ML22039A046
| ML22039A046 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 01/18/2022 |
| From: | Susquehanna |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML22039A046 (20) | |
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- MANUAL HARD COPY DISTRIBUTION DOCUMENT TRANSMITTAL 2022-959 USER INFORMATION:
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TO: GERLACH*ROSEY M 01/18/2022 LOCATION: USNRC FROM: NUCLEAR RECORDS DOCUMENT CONTROL CENTER (NUCSA-2)
THE FOLLOWING CHANGES HAVE OCCURRED TO THE HARDCOPY OR ELECTRONIC MANUAL ASSIGNED TO YOU. HARDCOPY USERS MUST ENSURE THE DOCUMENTS PROVIDED MATCH THE INFORMATION ON THIS TRANSMITTAL. WHEN REPLACING THIS MATERIAL IN YOUR HARDCOPY MANUAL, ENSURE THE UPDATE DOCUMENT ID IS THE SAME DOCUMENT ID YOU'RE REMOVING FROM YOUR MANUAL. TOOLS ROM THE HUMAN PERFORMANCE TOOL BAG SHOULD BE UTILIZED TO ELIMINATE THE CHANCE OF
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ATTENTION: "REPLACE" directions do not affect the Table of Contents, Therefore no TOC will be issued with the updated material.
TSB2 - TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL REMOVE MANUAL TABLE OF CONTENTS DATE: 12/21/2021 ADD MANUAL TABLE OF CONTENTS DATE: 01/17/2022 CATEGORY: DOCUMENTS TYPE: TSB2
Uctll . .LO 1 L:.UL:.L:.
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.USERS, ELECTRONICALLY REVIEW THE APPROPRIATE DOCUMENTS AND ACKNOWLEDGE COMPLETE IN YOUR NIMS INBOX .
SSES MANUAL
. Manual Name: TSB2
- Manual
Title:
TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL Table Of Contents Issue Date: 01/17/2022 Procedure Name Rev Issue Date Change ID Change Number TEXT LOES 138 01/03/2019
Title:
LIST OF EFFECTIVE SECTIONS TEXT TOC 25 03/05/2019
Title:
TABLE OF CONTENTS TEXT 2 .1.1 6 03/31/2021
Title:
SAFETY LIMITS (SLS) REACTOR CORE SLS TEXT 2 .1.2 1 TEXT 3.0 TEXT 3 .1.1 TEXT 3 .1.4 5 11/16/2016
Title:
REACTIVITY CONTROL SYSTEMS CONTROL ROD SCRAM TIMES TEXT 3.1.5 2 11/16/2016
Title:
REACTIVITY CONTROL SYSTEMS CONTROL ROD SCRAM ACCUMULATORS TEXT 3 .1. 6 5 03/31/2021
Title:
REACTIVITY CONTROL SYSTEMS ROD PATTERN CONTROL
- Page 1 of 8 Report Date: 01/17/22
SSES MANUAL Manual Name: TSB2
- Manual
Title:
TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL TEXT 3 .1. 7 4 11/16/2016
Title:
REACTIVITY CONTROL SYSTEMS STANDBY LIQUID CONTROL (SLC) SYSTEM TEXT 3 .*1.8 4 11/16/2016
Title:
REACTIVITY CONTROL SYSTEMS SCRAM DISCHARGE VOLUME (SDV) VENT AND DRAIN VALVES TEXT 3.2.1 6 03/31/2021
