ML16055A230
ML16055A230 | |
Person / Time | |
---|---|
Site: | Catawba |
Issue date: | 02/19/2016 |
From: | Henderson K Duke Energy Carolinas |
To: | Office of Nuclear Reactor Regulation |
Shared Package | |
ML16055A223 | List: |
References | |
CNS-16-010, TAC MF6166, TAC MF6167 | |
Download: ML16055A230 (52) | |
Text
ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesIntroduction Table F-i lists the threshold conditions that define the Loss and Potential Loss of the threefission product barriers (Fuel Clad, Reactor Coolant System, and Containment).
The table isstructured so that each of the three barriers occupies adjacent columns.
Each fission productbarrier column is further divided into two columns; one for Loss thresholds and one forPotential Loss thresholds.
The first column of the table (to the left of the Fuel Clad Loss column) lists the categories (types) of fission product barrier thresholds.
The fission product barrier categories are:A. NCS or SG Tube LeakageB. Inadequate Heat removalC. CMT Radiation
/ NCS Activity0. CMT Integrity or BypassE. Emergency Coordinator JudgmentEach category occupies a row in Table F-I thus forming a matrix defined by the categories.
The intersection of each row with each Loss/Potential Loss column forms a cell in which one ormore fission product barrier thresholds appear. If NEI 99-01 does not define a threshold for abarrier Loss/Potential Loss, the word "None" is entered in the cell.Thresholds are assigned sequential numbers Within each Loss and Potential Loss columnbeginning with number one. In this manner, a threshold can be identified by its category titleand number. For example, the first Fuel Clad barrier Loss in Category B would be assigned"FC Loss B.1," the third Containment barrier Potential Loss in Category D would be assigned"CMT P-Loss D.3," etc.If a cell in Table F-i Contains more than one numbered threshold, each of the numberedthresholds, if exceeded, signifies a Loss or Potential Loss of the barrier.
It is not necessary toexceed all of the thresholds in a category before declaring a barrier Loss/Potential Loss.Subdivision of Table F-I by category facilitates association of plant conditions to the applicable fission product barrier Loss and Potential Loss thresholds.
This structure promotes asystematic approach to assessing the classification status of the fission product barriers.
When equipped with knowledge of plant conditions related to the fission product barriers, theEAL-user first scans down the category column of Table F-I, locates the likely category andthen reads across the fission product barrier Loss and Potential Loss thresholds in thatcategory to determine if a threshold has been exceeded.
If a threshold has not been exceeded, the EAL-user proceeds to the next likely category and continues review of the thresholds in thenew categoryIf the EAL-user determines that any threshold has been exceeded, by definition, the barrier islost or potentially lost -even if multiple thresholds in the same barrier column are exceeded, only that one barrier is lost or potentially lost. The EAL-user must examine each of the threefission product barriers to determine if other barrier thresholds in the category are lost or ,potentially lost. For example, if containment radiation is sufficiently high, a Loss of the FuelClad and NCS barriers and a Potential Loss of the Containment barrier can occur. Barrier ,IRP/0/A/5000/001 Rev. 1 Page 196 of 247I ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesLosses and Potential Losses are then applied to the algorithms given in EALs FGI .1, FS1 .1,and FA1 .1 to determine the appropriate emergency classification.
In the remainder of this Attachment, the Fuel Clad barrier threshold bases appear first,followed by the NCS barrier and finally the Containment barrier threshold bases. In eachbarrier, the bases are given according category Loss followed by category Potential Lossbeginning with Category A, then B....E.lRPIOIN15000/100 Rev. 1 Page 197 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesTable F-I Fission Product Barrier Threshold MatrixFuel Clad (FC) Barrier Reactor Coolant System (NCS) Barrier Containment (CMT) Barriercategory Loss Potential Loss Loss Potential Loss Loss Potential LossA ,1 An automatic or manual ECCS(SI) actuation required byETE:1, CSFSTInetgrity-RED Path 1. Alealing or RUPTURED SG is NNCS or None None
- UNISOLABLE NCS conditions met FAULTED outside of containment NnSG Tube leakageLeakage *SG tobe RUPTURE1. CPTCi oln-RNi CSFST Core Cooling-REDAPat Bpath conditions met 1. CSFST Heat Sink-RED Path 1.cS T orutinme otngEDPtndqae 1. CSFST Core Cooling-RED
- 2. CSFST Heat Sink-RED Path conditions met cniin eIndqae Path conditions met conditions met None AND None ANDRestoration procedures notNeat AND Heat sink is required eftective within 15 min. (Note 1)Removal Heat sink is required, C 1. EMF53AIB
> Table F-2 columnCM CLs~1 EMF53A/E
- Table F-2 column NnNoe1. EMF53AIB s Table P-2 columRadiTio 2 F Dosesqiaet1-3" oln None 1."NCS Loss" NoeNn CMT Potential Loss"/ NCS acvitdy > 3001 pCi/gmActivity1. Containment isolation isrequiredAND EITHER: 1. CSFST Contalnmont-RED PathD Containment integrity has conditions metbeen Iost based on 2. Containment hydrogen concentretlol CMT None None None None EudmergncyCodiaot
-Injudgmen
- 3. Containment pressure
- 3 patg.*U NISOLABLE pathway from w~4th n one toll train of contalnen or Bypass Containment to the ennironment cooling operating per dnsign forexists > 15 main. (Note 1)2. Indicotmons of NCS leakageoutside of containment E 1. Any condition in the opinion of 1. Any condition in thie opinion of 1, Any condition n the opinion ~ .Ayodtoitepnoof the 1. Any condition in the opinion of 1. Anyconditionintheopinionutfthe the Emergency Coordinator that the Emergency Coordinator that 1 n odto nteoiinoEC indicotes lass of the fuel clad Indicates potential loss of the fool the Emergency Coordinator that Emergency Coordinator that the Emergency Coordinator that Emergency Coordinator thatJudgment bare ldbririndictaes Ions of the NCS bamrer baeindicotes potential lons of the NCS bareindicates loss of the containment cotimnindicotes potentialba elOSS of theSRP/OA/N50001001 Rev. 1 Page 198 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Fuel CladCategory:
INoneIRPIO/AI5000/O01 Rev. 1 Page 199 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Fuel CladCategory:
SNone[RPI/OIN50001001 lRev. 1I Page 200 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesFuel CladBarrier:Category:
B. InmDegradation Threat: Lossidequate Heat RemovalThreshold:
- 1. CSFST Core Cooling-RED Path conditions metDefinition(s):
NoneBasis:Critical Safety Function Status Tree (CSFST) Core Cooling-RED path indicates significant coreexit superheating and core uncovery.
The CSFSTs are normally monitored using the SPDSdisplay on the Operator Aid Computer (OAC) (ref. 1 ).This reading indicates temperatures within the core are sufficient to cause significant superheating of reactor coolant.CNS Basis Reference(s):
- 1. EP/I (2)/5000/F-0 Critical Safety Function Status Trees2. EP/I(2)IA/5OOO/FR-C.1 Response to Inadequate Core Cooling3. EP/I(2)/AI5000/FR-C.2 Response to Degraded Core Cooling4. NEI 99-01 Inadequate Heat Removal Fuel Clad Loss 2.AIRPIOIAI50001001 Rev. 1 Page 201 of 247I ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesFuel CladB. Inadequate Heat RemovalBarrier:Category:
DegraationThCreat Poo tentiOalG Loss oniiose1. CSFST Core Cooling-ORANGE Path conditions metDefinition(s):
NoneBasis:Critical Safety Function Status Tree (CSFST) Core Cooling-ORANGE path indicates indicates subcooling has been lost and that some fuel clad damage may potentially occur. The CSFSTsare normally monitored using the SPDS display on the Operator Aid Computer (OAC) (ref. 1).This reading indicates a reduction in reactor vessel water level sufficient to allow the onset ofheat-induced cladding damage.CNS Basis Reference(s):
- 1. EP/II(2)/5000/F-0 Critical Safety Function Status Trees2. EP/1(2)/A/5OOOIFR-C.1 Response to Inadequate Core Cooling3. EP/I1(2)/A/5000/FR-C.2 Response to Degraded Core Cooling4. NEI 99-01 Inadequate Heat Removal Fuel Clad Loss 2.AIRP/O/AI5000/O01 Rev. 1I Page 202 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Fuel CladCategory:
B. Inadequate Heat RemovalDegradation Threat: Potential LossThreshold:
- 2. CSFST Heat Sink-RED Path conditions metANDHeat sink is requiredDefinition(s):
NoneBasis:In combination with NCS Potential Loss B.1, meeting this threshold results in a Site AreaEmergency.
