ML17258A126
"Draft Meeting" is not in the list (Request, Draft Request, Supplement, Acceptance Review, Meeting, Withholding Request, Withholding Request Acceptance, RAI, Draft RAI, Draft Response to RAI, ...) of allowed values for the "Project stage" property.
| ML17258A126 | |
| Person / Time | |
|---|---|
| Site: | Technical Specifications Task Force |
| Issue date: | 09/12/2017 |
| From: | Technical Specifications Task Force |
| To: | Office of Nuclear Reactor Regulation |
| Honcharik M, 301-415-1774, DSS/STSB | |
| Shared Package | |
| ML17258A124 | List: |
| References | |
| Download: ML17258A126 (96) | |
Text
TECHNICAL SPECIFICATIONS TASK FORCE A JOINT OWNERS GROUP ACTIVIT Y TSTF3
-Aseveral -A inoperability of all trains of a TS required system-A these -A-A-Afollow the guidance in the attachments to this letter. Acti ons related to the inoperability of all trains of a TS required system should not be included in LARs submitted prior to approval of the companion traveler. and incorporating the other changes recommende d in the attachment s to this letter -A in LARs submitted prior to approval of the companion traveler. Attachment 1 also includes -A Attachment 2 contains a list of Actions revised by TSTF-505-A that have conditions on their inclus ion in a plant-specific LAR. Attachment 3 contains a revised Mode Applicatio n for requesting adoption of TSTF-505-A.-A-Afollow the recommendations in the attachments to this letter.
Mirella GavrilasJennifer WhitmanActing Chief of the Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests TSTF-505 Markup to Action 3.3.2.A Reactor Protection System (RPS) Manual Reactor Trip Do not include. Action 3.4.10.A Pressurizer Safety Valves Do not include. Action 3.4.14.C RCS Pressure Isolation Valve (PIV) Leakage Do not include. Action 3.5.1.B CFTs Do not include Action 3.5.3.B ECCS - Shutdown Do not include. Action 3.5.4.B BWST Do not include Action 3.6.3.B Containment Isolation Valves Do not include Action 3.6.3.D Containment Isolation Valves Do not include Action 3.7.4.B AVVs Do not include. Action 3.7.6.A CST Do not include.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests TSTF-505 Markup to Action 3.8.1.E AC Sources - Operating Do not include Action 3.8.4.A.1 DC Sources - Operating Do not include. Required Action outside the scope of TSTF-505.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.3.1.S RTS Instrumentation Do not include Action 3.3.1.V RTS Instrumentation Do not include Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.3.2.V ESFAS Instrumentation Do not include. Required Action outside the scope of TSTF-505. Action 3.4.10.A Pressurizer Safety Valves Do not include. Action 3.4.11.E Pressurizer Power Operated Relief Valves (PORVs) Do not include. Action 3.4.11.F Pressurizer Power Operated Relief Valves (PORVs) Do not include. Action 3.4.14.C RCS Pressure Isolation Valve (PIV) Leakage Do not include. Action 3.5.1.B Accumulators Do not include. Action 3.5.3.B ECCS - Shutdown Do not include. Action 3.5.4.B RWST Do not include. Action 3.5.6.A Boron Injection Tank Do not include. Action 3.6.3.B Containment Isolation Valves Do not include. Action 3.6.3.C Containment Isolation Valves Do not include. Action 3.6.3.D Containment Isolation Valves Do not include. Action 3.6.3.E Containment Isolation Valves Do not include.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.6.9.B Hydrogen Mixing System Do not include. Action 3.6.15.A Ice Bed Do not include. Action 3.6.17.A Divider Barrier Integrity (Ice Condenser) Do not include. Action 3.6.17.B Divider Barrier Integrity (Ice Condenser) Do not include. Action 3.7.6.A Condensate Storage Tank Do not include. Action 3.8.1.E AC Sources - Operating Do not include Action 3.8.4.A.1 DC Sources - Operating Do not include. Required Action outside the scope of TSTF-505.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.3.6.A ESFAS Logic and Manual Trip (Digital) Do not include. Action 3.4.10.A Pressurizer Safety Valves Do not include. Action 3.4.11.E Pressurizer Power Operated Relief Valves (PORVs) Do not include. Action 3.4.11.F Pressurizer Power Operated Relief Valves (PORVs) Do not include. Action 3.4.14.C RCS Pressure Isolation Valve (PIV) Leakage Do not include. Action 3.5.1.B SITs Do not include. Action 3.5.3.A ECCS - Shutdown Do not include. Action 3.5.4.B RWT Do not include. Action 3.6.3.C Containment Isolation Valves Do not include. Action 3.6.3.E Containment Isolation Valves Do not include. Action 3.6.3.F Containment Isolation Valves Do not include. Action 3.6.9.B Hydrogen Mixing System Do not include.