ML20248H330
ML20248H330 | |
Person / Time | |
---|---|
Site: | Technical Specifications Task Force |
Issue date: | 09/03/2020 |
From: | Technical Specifications Task Force |
To: | Office of Nuclear Reactor Regulation |
Honcharik, M., NRR/DSS, 301-415-1774 | |
References | |
Download: ML20248H330 (25) | |
Text
TSTF-583-T, Rev. 0 BWROG-143, Rev. 0 NUREGs Affected:
TSTF-582 Diesel Generator Variation Technical Specifications Task Force Improved Standard Technical Specifications Change Traveler 1430 1431 1432 1433 1434 Classification: 1) Technical Change Recommended for CLIIP?: Yes Correction or Improvement:
Correction Note: This "T" Traveler has been reviewed and approved by the Technical Specification Task Force and is made available as a template for plant-specific license amendments. This Traveler has not been reviewed and approved by the Nuclear Regulatory Commission.
NRC Fee Status:
Benefit:
Increases Equipment Operability Changes Marked on ISTS Rev 4.0 2194 PWROG RISD & PA (if applicable): None See attached.
Revision History Affected Technical Specifications OG Revision 0 Revision Status: Active Original Issue Revision
Description:
Revision Proposed by:
Owners Group Review Information Date Originated by OG:
20-Aug-20 Owners Group Comments (No Comments)
Date:
Owners Group Resolution:
TSTF Review Information TSTF Received Date:
20-Aug-20 Date Distributed for Review 20-Aug-20 TSTF Comments:
In response to TSTF commens, SR 3.8.2.1 was revised to list the TS 3.8.1 SRs that are applicable instead of the TS 3.8.1 SRs that are not applicable.
Date: 03-Sep-20 TSTF Resolution:
Approved for Use Appl. 3.3.8.1 LOP Instrumentation Appl. 3.3.8.1 Bases LOP Instrumentation Action 3.3.8.1.B Bases LOP Instrumentation SR 3.3.8.1.4 Bases LOP Instrumentation 03-Sep-20 Copyright(C) 2020, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.
TSTF-583-T, Rev. 0 BWROG-143, Rev. 0 LCO 3.8.2 Bases AC Sources - Shutdown SR 3.8.2.1 AC Sources - Shutdown SR 3.8.2.1 Bases AC Sources - Shutdown 03-Sep-20 Copyright(C) 2020, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.
TSTF-583, Rev. 0 Page 1
- 1.
SUMMARY
DESCRIPTION On August 13, 2020, the NRC approved TSTF-582, Revision 0, "RPV WIC Enhancements."
TSTF-582 revised Technical Specification (TS) 3.8.2, "AC Sources - Shutdown," Surveillance Requirement (SR) 3.8.2.1, to exclude SRs that verify the ability of the diesel generators to automatically start and load on an ECCS initiation signal or loss of offsite power signal.
However, TSTF-582 did not include all of the TS changes needed to reflect that TS 3.8.2 should not require automatic start and loading of a diesel generator within a specified time following on an ECCS initiation signal or a loss of offsite power signal. This proposed change makes additional changes needed to implement the intent of the TSTF-582 change.
- 2. DETAILED DESCRIPTION 2.1.
Current Requirements The proposed change affects the Standard Technical Specifications (STS) in NUREG-1433 and NUREG-14341.
- TS 3.3.8.1, "Loss of Power (LOP) Instrumentation," is applicable in Modes 1, 2, and 3, and when the associated diesel generator is required to be operable by TS 3.8.2.
- TS SR 3.8.2.1 provides a list of TS 3.8.1 SRs that must be met or are excluded while in the Applicability of TS 3.8.2. SR 3.8.2.1 requires SR 3.8.1.7 and SR 3.8.1.15 to be performed and SR 3.8.1.18 to be met.
o TS SR 3.8.1.7 and SR 3.8.1.15 require that the DG starts from standby or hot conditions, respectively, and achieve required voltage and frequency within [12]
seconds. The [12] second start requirement supports the assumptions in the design basis LOCA analysis.
o TS SR 3.8.1.18 states, "[Verify interval between each sequenced load block is within
+/- [10% of design interval] [for each load sequencer timer)). SR 3.8.1.18 is plant-specific, and the wording also varies depending on the plant design.
2.2.
Reason for the Proposed Change TSTF-582, "RPV WIC Enhancements," states that LCO 3.5.2, "RPV WIC," does not assume that the onsite electrical power source will start automatically on an ECCS or loss of power signal. In an oversight in TSTF-582, not all TS 3.8.1 SRs listed in SR 3.8.2.1 that test automatic start and loading of a diesel generator on an ECCS or loss of offsite power signal were excluded and the Applicability of TS 3.3.8.1 was not revised to reflect that the loss of power signal is not required in Modes 4 and 5.
1 NUREG-1433 provides the STS for BWR/4 plant designs, but is also representative of the BWR/2, BWR/3, and, in this case, BWR/5 designs. NUREG-1434 provides the STS for the BWR/6 plant design, and can be representative in some cases of the BWR/5 plant design.