Critical Safety Function Status Tree (CSFST) Heat Sink-RED path indicates the ultimate heatsink function is under extreme challenge and that some fuel clad damage may potentially occur (ref. 1).The CSFSTs are normally monitored using the SPDS display on the Operator Aid Computer(OAC) (ref. 1).The phrase "and heat sink required" precludes the need for classification for conditions inwhich NCS pressure is less than SG pressure or Heat Sink-RED path entry was createdthrough operator action directed by an EOP. For example, FR-H.1 is entered from CSFSTHeat Sink-Red.
Step 2 tells the operator to determine if heat sink is required by checking thatNCS pressure is greater than any non-faulted SG pressure and NCS Thot is greater than350°F. If these conditions exist, Heat Sink is required.
Otherwise, the operator is to eitherreturn to the procedure and step in effect or place ND in service for heat removal.
For largeLOCA events inside the Containment, the SGs are moot because heat removal through thecontainment heat removal systems takes place. Therefore, Heat Sink Red should not berequired and, should not be assessed for EAL classification because a LOCA event aloneshould not require higher than an Alert classification.
(ref. 2)This condition indicates an extreme challenge to the ability to remove NCS heat using thesteam generators (i.e., loss of an effective secondary-side heat sink). This condition represents a potential loss of the Fuel Clad Barrier.
In accordance with EOPs, there may beunusual accident conditions during which operators intentionally reduce the heat removalcapability of the steam generators; during these conditions, classification using threshold is notwarranted.
CNS Basis Reference(s):
- 1. EP/I1(2)/5000/
F-0 Critical Safety Function Status Trees2. EP/I (2)/A/5000/FR-H.1 Response to Loss of Secondary Heat SinkRPO/100/O1Re.
age 20 of 247l ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and Bases3. NEI 99-01 Inadequate Heat Removal Fuel Clad Loss 2.B[RPIOIA15000/O01 Rev. I Page 204 of 247 ATTACHMENT 2Fission Product Barrier L~oss/Potential Loss Matrix and BasesFuel CladC. CMT Radiation
/ NCS ActivityBarrier:Category:
Degradation Threat: LossThreshold:
- 1. EMF53A/B
> Table F-2 column "FC Loss"Table F-2 Containment Radiation
-R/hr (EM F53AIB)Time After SID FCLs C os CMT Potential (Hrs.) Loss0-1 550 8.8 55001-2 400 '8.4 40002-8 160 7.0 1600>8 100 6.2 1000Definition(s):
NoneBasis:The gamma dose rate resulting from a postulated loss of coolant accident (LOCA) is monitored by the containment high range monitors, EMF53A & B. EMF53A & B are located insidecontainment.
The detector range is approximately 1 to 1 E8 R/hr (logarithmic scale). Radiation Monitors EMF53A & B provide a diverse means of measuring the containment for high levelgamma radiation.
(ref. 1).The Table F-2 values, column FC Loss represents, based on core damage assessment procedure, the expected containment high range radiation monitor (EMF53A & B) responsebased on a LOCA, for periods of 1, 2, 8 and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after shutdown, no sprays and NCSpressure
< 1600 psig with -2% fuel failure (ref. 2).The value is derived as follows:RPI/OAI5000101 5 Figure 3 Containment Radiation Level vs. T]ime for 100% Clad Damage 1, 2,8 and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after shutdown without spray and NCS pressure
< 1600 psig x 0.02 (rounded)
(ref. 2).The radiation monitor reading corresponds to an instantaneous release of all reactor coolantmass into the containment, assuming that reactor coolant activity equals 300 IJCi/gm doseequivalent I-131. Reactor coolant activity above this level is greater than that expected foriodine spikes and corresponds to an approximate range of 2% to 5% fuel clad damage. SinceSRP/0/A/5000/001 Rev. I Page 205 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and Basesthis condition indicates that a significant amount of fuel clad damage has occurred, itrepresents a loss of the Fuel Clad Barrier.The radiation monitor reading in this threshold is higher than that specified for NCS BarrierLoss threshold C.1 since it indicates a loss of both the Fuel Clad Barrier and the NCS Barrier.Note that a combination of the two monitor readings appropriately escalates the ECL to a SiteArea Emergency.
CNS Basis Reference(s):
- 1. IP/0/3314/004 Radiation Monitoring System RP-2C High Range Process ChannelCalibration
- 2. RP/O/A15000101 5 Core Damage Assessment
- 3. NEI 99-01 CMT Radiation
/ RCS Activity Fuel Clad Loss 3.AIRPIoIAI50Iooo1o Rev. I Page 206 of 2471 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesFuel CladC. CMT Radiation
/ NCS ActivityBarrier:Category:
Degradation Threat: LossThreshold:
- 2. Dose equivalent 1-131 coolant activity
> 300 pCi/gmDefinition(s):
NoneBasis:Elevated reactor coolant activity represents a potential degradation in the level of safety of theplant and a potential precursor of more serious problems.
The threshold dose equivalent 1-131concentration is well above that expected for iodine spikes and corresponds to about 2% fuelclad damage. When reactor coolant activity reaches this level the Fuel Clad barrier isconsidered lost. (ref. 1).This threshold indicates that NCS radioactivity concentration is greater than 300 IJCi/gm doseequivalent 1-131. Reactor coolant activity above this level is greater than that expected foriodine spikes and corresponds to an approximate range of 2% to 5% fuel clad damage. Sincethis condition indicates that a significant amount of fuel clad damage has occurred, itrepresents a loss of the Fuel Clad Barrier.There is no Potential Loss threshold associated with NCS Activity
/ Containment Radiation.
CNS Basis Reference(s):
- 1. RP/0/A/5000/01 5 Core Damage Assessment
- 2. NEI 99-01 CMT Radiation
/ RCS Activity Fuel Clad Loss 3.BSRP/0/A/5000/001 Rev. 1 Page 207 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Fuel CladCategory:
C. CMT Radiation
/ NCS ActivityDegradation Threat: Potential LossThreshold:
SNoneIRP/0/A/5000/001 Rev. 1 Page 208 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Fuel CladCategory:
D. CMT Integrity or BypassDegradation Threat: LossThreshold:
None, ; i, :'{>'" " = "iI:: , t , : , .... .. .. .i)" ' .... "i: {% A $7* , : ÷ .SRP/oA150/ooo1o Rev. I Page 209of 2471 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Fuel CladCategory:
D. CMT Integrity or BypassDegradation Threat: Potential LossThreshold:
SNoneSRP/0/A/5000/001 Rev. 1 Page 210 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesFuel CladE. Emergency Coordinator JudgmentiBarrier:Category:
Degradation Threat: LossThreshold:
- 1. Any condition in the opinion of the Emergency Coordinator that indicates loss of theFuel Clad barrierDefinition(s):
NoneBasis:The Emergency Coordinator judgment threshold addresses any other factors relevant todetermining if the Fuel Clad barrier is lost. Such a determination should include imminentbarrier degradation, barrier monitoring capability and dominant accident sequences.
- Imminent barrier deqradation exists if the degradation will likely occur within two hoursbased on a projection of current safety system performance.
The term "imminent" refersto recognition of the inability to reach safety acceptance criteria before completion of allchecks.* Barrier monitorinqj capability is decreased if there is a loss or lack of reliable indicators.
This assessment should include instrumentation operability
- concerns, readings fromportable instrumentation and consideration of offsite monitoring results.*Dominant accident sequences lead to degradation of all fission product barriers andlikely entry to the EOPs: The Emergency Coordinator should be mindful of the Loss ofAC power (Station Blackout) and ATWS EALs to assure timely emergency classification declarations.
