of materials which are in contact with each other in borated water are stainless steels, Inconel, Stellite valve materials and Zircaloy fuel element cladding. Those materials have been shown to exhibit only an insignificant degree of galvanic corrosion when coupled to each other. For example, the galvanic corrosion of Inconel versus 304 stainless steel resulting from high temper.ature tests (575°F) in lithiated, boric acid solution was found to be less than -20.9 mg/dm2 for the test period of 9 days. Further galvanic corrosion would be trivial since the cell currents at the conclusion of the tests were approaching polarization. Zircaloy versus 304 stainless steel was shown to polarize at 180°F in lithiated, boric acid solution in less than 8 days with a total galvanic attack of -3.0 gm/dm2. Stellite versus 304 stainless steel was polarized in 7 days at 575°F in lithiated boric acid solution. The total galvanic corrosion for this couple was -0.97 gm/dm2* As can be seen from the tests, the effects of galvanic corrosion are insignificant to systems containing borated water. 9.3.4.4 Tests and Inspections Those portions of the eves associated with the Emergency Core Cooling System will be subject to the same type of inspections required for those systems as outlined in Section 6. Special tests and inspections for the remainder of the eves are not required 9.3-55 SGS-UFSAR Revision 20 May 6, 2003 because the system is in daily operation. Routine maintenance during refueling can be performed on system components. The contents of the boric acid tanks will be sampled at least once per week to assure required boric acid concentrations. 9.3.5 Failed Fuel Detection System 9.3.5.1 The Gross Failed Fuel Detection System consists of equipment designed to indicate gross fuel failure by monitoring the delayed neutron reactor coolant. in the 9.3.5.2 The gross failed fuel detector is connected to the hot leg of a primary coolant loop (Figure 9.3-9). The coolant sample passes through a cooler and then into a coil encompassing a neutron detector and moderator, then to a connection upstream of the mixed bed demineralizers after which it flows back into the volume control tank. The delay time on the length of tubing used. A transrni t ting flowmeter is installed for periodic checks of the flow rate. A sensor monitors the sample cooler outlet temperature. Figure 9.3-10 shows the block diagram of the gross failed fuel detector channel. The detector, preamp, sample coolers, and associated flow indication are located outside the containment. The signal processing equipment and readout are mounted in a rack located in the Control Room. The delayed neutron signal of the detector is displayed on a recorder located in the rack. The response time for the gross failed fuel detector is on the order of 60 seconds. 9.3-56 SGS-UFSAR Revision 6 February 15, 1987 *--*
9.3.5.3 Safety Evaluation The Gross Failed Fuel Detection System does not perform a safety-related function, and is not designed to satisfy any specific safety criteria. As shown on Figure 9.3-9, the gross failed fuel detector is outside of the containment and is installed in the primary coolant hot leg sample line. It is isolated from the containment by means of the Sampling System isolation valves. The safety evaluation of the Sampling System, including the isolation valves, is discussed in Section 9.3.2. A confirmatory radiochemical analysis for failed fuel in the primary system would be performed and would require approximately 1 1/2 hours of sampling, preparation, counting and calculations. In the event that personnel to perform analysis are not onsite, an additional 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> will be required for notification and travel time. The system measures gamma radiation in a continuously flowing sample of primary coolant. It is designed to monitor the coolant for gross gamma activity. This is accomplished by using a gamma scintillation detector. In addition to continuous indication of the reactor coolant activity, abnormal conditions are alarmed in the Control Room. The Unit 1 detector is capable of measuring up to 1 x 10 6 cpm. The Unit 2 detector is capable of measuring up to 1 x 109 cpm. Provision is made for desensitizing the system by two or more decades to compensate for permanent activity buildup resulting from long-term normal operation. This is accomplished by insertion of a lead spacer between the sensitive end of the detector and the letdown line. 9.3-57 SGS-UFSAR Revision 27 November 25, 2013 I With the with reactor coolant corresponding to one failed fuel, the concentration of all isotopes in the coolant will be about 226 l\ssuming that 11gross" fuel failure has occurred, the action tha1: would be taken is a function of both the magnitude of reactor coolant and the rate of change. For the case where is higher than previous values, but below Technical Specification limits, the following action would be taken: 1. Increase purif:Lcation flow to maximum. 