TSTF-583, Rev. 0 Page 2 2.3.
Description of the Proposed Change
- TS 3.3.8.1, "Loss of Power (LOP) Instrumentation," is applicable in Modes 1, 2, and 3, and when the associated diesel generator is required to be operable by TS 3.8.2. The Applicability of LCO 3.3.8.1 is revised to not include the specified condition "When the associated diesel generator is required to be OPERABLE by LCO 3.8.2, 'AC Sources -
Shutdown'."
- TS SR 3.8.2.1 is revised to include SR 3.8.1.7, SR 3.8.1.15, and SR 3.8.1.18 in the list of TS 3.8.1 SRs that are not applicable. As an editorial improvement, SR 3.8.2.1 is revised to list the TS 3.8.1 SRs that are applicable instead of the SRs that are not applicable.
The TS 3.8.2 LCO Bases were not updated to reflect that automatic start and loading of a diesel generator is not required. The LCO 3.8.2 and SR 3.8.2.1 Bases are revised to reflect the TS requirements.
The ECCS injection/spray subsystem required to be operable by LCO 3.5.2 must be capable of being manually started as defense-in-depth against an unexpected draining event. However, LCO 3.5.2 does not assume that the onsite electrical power source will start automatically on an ECCS or loss of power signal.
LCO 3.8.2, "AC Sources - Shutdown," requires one offsite circuit and one diesel generator to be operable in Modes 4 and 5. SR 3.8.2.1 lists the TS 3.8.1, "AC Sources -
Operating," SRs that are applicable in Modes 4 and 5. In an oversight in TSTF-542
["Reactor Pressure Vessel Water Inventory Control"], the TS 3.8.1 SRs that test automatic start and loading of a diesel generator on an ECCS or loss of offsite power signal were not excluded from SR 3.8.2.1.
TSTF-582 revised Technical Specification (TS) 3.8.2, "AC Sources - Shutdown," Surveillance Requirement (SR) 3.8.2.1, to exclude additional SRs that verify the ability of the diesel generators to automatically start and load on an ECCS initiation signal or loss of offsite power signal.
The NRC Safety Evaluation for TSTF-582 (ADAMS Accession No. ML20223A000, dated, August 13, 2020), Section 3.6, "Alternating Current Sources - Shutdown, STS 3.8.2," states:
STS 3.5.2, Reactor Pressure Vessel Water Inventory Control (RPV WIC), does not require automatic ECCS initiation to mitigate a draining event in Modes 4 and 5, and the ECCS initiation signal related to the automatic ECCS initiation is removed from the STS.
Because the automatic ECCS initiation and related ECCS initial signal in Modes 4 and 5 are eliminated, the automatic start of the DG on an ECCS initiation signal is not required in Modes 4 and 5. [T]he NRC staff finds that STS 3.5.2 provides enough time from the onset of the [loss of offsite power] LOOP event for the operator to manually start the DG required to supply power to the water injection equipment to mitigate the draining
TSTF-583, Rev. 0 Page 3 event in Modes 4 and 5. In addition, STS 3.5.2 does not require the automatic initiation of the ECCS injection/spray subsystem or the additional method of water injection.
Therefore, since STS 3.5.2 allows enough time to manually start the DG and the equipment for water injection, the NRC staff finds that the automatic start and loading of the DG are not necessary on a LOOP signal or LOOP concurrent with an ECCS initiation signal to mitigate a draining event in Modes 4 and 5.
Furthermore, the NRC staff notes that other events postulated in Modes 4 and 5 (e.g.,
FHA, waste gas tank rupture) and during movement of [recently] irradiated fuel assemblies in the [primary and secondary containment] do not assume a LOOP event or an automatic ECCS initiation.
TSTF-582 did not include all of the TS changes needed to reflect that TS 3.8.2 does not require automatic start and loading of a diesel generator within [12] seconds on an ECCS initiation signal or a loss of offsite power signal.
- TS 3.3.8.1, "Loss of Power (LOP) Instrumentation," is applicable in Modes 1, 2, and 3, and when the associated diesel generator is required to be operable by TS 3.8.2. TSTF-582 revised TS 3.8.2 to no longer require automatic start and loading of a diesel generator on a loss of offsite power signal. Consequently, the LOP instrumentation that generates the loss of offsite power signal should not be required to be operable when the diesel generator is required to be operable by TS 3.8.2. The Applicability of LCO 3.3.8.1 is revised to not include the specified condition "When the associated diesel generator is required to be OPERABLE by LCO 3.8.2, 'AC Sources - Shutdown'."
