ML16120A609
| ML16120A609 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 04/18/2016 |
| From: | Entergy Nuclear Operations |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML16120A302 | List:
|
| References | |
| PNP 2016-015 | |
| Download: ML16120A609 (50) | |
Text
FSAR CHAPTER 11 - RADIOACTIVE WASTE MANAGEMENT ANDRevision 30SECTION 11.5 RADIATION PROTECTIONPage 11.5-1 of 11.5-3 11.5PROCESS AND EFFLUENT RADIOLOGICAL MONITORING ANDSAMPLING SYSTEMThe process radiation and effluent radiological monitoring and samplingsystem was designed to assure that ionizing radiation levels are indicated andalarmed so that action, either automatic or manual, can be taken to preventradioactive release from exceeding the limits of 10 CFR 20.Detection devices are located in the various process systems and at selectedpositions throughout the containment and auxiliary buildings to monitorradiation levels and annunciate any abnormally high radiation activity.Instrument ranges and sensitivities are chosen to enable monitoring within therequirements of 10 CFR 20.11.5.1 DESIGN BASISRadiation monitoring devices using proven photomultiplier, scintillation andgeiger-type ionization detection chambers have been utilized in the processand effluent radiological monitoring and sampling system.Each process instrument has been selected according to the type of radiationto be measured, and sized to encompass the entire range of radiation activitywhich corresponds to the Plant's design power levels and failed fuel criteria.A listing of the process sample points, instrument sensitivity, and otherinformation pertaining to these instruments is presented in Table 11-15 andshown in Figures 9-17, 11-5 and 11-6.Additionally, all monitors in the stack-gas, containment air, off-gas, waste gas,engineered safeguards areas ventilating system discharge, radwasteventilation and radwaste liquid discharge systems have been supplied withcheck sources. The check source is to simulate a radioactive sample andserve as a check for both the readout and detector.11.5.2 SYSTEM DESCRIPTIONThe process and effluent radiological monitoring and sampling system is acollection of radiological instrumentation and, therefore, cannot be describedas a unique system by itself except for the stack monitoring subsystem(described in Subsection 11.5.3).The process sampling systems and area radiation monitors, individualdetectors, power supplies, and readout devices have been selected tooperate in humidity and temperature ranges appropriate for their service areas.Provisions are included to permit periodic testing while detection equipment isoperational.
FSAR CHAPTER 11 - RADIOACTIVE WASTE MANAGEMENT ANDRevision 30SECTION 11.5 RADIATION PROTECTIONPage 11.5-2 of 11.5-3The aforementioned detection devices display their information in radiationmonitoring equipment panels located inside the main control room. Thepanels provide mounting for indicators, power supplies and alarms for each ofthese radiation monitoring systems. Two of the panels are located beside thearea radiation monitoring panel. The process liquids radiation monitoringpanel and the gas radiation monitoring panel are fed by the instrument ac buswhich, in the event of a loss of power, is fed by the diesel generators. Thecirculating water discharge monitor sample pump is powered from a normallighting panel, with a low flow alarm powered from the instrument ac bus.The type of detectors used and the information displayed are listed inTable 11-15. The sensitivity and alarm conditions for each instrument arealso listed.11.5.3 EFFLUENT MONITORING AND SAMPLINGLiquid effluents which are discharged from the Plant are monitored by aprocess sampling detector located in the circulating water discharge structure.The process sample is obtained from a continuously flowing (freezeprotected) sample loop which is part of the monitoring system.In 1983 a main steam relief monitoring system was installed to monitoraccident releases in the event the atmospheric dump or safety valves lift.Two monitors, one viewing each main steam line, continuously monitor andrecord the activity present in the secondary steam.Gaseous effluents leaving the Plant via the stack discharge system aremonitored by the stack monitoring system. Abnormal gaseous releasesdetected by any of the process or area radiation monitors within the radiationcontrolled areas of the containment and auxiliary buildings are processed byengineered ventilation systems which ultimately discharge to the Plant's stack.The Radioactive Gaseous Effluent Monitoring System (RGEMS), installed in1983, consists of normal range particulate/radioiodine filters, NaI gammadetector, scintillation chamber beta detector, and an accident range filter andion chamber (refer to Figure 11-6). Flow through the system is provided bytwo 100% capacity diaphragm vacuum pumps. The flow is controlled byautomatic flow control valves to provide isokinetic sample flow based onvarying stack gas flows.During normal operation, an isokinetic sample of the stack effluent is routedthrough a particulate/radioiodine filter then through the beta detector. Thefilter is continuously monitored by the NaI detector to detect any buildup onthe filter. The filter is normally changed and counted on a weekly basis byPlant personnel.
