ML21278A356

Enclosure 3: AP1000 Plant At-Power Internal Events PRA Risk Assessment for Spatial Separation Criteria Nonconformances

ML21278A356
Person / Time
Site:	Vogtle
Issue date:	10/05/2021
From:	Southern Nuclear Operating Co, Westinghouse
To:	Office of Nuclear Reactor Regulation
Shared Package
ML21278A352	List: ML21278A353 ML21278A354 ML21278A355 ML21278A356 ND-21-0843, Enclosure 4: Westinghouse Electric Company - Affidavit for Withholding of Enclosure 5
References
EA-21-109, IR 2021010, ND-21-0843
Download: ML21278A356 (50)

Text

Southern Nuclear Operating Company ND-21-0843 AP1000 Plant At-Power Internal Events PRA Risk Assessment for Spatial Separation Criteria Nonconformances (non-proprietary version)

(This Enclosure consists of 49 pages, not including this cover page)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 1 of 49 Westlnghouse Westinghouse Non-Proprietary Class 3 To:

Anthony Schoedel Licensing Engineering Direct tel:

412-374-2584 e-mail:

detarh 1 @

west i nghouse.com Our ref:

LTR-APlOOO-PRA-21-011-NP Rev. 1 Date:

09/30/2021

Subject:

APIOOO Plant At-Power Internal Events PRA Risk Assessment for Spatial Separation Criteria Nonconformances The purpose of this report is to document the conclusions of the APIOOO plant Vogtle Unit 3 At-Power Internal Events Probabilistic Risk Assessment (PRA) to support an evaluation of the possible risk importance of the apparent nonconformances of IEEE 384 spatial separation criteria (Reference I) on PRA equipment. Appendix A of this report outlines the risk assessment performed and conclusions of this analysis. Note that SNC was a contributor to this report. Comments and clarifications provided by SNC are included in Attachment 11 and 12 (see Section 13).

Author:

Heather Detar Risk Analysis Electronically Approved"^

Reviewer:

Rachel Christian Electronically Approved'^

Risk Analysis Author (Attachment 3 and 4 Only):

Matthew C. Evans Electronically Approyed"^

Electrical Engineering Reviewer (Attachment 3 and 4 Only):

Mark DeMaglio Electronically Approyed*

Electrical Engineering Reviewer:

Michele Reed Risk Analysis Electronically Approved*

Manager:

Stacy A. Davis Risk Analysis Electronically Approved'^

Electronically approved records are authenticated in the electronic document management system.

[1] APIOOO is a trademark or registered trademark of Westinghouse Electric Company LLC, its affiliates and/or subsidiaries in the Unites States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners.

This document may contain technical data subject to the export control laws of the United States. In the event that this document does contain such information, the Recipient's acceptance of this document constitutes agreement that this information in document form (or any other medium), including any attachments and exhibits hereto, shall not be exported, released or disclosed to foreign persons whether in the United States or abroad by recipient except in compliance with all U.S. export control regulations. Recipient shall include this notice with any reproduced or excerpted portion of this document or any document derived from, based on, incorporating, using or relying on the information contained in this document.

©2021 Westinghouse Electric Company LLC All Rights Reserve

• • • This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 2 of 49 Westinghouse Non-Proprietary Class 3 Page 2 of 49 LTR-AP1OOO-PRA-21-011-NP Rev. 1 09/30/2021 Forward This document contains Westinghouse Electric Company LLC proprietary information and data which has been identified by brackets. Coding (a,c,e) associated with the brackets sets forth information which is considered proprietary.

The proprietary information and data contained within the brackets in this report were obtained at considerable Westinghouse expense and its release could seriously affect our competitive position.

This information is to be withheld from public disclosure in accordance with the Rules of Practice 10 CFR 2.390 and the information presented herein is safeguarded in accordance with 10 CFR 2.390. Withholding of this information does not adversely affect the public interest.

This information has been provided for your internal use only and should not be released to persons or organizations outside the Directorate of Regulation and the Advisory Committee on Reactor Safeguards (ACRS) without the express written approval of Westinghouse Electric Company LLC. Should it become necessary to release this information to such persons as part of the review procedure, please contact Westinghouse Electric Company LLC, which will make the necessary arrangements required to protect the Company's proprietary interests.