This threshold addresses any other factors that are to be used by the Emergency Coordinator in determining whether the Fuel Clad barrier is lost.CNS Basis Reference(s):
NEI 99-01 Emergency Director Judgment Fuel Clad Loss 6.ARP/0/A/5000/001 Rev. 1 Page 211 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Fuel CladCategory:
E. Emergency Coordinator JudgmentDegradation Threat: Potential LossThreshold:
- 1. Any condition in the opinion of the Emergency Coordinator that indicates potential lossof the Fuel Clad barrierBasis:The Emergency Coordinator judgment threshold addresses any other factors relevant todetermining if the Fuel Clad barrier is potentially lost. Such a determination should includeimminent barrier degradation, barrier monitoring capability and dominant accident sequences.
- Imminent barrier degradation exists if the degradation will likely occur within two hoursbased on a projection of current safety system performance.
The term "imminent" refersto recognition of the inability to reach safety acceptance criteria before completion of allchecks.*Barrier monitoring capability is decreased if there is a loss or lack of reliable indicators.
This assessment should include instrumentation operability
- concerns, readings fromportable instrumentation and consideration of offsite monitoring results.*.Dominant accident sequences lead to degradation of all fission product barriers andlikely entry to the EOPs. The Emergency Coordinator should be mindful of the Loss ofAC power (Station Blackout) and ATWS EALs to assure timely emergency classification declarations.
This threshold addresses any Other factors that are to be used by the Emergency Coordinator in determining whether the Fuel Clad barrier is potentially lost. The Emergency Coordinator should also consider whether or not to declare the barrier potentially lost in the event thatbarrier status cannot be monitored.
CNS Basis Reference(s):
- 1. NEI 99-01 Emergency Director Judgment Potential Fuel Clad Loss 6.AIRP/0/A/5000/0O1 Rev. 1I Page 212 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
A. NCS or SG Tube LeakageDegradation Threat: LossThreshold:
- 1. An automatic or manual ECCS (SI) actuation required by EITHER:* UNISOLABLE NCS leakage* SG tube RUPTUREDefinition(s):
UNISOLABLE
-An open or breached system line that cannot be isolated, remotely or locally.RUPTURE -The condition of a steam generator in which primary-to-secondary leakage is ofsufficient magnitude to require a safety injection.
Basis:ECCS (SI) actuation is caused by (ref. 1 ):* Pressurizer pressure
< 1845 psig* Containment pressure
> 1.2 psigThis threshold is based on an UNISOLABLE NCS leak of sufficient size to require anautomatic or manual actuation of the Emergency Core Cooling System (ECCS). This condition clearly represents a loss of the NCS Barrier.This threshold is applicable to unidentified and pressure boundary
- leakage, as well asidentified leakage.
It is also applicable to UNISOLABLE NCS leakage through an interfacing system. The mass loss may be into any location
-inside containment, to the secondary-side (i.e., steam generator tube leakage) or outside of containment.
A steam generator with primary-to-secondary leakage of sufficient magnitude to require asafety injection is considered to be RUPTURED.
If a RUPTURED steam generator is alsoFAULTED outside of containment, the declaration escalates to a Site Area Emergency sincethe Containment Barrier Loss threshold 1 .A will also be met.CNS Basis Reference(s):
- 1. EP/1(2)/AI5OOO/E-O Reactor Trip or Safety Injection
- 2. EP/1 (2)/AI5000/E-3 Steam Generator Tube Rupture3. NEI 99-01 ROS or SG Tube Leakage Reactor Coolant System Loss 1l.AIRP/0/A/5000/001 Rev. 1 Page 213 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:Category:
Reactor Coolant SystemA. NCS or SG Tube LeakageDegradation Threat: Potential LossThreshold:
- 1. CSFST Integrity-RED path conditions metDefinition(s):
NoneBasis:The "Potential Loss" threshold is defined by the CSFST Reactor Coolant Integrity
-Red Path plant conditions and associated PTS Limit Curve A indicates an extreme challenge to the safety function when plant parameters are to the left of the limitcurve following excessive NCS cooldown under pressure (ref. 1, 2).This condition indicates an extreme challenge to the integrity of the NCS pressure boundarydue to pressurized thermal shock -a transient that causes rapid NCS cooldown while the NCSis in Mode 3 or higher (i.e., hot and pressurized).
CNS Basis Reference(s):
- 1. EP/1I(2)/A/5000IF-0 Critical Safety Function Status Trees2. EP/I (2)/A15000/FR-P.1 Response to Imminent Pressurized Thermal Shock Condition
- 3. NEI 99-01 RCS or SG Tube Leakage Reactor Coolant System Potential Loss 1 .BIRP/O/A15000/O01 Rev. 1 Page 214 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
B. Inadequate Heat RemovalDegradation Threat: LossThreshold:
NoneIIRPIOIAI5000I100 Rev. 1 IPage 215 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
B. Inadequate Heat RemovalDegradation Threat: Potential LossThreshold:
- 1. CSFST Heat Sink-RED path conditions metANDHeat sink is requiredDefinition(s):
NoneBasis:In combination with FC Potential Loss B.2, meeting this threshold results in a Site AreaEmergency.
Critical Safety Function Status Tree (CSFST) Heat Sink-RED path indicates the ultimate heatsink function is under extreme challenge and that some fuel clad damage may potentially occur (ref. 1).The CSFSTs are normally monitored using the SPDS display on the Operator Aid Computer(QAC) (ref. 1).The phrase "and heat sink required" precludes the need for classification for conditions inwhich NCS pressure is less than SG pressure or Heat Sink-RED path entry was createdthrough operator action directed by an EOP. For example, FR-H.1 is entered from CSFSTHeat Sink-Red.
Step 2 tells the operator to determine if heat sink is required by checking thatNCS pressure is greater than any non-faulted SG pressure and NCS Thot is greater than350°F. If these conditions exist, Heat Sink is required.
Otherwise, the operator is to eitherreturn to the procedure and step in effect or place ND in service for heat removal.
For largeLOCA events inside the Containment, the SGs are moot because heat removal through thecontainment heat removal systems takes place. Therefore, Heat Sink Red should not berequired and, should not be assessed for EAL classification because a LOCA event aloneshould not require higher than an Alert classification.
(ref. 1, 2).This condition indicates an extreme challenge to the ability to remove NCS heat using thesteam generators (i.e., loss of an effective secondary-side heat sink). This condition represents a potential loss of the NCS Barrier.
In accordance with EOPs, there may beunusual accident conditions during which operators intentionally reduce the heat removalcapability of the steam generators; during these conditions, classification using threshold is notwarranted.
Meeting this threshold results in a Site Area Emergency because this threshold is identical toFuel Clad Barrier Potential Loss threshold B.2; both will be met. This condition warrants a SiteArea Emergency declaration because inadequate NCS heat removal may result in fuel heat-upIRP/°/A15°°°/°°O1 Rev. 1 Page 216 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and Basessufficient to damage the cladding and increase NCS pressure to the point where mass will belost from the system.CNS Basis Reference(s):
- 1. EP/I (2)/5000/F-0 Critical Safety Function Status Trees2. EP/I(2)/A/5000/FR-H.1 Response to Loss of Secondary Heat Sink3. NEI 99-01 Inadequate Heat Removal NCS Loss 2.BIRP/o/s0oA1 oo0100 Rev. I Page 217 of 2471 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesReactor Coolant SystemC. CMT Radiation!/NCS ActivityBarrier:Category:
D.egr 5Adatio Thrat: -2clmn"C Loss"1. EMF53A/B
> Table F-2 column "NCS Loss"Table F-2 Containment Radiation
-R/hr (EMF53A/B)
Time After SID CMT Potential (Hs)FC Loss NCS Loss Ls0-1 550 8.8 55001-2 400 8.4 40002-8 160 7.0 1600>8 100 6.2 1000Definition(s):
N/ABasis:The gamma dose rate resulting from a postulated loss of coolant accident (LOCA) is monitored by the containment high range monitors, EMF53A & B. EMF53A & B are located insidecontainment.