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.7.4.B Atmospheric Dump Valves Do not include. Action 3.7.6.A Condensate Storage Tank Do not include. Action 3.8.1.E AC Sources - Operating Do not include. Action 3.8.4.A.1 DC Sources - Operating Do not include. Required Action outside the scope of TSTF-505.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.1.7.C SLC System Do not include. Action 3.3.1.1.C Reactor Protection System (RPS) Instrumentation Do not include. Action 3.3.4.1.B End of Cycle Recirculation Pump Trip (EOC-RPT) Instrumentation Do not include. Action 3.3.4.2.B Anticipated Transient Without Scram Recirculation Pump Trip (ATWS-RPT)
InstrumentationDo not include. Action 3.3.4.2.C Anticipated Transient Without Scram Recirculation Pump Trip (ATWS-RPT) Do not include. Action 3.3.5.2.C Reactor Core Isolation Cooling (RCIC) System Instrumentation Do not include. Action 3.3.6.1.B Primary Containment Isolation Instrumentation Do not include. Action 3.3.6.3.C LLS Instrumentation Do not include. Action 3.6.1.3.B PCIVs Do not include. Required Action outside the scope of TSTF-505. Action 3.6.1.3.C PCIVs Do not include. Required Action outside the scope of TSTF-505. Action 3.6.2.3.B Residual Heat Removal (RHR) Suppression Pool Cooling Do not include. Action 3.6.2.4.B Residual Heat Removal (RHR) Suppression Pool Spray Do not include. Action 3.6.3.3.B Containment Atmosphere Dilution (CAD) System Do not include. Action 3.7.1.D Residual Heat Removal Service Water (RHRSW) System Do not include. Action 3.8.1.E AC Sources - Operating Do not include Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.8.4.A.1 DC Sources - Operating Do not include. Required Action outside the scope of TSTF-505.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.1.7.C SLC System Do not include. Action 3.3.1.1.C Reactor Protection System (RPS) Instrumentation Do not include. Action 3.3.4.1.B End of Cycle Recirculation Pump Trip (EOC-RPT) Instrumentation Do not include. Action 3.3.4.2.B Anticipated Transient Without Scram Recirculation Pump Trip (ATWS-RPT)
InstrumentationDo not include. Action 3.3.4.2.C Anticipated Transient Without Scram Recirculation Pump Trip (ATWS-RPT)
InstrumentationDo not include. Action 3.3.5.2.C Reactor Core Isolation Cooling (RCIC) System Instrumentation Do not include. Action 3.3.6.1.B Primary Containment Isolation Instrumentation Do not include. Action 3.3.6.4.B Suppression Pool Makeup (SPMU) System Instrumentation Do not include. Action 3.3.6.4.C Suppression Pool Makeup (SPMU) System Instrumentation Do not include. Action 3.6.1.3.B Primary Containment Isolation Valves (PCIVs) Do not include. Action 3.6.1.3.C Primary Containment Isolation Valves (PCIVs) Do not include. Action 3.6.1.3.D Primary Containment Isolation Valves (PCIVs) Do not include. Action 3.6.1.7.B Residual Heat Removal (RHR) Containment Spray System Do not include. Action 3.6.2.3.B Residual Heat Removal (RHR) Suppression Pool Cooling Do not include.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests Action 3.6.2.4.A SPMU System Do not include. Action 3.6.2.4.B SPMU System Do not include. Action 3.6.3.1.B Drywell Cooling System Fans Do not include. Action 3.6.3.2.B Drywell Purge System Do not include. Action 3.6.5.1.A Drywell Do not include. Action 3.6.5.3.B Drywell Isolation Valve[s] Do not include. Action 3.6.5.6.D Drywell Vacuum Relief System Do not include. Action 3.6.5.6.E Drywell Vacuum Relief System Do not include. Action 3.8.1.E AC Sources - Operating Do not include Action 3.8.4.A.1 DC Sources - Operating Do not include. Required Action outside the scope of TSTF-505.
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific Amendment Requests change to the , as defined in NEI 06-09-A, Appendix A,
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific Amendment Requests
Recommended Variations from TSTF-505-A in Near-Term Plant-Specific Amendment Requests Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperable See Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS
or both
or modify the Action to
not apply a RICT when
all required trains or
subsystems are
inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperable3.6.2.C LCO: [Two] containment air lock[s] shall be OPERABLE.
Condition:
One or more containment air locks inope rable for reasons other than an inoperable door or inoperable interlock
mechanism.