Several locations in this topical report contain proprietary information. Proprietary information is identified and bracketed. For each of the bracketed locations, the reason for the proprietary classification is provided, using a standardized system. The proprietary brackets are labeled with three (3) different letters, "a", "c", and "e" which stand for:

a. The information reveals the distinguishing aspects of a process or component, structure, tool, method, etc. The prevention of its use by Westinghouse's competitors, without license from Westinghouse, gives Westinghouse a competitive economic advantage,

c. The information, if used by a competitor, would reduce the competitor's expenditure of resources or improve the competitor's advantage in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product,

e. The information reveals aspects of past, present, or future Westinghouse-or customer-funded development plans and programs of potential commercial value to Westinghouse.

The proprietary information in the brackets has been deleted in the non-proprietary version of the report (LTR-APl 000-21-007-NP).

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 3 of 49 Westinghouse Non-Proprietary Class 3 Page 3 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 Appendix A: Risk Assessment for Spatial Separation Criteria Nonconformance 1

BACKGROUND The purpose of this risk assessment is to evaluate the possible risk importance of the non-IE cable nonconformances of IEEE 384 spatial separation criteria (Reference 1) for PRA equipment on the Vogtle API 000 PRA Model in support of an SDP determination.

An extent of condition inspection review for IDS equipment were performed and documented to identify Non-IE cables which have less than the required separation of I inch from Class IE cables. Condition Reports (CRs) have been issued for the following IDS equipment:

250V DC Distribution Panels (Example SV3-IDSB-DS-I) 250V DC MCCs (example SV3-IDSB-DK-I) 20V AC Distribution Panels (example SV3-IDSB-EA-1)

I20V AC Inverter (example SV3-IDSB-DU-1)

Battery Chargers (example SV3-IDSB-DC-1)

Fuse Panels (example SV3-IDSB-EA-4)

Fused Transfer Switch Boxes (example SV3-IDSB-DF-1)

IDS Inverter and Static Switch (example SV3-IDSA-DU-1)

IDS Regulating Transformer (example SV3 -IDSA-DT-1)

In addition to IDS equipment, issues pertaining to the installation of wires and cables in accordance with IEEE 384 have been identified at the Division A and Division C Reactor Trip Switchgear (RTS; PMS-JD-RTSA(C)01 and PMS-JD-RTSA(C)02) and inside the Reactor Coolant Pump Switchgear (RCPS; ECS-ES-31(41,51,61) and ECS-ES-32(42,52,62)).

2 GENERAL APPROACH The difficulty in this risk assessment is that it deals with failures and effects that are not modeled in PRAs and that have significant uncertainties. Therefore, the approach to this risk assessment is to assure that the result obtained is adequately conservative to compensate for these uncertainties without being so conservative that the results are meaningless. As there are various inputs required by the assessment and the extent of information available for each one varies, the approach followed was to be as realistic as possible where adequate information existed, bounding where no information existed, and conservative where some information existed. These are discussed in detail in the various sections of this document, and the approach to each one is summarized briefly below.

Impact of a non-IE (i.e., "source") cable failure on the IE (i.e., "target) circuit system function.

Circuit failure analysis indicates that a number of the IE (i.e., "target") circuits cannot fail in a way that would cause failure of the associated system function.

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 4 of 49 Westinghouse Non-Proprietary Class 3 Page 4 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 o

In general (except as noted in Section 3) no credit is taken for this in the risk assessment even when the impact assessment circuit analysis (Reference 8 or Reference 9) concluded that failure of a non-IE cable nonconformance would not fail the safety related system function. That is, failure of a safety related (i.e. IE) cable induced by failure of a non-IE cable is conservatively assumed to fail the associated IE function in all cases. Overall, this assumption is conservative. See Section 8, Item 8 for more information on this assumption.

The consequential probability that a failure of a non-IE cable will fail the nonconforming IE cable's safety related function is assumed to be I.O. As there is no generic information available to assess this probability, a failed non-IE cable is assumed to also fail the safety related function of its corresponding panel or switchgear (i.e., that do not have adequate separation) with probability 1.0. Overall, this assumption is conservative. See Section 8, Item 9 for more information on this assumption.