The detector range is approximately I to 1 E8 R/hr (logarithmic scale). Radiation Monitors EMF53A & B provide a diverse means of measuring the containment for high levelgamma radiation.
(ref. 1).The value specified represents, based on core damage assessment procedure RP/0/A/5000/01 5 Figure 1, the expected containment high range radiation monitor (EMF53A &B) response based on a LOCA, for periods of 1, 2, 8 and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after shutdown with no fuelfailure (ref. 2).The value is derived as follows:RP/0/A/5000/015 Figure 1 Containment Radiation Level vs. Time for RCS Release for periodsof 1, 2, 8 and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after shutdown (rounded)
(ref. 2).The radiation monitor reading corresponds to an instantaneous release of all reactor coolantmass into the containment, assuming that reactor coolant activity equals Technical Specification allowable limits. This value is lower than that specified for Fuel Clad Barrier Lossthreshold C.1 since it indicates a loss of the NCS Barrier only.There is no Potential Loss threshold associated with NCS Activity!/Containment Radiation.
RP/0/A/5000/001 Rev.1IPg 18o 4 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesCNS Basis Reference(s):
- 1. IP/0/3314/004 Radiation Monitoring System RP-2C High Range Process ChannelCalibration
- 2. RP/0/A/5000/01 5 Core Damage Assessment
- 3. NEI 99-01 CMT Radiation
/ RCS Activity NCS Loss 3.ASRP/0/A/5000/001 Rev. 1 Page 219 of 247I ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
B. CMT Radiation/
NCS ActivityDegradation Threat: Potential LossThreshold:
NoneIRP/O/A/5000/O01 Rev. 1 Page 220 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
D. CMT Integrity or BypassDegradation Threat: LossThreshold:
SNoneSRP/0/A/5000/001 Rev. 1 Page 221 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
- 0. CMT Integrity or BypassDegradation Threat: Potential LossThreshold:
None1i ....t, -,,_'2',o,,i ,t -ri *;..r RP/0/A/5000/001 Rev. I Page 222 of 2471 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
E. Emergency Coordinator JudgmentDegradation Threat: LossThreshold:
- 1. Any condition in the opinion of the Emergency Coordinator that indicates loss of theNCS barrierDefinition(s):
NoneBasis:The Emergency Coordinator judgment threshold addresses any other factors relevant todetermining if the NCS barrier is lost. Such a determination should include imminent barrierdegradation, barrier monitoring capability and dominant accident sequences.
aImminent barrier deqradation exists if the degradation will likely occur within two hoursbased on a projection of current safety system performance.
The term "imminent" refersto the recognition of the inability to reach safety acceptance criteria before completion ofall checks.*Barrier monitorinq capability is decreased if there is a loss or lack of reliable indicators.
This assessment should include instrumentation operability
- concerns, readings fromportable instrumentation and consideration of offsite monitoring results.*Dominant accident sequences lead to degradation of all fission product barriers andlikely entry to the EOPs. The Emergency Coordinator should be mindful of the Loss ofAC power (Station Blackout) and ATWS EALs to assure timely emergency classification declarations.
This threshold addresses any other factors that may be used by the Emergency Coordinator indetermining whether the NCS Barrier is lost.CNS Basis Reference(s):
- 1. NEI 99-01 Emergency Director Judgment NCS Loss 6.ARP/0/A/5000/001 Rev. 1 Page 223 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Reactor Coolant SystemCategory:
E. Emergency Coordinator JudgmentDegradation Threat: Potential LossThreshold:
- 1. Any condition in the opinion of the Emergency Coordinator that indicates potential lossof the NCS barrierDefinition(s):
NoneBasis:The Emergency Coordinator judgment threshold addresses any other factors relevant todetermining if the NCS barrier is potentially lost. Such a determination should include imminentbarrier degradation, barrier monitoring capability and dominant accident sequences.
a Imminent barrier deqradation exists if the degradation will likely occur within two hoursbased on a projection of current safety system performance.
The term "imminent" refersto the inability to reach final safety acceptance criteria before completing all checks.*Barrier monitoring capability is decreased if there is a loss or lack of reliable indicators.
This assessment should include instrumentation operability
- concerns, readings fromportable instrumentation and consideration of offsite monitoring results.*Dominant accident seguences lead to degradation of all fission product barriers andlikely entry to the EOPs. The Emergency Coordinator should be mindful of the Loss ofAC power (Station Blackout) and ATWS EALs to assure timely emergency classification declarations.
This threshold addresses any other factors that may be used by the Emergency Coordinator indetermining whether the NCS Barrier is potentially lost. The Emergency Director should alsoconsider whether or not to declare the barrier potentially lost in the event that barrier statuscannot be monitored.
CNS Basis Reference(s):
- 1. NEI gg-oi Emergency Director Judgment NCS Potential Loss 6.ASRP/0/A/5000/001 Rev. 1I Page 224 of 247I ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
A. NCS or SG Tube LeakageDegradation Threat: LossThreshold:
- 1. A leaking or RUPTURED SG is FAULTED outside of containment Definition(s):
FAULTED -The term applied to a steam generator that has a steam leak on the secondary side of sufficient size to cause an uncontrolled drop in steam generator pressure or the steamgenerator to become completely depressurized.
RUPTURED
-The condition of a steam generator in which primary-to-secondary leakage is ofsufficient magnitude to require a safety injection.
Basis:This threshold addresses a leaking or RUPTURED Steam Generator (SG) that is alsoFAULTED outside of containment.
The condition of the SG, whether leaking or RUPTURED,
- is determined in accordance with the thresholds for NCS Barrier Potential Loss A.1 and LossA.1,respectively.
This condition represents a bypass of the containment barrier.FAULTED is a defined term within the NEI 99-01 methodology; this determination is notnecessarily dependent upon entry into, or diagnostic steps within, an EOP. For example, if thepressure in a steam generator is decreasing uncontrollably (part of the FAULTED definition) and the FAULTED steam generator isolation procedure is not entered because EOP user rulesare dictating implementation of another procedure to address a higher priority condition, thesteam generator is still considered FAULTED for emergency classification purposes.
The FAULTED criterion establishes an appropriate lower bound on the size of a steam releasethat may require an emergency classification.
Steam releases of this size are readilyobservable with normal Control Room indications.
The lower bound for this aspect of thecontainment barrier is analogous to the lower bound criteria specified in IC SU4 for the fuelclad barrier (i.e., NCS activity values) and IC SU5 for the NCS barrier (i.e., NCS leak ratevalues).This threshold also applies to prolonged steam releases necessitated by operational considerations such as the forced steaming of a leaking or RUPTURED steam generator directly to atmosphere to cooldown the plant, or to drive an auxiliary (emergency) feed waterpump. These types of conditions will result in a significant and sustained release of radioactive steam to the environment (and are thus similar to a FAULTED condition).
The inability toisolate the steam flow without an adverse effect on plant cooldown meets the intent of a loss ofcontainment.
SRP/0/A/5000/001 Rev. I Page 225 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesSteam releases associated with the expected operation of a SG power operated relief valve orsafety relief valve do not meet the intent of this threshold.
Such releases may occurintermittently for a short period of time following a reactor trip as operators process throughemergency operating procedures to bring the plant to a stable condition and prepare to initiatea plant cooldown.
Steam releases associated with the unexpected operation of a valve (e.g., astuck-open safety valve) do meet this threshold.
Following an SG tube leak or rupture, there may be minor radiological releases through asecondary-side system component (e.g., air ejectors, glad seal exhausters, valve packing,etc.). These types of releases do not constitute a loss or potential loss of containment butshould be evaluated using the Recognition Category R ICs.The ECLs resulting from primary-to-secondary
- leakage, with or without a steam release fromthe FAULTED SG, are summarized below.Affected SG is FAULTEDOutside of Containment?