- SR 3.8.2.1 requires TS SR 3.8.1.7 and SR 3.8.1.15 to be met. SR 3.8.1.7 and SR 3.8.1.15 require that the DG starts from standby or hot conditions, respectively, and achieves required voltage and frequency within [12] seconds. The [12] second start requirement supports the assumptions in the design basis LOCA analysis. This capability is not required during a manual diesel generator start to respond to a draining event, which has a minimum Drain Time of one hour. Therefore, SR 3.8.2.1 is revised to add SR 3.8.1.7 and SR 3.8.1.15 to the list of TS 3.8.1 SRs that are not applicable.
- SR 3.8.2.1 requires SR 3.8.1.18 to be met but not performed. SR 3.8.1.18 states, "[Verify interval between each sequenced load block is within +/- [10% of design interval] [for each load sequencer timer))." The load sequencer is only used for the automatic start and loading of the diesel generator is not used during a manual diesel generator start. Therefore, SR 3.8.2.1 is revised to add SR 3.8.1.18 to the list of TS 3.8.1 SRs that are not applicable.
- SR 3.8.2.1 lists the TS 3.8.1 SRs that are not applicable to TS 3.8.2. With the proposed change, half of the TS 3.8.1 SRs are not applicable. Therefore, as an editorial improvement, SR 3.8.2.1 is revised to list the TS 3.8.1 SRs that are applicable instead of the TS 3.8.1 SRs that are not applicable. This has no effect on the requirements. The SR 3.8.2.1 Bases continue to explain why certain TS 3.8.1 SRs are omitted from the list.
The TS Bases are revised to reflect the proposed change. The TS 3.3.8.2 Bases are revised to reflect the change in the TS Applicability. The TS 3.8.2 LCO and SR 3.8.2.1 Bases are revised
TSTF-583, Rev. 0 Page 4 to reflect the proposed change and to state that TS 3.8.2 assumes that a required diesel generator is manually started. An editorial correction is made to the NUREG-1434 SR 3.8.2.1 Bases. The phrase, "and to preclude deenergizing a required 4160 V ESF bus or disconnecting a required offsite circuit during performance of SRs" was inserted in the incorrect location during incorporation of an earlier traveler. The Bases are revised to be consistent with the Bases of the other STS NUREGs.
The proposed change provides consistency within the TS after incorporating TSTF-582.
- 4. REGULATORY EVALUATION A regulatory evaluation, regulatory analysis, No Significant Hazards Consideration Analysis, and Environmental Consideration is not required for a "T" traveler.
- 5. REFERENCES None.
TSTF-583, Rev. 0 Technical Specifications and Bases Markup
LOP Instrumentation (Without Setpoint Control Program) 3.3.8.1A General Electric BWR/4 STS 3.3.8.1A-1 Rev. 4.0 3.3 INSTRUMENTATION 3.3.8.1A Loss of Power (LOP) Instrumentation (Without Setpoint Control Program)
LCO 3.3.8.1A The LOP instrumentation for each Function in Table 3.3.8.1-1 shall be OPERABLE.
APPLICABILITY:
MODES 1, 2, and 3, When the associated diesel generator is required to be OPERABLE by LCO 3.8.2, "AC Sources - Shutdown."
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each channel.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or more channels inoperable.
A.1 Place channel in trip.
1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> B. Required Action and associated Completion Time not met.
B.1 Declare associated diesel generator (DG) inoperable.
Immediately TSTF-583, Rev. 0
AC Sources - Shutdown 3.8.2 General Electric BWR/4 STS 3.8.2-3 Rev. 4.0 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B.3 Initiate action to restore required DG to OPERABLE status.
Immediately SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.2.1
NOTES-----------------------------
- 1.
The following SRs are not required to be performed: SR 3.8.1.3, SR 3.8.1.9, through SR 3.8.1.101, SR 3.8.1.143, and through SR 3.8.1.16, [SR 3.8.1.18], and SR 3.8.1.19.
- 2. SR 3.8.1.12 and SR 3.8.1.19 are not required to be met when associated ECCS subsystem(s) are not required to be OPERABLE per LCO 3.5.2, "ECCS-Shutdown."
The following SRs are applicable for For AC sources required to be OPERABLE:
SR 3.8.1.1 SR 3.8.1.6 SR 3.8.1.2 SR 3.8.1.9 SR 3.8.1.3 SR 3.8.1.10 SR 3.8.1.4 SR 3.8.1.14 SR 3.8.1.5 SR 3.8.1.16 the SRs of Specification 3.8.1, except SR 3.8.1.8, SR 3.8.1.17, and SR 3.8.1.20, are applicable.
In accordance with applicable SRs TSTF-583, Rev. 0
LOP Instrumentation (Without Setpoint Control Program)
B 3.3.8.1A General Electric BWR/4 STS B 3.3.8.1A-3 Rev. 4.0 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
The Bus Undervoltage Allowable Values are low enough to prevent inadvertent power supply transfer, but high enough to ensure that power is available to the required equipment. The Time Delay Allowable Values are long enough to provide time for the offsite power supply to recover to normal voltages, but short enough to ensure that power is available to the required equipment.