Frequency/probability of non-IE cable failure is estimated based on available generic data sources.

The cable failure data that was most applicable is available in a per plant frequency for a given type of circuit. See Section 8, Item 4 for more information on this assumption.

A conditional probability is applied to account for non-1E cable fault occurring in the non-separated section (location of the nonconformance). The conditional probability that a failure will occur in the unseparated section was determined as a fraction of the total cable length. The unseparated length was chosen conservatively, the total length was chosen realistically. See Section 8, Item I for more information on this conservative assumption.

Common cause is addressed for non-IE cable in this risk assessment. Common cause groups are established based on cable type and system. CCF is only applied within a system (intra-system),

not across systems (intersystem). This is consistent with the requirements of the ASME/ANS standard. See Section 8, Item 5 for more information on this assumption.

There are additional DID features that could be credited for manual RCP trip like the plant control system (PLS) and DAS trip by means of the 6.9kV feeder breakers (Section 4.5 of Reference 8) that is currently not credited in the PRA.

Given the discussion above, it can be seen that the overall risk assessment will yield a conservative delta-risk estimate, adequate for an SDP determination. Since all of the above aspects are utilized in each calculation, the effects of each conservatism are cumulative. Therefore, the overall results of this risk assessment are deemed to be conservative.

3 IMPACT ASSMENT ON MITIGATION FUNCTIONS The following is a summary of the deterministic consequence analyses for Non-IE cables which have less than the required separation of 1 inch from Class IE cables on the IDS equipment, Reactor Trip Switchgears, and Reactor Coolant Pump Switchgears.

3.1 Impact Assessment on IDS Mitigation Functions For each IDS panel with a non-1 E cable nonconformance a Condition Report was generated and categorized by the circuit application and design properties. For each circuit application type, electrical faults consistent with IEEE 384 were reviewed for failure consequence on the IDS equipment. The following is a summary This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 5 of49 Westinghouse Non-Proprietary Class 3 Page 5 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 of the consequence analyses and type of circuits identified and analyzed in Reference 9. Note that the circuit type names are consistent with the deterministic report (Reference 9).

3.1.1 Instrumentation Cables The following subsections outline the non-IE cable nonconformance categorized as instrumentation cables.

3.1.1.1 Circuits with Class IE-Supplied Instrumentation Cable Circuits of this type are related to the non-IE Diverse Actuation System (DAS) motor operated valve (MOV) control circuit and the Class IE MCC internal wiring. DAS control circuits are not considered a credible failure mode in the impact assessment since the design and quality pedigree of the circuit design and the materials used in the installation are consistent with the safety-related functions of the MCC.

Furthermore, the isolation components in the circuit, an isolation relay, fuse, and wire, have been designed and tested with the maximum credible fault and adequately demonstrate the robustness of the circuit. All of this type are instrumentation circuits. For more information on the consequence analyses for circuits with class IE-supplied cables refer to Section 4.2 of Reference 9.

Treatment in PRA Assessment:

Regardless of the results of the impact assessment in Reference 9, all nonconforming DAS circuits with class 1E supplied instrumentation cable are retained as a potential failure of the corresponding PRA credited IDS panel's safety related function.

3.1.1.2 Instrument Circuits This group consists of low voltage digital feedback instrumentation circuits. Instrumentation and control circuits have a normal operating voltage of less than or equal to 50 V. Based on the conclusions in Section 4.3.5 of Reference 9 it is anticipated that failures of instrumentation circuits are limited to the non IE cable and are not anticipated to fail its corresponding IDS panel safety related function. For more information on the consequence analyses for instrument circuit cables refer to Section 4.3 of Reference 9.

Treatment in PRA Assessment:

Regardless of the results of the impact assessment in Reference 9, all nonconforming instrument circuits are retained as a potential failure of the corresponding PRA credited IDS panel's safety related function.

3.1.2 Power Cables The following subsections outline the non-IE cable nonconformance categorized as power cables.

3.1.2.1 Regulating Transformer Power Circuits The IDS regulating transformers are provided to I) supply backup AC power to the IE instrument bus normally supplied by the IDS inverter and 2) supply normal IE AC power to selected non-safety loads. For This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 6 of 49 Westinghouse Non-Proprietary Class 3 Page 6 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 more information on the consequence analyses for regulating transformer cables refer to Section 4.4 of Reference 9.