P-to-S Leak RateYesNoLess than or equal to 25 gpmNo classification No classification Greater than 25 gpmUnusual Event per SU5.1 Unusual Event per SU5.1Requires operation of a standby Site Ae mrec echarging (makeup) pump (NCS AraSmegecype Barrier Potential Loss) Ei.Requires an automatic or manual SieAaEmrncpr ECCS (SI) actuation (NCS Barrier FSi1.1Loss)Alert per FA1.1Alert per FA1 .1There is no Potential Loss threshold associated with NCS or SG Tube Leakage.CNS Basis Reference(s):
- 1. EP/I (2)/A/5000/E-0 Reactor Trip or Safety Injection
- 2. EPII(2)1A/5000/E-3 Steam Generator Tube Rupture3. NEI 99-01 RCS or SG Tube Leakage Containment Loss 1I.AIRPIO/A/5000/O01l Rev. 1 Page 226 of 2471 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
A. NCS or SG Tube LeakageDegradation Threat: Potential LossThreshold:
NoneIRPIOIAI5000I100 Rev. 1 IPage 227 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
B. Inadequate heat RemovalDegradation Threat: Potential LossThreshold:
- 1. CSFST Core Cooling-RED path conditions metANDRestoration procedures not effective within 15 min. (Note 1)Definition(s):
NoneBasis:Critical Safety Function Status Tree (CSFST) Core Cooling-RED path indicates significant coreexit superheating and core uncovery.
The CSFSTs are normally monitored using the SPDSdisplay on the Operator Aid Computer (OAC) (ref. 1).The function restoration procedures are those emergency operating procedures that addressthe recovery of the core cooling critical safety functions.
The procedure is considered effective if the temperature is decreasing or if the vessel water level is increasing (ref. 1, 2, 3).A direct correlation to status trees can be made if the effectiveness of the restoration procedures is also evaluated.
If core exit thermocouple (TC) readings are greater than 1 ,200°F(ref. 1), Fuel Clad barrier is also lost.This condition represents an IMMINENT core melt sequence which, if not corrected, could leadto vessel failure and an increased potential for containment failure.
For this condition to occur,there must already have been a loss of the NCS Barrier and the Fuel Clad Barrier.
Ifimplementation of a procedure(s) to restore adequate core cooling is not effective (successful) within 15 minutes, it is assumed that the event trajectory will likely lead to core melting and asubsequent challenge of the Containment Barrier.The restoration procedure is considered "effective" if core exit thermocouple readings aredecreasing and/or if reactor vessel level is increasing.
Whether or not the procedure(s) will beeffective should be apparent within 15 minutes.
The Emergency Coordinator should escalatethe emergency classification level as soon as it is determined that the procedure(s) will not beeffective.
Severe accident analyses (e.g., NUREG-1 150) have concluded that function restoration procedures can arrest core degradation in a significant fraction of core damage scenarios, andthat the likelihood of containment failure is very small in these events. Given this, it isappropriate to provide 15 minutes beyond the required entry point to determine if procedural actions can reverse the core melt sequence.
CNS Basis Reference(s):
- 1. EP/1 (2)/5000/F-0 Critical Safety Function Status Trees ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and Bases2. EP/I(2)/AI5000IFR-C.1 Response to Inadequate Core Cooling3. EP/I(2)IAI5000/FR-C.2 Response to Degraded Core Cooling4. NEI 99-01 Inadequate Heat Removal Containment Potential Loss 2.AIRPIO/A150001001 Rev. 1I Page 229 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
C. CMT Radiation/NCS ActivityDegradation Threat: LossThreshold:
SNoneSRP/O/N15000/Q100 Rev. 1 Page 230 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
C. CMT Radiation/NCS ActivityDegradation Threat: Potential LossThreshold:
- 1. EMF53AIB
> Table F-2 column "CMT Potential Loss"Table F-2 Containment Radiation
-R/hr (EMF53A/B)
Time After SID FCLs C os CMT Potential (Hrs.) Loss0-1 550 8.8 55001-2 400 8.4 40002-8 160 7.0 1600>8 100 6.2 1000Definition(s):
NoneBasis:The gamma dose rate resulting from a postulated loss of coolant accident (LOCA) is monitored by the containment high range monitors, EMF53A & B. EMF53A & B are located insidecontainment.
The detector range is approximately 1 to 1 E8 R/hr (logarithmic scale). Radiation Monitors EMF53A & B provide a diverse means of measuring the containment for high levelgamma radiation.
(ref. 1).The Table F-2 values, column CMT Potential Loss represents, based on core damageassessment procedure, the expected containment high range radiation monitor (EMF53A & B)response based on a LOCA, for periods of 1, 2, 8 and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after shutdown, no sprays andNCS pressure
< 1600 psig with ~20% fuel failure (ref. 2).The value is derived as follows:RPIOIA15000101 5 Figure 3 Containment Radiation Level vs. Time for 100% Clad Damage 1, 2,8 and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after shutdown with no spray and NCS pressure
< 1600 psig x 0.20 (rounded)
(ref. 2).The radiation monitor reading corresponds to an instantaneous release of all reactor coolantmass into the containment, assuming that 20% of the fuel cladding has failed. This level offuel clad failure is well above that used to determine the analogous Fuel Clad Barrier Loss andNCS Barrier Loss thresholds.
IRP/°/N5°°°/°°l1 Rev. 1I Page 231 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesNUREG-1228, Source Estimations During Incident Response to Severe Nuclear Power PlantAccidents, indicates the fuel clad failure must be greater than approximately 20% in order forthere to be a major release of radioactivity requiring offsite protective actions.
For thiscondition to exist, there must already have been a loss of the NCS Barrier and the Fuel CladBarrier.
It is therefore prudent to treat this condition as a potential loss of containment whichwould then escalate the ECL to a General Emergency.
CNS Basis Reference(s):
- 1. IP/0/3314/004 Radiation Monitoring System RP-2C High Range Process ChannelCalibration
- 2. RP/0/A/5000/015 Core Damage Assessment
- 3. NEI 99-01 CMT Radiation
/ RCS Activity Containment Potential Loss 3.ARP0A50001Rv.1Pg 22o 4 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
D. CMT Integrity or BypassDegradation Threat: LossThreshold:
- 1. Containment isolation is requiredAND EITHER:* Containment integrity has been lost based on EC judgment* UNISOLABLE pathway from containment to the environment existsDefinition(s):
UNISOLABLE
-An open or breached system line that cannot be isolated, remotely or locally.Basis:These thresholds address a situation where containment isolation is required and one of twoconditions exists as discussed below. Users are reminded that there may be accident andrelease conditions that simultaneously meet both bulleted thresholds.
First Threshold
-Containment integrity has been lost, i.e., the actual containment atmospheric leak rate likely exceeds that associated with allowable leakage (or sometimes referred to asdesign leakage).
Following the release of NCS mass into containment, containment pressurewill fluctuate based on a variety of factors; a loss of containment integrity condition may (ormay not) be accompanied by a noticeable drop in containment pressure.
Recognizing theinherent difficulties in determining a containment leak rate during accident conditions, it isexpected that the Emergency Coordinator will assess this threshold using judgment, and withdue consideration given to current plant conditions, and available operational and radiological data (e.g., containment
- pressure, readings on radiation monitors outside containment, operating status of containment pressure control equipment, etc.).Refer to the middle piping run of Figure 1. Two simplified examples are provided.
One isleakage from a penetration and the other is leakage from an in-service system valve.Depending upon radiation monitor locations and sensitivities, the leakage could be detected byany of the four monitors depicted in the figure.Another example would be a loss or potential loss of the NCS barrier, and the simultaneous occurrence of two FAULTED locations on a steam generator where one fault is located insidecontainment (e.g., on a steam or feedwater line) and the other outside of containment.
In thiscase, the associated steam line provides a pathway for the containment atmosphere to escapeto an area outside the containment.
Following the leakage of NCS mass into containment and a rise in containment
- pressure, theremay be minor radiological releases associated with allowable (design) containment leakagethrough various penetrations or system components.
These releases do not constitute a lossor potential loss of containment but should be evaluated using the Recognition Category RICs.
ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesSecond Threshold
-Conditions are such that there is an UNISOLABLE pathway for themigration of radioactive material from the containment atmosphere to the environment.