Title:
POWER DISTRIBUTION LIMITS AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR)
TEXT 3.2.2 5 03/31/2021
Title:
POWER DISTRIBUTION LIMITS MI~IMUM CRITICAL POWER RATIO (MCPR)
TEXT 3.2.3 4 03/31/2021
Title:
POWER DISTRIBUTION LIMITS LINEAR HEAT GENERATION RATE LHGR TEXT 3.3.1.1 6 ll/16/20i6
Title:
INSTRUMENTATION REACTOR PROTECTION SYSTEM (RPS) INSTRUMENTATION TEXT 3 . 3 . 1. 2 4 01/23/2018
Title:
INSTRUMENTATION SOURCE RANGE MONITOR (SRM) INSTRUMENTATION TEXT 3.3.2.1 4 11/16/2016
Title:
INSTRUMENTATION~CONTROL ROD BLOCK INSTRUMENTATION TEXT 3.3.2.2 3 11/16/2016
Title:
INSTRUMENTATION FEEDWATER - MAIN TURBINE HIGH WATER*LEVEL TRIP INSTRUMENTATION TEXT 3.3.3.1 9 11/16/2016
Title:
INSTRUMENTATION POST ACCIDENT MONITORING (PAM) INSTRUMENTATION TEXT 3.3.3.2 2 11/16/2016
Title:
INSTRUMENTATION REMOTE SHUTDOWN SYSTEM TEXT 3.3.4.1 2 11/16/2016
Title:
INSTRUMENTATION END OF CYCLE RECIRCULATION PUMP TRIP (EOC-RPT) INSTRUMENTATION Page 2 of 8 Report Date: 01/17/22
SSES MANUAL Manual Name: TSB2 Manual
Title:
TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL TEXT 3.3.4.2 1 11/16/2016
Title:
INSTRUMENTATION ANTICIPATED TRANSIENT WITHOUT SCRAM RECIRCULATION PUMP TRIP (ATWS-RPT) INSTRUMENTATION TEXT 3.3.5.1 7 *03/05/2019
Title:
INSTRUMENTATION EMERGENCY CORE COOLING SYSTEM (ECCS) INSTRUMENTATION TEXT 3.3.5.2 3 03/18/2021
Title:
REACTOR PRESSURE VESSEL (RPV) WATER INVENTORY CONTROL INSTRUMENTATION TEXT 3.3.5.3 0 03/05/2019
Title:
INSTRUMENTATION REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM INSTRUMENTATION (PREVIOUSLY TEXT 3.3.5.2 REVISION 1)
TEXT 3.3.6.1 9 03/05/2019
Title:
INSTRUMENTATION PRIMARY CONTAINMENT ISOLATION INSTRUMENTATION
- TEXT 3.3.6.2 6 03/05/2019
Title:
INSTRUMENTATION SECONDARY CONTAINMENT ISOLATION INSTRUMENTATION TEXT 3.3.7.1 4 03/05/2019
Title:
INSTFUMENTATION CONTROL ROOM EMERGENCY OUTSIDE AIR SUPPLY (CREOAS) SYSTEM INSTRUMENTATION TEXT 3. 3. 8 .1. 5 03/18/2021
Title:
INSTRUMENTATION LOSS OF POWER (LOP) INSTRUMENTATION TEXT 3.3.8.2 1 11/16/2016
Title:
INSTRUMENTATION REACTOR PROTECTION SYSTEM (RPS) ELECTRIC POWER MONITORING TEXT 3.4.1 6 03/31/2021
Title:
REACTOR COOLANT SYSTEM (RCS) RECIRCULATION LOOPS OPERATING TEXT 3 .. 4. 2 4 11/16/2016
Title:
REACTOR COOLANT SYSTEM (RCS) JET PUMPS TEXT 3.4.3 3 01/13/2012
Title:
REACTOR COOLANT SYSTEM (RCS) SAFETY/RELIEF VALVES (S/RVS)
Page 3 of 8 Report Date: 01/17/22
SSES MANUAL.