2. Calculate coolant act:Lv] ty in )lCi/cc and new g if greater than predetermined change in activity has occurred, 3. Increase sampling frequency to a minimum of once per day until I: rends are clearly established. 4. If coolant Specification equilibrium. limits, is reduce power and approaching and attempt to 'l'echnical establish r* ::) . Verify reactor power dj.atribution to assure that rod patterns and flux shapes are within normal vaJ.ues. In event that coolant activity is increasing x*apidly to the TE1chnical Specification limit or has reached that limit, the plant would be shut down and cooled to 500°P or less. The above actions would be initiated promptly following confirmatory radiochemical analysis. the failed fuel alarm, Most of these actions can be initiated upon receipt of for trending, which will require several samples. In the cwent the Failed fi'ue:l Monitoring Sysl:em is inoperable while the .reactor is critical, the RCS wJ.ll be analyzed for dose (*"quivalent I-131 five days per week with not longer than 72 honrs between sampling intervals. 9.3-58 SGS-OFSAR Revision 23 October 17, 2007 * * *
- *
- 9.3.5.4 The Gross Failed Fuel Detection system is equipped with a test oscillator in the preamplifier and a test oscillator in the electronics drawer, each of which can be used to test the proper of the signal processing circuitry. 9.3.5.5 Instrument Applications Instrumentation associated with the Gross Failed Fuel Detection System is described in Section 9.3.5.2. 9.3.6 Post Accident Sampling System The eight PASS sample and return lines for Salem Units 1 and 2 have been cut and capped on both sides of the applicable containment penetration. The RCS sample lines were also cut and capped at the connection point to the sample system tubing. 9.3.6.1 License Amendments 254/235 removed the Post Accident Sampling System from the license base for Salem Units 1 & 2. NRC approval of PASS elimination was based on the following contingencies: -PSEG has developed contingency plans for obtaining and analyzing highly radioactive samples of RCS, containment sump and containment atmosphere. -PSEG has verified that it has the capability for classifying fuel damage events at the alert level threshold and has committed to maintain the capability for the alert classification in plant implementing procedures. -PSEG has verified that it has the capability to monitor radioactive iodines that have been released to offsite environs and has committed to maintain the capability for monitoring iodines in plant implementing Subsequent text regarding PASS is maintained for historical purposes . 9.3-59 SGS-UFSAR Revision 23 October 17, 2007 The functional and design requirements for the Post Accident Sampling System (PASS) are contained in NUREG-0737, Item II.B.3 and in Regulatory Guide 1.97. The seismic design and quality group classification of the PASS sampling lines and components conform to the classification of the system to which each sampling line is connected. Seismic design and quality group classification for components and piping downstream of the second isolation valve in the PASS conform to NUREG-0737 requirements. Additionally, filtered with high-efficiency particulate (HEPA) the ventilation exhaust is filters. Section 9.4.2 describes Auxiliary Building Ventilation filtering modes. PASS ventilation exhaust is not aligned to the charcoal adsorbers during emergency plant operations. The PASS provides the capability to obtain, under accident conditions, a containment air grab sample, liquid and stripped gas reactor coolant grab samples (diluted and undiluted) and to perform various analyses using inline instrumentation. Grab samples are used to determine isotopic and hydrogen concentrations in containment air, and isotopic, boron, pH, chloride and hydrogen concentrations in reactor coolant. The inline instrumentation provides analysis of dissolved hydrogen, dissolved oxygen, chlorides, boron, conductivity and pH for reactor coolant. Acquisition and analysis of these samples can be performed in a manner which limits radiation exposure to personnel to 5 rem/year whole body and 75 rem/year to the extremities. 