Asused here, the term "environment" includes the atmosphere of a room or area, outside thecontainment, that may, in turn, communicate with the outside-the-plant atmosphere (e.g.,through discharge of a ventilation system or atmospheric leakage).
Depending upon a varietyof factors, this condition may or may not be accompanied by a noticeable drop in containment pressure.
Refer to the top piping run of Figure 1. In this simplified
- example, the inboard and outboardisolation valves remained open after a containment isolation was required (i.e., containment isolation was not successful).
There is now an UNISOLABLE pathway from the containment tothe environment.
The existence of a filter is not considered in the threshold assessment.
Filters do not removefission product noble gases. In addition, a filter could become ineffective due to iodine and/orparticulate loading beyond design limits (i.e., retention ability has been exceeded) or watersaturation from steam/high humidity in the release stream.Leakage between two interfacing liquid systems, by itself, does not meet this threshold.
Refer to the bottom piping run of Figure 1. In this simplified
- example, leakage in an RCP sealcooler is allowing radioactive material to enter the Auxiliary Building.
The radioactivity wouldbe detected by the Process Monitor.
If there is no leakage from the closed water coolingsystem to the Auxiliary
- Building, then no threshold has been met. If the pump developed aleak that allowed steam/water to enter the Auxiliary
- Building, then second threshold would bemet. Depending upon radiation monitor locations and sensitivities, this leakage could bedetected by any of the four monitors depicted in the figure and cause the first threshold to bemet as well.Following the leakage of NCS mass into containment and a rise in containment
- pressure, theremay be minor radiological releases associated with allowable containment leakage throughvarious penetrations or system components.
Minor releases may also occur if a containment isolation valve(s) fails to close but the containment atmosphere escapes to an enclosedsystem. These releases do not constitute a loss or potential loss of containment but should beevaluated using the Recognition Category R ICs.The status of the containment barrier during an event involving steam generator tube leakageis assessed using Loss Threshold A.I.CNS Basis Reference(s):
- 1. NEI 99-01 CMT Integrity or Bypass Containment Loss 4.ABarrier:
Containment Category:
D. CMT Integrity or BypassDegradation Threat: LossThreshold:
- 2. Indications of NCS leakage outside of containment RP/0/A/5000/001 Rev. 1 Page 234 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesDefinition(s):
NoneBasis:ECA-1 .2 LOCA Outside Containment (ref. 1 ) provides instructions to identify and isolate aLOCA outside of the containment.
Potential NCS leak pathways outside containment include(ref. 1,2):* Residual Heat Removal (ND)° Safety Injection (NI)* Chemical
& Volume Control (NV)* RCP seals (NC)* PZRINCS Loop sample lines (NM)Containment sump, temperature, pressure and/or radiation levels will increase if reactorcoolant mass is leaking into the containment.
If these parameters have not increased, then thereactor coolant mass may be leaking outside of containment (i.e., a containment bypasssequence).
Increases in sump, temperature,
- pressure, flow and/or radiation level readingsoutside of the containment may indicate that the NCS mass is being lost outside ofcontainment.
Unexpected elevated readings and alarms on radiation monitors with detectors outsidecontainment should be corroborated with other available indications to confirm that the sourceis a loss of NCS mass outside of containment.
If the fuel clad barrier has not been lost,radiation monitor readings outside of containment may not increase significantly; however,other unexpected changes in sump levels, area temperatures or pressures, flow rates, etc.should be sufficient to determine if NCS mass is being lost outside of the containment.
Refer to the middle piping run of Figure 1. In this simplified
- example, a leak has occurred at areducer on a pipe carrying reactor coolant in the Auxiliary Building.
Depending upon radiation monitor locations and sensitivities, the leakage could be detected by any of the four monitorsdepicted in the figure and cause threshold D.1 to be met as well.To ensure proper escalation of the emergency classification, the NCS leakage outside ofcontainment must be related to the mass loss that is causing the NCS Loss and/or Potential Loss threshold A.1 to be met.CNS Basis Reference(s):
- 1. EP/I (2)/AI5000/ECA-1
.2 LOCA Outside Containment
- 2. EP/I(2)/A/5000/E-1 Loss of Reactor or Secondary Coolant3. NEI 99-01 CMT Integrity or Bypass Containment LossiRP/01A15000/001 IRev. I Page 235 of 2471 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesFigure 1: Containment Integrity or Bypass Examples" hreshod-" "Airesolne-." i releaseEffluent
.0 i_. from .Auxiliary Building
._M__nit°rs
- ":* VentRCPSealCoolingRI poN50oo0oo I Rev. 1 Page 236 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:Category:
Containment
- 0. CMT Integrity or BypassDegradaSTiConThet:aPotentiRDalh Losdtos me1. CSFST Containment-RED path conditions metDefinition(s):
NoneBasis:Critical Safety Function Status Tree (CSFST) Containment-RED path is entered if containment pressure is greater than or equal to 15 psig and represents an extreme challenge to safetyfunction.
The CSFSTs are normally monitored using the SPDS display on the Operator AidComputer (OAC) (ref. 1).15 psig is based on the containment design pressure (ref. 2).If containment pressure exceeds the design pressure, there exists a potential to lose theContainment Barrier.
To reach this level, there must be an inadequate core cooling condition for an extended period of time; therefore, the NCS and Fuel Clad barriers would already belost. Thus, this threshold is a discriminator between a Site Area Emergency and GeneralEmergency since there is now a potential to lose the third barrier.CNS Basis Reference(s):
- 1. EP/II(2)/AN5000IF-O Critical Safety Function Status Trees2. UFSAR Section 6.2 Containment Systems3. NEI 99-01 CMT Integrity or Bypass Containment Potential Loss 4.AIRPIOIAI5000I100 Rev. 1I Page 237 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
D. CMT Integrity or BypassDegradation Threat: Potential LossThreshold:
- 2. Containment hydrogen concentration
> 6%Definition(s):
NoneBasis:Following a design basis accident, hydrogen gas may be generated inside the containment byreactions such as zirconium metal with water, corrosion of materials of construction andradiolysis of aqueous solution in the core and sump. (ref. 1).The Containment Hydrogen Purge and Sample System (VY) is used to monitor the hydrogenconcentration inside containment after a severe accident involving core damage. Samples ofContainment air are obtained via the containment hydrogen/oxygen sample lines to the PostAccident Containment Sample (PACS) panel located in the auxiliary building.
Additionally, thecontainment hydrogen analyzer system continuously monitors the hydrogen concentration inside containment (ref. 1).The lower limit of deflagration of hydrogen in air is approximately 6% and is the maximumconcentration at which hydrogen igniters can be placed in service (ref. 2).To generate such levels of combustible gas, loss of the Fuel Clad and NCS barriers must haveoccurred.
With the Potential Loss of the containment
- barrier, the threshold hydrogenconcentration, therefore, will likely warrant declaration of a General Emergency.
The existence of an explosive mixture means, at a minimum, that the containment atmospheric hydrogen concentration is sufficient to support a hydrogen burn (i.e., at the lower deflagration limit). A hydrogen burn will raise containment pressure and could result in collateral equipment damage leading to a loss of containment integrity.
It therefore represents a potential loss ofthe Containment Barrier.CNS Basis Reference(s):
- 1. UFSAR Section 6.2 Containment Systems2. EP/1(2)/A/5000/FR-Z.4 Response to High Containment Hydrogen Concentration
- 3. NEI 99-01 CMT Integrity or Bypass Containment Potential Loss 4.BIRP/O/A/5000/O01 Rev. 1 Page 238 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
- 0. CMT Integrity or BypassDegradation Threat: Potential LossThreshold:
- 3. Containment pressure
> 3 psig with < one full train of containment cooling operating
.per design for > 15 mai. (Notes 1, 10) INote 1 : The Emergency Director should declare the event promptly upon determining that time limit has beenexceeded, or will likely be exceeded.