Table 7 of Section 4.4 (Reference 9) outlines the normal regulating transformer non-safety loads and corresponding failure effects. None of the non-safety functions outlined in the table are included in the PRA model as they do not support any mitigation functions or support systems credited in the PRA. A regulating transformer would be aligned to supply backup AC power to the IE instrument bus when a IE IDS inverter is inoperable. This would only be anticipated during testing and maintenance activities on the IE IDS inverter. Based on the expected reliability and unavailability of the inverter, it is anticipated to be a small fraction of time that the regulating transformer would be aligned to the IE instrument bus. This is based on insights from NUREG/CR-6928 where Bus (ac) Test or Maintenance has a 2.15E-04 unavailability, Battery Charger Test or Maintenance has a 2.20E-03 unavailability, and Inverter Fail to Operate has a failure rate of 5.28E-06/hour.

Treatment in PRA Assessment:

Failures of regulating transformers power circuits are not included due to the limited time that the alignment could impact the IDS safety related functions.

3.1.2.2 Battery Charger Power Circuits The battery charger power supply cables operate at 480Vac. The API 000 plant battery charger has been evaluated and tested for consideration of short circuit events outside of the battery charger enclosure. The battery charger power supply cables are not considered credible failure mode in the impact assessment because the operating configuration was tested to the maximum fault conditions and mitigation has been adequately demonstrated using Class IE components. For more information on the consequence analyses for battery charger power cables refer to Section 4.5 of Reference 9.

Treatment in PRA Assessment:

Regardless of the results of the impact assessment in Reference 9, failures of all nonconforming battery charger power supply cables are retained as a potential failure of the corresponding PRA credited IDS battery charger's safety related function.

3.1.2.3 Battery Charger Battery Test Circuits The battery charger battery test are provided to 1) connect the DC to the IDS DC switchboard during normal operation and 2) permit switching the IDS division to the spare battery and removal of the primary battery and charger from service during abnormal alignment. For more information on the consequence analyses for battery charger power cables refer to Section 4.6 of Reference 9.

Similar to the regulating transformer, the expected reliability and unavailability is anticipated to be a small fraction of time that the battery test circuit would be aligned to the 1E instrument bus. This is based on insights from NUREG/CR-6928 where Bus (ac) Test or Maintenance has a 2.15E-04 unavailability. Battery This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 7 of49 Westinghouse Non-Proprietary Class 3 Page 7 of 49 LTR-AP1OOO-PRA-21 -0II -NP Rev. 1 09/30/2021 Charger Test or Maintenance has a 2.20E-03 unavailability, and Battery (do) Fail to Operate has a failure rate of 1.86E-06/hour.

Treatment in PRA Assessment:

Failures of battery charger test circuits are not included due to the limited time that their alignment could impact the IDS safety related functions.

3.2 Impact Assessment on Reactor Trip Switchgear Mitigation Functions The non-IE cable nonconformances for the reactor trip switchgear are limited to the rod drive power supply cables identified in Table 3-1 of Reference 8. The following is a summary of the type of circuits identified and analyzed in Reference 8.

3.2.1 Power Cables 3.2.1.1 Rod Drive Power Supply Circuit Section 3.1 of Reference 8 outlines the power cables non-IE cable nonconformances. Each of these are related to the control rod drive power circuit cables supplied by the Plant Control System (PLS) Rod Drive Motor Generator (MG) sets.

From the perspective of power supply, the postulated faults/failures remove the required AC power from the rod control system to maintain control rods withdrawn from the core. Figure 3-1 provides a simplified diagram of the two reactor trip switchgear cabinets each containing 4 reactor trip breakers/termination units.

A fault in the control rod drive power circuit, will place the plant in a safe condition (control rods enter the core). No impact is anticipated to reduce the reliability of reactor trip within the PRA due to the Reactor Trip Switchgear non-IE cable nonconformances.

This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 8 of49 Westinghouse Non-Proprietary Class 3 Page 8 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 Cables from MG Set Output Bus Duct or Cable Crmnediofl Between C^3fnets Cabinet 1 Bus Duct to trie Rod Drive Cabinets L

J L

)"

)-

1

)<<

1)

=

1

1) 1)"

Cabinet Configuration Cabinet 2 Cables from MG Set Output Breakers.