Two channels of 4.16 kV Emergency Bus Undervoltage (Loss of Voltage)
Function per associated emergency bus are only required to be OPERABLE when the associated DG is required to be OPERABLE to ensure that no single instrument failure can preclude the DG function.
(Two channels input to each of the three DGs.) Refer to LCO 3.8.1, "AC Sources - Operating," and 3.8.2, "AC Sources - Shutdown," for Applicability Bases for the DGs.
- 2. 4.16 kV Emergency Bus Undervoltage (Degraded Voltage)
A reduced voltage condition on a 4.16 kV emergency bus indicates that, while offsite power may not be completely lost to the respective emergency bus, available power may be insufficient for starting large ECCS motors without risking damage to the motors that could disable the ECCS function. Therefore, power supply to the bus is transferred from offsite power to onsite DG power when the voltage on the bus drops below the Degraded Voltage Function Allowable Values (degraded voltage with a time delay). This ensures that adequate power will be available to the required equipment.
The Bus Undervoltage Allowable Values are low enough to prevent inadvertent power supply transfer, but high enough to ensure that sufficient power is available to the required equipment. The Time Delay Allowable Values are long enough to provide time for the offsite power supply to recover to normal voltages, but short enough to ensure that sufficient power is available to the required equipment.
Two channels of 4.16 kV Emergency Bus Undervoltage (Degraded Voltage) Function per associated bus are only required to be OPERABLE when the associated DG is required to be OPERABLE to ensure that no single instrument failure can preclude the DG function. (Two channels input to each of the three emergency buses and DGs.) Refer to LCO 3.8.1 and LCO 3.8.2 for Applicability Bases for the DGs.
TSTF-583, Rev. 0
LOP Instrumentation (Without Setpoint Control Program)
B 3.3.8.1A General Electric BWR/4 STS B 3.3.8.1A-4 Rev. 4.0 BASES ACTIONS A Note has been provided to modify the ACTIONS related to LOP instrumentation channels. Section 1.3, Completion Times, specifies that once a Condition has been entered, subsequent divisions, subsystems, components, or variables expressed in the Condition, discovered to be inoperable or not within limits, will not result in separate entry into the Condition. Section 1.3 also specifies that Required Actions of the Condition continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for inoperable LOP instrumentation channels provide appropriate compensatory measures for separate inoperable channels. As such, a Note has been provided that allows separate Condition entry for each inoperable LOP instrumentation channel.
A.1 With one or more channels of a Function inoperable, the Function is not capable of performing the intended function. Therefore, only 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is allowed to restore the inoperable channel to OPERABLE status. If the inoperable channel cannot be restored to OPERABLE status within the allowable out of service time, the channel must be placed in the tripped condition per Required Action A.1. Placing the inoperable channel in trip would conservatively compensate for the inoperability, restore capability to accommodate a single failure (within the LOP instrumentation), and allow operation to continue. Alternately, if it is not desired to place the channel in trip (e.g., as in the case where placing the channel in trip would result in a DG initiation), Condition B must be entered and its Required Action taken.
The Completion Time is intended to allow the operator time to evaluate and repair any discovered inoperabilities. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is acceptable because it minimizes risk while allowing time for restoration or tripping of channels.
B.1 If any Required Action and associated Completion Time are not met, the associated Function is not capable of performing the intended function.
Therefore, the associated DG(s) is declared inoperable immediately. This requires entry into applicable Conditions and Required Actions of LCO 3.8.1 and LCO 3.8.2, which provides appropriate actions for the inoperable DG(s).
TSTF-583, Rev. 0
LOP Instrumentation (Without Setpoint Control Program)
B 3.3.8.1A General Electric BWR/4 STS B 3.3.8.1A-7 Rev. 4.0 BASES SURVEILLANCE REQUIREMENTS (continued) those established by the setpoint methodology. CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
[ The Frequency is based upon the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
REVIEWERS NOTE-----------------------------------
Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.
]
SR 3.3.8.1.4 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required actuation logic for a specific channel. The system functional testing performed in LCO 3.8.1 and LCO 3.8.2 overlaps this Surveillance to provide complete testing of the assumed safety functions.
[ The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillance when performed at the 18 month Frequency.
OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/4 STS B 3.8.2-2 Rev. 4.0 BASES APPLICABLE SAFETY ANALYSES (continued) maintenance activities must be conducted, provided an acceptable level of risk is not exceeded. During MODES 4 and 5, performance of a significant number of required testing and maintenance activities is also required. In MODES 4 and 5, the activities are generally planned and administratively controlled. Relaxations from typical MODES 1, 2, and 3 LCO requirements are acceptable during shutdown MODES, based on:
- a.
The fact that time in an outage is limited. This is a risk prudent goal as well as a utility economic consideration.
- b.
Requiring appropriate compensatory measures for certain conditions.
These may include administrative controls, reliance on systems that do not necessarily meet typical design requirements applied to systems credited in operation MODE analyses, or both.
- c.
Prudent utility consideration of the risk associated with multiple activities that could affect multiple systems.