Note 10: If the loss of containment cooling threshold is exceeded due to loss of both trains of VX-CARF, this EALonly applies if at least one train of VX-CARF is not operating, per design, after the 10 minute actuation delay for greater than or equal to 15 minutes.Definition(s):
NoneBasis:The containment Phase B pressure setpoint (3 psig, ref. 1, 2) is the pressure at which thecontainment cooling systems should actuate and begin performing their function.
One full train of containment cooling operating per design is considered (ref. 1, 2):* One train of Containment Air Return Fan System (VX-CARF),
and* One train of Containment Spray System (NS)Once the Residual Heat Removal system is taking suction from the containment sump, withcontainment pressure greater than 3 psig and procedural
- guidance, one train of containment spray is manually aligned to the containment sump. If unable to place one NS train in serviceor without an operating train of VX-CARF (the CARF with a 10-minute delay) within 15 minutesa potential loss of containment exists. At this point a significant portion of the ice in the icecondenser would have melted and the NS system would be needed for containment pressurecontrol.
The potential loss of containment applies after automatic or manual alignment of thecontainment spray system has been attempted with containment pressure greater than 3 psigand less than one full train of NS is operating for greater than or equal to 15 minutes.The potential loss of containment also applies if containment pressure is greater than 3 psigand at least one train of VX-CARF is not operating after a 10 minute delay for greater than orequal to 15 minutes.
Without a single train of VX-CARF in service following actuation, thepotential loss should be credited regardless of whether ECCS is in injection or sumprecirculation mode after 15 minutes.This threshold describes a condition where containment pressure is greater than the setpointat which containment energy (heat) removal systems are designed to automatically actuate,and less than one full train of equipment is capable of operating per design. The 15-minute criterion is included to allow operators time to manually start equipment that may not haveautomatically
- started, if possible.
This threshold represents a potential loss of containment in ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and Basesthat containment heat removal/depressurization systems (e.g., containment sprays, icecondenser fans, etc., but not including containment venting strategies) are either lost orperforming in a degraded manner.CNS Basis Reference(s):
- 1. CNS Technical Specification 3.6.62. CNS Technical Specification 3.6.6 Bases3. CNS Technical Specification 3.3.24. UFSAR Section 6.2 Containment Systems5. NEI 99-01 CMT Integrity or Bypass Containment Potential Loss 4.CIRPIO/AI5000/O01 IRev. 1 Page 240 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment Category:
F. Emergency Coordinator JudgmentDegradation Threat: LossThreshold:
- 1. Any condition in the opinion of the Emergency Coordinator that indicates loss of theContainment barrierDefinition(s):
NoneBasis:The Emergency Coordinator judgment threshold addresses any other factors relevant todetermining if the Primary Containment barrier is lost. Such a determination should includeimminent barrier degradation, barrier monitoring capability and dominant accident sequences.
- Imminent barrier deqradation exists if the degradation will likely occur within two hoursbased on a projection of current safety system performance.
The term "imminent" refersto recognition of the inability to reach safety acceptance criteria before completion of allchecks.* Barrier monitoringq capability is decreased if there is a loss or lack of reliable indicators.
This assessment should include instrumentation operability
- concerns, readings fromportable instrumentation and consideration of offsite monitoring results.*Dominant accident sequences lead to degradation of all fission product barriers andlikely entry to the EOPs. The Emergency Coordinator should be mindful of the Loss ofAC power (Station Blackout) and ATWS EALs to assure timely emergency classification declarations.
This threshold addresses any other factors that may be used by the Emergency Coordinator indetermining whether the Containment Barrier is lost.CNS Basis Reference(s):
- 1. NEI 99-01 Emergency Director Judgment PC Loss 6.ARP/0/AI5000/001 Rev. 1 Page 241 of 247 ATTACHMENT 2Fission Product Barrier Loss/Potential Loss Matrix and BasesBarrier:
Containment
- Category
F. Emergency Coordinator JudgmentDegradation Threat: Potential Loss iThreshold:
- 1. Any condition in the opinion of the Emergency Coordinator that indicates potential lossof the Containment barrierDefinition(s):
NoneBasis:The Emergency Coordinator judgment threshold addresses any other factors relevant todetermining if the Primary Containment barrier is potentially lost. Such a determination shouldinclude imminent barrier degradation, barrier monitoring capability and dominant accidentsequences.
- Imminent barrier deqradation exists if the degradation will likely occur within two hoursbased on a projection of current safety system performance.
The term "imminent" refersto recognition of the inability to reach safety acceptance criteria before completion of allchecks.* Barrier monitoringq capability is decreased if there is a loss or lack of reliable indicators.
This assessment should include instrumentation operability
- concerns, readings fromportable instrumentation and consideration of offsite monitoring results.* Dominant accident sequences lead to degradation of all fission product barriers andlikely entry to the EOPs. The Emergency Coordinator should be mindful of the Loss ofAC power (Station Blackout) and ATWS EALs to assure timely emergency classification declarations.
This threshold addresses any other factors that may be used by the Emergency Coordinator indetermining whether the Containment Barrier is lost.CNS Basis Reference(s):
- 1. NEI 99-01 Emergency Director Judgment PC Potential Loss 6.AIRP/0/A/5000/001 Rev. 1 Page8242 of2471 ATTACHMENT 3Safe Operation
& Shutdown Rooms/Areas Tables R-2 & H-2 BasesBackground NEI 99-01 Revision 6 ICs AA3 and HA5 prescribe declaration of an Alert based on impededaccess to rooms or areas (due to either area radiation levels or hazardous gas concentrations) where equipment necessary for normal plant operations, cooldown or shutdown is located.These areas are intended to be plant operating mode dependent.
Specifically the Developers Notes for AA3 and HA5 states:The "site-specific list of plant rooms or areas with entry-related mode applicability identified" should specify those rooms or areas that contain equipment which require a manual/local action as specified in operating procedures used for normal plant operation, coo/down andshutdown.
Do not include rooms or areas in which actions of a contingent or emergency nature would be performed (e.g., an action to address an off-normal or emergency condition such as emergency
- repairs, corrective measures or emergency operations).
In addition, thelist should specify the plant mode(s) during which entry would be required for each room orarea.The list should not include rooms or areas for which entry is required solely to performactions of an administrative or record keeping nature (e.g., normal rounds or routineinspections).
- Further, as specified in IC HA5:The list need not include the Control Room if adequate engineered safety/design featuresare in place to preclude a Control Room evacuation due to the release of a hazardous gas.Such features may include, but are not limited to, capability to draw air from multiple airintakes at different and separate locations, inner and outer atmospheric boundaries, or thecapability to acquire and maintain positive pressure within the Control Room envelope.
The review at CNS was completed using the following Controlling Procedures:
- OP/i1(2)/A/61 00/003 (Controlling Procedure For Unit Operation)
- OP/I1(2)/A/6100/002 (Controlling Procedure For Unit Shutdown)
SRP/0/A/5000/001 Rev. 1 Page 243 of 247 ATTACHMENT 3Safe Operation
& Shutdown Rooms/Areas Tables R-2 & H-2 BasesCNS Table R-2 and H-2 BasesA review of station operating procedures identified the following mode dependent in-plantactions and associated areas that are required for normal plant operation, cooldown orshutdown:
OPI1/AI6100/003 Coordinate with Chemistry Building (VariousEnclosure 4.3 Step and Radwaste while Locations) f3.19: U2 Encd. 4.3 performing NC System 1No Step 3.20 Degas. Radwastecontinues Degas OPS thru shutdown
& cooldownOP/I /A6100/003, Align heater vent orifices Turbine Building (VariousEnclosure 4.3, Steps per OP/1 (2)/B162501004 Locations)
!:3.26, 3.27 and 3.28; (Feedwater
- Heaters, Vents, N 'U2 Encd. 4.3, Steps Drains and Bleed Systems) 1 No3.28, 3.29 and 3.30 ,Align VI and SP valvesassociated with CFPTsOP/I11AI61001003, Align Auxiliary Steam to Turbine Building (VariousEnclosure 4.2, Step CFPTs. Locations) 1No3.11: U2 Endl. 4.2.Step 3.10OP/I1&21A61001003, Align "C" Htr Drain Turbine Building (568') iEnclosure 4.2, Steps Pump per3.13; U2 Endl. 4.2 OP/1(2)IB/62501004 iStep 3.12 (Feedwater
- Heaters, INoVents, Drains and iBleed Systems) forremoval from service ,OP/i11AI61001003, Plant activities to ensure Turbine Building (594')Enclosure 4.2, Step Main Turbine Sealing Steam 1No i3.14; U2 End. 4.2 system responds asStep 3.13 required.