Bus Duct

_ to the Rod Drive Cabinets One Line Diagram Figure 3-1: PMS Simplified Diagram Sheet 4: RTBs (Reference 17, Figure 1.3-1)

Treatment in PRA Assessment:

Failures of the rod drive power supply cables are not included for impact on the reactor trip mitigation function since anticipated faults do not degrade the reliability of reactor trip. Failures of the rod drive power supply cables are included in the assessment as a potential means to generate a reactor trip.

3.3 Impact Assessment on Reactor Coolant Pump Switchgear Mitigation Function Based on insights from Section 4.1 of Reference 8 the RCP switchgear (ECS-ES-31(41,51,61) and ECS-ES-32(42,52,62)) contains non-Class IE cables that support the following Class IE functions:

Breaker Ready Indication RCPS Local Control Panel Variable Frequency Drive (VFD) Emergency Stop This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 9 of 49 Westinghouse Non-Proprietary Class 3 Page 9 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 The identification of non-1 E cable nonconformances and circuit impact assessment for the RCP switchgears (ECS-ES-31(41,51,61) and ECS-ES-32(42,52,62) was not available for this revision of this report. Based on the non-Class IE functions outlined a postulated non-IE cable nonconformance could include power and/or instrumentation cables. This section should be reviewed and updated if additional information is available for the RCP switchgear non-IE cable nonconformances (See Open Item 2 of Section 10).

Treatment in PRA Assessment:

Regardless of the results of the impact assessment in Reference 8, failures of the nonconforming RCP Switchgear cables are retained as a potential failure of the corresponding PRA credited RCP switchgear safety related function.

Note that the identification of non-IE cable nonconformance and circuit impact assessment review for the RCP switchgears was not available for this revision of this report. In lieu of having cables identified, five (5) independent non-IE cable nonconformances are assumed for each reactor coolant pump switchgear.

Each non-IE cable nonconformance is assumed to be an instrumentation cable (See Open Item 2 of Section 10). Instrumentation cables were selected over power cables based on insights from Section 4.2 This was done to apply the higher failure rate when the exact number and type of cables is currently unknown.

4 RISK ASSESSMENT To assess the possible risk importance of the non-1 E cable nonconformances of IEEE 384 spatial separation criteria a set of model runs were performed against the at-power Vogtle APIOOO PRA internal events model.

The baseline internal events model used to support this risk assessment is attached to the internal events quantification notebook (MOR-SVO-PRA-GSC-322.zip from Reference 2).

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 10 of 49 Westinghouse Non-Proprietary Class 3 Page 10 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 4.1 Cable Failure Independent Basic Events Added Based on insights from the condition reports, inspection reviews, and the deterministic consequence analysis non-IE cables that have less than the required separation of 1 inch from Class IE circuits have been retained for this PRA assessment per Section 3. These were mapped to the associated safety related equipment. The PRA basic events associated with the corresponding safety related equipment were identified, and for each non-IE cable nonconformance a new basic event was added to the model to represent the potential cable failure.

4.1.1 Cable Failure Independent Basic Events Added for IDS Panel Impacts The tables in Appendix B outline this mapping of PRA mitigation equipment to all applicable non-IE cable nonconformances retained for this PRA sensitivity. Table B-1 outlines the non-IE cable nonconformances on the IDS panels. The basic event name and description column information is from the at-power PRA IDS system model (Appendix B of Reference 5). Non-IE cable nonconformance cable identifiers and corresponding type of circuit for the cable is extracted from the deterministic consequence analyses (Reference 9). The last two columns of Table B-1 outline the basic events that were added to the model to account for possible cable failures impacting its corresponding safety related equipment.

In some instances, more than one target SSC has been identified for a single source cable in the deterministic consequence analyses (Reference 9). An example of this is for cable IDS-BUS-FOP-DSl/B with impact on the IDS panel DSB-DS-1. In each of these cases the cable type is the same and a note is added to Table B-1 to clarify.