- d.
Maintaining, to the extent practical, the ability to perform required functions (even if not meeting MODES 1, 2, and 3 OPERABILITY requirements) with systems assumed to function during an event.
In the event of an accident during shutdown, this LCO ensures the capability of supporting systems necessary for avoiding immediate difficulty, assuming either a loss of all offsite power or a loss of all onsite (diesel generator (DG)) power.
The AC sources satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO One offsite circuit capable of supplying the onsite Class 1E power distribution subsystem(s) of LCO 3.8.10, "Distribution Systems -
Shutdown," ensures that all required loads are powered from offsite power. An OPERABLE DG, associated with a Distribution System Engineered Safety Feature (ESF) bus required OPERABLE by LCO 3.8.10, ensures that a diverse power source is available for providing electrical power support assuming a loss of the offsite circuit.
Together, OPERABILITY of the required offsite circuit and the ability to manually start a DG ensures the availability of sufficient AC sources to operate the plant in a safe manner and to mitigate the consequences of postulated events during shutdown (e.g., fuel handling accidents
[involving handling recently irradiated fuel] ). Automatic initiation of the required DG during shutdown conditions is specified in LCO 3.3.8.1, LOP Instrumentation.
TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/4 STS B 3.8.2-3 Rev. 4.0 BASES LCO (continued)
The qualified offsite circuit(s) must be capable of maintaining rated frequency and voltage while connected to their respective ESF bus(es),
and of accepting required loads during an accident. Qualified offsite circuits are those that are described in the FSAR and are part of the licensing basis for the unit. [The offsite circuit consists of incoming breaker and disconnect to the 2C or 2D startup auxiliary transformer (SAT), associated 2C or 2D SAT, and the respective circuit path including feeder breakers to all 4.16 kV ESF buses required by LCO 3.8.10.]
The required DG must be capable of being manually startedstarting, accelerating to rated speed and voltage, connecting to its respective ESF bus on detection of bus undervoltage, and accepting required loads. This sequence must be accomplished within [12] seconds. Each DG must also be capable of accepting required loads within the assumed loading sequence intervals, and must continue to operate until offsite power can be restored to the ESF buses. These capabilities are required to be met from a variety of initial conditions such as DG in standby with engine hot and DG in standby with engine at ambient conditions. Additional DG capabilities must be demonstrated to meet required Surveillances, e.g.,
capability of the DG to revert to standby status on an ECCS signal while operating in parallel test mode.
Proper sequencing of loads, including tripping of nonessential loads, is a required function for DG OPERABILITY. [In addition, proper sequence operation is an integral part of offsite circuit OPERABILITY since its inoperability impacts the ability to start and maintain energized loads required OPERABLE by LCO 3.8.10.]
It is acceptable for divisions to be cross tied during shutdown conditions, permitting a single offsite power circuit to supply all required divisions. No fast transfer capability is required for offsite circuits to be considered OPERABLE.
APPLICABILITY The AC sources are required to be OPERABLE in MODES 4 and 5 and during movement of [recently] irradiated fuel assemblies in the secondary containment to provide assurance that:
- a.
Systems that provide core cooling are available,
- b.
Systems needed to mitigate a fuel handling accident [involving handling recently irradiated fuel (i.e., fuel that has occupied part of a critical reactor core within the previous [X] days)] are available, TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/4 STS B 3.8.2-5 Rev. 4.0 BASES ACTIONS (continued)
Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition. These actions minimize the probability of the occurrence of postulated events. It is further required to immediately initiate action to restore the required AC sources and to continue this action until restoration is accomplished in order to provide the necessary AC power to the plant safety systems.
The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. The restoration of the required AC electrical power sources should be completed as quickly as possible in order to minimize the time during which the plant safety systems may be without sufficient power.
Pursuant to LCO 3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it are inoperable, resulting in de-energization. Therefore, the Required Actions of Condition A have been modified by a Note to indicate that when Condition A is entered with no AC power to any required ESF bus, ACTIONS for LCO 3.8.10 must be immediately entered. This Note allows Condition A to provide requirements for the loss of the offsite circuit whether or not a division is de-energized. LCO 3.8.10 provides the appropriate restrictions for the situation involving a de-energized division.
SURVEILLANCE SR 3.8.2.1 REQUIREMENTS SR 3.8.2.1 requires the SRs from LCO 3.8.1 that are necessary for ensuring the OPERABILITY of the AC sources in other than MODES 1, 2, and 3. SR 3.8.1.8 is not required to be met since only one offsite circuit is required to be OPERABLE. SR 3.8.1.7, SR 3.8.1.11, SR 3.8.1.12, SR 3.8.1.13, SR 3.8.1.15, [SR 3.8.1.18], and SR 3.8.1.19 are not required to be met because DG start and load within a specified time and response on an offsite power or ECCS initiation signal is not required. SR 3.8.1.17 is not required to be met because the required OPERABLE DG(s) is not required to undergo periods of being synchronized to the offsite circuit. SR 3.8.1.20 is excepted because starting independence is not required with the DG(s) that is not required to be OPERABLE. Refer to the corresponding Bases for LCO 3.8.1 for a discussion of each SR.