Manual Name: TSB2 Manual
Title:
TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL TEXT 3.4.4 1 11/16/2016
Title:
REACTOR COOLANT SYSTEM (RCS) RCS OPERATIONAL LEAKAGE TEXT 3.4.5 3 03/10/2010
Title:
REACTOR COOLANT SYSTEM (RCS) RCS PRESSURE ISOLATION VALVE (PIV) LEAKAGE TEXT 3.4.6 5 11/16/2016
Title:
REACTOR COOLANT SYSTEM (RCS) RCS LEAKAGE DETECTION INSTRUMENTATION TEXT 3.4.7 3 11/16/2016
Title:
REACTOR COOLANT SYSTEM (RCS) RCS SPECIFIC ACTIVITY TEXT 3.4.8 3 11/16/2016
Title:
REACTOR COOLANT SYSTEM (RCS) RESIDUAL HEAT.REMOVAL (RHR) SHUTDOWN COOLING SYSTEM
- HOT SHUTDOWN TEXT 3.4.9 TEXT 3.4.10
- COLD SHUTDOWN 2
6 11/16/2016
Title:
REACTOR COOLANT SYSTEM (RCS) . RESIDUAL HEAT REMOVAL (RHR) SHUTDOWN CO.OLING SYSTEM.
05/14/2019
Title:
REACTOR COOLANT SYSTEM (RCS) RCS PRESSURE AND TEMPERATURE (P/T) LIMITS TEXT 3.4.11 1 11/16/2016
Title:
REACTOR COOLANT SYSTEM (RCS) REACTOR STEAM DOME PRESSURE TEXT 3.5.1 7 03/31/2021 T.itle: EMERGENCY CORE COOLING SYST~MS (ECCS) REACTOR PRESSURE VESSEL (RPV) WATER INVENTORY CONTROL AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM ECCS OPERATING TEXT 3.5.2 6 03/18/2021
Title:
EMERGENCY CORE COOLING SYSTEMS (ECCS) REACTOR PRESSURE VESSEL (RPV) WATER INVENTORY CONTROL AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM ECCS OPERATING TEXT 3.5.3 6 03/05/2019
Title:
EMERGENCY CORE COOLING SYSTEMS (ECCS) REACTOR. PRESSURE VESSEL (RPV) WATER INVENTORY CONTROL AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM ECCS OPERATING Page 4 of 8 Report Date: 01/17/22
SSES MANUAL Manual Name: TSB2 Manual Title_: TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL TEXT 3 . 6 . 1. 1 6 11/16/2016
Title:
PRIMARY CONTAINMENT TEXT 3 . 6 . 1. 2 2 11/16/2016
Title:
CONTAINMENT SYSTEMS PRIMARY CONTAINMENT AIR LOCK TEXT 3 . 6 . 1. 3 19 03/18/2021
Title:
CONTAINMENT SYSTEMS PRIMARY CONTAINMENT ISOLATION VALVES (PCIVS)
TEXT 3.6.1.4 2 11/16/2016
Title:
CONTAINMENT SYSTEMS CONTAINMENT PRESSURE TEXT 3 . 6 . 1. 5 2 11/16/2016
Title:
CONTAINMENT SYSTEMS DRYWELL AIR TEMPERATURE
- TEXT 3 . 6 . 1. 6 1 J,1/16/2016
Title:
CONTAINMENT SYSTEMS SUPPRESSION CHAMBER-TO-DRYWELL VACUUM BREAKERS TEXT 3.6.2.1 3 11/16/2016
Title:
CONTAINMENT SYSTEMS SUPPRESSION POOL AVERAGE TEMPERATURE TEXT 3.6.2.2 . 2 03/05/2019
Title:
CONTAINMENT SYSTEMS SUPPRESSION POOL WATER LEVEL TEXT 3.6.2.3 2 _11/16/2016
Title:
CONTAINMENT SYSTEMS RESIDUAL HEAT REMOVAL (RHR) SUPPRESSION POOL COOLING TEXT 3. 6*. 2. 4 1 11/16/2016
Title:
CONTAINMENT SYSTEMS RESIDUAL .HEAT REMOVAL (RHR) SUPPRESSION POOL SPRAY TEXT 3.6.3.1 2 06/13/2006
Title:
CONTAINMENT SYSTEMS INTENTIONALLY LEFT BLANK TEXT 3.6.3.2 4 08/02/2021
Title:
CONTAINMENT SYSTEMS DRYWELL AIR FLOW SYSTEM Page 5 of 8 Report Date: 01/17/22
SSES MANUAL Manual Name: TSB2 Manual
Title:
TECHNICAL SPECIFICATIONS BASES UNIT. 2 MANUAL TEXT 3.6.3.3 3 09/29/2017
Title:
CONTAINMENT SYSTEMS PRIMARY CONTAINMENT OXYGEN CQNCENTRATION TEXT 3.6.4.1 17 12/16/2020
Title:
CONTAINMENT SYSTEMS SECONDARY CONTAINMENT TEXT 3.6.4.2 14 03/05/2019
Title:
CONTAINMENT SYSTEMS SECONDARY CONTAINMENT ISOLATION VALVES (SCIVS)
TEXT 3.6.4.3 7 03/05/2019
Title:
CONTAINMENT SYSTEMS STANDBY GAS TREATMENT (SGT) SYSTEM TEXT 3.7.1 8 03/03/2020
Title:
PLANT SYSTEMS RESIDUAL HEAT REMOVAL SERVICE WATER (RHRSW) SYSTEM A,ND THE.