FSAR CHAPTER 11 - RADIOACTIVE WASTE MANAGEMENT ANDRevision 30SECTION 11.5 RADIATION PROTECTIONPage 11.5-3 of 11.5-3On indication of abnormal stack effluent activity (alert level), a 15-second grabsample is automatically trapped in a sample bottle and an annunciator in thecontrol room indicates the off-normal condition.Following a high level indication, the normal sample loop is bypassed and thesample flow is split with approximately 0.02 scfm directed through thehigh-range filter and the balance through the ion chamber. To avert a toorapid buildup of activity on the filter, the capability exists to interrupt thesample flow through the filter periodically for periods ranging from 6 secondsto 54 seconds every minute. The continuous monitoring capability of thehigh-range noble gas monitor is not affected during filter flow interruption. A"high radiation" annunciator in the control room alerts the Plant operators tothe condition.Systems may be controlled either locally or remotely from the control room.Dual microprocessor controllers provide system control through the normal,alert and high operating modes. Normally the controller located in the controlroom provides full system control. In the event of failure the local controllertakes control of the system functions.Refer to Table 11-15 for details of the monitors.11.5.4 SYSTEM EVALUATIONAll process systems which contribute to Plant discharges are monitored priorto entering the various discharge systems. Each discharge system is alsomonitored, providing redundancy of radiation detection for Plant effluents.The radwaste area, containment air, waste gas, engineered safeguards pumproom, and the off-gas radiation monitoring systems are backed up by thestack-gas monitoring system. The service water, radwaste liquids discharge,component cooling and the steam generator blowdown radiation monitoringsystems are backed up by the circulating water discharge monitor.Testing and maintenance for all systems, circuit testing of readout equipmentand power supplies can be performed from the panels located in the controlroom. The circuit being tested or repaired is inoperative during that time andacts as if it were a tripped channel. The containment high-radiation monitorsare continuously monitored while in service for loss of power, loss of detectorhigh voltage and for loss of detector signal.
FSAR CHAPTER 11 - RADIOACTIVE WASTE MANAGEMENT ANDRevision 30SECTION 11.5 RADIATION PROTECTIONPage 11.5-1 of 11.5-3 11.5PROCESS AND EFFLUENT RADIOLOGICAL MONITORING ANDSAMPLING SYSTEMThe process radiation and effluent radiological monitoring and samplingsystem was designed to assure that ionizing radiation levels are indicated andalarmed so that action, either automatic or manual, can be taken to preventradioactive release from exceeding the limits of 10 CFR 20.Detection devices are located in the various process systems and at selectedpositions throughout the containment and auxiliary buildings to monitorradiation levels and annunciate any abnormally high radiation activity.Instrument ranges and sensitivities are chosen to enable monitoring within therequirements of 10 CFR 20.11.5.1 DESIGN BASISRadiation monitoring devices using proven photomultiplier, scintillation andgeiger-type ionization detection chambers have been utilized in the processand effluent radiological monitoring and sampling system.Each process instrument has been selected according to the type of radiationto be measured, and sized to encompass the entire range of radiation activitywhich corresponds to the Plant's design power levels and failed fuel criteria.A listing of the process sample points, instrument sensitivity, and otherinformation pertaining to these instruments is presented in Table 11-15 andshown in Figures 9-17, 11-5 and 11-6.Additionally, all monitors in the stack-gas, containment air, off-gas, waste gas,engineered safeguards areas ventilating system discharge, radwasteventilation and radwaste liquid discharge systems have been supplied withcheck sources. The check source is to simulate a radioactive sample andserve as a check for both the readout and detector.11.5.2 SYSTEM DESCRIPTIONThe process and effluent radiological monitoring and sampling system is acollection of radiological instrumentation and, therefore, cannot be describedas a unique system by itself except for the stack monitoring subsystem(described in Subsection 11.5.3).The process sampling systems and area radiation monitors, individualdetectors, power supplies, and readout devices have been selected tooperate in humidity and temperature ranges appropriate for their service areas.Provisions are included to permit periodic testing while detection equipment isoperational.