This SR is modified by two a Notes which precludes. The reason for Note 1 is to preclude requiring the OPERABLE DG(s) from being paralleled with the offsite power network or otherwise rendered inoperable during the performance of SRs, and to preclude deenergizing a required 4160 V ESF bus or disconnecting a required offsite circuit during performance of SRs. With limited AC sources available, a single event could compromise both the required circuit and the DG. It is the TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/4 STS B 3.8.2-6 Rev. 4.0 BASES SURVEILLANCE REQUIREMENTS (continued) intent that these SRs must still be capable of being met, but actual performance is not required during periods when the DG and offsite circuit is required to be OPERABLE. Note 2 states that SRs 3.8.1.12 and 3.8.1.19 are not required to be met when its associated ECCS subsystem(s) are not required to be OPERABLE. These SRs demonstrate the DG response to an ECCS signal (ether alone or in conjunction with a loss-of-power signal). This is consistent with the ECCS instrumentation requirements that do not require the ECCS signals when the ECCS System is not required to be OPERABLE.
REFERENCES None.
TSTF-583, Rev. 0
LOP Instrumentation (Without Setpoint Control Program) 3.3.8.1A General Electric BWR/6 STS 3.3.8.1A-1 Rev. 4.0 3.3 INSTRUMENTATION 3.3.8.1A Loss of Power (LOP) Instrumentation (Without Setpoint Control Program)
LCO 3.3.8.1A The LOP instrumentation for each Function in Table 3.3.8.1-1 shall be OPERABLE.
APPLICABILITY:
MODES 1, 2, and 3, When the associated diesel generator (DG) is required to be OPERABLE by LCO 3.8.2, "AC Sources - Shutdown."
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each channel.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or more channels inoperable.
A.1 Place channel in trip.
1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> B. Required Action and associated Completion Time not met.
B.1 Declare associated DG inoperable.
Immediately TSTF-583, Rev. 0
AC Sources - Shutdown 3.8.2 General Electric BWR/6 STS 3.8.2-4 Rev. 4.0 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.2.1
NOTES-----------------------------
- 1.
The following SRs are not required to be performed: SR 3.8.1.3, SR 3.8.1.9, through SR 3.8.1.101, SR 3.8.1.14, and 3 through SR 3.8.1.16, [SR 3.8.1.18], and SR 3.8.1.19.
- 2. SR 3.8.1.12 and SR 3.8.1.19 are not required to be met when associated ECCS subsystem(s) are not required to be OPERABLE per LCO 3.5.2, "ECCS-Shutdown."
The following SRs are applicable for For AC sources required to be OPERABLE:
SR 3.8.1.1 SR 3.8.1.6 SR 3.8.1.2 SR 3.8.1.9 SR 3.8.1.3 SR 3.8.1.10 SR 3.8.1.4 SR 3.8.1.14 SR 3.8.1.5 SR 3.8.1.16
, the SRs of Specification 3.8.1, except SR 3.8.1.8, SR 3.8.1.17, and SR 3.8.1.20, are applicable.
In accordance with applicable SRs TSTF-583, Rev. 0
LOP Instrumentation (Without Setpoint Control Program)
B 3.3.8.1A General Electric BWR/6 STS B 3.3.8.1A-3 Rev. 4.0 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
The Bus Undervoltage Allowable Values are low enough to prevent inadvertent power supply transfer, but high enough to ensure power is available to the required equipment. The Time Delay Allowable Values are long enough to provide time for the offsite power supply to recover to normal voltages, but short enough to ensure that power is available to the required equipment.
Four channels of 4.16 kV Emergency Bus Undervoltage (Loss of Voltage)
Function per associated emergency bus are only required to be OPERABLE when the associated DG is required to be OPERABLE to ensure that no single instrument failure can preclude the DG function.
(Four channels input to each of the three DGs.) Refer to LCO 3.8.1, "AC Sources - Operating," and LCO 3.8.2, "AC Sources - Shutdown," for Applicability Bases for the DGs.
1.c, 1.d, 2.c, 2.d, 2.e. 4.16 kV Emergency Bus Undervoltage (Degraded Voltage)
A reduced voltage condition on a 4.16 kV emergency bus indicates that while offsite power may not be completely lost to the respective emergency bus, power may be insufficient for starting large motors without risking damage to the motors that could disable the ECCS function. Therefore, power supply to the bus is transferred from offsite power to onsite DG power when the voltage on the bus drops below the Degraded Voltage Function Allowable Values (degraded voltage with a time delay). This ensures that adequate power will be available to the required equipment.
The Bus Undervoltage Allowable Values are low enough to prevent inadvertent power supply transfer, but high enough to ensure that sufficient power is available to the required equipment. The Time Delay Allowable Values are long enough to provide time for the offsite power supply to recover to normal voltages, but short enough to ensure that sufficient power is available to the required equipment.