TEXT 3.7.2 4 03/03/2020
Title:
PLANT SYSTEMS EMERGENCY SERVICE WATER (ESW) SYSTEM TEXT 3.7.3 4 03/05/2019
Title:
PLANT SYSTEMS CONTROL ROOM EMERGENCY OUTSIDE AIR SUPPLY (CREOAS) SYSTEM TEXT 3.7..4 2 03/05/2019
Title:
PLANT SYSTEMS CONTROL ROOM FLOOR COOLING SYSTEM TEXT 3:7.5 2 11/16/2016.
Title:
PLANT SYSTEMS MAIN CONDENSER OFFGAS TEXT 3.7.6 4 li/16/2016
Title:
PLANT SYSTEMS MAIN TURBINE BYPASS SYSTEM TEXT 3.7.7 2 11/16/2016
Title:
PLANT SYSTEMS SPENT FUEL STORAGE POOL WATER LEVEL TEXT 3.7.8 1 11/16/2016
Title:
MAINE TURBINE PRESSURE REGULATION SYSTEM Page 6 of 8 Report Date: 01/17/22
SSES MANUAL Manual Name: TSB2 Manual
Title:
TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL .
TEXT 3.8.1 16 05/26/2021
Title:
ELECTRICAL POWER SYSTEMS AC SOURCES - OPERATING TEXT 3.8.2 2 03/18/2021
Title:
ELECTRICAL POWER SYSTEMS AC SOURCES - SHUTDOWN TEXT 3.8.3 7 08/07/2019
Title:
ELECTRICAL POWER SYSTEMS DIESEL FUEL OIL LUBE OIL AND STARTING AIR TEXT 3.8.4 4 11/16/2016
Title:
ELECTRICAL POWER SYSTEMS DC SOURCES - OPERATING TEXT 3.8.5 *2 03/05/2019
Title:
. ELECTRICAL POWER SYSTEMS DC SOURCES - SHUTDOWN
- - TEXT 3.8.6 2 11/16/2016
Title:
ELECTRICAL POWER SYSTEMS BATTERY CELL PARAMETERS TEXT .3.8.7 8 01/17/2022
Title:
ELECTRICAL POWER SYSTEMS DISTRIBUTION SYSTEMS - OPERATING TEXT 3.8.8 2 03/05/2019
Title:
ELECTRICAL POWER SYSTEMS DISTRIBUTION SYSTEMS - SHUTDOWN TEXT 3.9.1 1 11/16/2016
Title:
REFUELING OPERATIONS REFUELING EQUIPMENT INTERLOCKS TEXT 3.9.2 2 11/16/2016
- Title: REFUELING OPERATIONS REFUEL POSITION ONE-ROD-OUT INTERLOCK TEXT 3.9.3 1
- 11/16/2016
Title:
REFUELING OPERATIONS CONTROL ROD POSITION TEXT 3.9.4 0 11/18/2002
Title:
REFUELING OPERATIONS CONTROL ROD POSITION INDICATION Page 7 of 8 Report Date: 01/17/22
SSES MANUAL Manual Name:. TSB2 Manual
Title:
TECHNICAL SPECIFICATIONS BASES UNIT 2 MANUAL TEXT 3.9s5 1 11/16/2016
Title:
REFUELING OPERATIONS CONTROL ROD OPERABILITY - REFUELING TEXT 3.9.6 2 11/16/2016
Title:
REFUELING OPERATIO_NS REACTOR PRESSURE VESSEL (RPV) WATER LEVEL TEXT 3.9.7 1 11/16/2016
Title:
REFUELING OPERATIONS RESIDUAL HEAT REMOVAL (RHR) - HIGH WATER LEVEL TEXT 3. 9 .. 8 1 11/16/2016
Title:
REFUELING OPERATIONS RESIDUAL HEAT REMOVAL (RHR) - LOW WATER LEVEL TEXT 3.10.1 2 03/05/2019
Title:
SPECIAL OPERATIONS INSERVICE LEAK AND HYDROSTATIC.TESTING OPERATION TEXT 3.10.2 1 11/16/2016
Title:
SPECIAL OPERATIONS REACTOR MODE SWITCH INTERLOCK TESTING TEXT 3.10.3 1 11/16/2016
Title:
SPECIAL OPERATIONS SINGLE CONTROL ROD WITHDRAWAL - HOT SHUTDOWN TEXT 3.10.4 1 11/16/2016
Title:
SPECIAL OPERATIONS SINGLE CONTROL ROD WITHDRAWAL - COLD SHUTDOWN TEXT 3.10.5 1 11/16/2016
Title:
SPECIAL OPERATIONS SINGLE CONTROL ROD DRIVE (CRD) REMOVAL - REFUELING TEXT 3.10.6 1 11/16/2016
Title:
SPECIAL OPERATIONS MULTIPLE CONTROL ROD WITHDRAWAL - REFUELING TEXT 3.10.7 2 03/31/2021
Title:
SPECIAL OPERATIONS CONTROL ROD TESTING - OPERATING*
TEXT 3.10.8 4 03/31/2021
Title:
SPECIAL OPERATIONS SHUTDOWN MARGIN (SDM) TEST - REFUELING Page 8 of 8 Report Date: 01/17/22
Rev.8 Distribution Systems-Operating B 3.8.7 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.7 Distribution Systems-Operating BASES BACKGROUND The onsite Class 1E AC and DC electrical power distribution system is divided into redundant and independent AC and DC electrical power a
distribution subsystems and DG E electrical power distribution subsystem.
The primary AC distribution system consists of four 4.16 kV Engineered Safeguards System (ESS) buses each having a primary and alternate offsite source of power as well as an onsite diesel generator (DG) source that supports one 4.16 kV ESS bus in each unit. Each 4.16 kV ESS bus is normally supplied by either Startup Transformer (ST) No. 10 or ST No. 20.
ST No. 1O and ST No. 20 each provide the normal source of power to two of the four 4.16 kV ESS buses in each Unit and the alternate source of power to the remaining two 4.16 kV ESS buses in each Unit. If any 4.16 kV ESS bus loses power, an automatic transfer from the normal to the alternate occurs after the normal supply breaker trips. If both offsite sources are unavailable, the onsite emergency DGs supply power to the 4.16 kV ESS buses.
There are two 250 VDC electrical power distribution subsystems; four 125 VDC electrical power distribution subsystems; and, and one 125 VDC DG E electrical power distribution subsystem, all of which support the necessary power for ESF functions.
In addition, some components required by Unit 2 receive power through Unit 1 electrical power distribution subsystems, the Unit 1 AC and DC electrical power distribution subsystems needed to support the required equipment are addressed in Unit 2 LCO 3.8.7.
Required distribution subsystems are listed in LCO 3.8.7, Table 3.8.7-1.