Licensee must justify that an inoperable containment air lock is not a condition in
which all required
trains or subsystems of
a TS required system
are inoperable. An
acceptable argument
may be that a note in
TS 3.6.2 requires the
condition to be
assessed in accordance
with TS 3.6.1, Containment Integrity, and any loss of function
would require an
immediate plant
shutdown under that
TS.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS
two ormore Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1430, Babcock and Wilcox STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS
The justification can
include that the Actions
require periodic
monitoring of spacial
power distribution and imposition of compensatory limits
and reduced power.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS The licensee must include information regarding how the
TSTF-411 conditions and limitations will be implemented (or similar conditions if
TSTF-411 has not been adopted), including
discussion of ATWS
Mitigation System Actuation (AMSAC),
and why those actions
are sufficient, including
a discussion of defense
in depth.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS or more
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS 3.6.2.C LCO: [Two] containment air lock[s] shall be OPERABLE.
Condition:
One or more containment air locks inope rable for reasons other than an inoperable door or inoperable interlock
mechanism.
Licensee must justify that an inoperable containment air lock is not a condition in
which all required
trains or subsystems of
a TS required system
are inoperable. An
acceptable argument
may be that a note in
TS 3.6.2 requires the
condition to be
assessed in accordance
with TS 3.6.1, Containment Integrity, and any loss of function
would require an
immediate plant
shutdown under that
TS.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS
or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS or more ormore
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1431, Westinghouse STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS more than two
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS or more
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS 3.6.2.C LCO: [Two] containment air lock[s] shall be OPERABLE.
Condition:
One or more containment air locks inope rable for reasons other than an inoperable door or inoperable interlock
mechanism.
Licensee must justify that an inoperable containment air lock is not a condition in
which all required
trains or subsystems of
a TS required system
are inoperable. An
acceptable argument
may be that a note in
TS 3.6.2 requires the
condition to be
assessed in accordance
with TS 3.6.1, Containment Integrity, and any loss of function
would require an
immediate plant
shutdown under that
TS.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS
two ormore Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1432, Combustion Engineering STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperableSee Note 1 at the end of
.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS or more Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS
or more
or modify the Action to
not apply a RICT when
all required trains or
subsystems are
inoperableSee Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS 3.6.1.2.C LCO: The primary containment air lock shall be OPERABLE.
Condition:
Primary containment air lock inoperable for reasons other than Condition A
or B. Licensee must justify that an inoperable
containment air lock is
not a condition in
which all required
trains or subsystems of
a TS required system
are inoperable. An
acceptable argument
may be that a note in
TS 3.6.1.2 requires the
condition to be
assessed in accordance
with TS 3.6.1.1, Primary Containment, and any loss of function
would require an
immediate plant
shutdown under that
TS.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS
oneor more
two or more lines
or modify the Action to not apply a RICT when all
required trains or
subsystems are
inoperable See Note 1 at the end of
.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1433, BWR/4 STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS or more
or modify the Action to not apply a RICT when all
required trains or
subsystems are inoperableSee Note 1 at the end of
.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS or more
or modify the Action to
not apply a RICT when
all required trains or
subsystems are
inoperableSee Note 1 at the end of
.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS or more Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS
or more
or modify the Action to not apply a RICT when
all required trains or
subsystems are
inoperable See Note 1 at the end of .
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS 3.6.1.2.C LCO: The primary containment air lock shall be OPERABLE.
Condition:
Primary containment air lock inoperable for reasons other than Condition A
or B. Licensee must justify that an inoperable
containment air lock is
not a condition in
which all required
trains or subsystems of
a TS required system
are inoperable. An
acceptable argument
may be that a note in
TS 3.6.1.2 requires the
condition to be
assessed in accordance
with TS 3.6.1.1, Primary Containment, and any loss of function would require an immediate plant
shutdown under that
TS.
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests NUREG-1434, BWR/6 STS
Conditional Variations from TSTF-505-A in Near-Term Plant-Specific License Amendment Requests
Note 1 Some Conditions are applicable when an unspecified number of subsystems or instrument channels are inoperable, typically written as "One or more-" or "Two or more-". These conditions currently apply when all subsystems or channels required to be operable to perform a function are inoperable, and application of a RICT in this situation is prohibited in the near-term TSTF-505 submittals.
To address this, it is recommended that the follo wing modification to TSTF-505 be made to the Required Actions indicated in the Attachment 2 t ables for Completion Time s potentially applicable when all required subsystems or channels are inoperable.