Four channels of 4.16 kV Emergency Bus Undervoltage (Degraded Voltage) Function per associated emergency bus are only required to be OPERABLE when the associated DG is required to be OPERABLE to ensure that no single instrument failure can preclude the DG function.
(Four channels input to each of the three DGs.) Refer to LCO 3.8.1 and LCO 3.8.2 for Applicability Bases for the DGs.
TSTF-583, Rev. 0
LOP Instrumentation (Without Setpoint Control Program)
B 3.3.8.1A General Electric BWR/6 STS B 3.3.8.1A-4 Rev. 4.0 BASES ACTIONS A Note has been provided to modify the ACTIONS related to LOP instrumentation channels. Section 1.3, Completion Times, specifies that once a Condition has been entered, subsequent divisions, subsystems, components, or variables expressed in the Condition discovered to be inoperable or not within limits will not result in separate entry into the Condition. Section 1.3 also specifies that Required Actions of the Condition continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for inoperable LOP instrumentation channels provide appropriate compensatory measures for separate inoperable channels. As such, a Note has been provided that allows separate Condition entry for each inoperable LOP instrumentation channel.
A.1 With one or more channels of a Function inoperable, the Function may not be capable of performing the intended function. Therefore, only 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is allowed to restore the inoperable channel to OPERABLE status.
If the inoperable channel cannot be restored to OPERABLE status within the allowable out of service time, the channel must be placed in the tripped condition per Required Action A.1. Placing the inoperable channel in trip would conservatively compensate for the inoperability, restore capability to accommodate a single failure, and allow operation to continue. Alternately, if it is not desired to place the channel in trip (e.g.,
as in the case where placing the channel in trip would result in a DG initiation), Condition B must be entered and its Required Action taken.
The Completion Time is intended to allow the operator time to evaluate and repair any discovered inoperabilities. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is acceptable because it minimizes risk while allowing time for restoration or tripping of channels.
B.1 If any Required Action and associated Completion Time is not met, the associated Function may not be capable of performing the intended function. Therefore, the associated DG(s) are declared inoperable immediately. This requires entry into applicable Conditions and Required Actions of LCO 3.8.1 and LCO 3.8.2, which provides appropriate actions for the inoperable DG(s).
TSTF-583, Rev. 0
LOP Instrumentation (Without Setpoint Control Program)
B 3.3.8.1A General Electric BWR/6 STS B 3.3.8.1A-7 Rev. 4.0 BASES SURVEILLANCE REQUIREMENTS (continued) those established by the setpoint methodology. CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
[ The Frequency is based on the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
REVIEWERS NOTE-----------------------------------
Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.
]
SR 3.3.8.1.4 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required actuation logic for a specific channel. The system functional testing performed in LCO 3.8.1 and LCO 3.8.2 overlaps this Surveillance to provide complete testing of the assumed safety functions.
[ The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillance when performed at the 18 month Frequency.
OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/6 STS B 3.8.2-3 Rev. 4.0 BASES LCO (continued)
Item a., or a circuit required to meet LCO Item c. may be connected, with the second source available for connection. Together, OPERABILITY of the required offsite circuit(s) and the ability to manually start a DG(s) ensures the availability of sufficient AC sources to operate the plant in a safe manner and to mitigate the consequences of postulated events during shutdown (e.g., fuel handling accidents [involving handling recently irradiated fuel]). Automatic initiation of the required DG during shutdown conditions is specified in LCO 3.3.8.1, LOP Instrumentation.
The qualified offsite circuit(s) must be capable of maintaining rated frequency and voltage while connected to their respective ESF bus(es),
and of accepting required loads during an accident. Qualified offsite circuits are those that are described in the FSAR and are part of the licensing basis for the plant. [The offsite circuit consists of incoming breaker and disconnect to the respective service transformers 11 and 21, the 11 and 21 service transformers, the ESF transformers 11 and 21, and the respective circuit path including feeder breakers to all 4.16 kV ESF buses required by LCO 3.8.10.]
The required DG must be capable of being manually startedstarting, accelerating to rated speed and voltage, and connecting to its respective ESF bus on detection of bus undervoltage, and accepting required loads.
This sequence must be accomplished within [10] seconds. Each DG must also be capable of accepting required loads within the assumed loading sequence intervals, and must continue to operate until offsite power can be restored to the ESF buses. These capabilities are required to be met from a variety of initial conditions such as: DG in standby with the engine hot and DG in standby with the engine at ambient conditions.
Additional DG capabilities must be demonstrated to meet required Surveillances, e.g., capability of the DG to revert to standby status on an ECCS signal while operating in parallel test mode.
Proper sequencing of loads, including tripping of nonessential loads, is a required function for DG OPERABILITY. [In addition, proper sequencer operation is an integral part of offsite circuit OPERABILITY since its inoperability impacts on the ability to start and maintain energized loads required OPERABLE by LCO 3.8.10.]