APPLICABLE The initial conditions of Design Basis Accident (OBA) and transient SAFETY analyses in the FSAR, Chapter 6 (Ref. 1) and Chapter 15 (Ref. 2),
ANALYSES assume ESF systems are OPERABLE. The AC and DC electrical power distribution systems are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems so that the fuel, Reactor Coolant System, and containment design limits are not exceeded. These limits are discussed in more detail in the Bases SUSQUEHANNA- UNIT 2 3.8-84
Rev.8 Distribution Systems-Operating B 3.8.7 BASES APPLICABLE for Section 3.2, Power Distribution Limits; Section 3.4, Reactor Coolant SAFETY System (RCS); and Section 3.6 Containment Systems.
ANALYSES' (continued) The OPERABILITY of the AC and DC electrical power distribution subsystems is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the unit. This includes maintaining distribution systems OPERABLE during accident conditions in the event of:
- a. An assumed loss of all offsite power or all onsite AC electrical power; and *
- b. A worst case single failure.
The AC arid DC electrical power distribution system satisfies Criterion 3 of the NRC Policy Statement (Ref. 4).
LCO The required electrical power distribution subsystems listed in Table 3.8.7-1 ensure the availability of AC and DC electrical power for the systems required to *shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (AOO) or a postulated OBA. The AC and DC electrical power c:listribution subsystems are required to be OPERABLE.
Maintaining the AC and DC electrical power distribution subsystems OPERABLE ensures that the redundancy incorporated into the design of ESF is not defeated. Therefore, a single failure within any system or within the electrical power distribution subsystems will not prevent safe shutdown of the reactor.
AC electrical power distribution subsystems require the associated buses and electrical circuits to be energized to their proper voltages.
DC electrical power distribution subsystems require the associated buses to be energized to their proper voltage from either the associated battery or charger. The AC and DC electrical power distribution subsystem is only considered Inoperable when the subsystem is not energized to its proper voltage .
- SUSQUEHANNA- UNIT 2 3.8-85
Rev. 8 Distribution Systems-Operating B 3.8.7 BASES APPLICABILITY The electrical power distribution subsystems are required to be OPERABLE in MODES 1, 2, and 3 to ensure that:
- a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of AOOs or abnormal transients; and
- b. Adequate core cooling is provided, and containment OPERABILITY and other vital functions are maintained in the event of a postulated OBA Electrical power distribution subsystem requirements for MODES 4 and 5 are covered in the Bases for LCO 3.8.8, "Distribution Systems - Shutdown."
ACTIONS A.1 With one or more required Unit 2 AC buses, load centers, motor control centers, or distribution panels inoperable but not resulting in a loss of safety function, or two Unit 1 AC electrical power distribution subsystems on one Division inoperable for performance of Unit 1 SR 3.8.1.19, the remaining AC electrical power distribution subsystems are capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in the remaining power distribution subsystems could result in the minimum required ESF functions not being supported. Therefore, the required AC buses, load centers, motor control centers, and distribution panels must be restored to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
The Condition A worst scenario is one division without AC power (i.e., no offsite power to the division and the associated DG inoperable). In this Condition, the unit is more vulnerable to a complete loss of AC power. It is, therefore, imperative that the unit operators' attention be focused on minimizing the potential for loss of power to the remaining division by
- stabilizing the unit, and on restoring power to the affected division. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> time limit before requiring a unit shutdown in this Condition is acceptable because:
- a. There is a potential for decreased safety if the attention of unit operators is diverted from the evaluations and actions necessary to restore power to the affected division to the actions associated with taking the unit to shutdown within this time limit.
- SUSQUEHANNA - UNIT 2 3.8-86
Rev. 8 Distribution Systems-Operating B 3.8.7 BASES ACTIONS A.1 (continued)
(continued)
- b. The potential for an event in conjunction with a single failure of a redundant component in the division with AC power. (The redundant component is verified OPERABLE in accordance with Specification 5.5.11, "Safety Function Determination Program (SFDP).")
Condition A is modified by a Note that states that Condition A is not applicable to the DG E DC electrical power subsystem. Condition F or G is applicable to an inoperable DG E DC electrical power subsystem.