OP/i1&21I61001003, Ensure Moisture Separator Turbine Building (619')Enclosure 4.2, Step Reheater low load valve i3.18: U2 Endl. 4.2 operation per INoStep 3.17 O P/I(2)/B/6250/013 (Moisture Separator tReheater Operation)
OPI11A/61001003 Secure one Main CFPT per Turbine Building (MainlyEnclosure 4.2 Step OP/i (2)1AN6250/001 594') 1N oi3.19: U2 Endl. 4.2 (Condensate andStep 3.18 Feedwater System)OPIAI61001003, Secure half Main Outside in Main iEnclosure 4.2, Step Transformer Cooling Fans Transformer yard 1No3.20; U2 End. 4.2 and oil pumps-Step 3.19 -!°__ _ _ __ _ _I _ _rP//10001Rv ae24o 4:- 7;: ,-ii7--:
.... :-: ...............
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< '" '<iIJI Rev. 1Page 244 of 247 ATTACHMENT 3Safe Operation
& Shutdown Rooms/Areas Tables R-2 & H-2 BasesOP/1 (2)/A/6100/0 03Enclosure 4.2 Step3.21:Shutdown the Main Turbineper OP/I1(2)/B/6300/001 (Turbine generator)
Turbine Building andTransformer YardNoOP/i1(2)1A!61 00/003, Bypass "F" LP heaters Turbine Building (594" LPEnclosure 4.2, Step Htr Panel). 1No i3.28 &3.29OP/I1(2)/A/6100/003, Transfer of Aux Steam to Service Bldg. (568')Enclosure 4.2, Step on line Unit per3.34 OP/O/B/6250/007 A(Auxiliary Steam System INo !Align ment) or place AuxElectric Boiler in service .per OP/1/B/6250/007 B '(Auxiliary Electric Boilers'li OP/I1(2)/A/61 00/003, Isolate Unit Related Turbine Building.
(594') ,Enclosure 4.2, Step Steam supply to Aux 1No3.37 Steam HeaderOP/i1(2)/A/6100/002, Initiate action to reduce Auxiliary Building (577' fEnclosure 4.1, Step VCT pressure per Mechanical Pent. Room)3.4 OP/I1(2)/6200/001 1, 2, 3 No (Chemical and VolumeControl System)OP/1(2)/A/6100/002, Align S/G reverse purge. Both Doghouses 1 NEnclosure 4.1, Step N "3.9OP/1(2)/A/6100/002, Align CM system flow for Turbine Building (619') 3 NEnclosure 4.1, Step Low Pressure
'cleanupNo
!3.52 thru Upper Surge Tank. 'OP/I1(2)/A/I6100/002 Shutdown Rod Control Auxiliary Building (594'Enclosure 4.2 or 4.7, System per Electrical Pent Room) 3NoStep 3.3 OP/1 (2)/6150/008 (Rod iControl)OP/I1(2)/A/61 00/002 Chemistry obtains Auxiliary Building (543'fEnclosure 4.2 or 4.7 samples to ensure boron Sample Lab) 3NStep 3.10 concentration good to N 'allow NCS cooldown tobeginOP/I1(2)/A/6i00/002 Perform PZR PORVs Auxiliary.
Building (577', IEnclosure 4.2 or 4.7, stroke testing per IF performing IWVRStep 3.22 PT/I1(2)/A/4200/023 A Containment 635' as (NC valve Inservice Test) well) .4IRPIOIAI50001001 Rev. 1I Page 245 of 247 ATTACHMENT 3Safe Operation
& Shutdown Rooms/Areas Tabies R-2 & H-2 BasesOP/1 (2)/A/6100/002 Enclosure 4.2 or 4.7Step 3.23Support placing N2Cover gas on NCDT perOP/Il(2)/A!6500/01 4(Operations Controlled Liquid Waste Systems)Auxiliary Building(Various Locations on577' & 560')3NoOP/I1(2)IAN6100/002, Removing CLAs from Auxiliary Building (577' &Enclosure 4.2 or 4.7 service per 560' Ess. MCC Bkrs) 3 NStep 3.31 OP/I (2)/A/6200/009 N(Cold Leg Accumulator Operation).
OP/i1&2/A/6100/002 Remove CAPT and one Auxiliary Building.
(577' &Enclosure 4.2 or 4.7, Motor Driven CA Pump from 560 Ess MCC Bkrs)Step 3.45.1 service per 4NoOP/I1(2)/A/6250/002 (Auxiliary Feedwater SystemV)
=OP/I1(2)/A/6100/O02 Open NCS Loop Suction Auxiliary.
Building.
(577' Enclosure 4.2 or 4.7, Vlvs for train of ND to be & 560' Ess. MCC Bkrs)Step 3.46.3 placed in service per 4YesOP/i1(2)/A/6200/004 (Residual Heat removal OP/i1(2)/A/61001002 Rack out appropriate NI and Auxiliary Building (577' & !Enclosure 4.2 or 4.7, NV Pump Motor Bkrs per 560 Electrical PentStep 3.48.2 OPIOIA/63501010 (Operation Rooms) 4Yesof Station Breakers and iDisconnects)
OPI1(2)IA/61001002 Support placing first train of Auxiliary Building (577' or~iEnclosure 4.2 or 4.7 ND in service per 560' Ess MCC Bkr s) YeStep 3.52.2 OP/I (2)1N/620010044Ye, (Residual Heat removalSystem) ___________________________
- ]/i, ' ), }IRPIoIA/5000/001 IRev. I Page 246 of 2471 ATTACHMENT 3Safe Operation
& Shutdown Rooms/Areas Tables R-2 & H-2 BasesTable R-2 & H-2 ResultsTable R-2/H-2 Safe Operation & Shutdown Rooms/Areas Bldg. Elevation Unit I RoomlArea Unit 2 RoomlArea ModeRrm 478 (1EMXA) Rm 469 (2EMXA) 4Rm 496 (1ETA) Rm 486 (2ETA) 4Auxiliary 577' Rm 496 (1EMXS) Rm 486 (2EMXS) 4________AB-577', J J-57 (1MXK) AB-577', J J-57 (2MXK) 4Rm 330 (1EMXJ) Rm 320 (2EMXJ) 4Auxiliary 560' Rm 372 (1 ETB) Rm 362 (2ETB) 4Rm 372 (1EMXD) Rm 362 (2EMXD) 4Plant Operating Procedures Reviewed1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.OP/i1(2)/A/6100/003 (Controlling Procedure for Unit Operation) OP/I1(2)/A/6100/002 (Controlling Procedure for Unit Shutdown) OP/I (2)/B/6250/004 (Feedwater
- Heaters, Vents, Drains and Bleed Systems)OP/i1(2)/B/6250/01 3 (Moisture Separator Reheater Operation)
OP/i1(2)/A/6250/001 (Condensate and Feedwater System)OP/i1(2)/B/6300/O001 (Turbine generator) OP/0/B/6250/007 A (Auxiliary Steam System Alignment) OP/I1/B/6250/007 B (Auxiliary Electric Boilers)OP/i1(2)/6200/001 (Chemical and Volume Control System)OP/I (2)/6150/008 (Rod Control)PT/i (2)/A/4200/023 A (NC valve Inservice Test)OP/i1(2)/A/6500/014 (Operations Controlled Liquid Waste Systems)OP/i1(2)/A/6200/009 (Cold Leg Accumulator Operation) OP/i (2)/A/6250/002 (Auxiliary Feedwater System)OP/i1(2)/A/6200/004 (Residual Heat removal System)OP/O/A/6350/01 0 (Operation of Station Breakers and Disconnects) IRP/O/A/5000/O01 Rev. 1 Page 247 of 247}}