FSAR CHAPTER 11 - RADIOACTIVE WASTE MANAGEMENT ANDRevision 30SECTION 11.5 RADIATION PROTECTIONPage 11.5-2 of 11.5-3The aforementioned detection devices display their information in radiationmonitoring equipment panels located inside the main control room. Thepanels provide mounting for indicators, power supplies and alarms for each ofthese radiation monitoring systems. Two of the panels are located beside thearea radiation monitoring panel. The process liquids radiation monitoringpanel and the gas radiation monitoring panel are fed by the instrument ac buswhich, in the event of a loss of power, is fed by the diesel generators. Thecirculating water discharge monitor sample pump is powered from a normallighting panel, with a low flow alarm powered from the instrument ac bus.The type of detectors used and the information displayed are listed inTable 11-15. The sensitivity and alarm conditions for each instrument arealso listed.11.5.3 EFFLUENT MONITORING AND SAMPLINGLiquid effluents which are discharged from the Plant are monitored by aprocess sampling detector located in the circulating water discharge structure.The process sample is obtained from a continuously flowing (freezeprotected) sample loop which is part of the monitoring system.In 1983 a main steam relief monitoring system was installed to monitoraccident releases in the event the atmospheric dump or safety valves lift.Two monitors, one viewing each main steam line, continuously monitor andrecord the activity present in the secondary steam.Gaseous effluents leaving the Plant via the stack discharge system aremonitored by the stack monitoring system. Abnormal gaseous releasesdetected by any of the process or area radiation monitors within the radiationcontrolled areas of the containment and auxiliary buildings are processed byengineered ventilation systems which ultimately discharge to the Plant's stack.The Radioactive Gaseous Effluent Monitoring System (RGEMS), installed in1983, consists of normal range particulate/radioiodine filters, NaI gammadetector, scintillation chamber beta detector, and an accident range filter andion chamber (refer to Figure 11-6). Flow through the system is provided bytwo 100% capacity diaphragm vacuum pumps. The flow is controlled byautomatic flow control valves to provide isokinetic sample flow based onvarying stack gas flows.During normal operation, an isokinetic sample of the stack effluent is routedthrough a particulate/radioiodine filter then through the beta detector. Thefilter is continuously monitored by the NaI detector to detect any buildup onthe filter. The filter is normally changed and counted on a weekly basis byPlant personnel.
FSAR CHAPTER 11 - RADIOACTIVE WASTE MANAGEMENT ANDRevision 30SECTION 11.5 RADIATION PROTECTIONPage 11.5-3 of 11.5-3On indication of abnormal stack effluent activity (alert level), a 15-second grabsample is automatically trapped in a sample bottle and an annunciator in thecontrol room indicates the off-normal condition.Following a high level indication, the normal sample loop is bypassed and thesample flow is split with approximately 0.02 scfm directed through thehigh-range filter and the balance through the ion chamber. To avert a toorapid buildup of activity on the filter, the capability exists to interrupt thesample flow through the filter periodically for periods ranging from 6 secondsto 54 seconds every minute. The continuous monitoring capability of thehigh-range noble gas monitor is not affected during filter flow interruption. A"high radiation" annunciator in the control room alerts the Plant operators tothe condition.Systems may be controlled either locally or remotely from the control room.Dual microprocessor controllers provide system control through the normal,alert and high operating modes. Normally the controller located in the controlroom provides full system control. In the event of failure the local controllertakes control of the system functions.Refer to Table 11-15 for details of the monitors.11.5.4 SYSTEM EVALUATIONAll process systems which contribute to Plant discharges are monitored priorto entering the various discharge systems. Each discharge system is alsomonitored, providing redundancy of radiation detection for Plant effluents.The radwaste area, containment air, waste gas, engineered safeguards pumproom, and the off-gas radiation monitoring systems are backed up by thestack-gas monitoring system. The service water, radwaste liquids discharge,component cooling and the steam generator blowdown radiation monitoringsystems are backed up by the circulating water discharge monitor.Testing and maintenance for all systems, circuit testing of readout equipmentand power supplies can be performed from the panels located in the controlroom. The circuit being tested or repaired is inoperative during that time andacts as if it were a tripped channel. The containment high-radiation monitorsare continuously monitored while in service for loss of power, loss of detectorhigh voltage and for loss of detector signal.