Required Action A.1 is modified by a Note that requires the applicable Conditions and Required Actions of LCO 3.8.4 "DC Sources - Operating,"
to be entered for DC subsystems made inoperable by inoperable AC electrical power distribution subsystems. This is an exception to LCO 3.0.6 and ensures the proper actions are taken for inoperable DC sources.
lnoperability of a distribution subsystem can result in loss of charging power to batteries and eventual loss of DC power. This Note ensures that the appropriate attention is given to restoring charging power to batteries, if
- necessary, after loss of distribution systems.
B.1 With one or more Unit 2 DC buses inoperable, the remaining DC electrical power distribution subsystems may be capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in one of the remaining DC electrical power distribution subsystems could result in the minimum required ESF functions not being supported. Therefore, the required DC buses must be restored to OPERABLE status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> by powering the bus from the associated battery or charger.
Condition B represents one subsystem or multiple DC Buses without adequate DC power, potentially with both the battery significantly degraded and the associated charger non-functioning. In this situation, the plant is significantly more vulnerable to a loss of minimally required DC power. It is, therefore, imperative that the operator's attention focus on stabilizing the plant, minimizing the potential for loss of power to the remaining divisions, and restoring power to the affected division.
- SUSQUEHANNA - UNIT 2 3.8-87
Rev. 8 Distribution Systems-Operating B 3.8.7 BASES ACTIONS 8.1 (continued)
. (continued)
This 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limit is more conservative than Completion Times allowed for the majority of components that would be without power. Taking exception to LCO 3.0.2 for components without adequate DC power, which would have Required Action Completion Times shorter than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, is acceptable because of:
- a. The potential for decreased safety when requiring a change in plant conditions (i.e., requiring a shutdown) while not allowing stable operations to continue;
- b. The potential for decreased safety when requiring entry into' numerous applicable Conditions and Required Actions for components without DC power, while not providing sufficient time for the operators to perform the necessary evaluations and actions for
. restoring power to the affected division;
- c. The potential for an event in conjunction with a single failure of a
- redundant component.
- The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> Completion Time for DC buses is consistent with Regulatory Guide 1.93 (Ref. 3).
Condition B is modified by a Note that states that Condition B is not applicable to the DG E DC electrical power subsystem. Condition F or G is applicable to an inoperable DG E DC electrical power subsystem.
C.1 With one Unit 1 AC electrical power distribution subsystem that support Unit 2 inoperable, the remaining Unit 1 AC electrical power distribution subsystems are capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming no single failure. However, the overall reliability is reduced because a single failure in the remaining AC electrical power distribution subsystem could result in the minimum required ESF functions .
not being supported. The Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is consistent with the Completion Times associated with LCOs for the Unit 2 and common equipment .potentially affected by loss of a Unit 1 AC electrical power subsystem .
- SUSQUEHANNA - UNIT 2 3.8-88
Rev.8 Distribution Systems-Operating B 3.8.7 BASES ACTIONS C.1 (continued)
(continued)
The Completion Time has been extended to 7 days in order to complete the replacement of Unit 1 480 VESS Load Center Transformers 1X230 and 1X240. This is a temporary extension of the Completion Time. Upon completion of the transformer replacement, this temporary extension is no longer applicable and will expire on June 15, 2024.
D.1 With two required Unit 1 AC buses, load centers, motor control centers, or distribution panels inoperable for the performance of Unit 1 SR 3.8.1.19 but not resulting in a loss of safety function, the remaining AC electrical power distribution subsystems are capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in the remaining power distribution subsystems could result in the minimum required ESF functions not being supported. Therefore, the required AC buses, load centers, motor control centers, and distribution panels must be restored to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> .
E.1 and E.2 If the inoperable distribution subsystem cannot be restored to OPERABLE status within the associated Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and to MODE 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.
Ll If Diesel Generator E is not aligned to the Class 1E distribution system, the only supported safety function is for the ESW system. Therefore, under this condition, if Diesel Generator E DC power distribution subsystem is not OPERABLE, to ensure the OPERABILITY of the ESW system, actions are taken to either restore the power distribution subsystem to OPERABLE status or shutdown Diesel Generator E and close the associated ESW valves. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limit is consistent with the allowed time for other inoperable DC power distribution subsystems and provides sufficient time to evaluate the condition and take the corrective actions.