For each non-IE cable nonconformance a basic event that results in the failure of the associated IDS equipment mitigation function is added into the model to represent an independent cable failure. Note that loss of IDS is identified as an initiating event in the baseline internal events model. A support system initiating event (SSIE) fault tree is used to estimate the initiating event frequency (Section 7.3.2 of Reference 5) for loss of an IDS bus. If a non-IE cable nonconformance is related to an IDS panel that is utilized in the IDS SSIE fault tree an Initiating Event (IE) basic event is added into the model to represent the independent cable failure that could contribute to an initiating event. If a cable failure is addressed in a SSIE fault tree it is identified in the IE Basic Events Added to Model (if applicable) column in Table B-1.

All SSIE basic events names are identified by the suffix "-IE."

Table 4-1 is an extraction of Table B-1 for the IDS 250V DC Distribution Panel IDSA-DS-1 example. In this case distribution panel IDSA-DS-1 has two basic events in the internal events model. IDS-BUS-FOP-DSI/A is used in the mitigation logic and IDS-BUS-FOP-DSI/A-IE is used in the SSIE tree logic for estimating the loss of an IDS bus. The IDS SSIE modeled equipment from the baseline internal events model Table B-1 is limited to the 250V DC distribution panels and battery chargers.

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 11 of 49 WestinghoLise Non-Proprietary Class 3 Page 11 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 Table 4-1: Non-IE Cable Nonconformance Mapping to PRA Equipment For IDSA-DS-1 Component Basic Event IEEE Cable Impacts Basic Events Added For Cable Failure Sensitivity 250V DC Distribution Panels Impacted Non IE Cable Type of Cable Mitigation Basic Events Added to Model IE Basic Events Added to Model (if applicable)

IDSA-DS-1 IDSA-EW-DDIAZN Instrumentation C

A B-IC-FOP-IDS A-E W-DD1AZN C

AB-IC-FOP-IDS A-EW-DD1AZN-IE IDS-BUS-FOP-DSl/A IDSA-EW-DKIAZN Instrumentation C

AB-IC-FOP-IDS A-EW-DK1 AZN CAB-IC-FOP-IDSA-EW-DKl AZN-IE IDS-BUS-FOP-DSl/A-IE IDSA-EW-DSILZN Instrumentation C

AB-IC-FOP-IDSA-EW-DS1LZN C

AB-IC-FOP-IDSA-EW-DS 1LZN-IE IDSA-EW-DSINZN Instrumentation CAB-IC-FOP-IDSA-EW-DSINZN C

AB-IC-FOP-IDSA-EW-DS INZN-IE This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 12 of 49 Westinghouse Non-Proprietary Class 3 Page 12 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 The last two columns of Table B-1 outline the basic events that were added into the model to account for possible cable failures impacts. The basic events are added into the logic at the same level as the identified BEs for its corresponding safety related equipment. Figure 4-1 though Figure 4-4 outline the model updates performed to add in basic event failures for each corresponding non-IE cable nonconformance for IDSA-DS-1. In some cases the mitigation basic event may have more than one (1) parent gate. To ensure the cable impacts are addressed in every location in the model the basic event (example IDS-BUS-FOP-DSl/A) was updated to an OR gate and renamed with a G-designator in front. The inputs to the gate include the original basic event (example IDS-BUS-FOP-DSl/A) and the newly added cable impact BEs. This was done consistently for all impacts outlined in Table B-1.

ICS-^^fWE-OisI iM<W<<.KaE<0i5((>>>

nOETMNSmOUS

-ii-icMfira-ciaJ Bfrmftr POWER ocsmsmotm foSyos^io^

Figure 4-1: IDS-BUS-FOP-DSl/A Logic Before CSkSHtOBILAMiLa 1C/OK CP C&TW DStL>>l T;

o wwnwu cnuieui*

ntnmtMCTuii CUM PUMVOfNDQikEMSmai CJ D

Figure 4-2; IDS-BUS-FOP-DSl/A Logic After moMoepacR ClflLEMnCTBFCR hi o

toftwiiwia Figure 4-3: IDS-BUS-FOP-DSl/A-lE Logic Before ntniAMt CsM OaE D9AOV-C<<M2Nn<<.5 c