It is acceptable for divisions to be cross tied during shutdown conditions, permitting a single offsite power circuit to supply all required divisions.
[No fast transfer capability is required for offsite circuits to be considered OPERABLE.]
TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/6 STS B 3.8.2-4 Rev. 4.0 BASES LCO (continued)
As described in Applicable Safety Analyses, in the event of an accident during shutdown, the TS are designed to maintain the plant in a condition such that, even with a single failure, the plant will not be in immediate difficulty.
APPLICABILITY The AC sources required to be OPERABLE in MODES 4 and 5 and during movement of [recently] irradiated fuel assemblies in the [primary or secondary] containment provide assurance that:
- a.
Systems that provide core cooling are available,
- b.
Systems needed to mitigate a fuel handling accident [involving handling recently irradiated fuel (i.e., fuel that has occupied part of a critical reactor core within the previous [X] days)] are available,
- c.
Systems necessary to mitigate the effects of events that can lead to core damage during shutdown are available, and
- d.
Instrumentation and control capability is available for monitoring and maintaining the unit in a cold shutdown condition or refueling condition.
The AC power requirements for MODES 1, 2, and 3 are covered in LCO 3.8.1.
ACTIONS LCO 3.0.3 is not applicable while in MODE 4 or 5. However, since irradiated fuel assembly movement can occur in MODE 1, 2, or 3, the ACTIONS have been modified by a Note stating that LCO 3.0.3 is not applicable. If moving irradiated fuel assemblies while in MODE 4 or 5, LCO 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, or 3, the fuel movement is independent of reactor operations. Entering LCO 3.0.3, while in MODE 1, 2, or 3 would require the unit to be shutdown unnecessarily.
A.1 An offsite circuit is considered inoperable if it is not available to one required ESF division. If two or more ESF 4.16 kV buses are required per LCO 3.8.10, division(s) with offsite power available may be capable of supporting sufficient required features to allow continuation of CORE TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/6 STS B 3.8.2-6 Rev. 4.0 BASES ACTIONS (continued)
C.1 When the HPCS is required to be OPERABLE, and the additional required Division 3 AC source is inoperable, the required diversity of AC power sources to the HPCS is not available. Since these sources only affect the HPCS, the HPCS is declared inoperable and the Required Actions of the affected Emergency Core Cooling Systems LCO entered.
In the event all sources of power to Division 3 are lost, Condition A will also be entered and direct that the ACTIONS of LCO 3.8.10 be taken. If only the Division 3 additional required AC source is inoperable, and power is still supplied to HPCS, 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed to restore the additional required AC source to OPERABLE. This is reasonable considering HPCS will still perform its function, absent an additional single failure.
SURVEILLANCE SR 3.8.2.1 REQUIREMENTS SR 3.8.2.1 requires the SRs from LCO 3.8.1 that are necessary for ensuring the OPERABILITY of the AC sources in other than MODES 1, 2, and 3. SR 3.8.1.8 is not required to be met since only one offsite circuit is required to be OPERABLE. SR 3.8.1.7, SR 3.8.1.11, SR 3.8.1.12, SR 3.8.1.13, SR 3.8.1.15, [SR 3.8.1.18], and SR 3.8.1.19 are not required to be met because DG start and load within a specified time and response on an offsite power or ECCS initiation signal is not required. SR 3.8.1.17 is not required to be met because the required OPERABLE DG(s) is not required to undergo periods of being synchronized to the offsite circuit. SR 3.8.1.20 is excepted because starting independence is not required with the DG(s) that is not required to be OPERABLE. Refer to the corresponding Bases for LCO 3.8.1 for a discussion of each SR.
This SR is modified by atwo Notes which precludes. The reason for Note 1 is to preclude requiring the OPERABLE DG(s) from being paralleled with the offsite power network or otherwise rendered inoperable during the performance of SRs, and to preclude deenergizing a required 4160 V ESF bus or disconnecting a required offsite circuit during performance of SRs. With limited AC sources available, a single event could compromise both the required circuit and the DG, and to preclude deenergizing a required 4160 V ESF bus or disconnecting a required offsite circuit during performance of SRs. It is the intent that these SRs must still be capable of being met, but actual performance is not required during periods when the DG and offsite circuit is required to be OPERABLE. Note 2 states that SRs 3.8.1.12 and 3.8.1.19 are not TSTF-583, Rev. 0
AC Sources - Shutdown B 3.8.2 General Electric BWR/6 STS B 3.8.2-7 Rev. 4.0 BASES SURVEILLANCE REQUIREMENTS (continued) required to be met when its associated ECCS subsystem(s) are not required to be OPERABLE. These SRs demonstrate the DG response to an ECCS signal (either alone or in conjunction with a loss-of-power signal). This is consistent with the ECCS instrumentation requirements that do not require the ECCS signals when the ECCS System is not required to be OPERABLE.
REFERENCES None.
TSTF-583, Rev. 0