9.3.6.2 System Description Sample Lines and Sample Points Two redundant sample loops are utilized per unit {two separate channels). Reactor coolant sample lines connect into the Nos. 11, 13, 21, and 23 hot legs. Sample return lines are routed to the containment sump. Containment atmosphere samples are tied into the Radiation Monitoring System sample supply lines. Samples are returned to the containment. Sample lines are designed to minimize crud traps and dead legs. The lines are separated to provide assurance that a single pipe break will not render both loops inoperative. 9.3-60 SGS-UFSAR Revision 20 May 6, 2003 Penetrations are cooled with compressed air to limit the temperature of the containment wall surrounding the penetrations from exceeding 150°F. Shielding is provided on the Unit 1 sampling lines where the lines cross the access corridors on the 100-foot elevation of the Auxiliary Building. All other sampling lines pass through shielded areas of the Auxiliary Building. Where feasible, lines are run along floors to facilitate the use of lead blankets should the need arise. Analysis Equipment The following PASS equipment processes the reactor coolant and containment air samples. The Liquid sampling Panel (LSP) routes reactor coolant samples to the Chemical Analysis Panel (CAP) for online gas and liquid analysis. The LSP also captures gases stripped from pressurized reactor coolant for hydrogen and isotopic analysis; depressurized, reactor coolant for pH and isotopic analysis; and depressurized, diluted reactor coolant for boron, chloride, and isotopic analysis. The CAP provides the capability for online determination of the pH, specific conductivity, oxygen content, and chloride content of a liquid sample. In addition, the gas chromatograph permits determination of the hydrogen content of the gas stripped from the reactor coolant. The containment air sampling panel (CASP) collects grab samples. 9.3-61 SGS-UFSAR Revision 16 January 31, 1998 The CASP control panel is used to select, start and monitor the CASP sample exercises. once the operator has started the CASP, a programmer automatically performs the exercise. Both the CASP control panel and the CAP monitor panel are separated from the LSP, CASP, and CAP by shielding to minimize operator exposure while operating the equipment. The shielding in the panels limits the maximum dose from the panel to an operator in accordance with sampling exercise to 100 mrem. Analytical equipment for isotopic analysis is located in the Counting Room on the 100-foot elevation on the Unit 2 side of the Auxiliary Building. Sample preparation and boron analysis equipment are located in the Chemistry Lab on the 100-foot elevation on the Unit l side of the Auxiliary Building. This equipment serves both Units 1 and 2. The Sampling Room cooler maintains an environment that is satisfactory for both personnel and equipment operation. Analysis equipment is not seismically qualified. Interfaces Piping connections to other fluid systems are designed consistent with the safety class and seismic category of the interfacing system. In particular, interfaces with non-seismic portions are designed in such a way that failure of non-seismic portions of the PASS will not degrade the interfacing system performance. Ten gallons per minute of component cooling water is supplied to the sample cooler rack to cool reactor coolant samples. Redundant control air is provided for pneumatic operation of the containment isolation valves. 9.3-62 SGS-UFSAR Revision 6 February 15, 1987 Demineralized water is provided for flushing the sample lines and analysis equipment after a sampling operation. Nitrogen is provided for purging the containment air sampling lines and for the nitrogen-operated eductor which induces the flow of air from the containment to the CASP and back to containment. 9.3.6.3 Design Evaluation Electric power is supplied from the lE vital bus. Beat tracing is supplied with redundant power. Consequently the PASS is expected to remain operable during accidents concurrent with loss of offsite power. The PASS is not designed to operate following certain single failures, e.g., failure of sampling analysis equipnent. 9.3.7 Reference for Section 9.3 1. Sammarone, D. G., '"The Galvanic Behavior of Materials in Reactor Coolants," WCAP-1844, August 1961. 2. ABB Report '"Boric Acid Concentration Reduction Effort" CEH-606, Revision 00, Technical Bases and Operational Analysis for Salem Nuclear Generating Station Units 1 and 2. 3. NRC Letter from J.F. Stolz (NRC) to L.R. Eliason (PSE&G), "Salem Nuclear Generating Station Unit No.s 1 and 2 Section III Relief Request," November 6, 1995. 9.3-63 SGS-UFSAR Revision 16 January 31, 1998