SUSQUEHANNA - UNIT 2 3.8-89
Rev. 8 Distribution Systems-Operating B 3.8.7 BASES ACTIONS G.1 (continued)
If the Diesel Generator E is aligned to the class 1E distribution system, the loss of Diesel Generator E DC power distribution subsystem will result in the loss of a on-site Class 1E power source. Therefore, under this condition, if Diesel Generator E DC power distribution subsystem is not OPERABLE actions are taken to either restore the power distribution subsystem to OPERABLE status or declare DieserGenerator E inoperable and take Actions of LCO 3.8.1. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limit is consistent with the allowed time for other DC sources and provides sufficient time to evaluate the condition and take the *necessary corrective actions.
H.1 Condition H corresponds to a level of degradation in the electrical distribution system that causes a required safety function to be lost. When
_more than one AC or DC electrical power distribution subsystem is lost, and this results in the loss of a required function, the plant is in a condition outside the accident analysis. Therefore, no additional time is justified for continued operation. LCO 3.0.3 must be entered immediately to commence a controlled shutdown. Entry into Condition G is not required if the loss of safety function is the result of entry into Condition A in combination with the loss of safety functions governed by LCOs other thari LCO 3.8.7. In this case, enter LCO 3.8.7, Condition A, and the Condition for loss of function in the LCO that governs the safety function that is lost.
11 With one or mor~ Unit 1 DC electrical power subsystems inoperable, the remaining DC electrical power distribution subsystems are capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming nq single failure. However, The overall reliability is reduced because a single failure in the remaining DC electrical power distribution subsystem could result in the minimum required ESF functions not being supported. The Completion Time of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> is consistent with the Completion Times associated with a loss of one or more DC distribution subsystems and will allow sufficient time to restore power.
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Rev. 8 Distribution Systems-Operating B 3.8.7 BASES ACTIONS 11 (continued)
(continued)
Completion of Required Action 1.1 causes Unit 1 loads to be powered from a Unit 2 DC electrical power subsystem. Although the corresponding Unit 2 DC electrical power subsystem is evaluated for this condition, this condition is outside the design commitment to maintain DC power separation between units. To minimize the time this condition exists, Required Action 1.2 direct
. power to be restored from the corresponding Unit 1 DC electrical power subsystem, which restores power to the common loads, or requires that the Unit 1 and common loads be declared inoperable.
The Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provides sufficient time to restore power and acknowledges the fact that the condition, although not consistent with all design requirements, maintains all required safety systems available.
Jj_
If Unit 1 and common loads required to support Unit 2 cannot be transferred to corresponding Unit 2 DC electrical power subsystem when Unit 1 DC sources are inoperable; or, cannot be transferred back to a Unit 1 DC source when the Unit 1 DC source becomes OPERABLE,.the
- associated loads may be incapable of performing their intended function and must be declared inoperable immediately.
SURVEILLANCE SR 3.8.7.1 REQUIREMENTS This Surveillance verifies that the AC and DC, electrical power distribution systems are functioning properly, with the correct circuit breaker alignment.
The correct breaker alignment ensures the appropriate independence of the electrical buses are maintained, and the appropriate voltage or indicated power is available to each required bus. This includes a verification that Unit 1 and common 125 VDC loads are aligned to a Unit 1 DC power distribution subsystem. The verification of voltage availability on the buses ensures that the required voltage is readily available for motive as well as control functions for critical system loads connected to these buses. The Surveillance Frequency is controHed under the Surveillance Frequency Control Program .
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Rev. 8 Distribution Systems-Operating B 3.8.7 BASES REFERENCES 1. FSAR, Chapter 6.
- 2. FSAR, Chapter 15.
- 3. Regulatory Guide 1.93, December 1974.
- 4. Final Policy Statement on Technical Specifications Improvements, July 22, 1993 (58 FR 39132) .
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