The typical Completion Time is m odified by TSTF-505 to state: 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (i.e., the existing Completion Time)
OR In accordance with the Risk Informed
Completion Time
Program It is recommended that the second Completion Time be modified with a Note, as shown below: 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (i.e., the existing Completion Time)
OR -------------NOT E------------- Not applicable when [all/four/both] required channels are inoperable.
In accordance with the Risk Informed
Completion Time
Program The bracketed number of channels will depend on the specification. This approach retains the existing requirements and limits the use of a RICT to conditions in which the function can still be performed. The licensee must justify that the required functio n can still be performed absent an additional failure when a RICT is applied.
Alternatively, the licensee may m odify the Condition to only apply wh en at least one subsystem or channel is operable, but this approach may require creating a new Condition or modifying an existing condition to retain the current requirements, or a ccepting a more restrictive requirement (such a LCO 3.0.3 entry).
REFERENCE:
Letter from the TSTF to U.S. NRC, "Response to NRC Questions on TSTF-505, 'Provide Risk-Informed Extended Completion Times'," dated
DATE
Code of Federal Regulations
, as modified by the [DATE] letter from the TSTF to the NRC (Reference).
March 15, 2012 7715399)**
-ANEI -A
, as modified by the TSTF's [DATE] letter to the NRC, "Response to NRC Questions on TSTF-505, 'Provide Risk-Informed Extended Completion Times'."
, as well as the TSTF's [DATE] letter on TSTF-505
, , as modified by the TSTF letter on TSTF-505
-A
, except as described in the TSTF letter dated [DATE]
TS conditions with insufficient TS operable equipment to meet the specified safety function of the system, ar e not to be included in the application.
List each TS Required Action to which the RICT Program may be applied and, for each Required Action, describe the following:
- The TS Required Action;
- The corresponding SSC;
- Each design basis function of the SSC;
- How each design basis function is modeled in the PRA. If one of the design basis functions of an SSC or the SSC is not modeled in the PRA, describe any proposed surrogates and why the proposed surrogate adequately captures the configuration risk; and
- The success criteria used in the PRA model compared to the licensing basis criteria. The success criteria should include both train-level and component/parameter level.
Note that the above description should be at the level of the TS condition/TS Required Action (not at the LCO level only). If the TS condition
/ TS Required action covers multiple SSCs or multiple design basis functions, such as in the case ESFAS Instrumentation or Containment Sprays, describe each one individually.
The enclosure should also include clear definit ions of any used terms, such as "train," "division," "loop," "subsystem," etc.
The enclosure should provide a detailed system description of TS 3.8, "Electrical Power Systems," Required Actions if the loading scheme is not uniform (e.g., Train A and B have similar loading, except Train B supplies power to additi onal SSCs.) Also, provide a description in Enclosure 12 of representative RMAs for non-uniform trains to demonstrate that the system's safety function is ma intained with either train or subsystem operable.
Licensees are strongly encouraged to apply the guidance in Appendix X, "Close out of Facts and Observations," of NEI 05-04, "Process for Performing Internal Events PRA Peer Reviews Using the ASME/ANS PRA Standard, Rev 3, November 2009," NEI 07-12, "Fire Probabilistic Risk Assessment Peer Review Process Guidelines, Rev 1, June 2010," and NEI 12-13, "External Hazards PRA Peer Review Process Guidelines, Rev 0, August 2012," to close PRA peer review findings , as this will make more efficient use of the NRC and industry resources needed to develop and review of the application.
External hazards screened out from incl usion in RICT calculations should be clearly identified as such, and should be done in a manner consistent with Part 6 of the ASME ANS PRA Standard. The justification should address baseline and configuration-specific considerations.
For external hazards that are not screened out from inclusion in RICT calculations, the licensee may propos e a bounding approach to address the hazard. If the bounding approach involves assuming a uniform increase in
baseline risk to address the hazard, t he licensee will need to address potential RICT-specific impacts by doing one of the following:
- Establish a procedure to evaluate the validity of the bounding approach when calculating an RICT that is not de monstrated to be bounded in the LAR, or
- For RICTs not demonstrated to be bounded in the LAR, establish a procedure to qualitatively evaluate the impact of the specific external hazard for each RICT when calculated and apply risk m anagement actions as appropriate.
- Provide example RMAs for TS 3.8 Required Actions. These should be representative examples, such as a long and short RICTs.
See the Plant Vogtle April 14, 2017 RAI response (ADAMS Accession No. ML17108A253) for an example.
If the TS-required electrical power loading scheme is not uniform (e.g., Train A and B have similar loading, except Train B supplies power to additional SSCs,) provide a description of representative RMAs for non-uniform trains to ensure that the system's safety function is maintained with either train or subsystem inoperable.