ICAB-ICOP CSUW.CDI'ZliiEl liys-CF0P-a)S*.EW-D9ILIN-l Mvntfi i>cs<< Cut*

CMVihC*; UZN rts s

is(un*r40ei)<CaU<<

CMCW-OSrrON FMkS

.E D

D Figure 4-4: IDS-BUS-FOP-DSl/A-lE Logic After

' This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon Its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 13 of 49 Westinghoiise Non-Proprietary Class 3 Page 13 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 The newly added cable basic events are named base on the type code assigned and unique cable identifier (column "Impacted None IE Cable" from Table B-1). Table 4-2 outlines the different circuit types which have been retained for the PRA assessment per Section 3 and their associated type code. The failure rates assigned for each type code are outlined in Section 4.2. Consistent with its associated PRA equipment the failure probability for mitigation basic events is estimated using a 24-hour mission time and the SSIE basic events frequency is estimated using a 1-year mission time.

Table 4-2 : Cable Failure Type Codes Description Type Code Power Cable Fails CAB-PC-FOP Instrumentation Cable Fails CAB-IC-FOP 4.1.2 Cable Failure Independent Basic Events Added for RCP Switchgear Impacts Table B-2 outlines the non-IE cable nonconformances on the RCP switchgears. This supports the mapping of PRA mitigation equipment to all applicable non-IE cable nonconformances retained for this PRA sensitivity. The basic event name and description column information is from the at-power PRA PXS system model (Appendix B of Reference 15). The last two columns of Table B-2 outline the basic events that were added to the model to account for possible cable failures impacting its corresponding safety related equipment. For each non-IE cable nonconformance a mitigation basic event is added into the model to represent an independent cable failure consistent with the guidance outlined in Section 4.1.1 for the IDS panels.

Note that for the RCP switchgears the identification of non-IE cable nonconformances was not available for this revision of this report. In lieu of having cables identified 5 independent non-IE cable nonconformances are assumed for each reactor coolant pump switchgear (See Open Item 2 of Section 10).

4.1.3 Cable Failure Independent Basic Events Added for Reactor Trip Switchgear Impacts To address the control rod drive power non-IE cable nonconformances that impact the reactor trip switchgears, basic events were also added into the model to represent the independent cable failures that could lead to a reactor trip. Table 4-3 below identifies the non-IE cable nonconformance cables from Table 4-1 of Reference 8 for the reactor trip switchgears. Similar to how the mitigation basic events were added into the model IE basic event was added into the model for each of these cable nonconformances. Spurious reactor trip lEs are grouped with the GTRAN with main feedback available IE (%GTRAN-WFW)

(Reference 20).

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 14 of 49 Westinghouse Non-Proprietary Class 3 Page 14 of 49 LTR-AP1000-PRA-2I-01 Rev. 1 09/30/2021 i-NP Table 4-3: Non-IE Cable Nonconformance Mapping to PRA Equipment for the Reactor Trip Switchgears Impacted Non IE Cable Type of Cable IE Basic Events Added to Model PMS-EW-JDRTSAOIAXN Power CAB-PC-FOP-EW-JDRTSAOIAXN-IE PMS-EW-JDRTSAO1BXN Power CAB-PC-FOP-EW-JDRTS AO 1BXN-IE PMS-EW-JDRTSAO1CXN Power CAB-PC-FOP-E W-JDRTS AO 1CXN-IE PMS-EW-JDRTSAO 1DXN Power CAB-PC-FOP-EW-JDRTS AO 1DXN-IE PMS-EW-JDRTSA02EXN Power CAB-PC-FOP-EW-JDRTSA02EXN-1E PMS-EW-JDRTSA02FXN Power CAB-PC-FOP-EW-JDRTSA02FXN-1E PMS-EW-JDRTSA02GXN Power CAB-PC-FOP-EW-JDRTSA02GXN-1E PMS-EW-JDRTSA02HXN Power CAB-PC-FOP-EW-JDRTSA02HXN-IE PMS-EW-EBRCCOIAXN Power CAB-PC-FOP-EW-EBRCCO1AXN-IE PMS-E W-EBRCCO1 BXN Power CAB-PC-FOP-EW-EBRCCO1BXN-IE PMS-EW-EBRCCOICXN Power CAB-PC-FOP-EW-EBRCCO 1 CXN-IE PMS-EW-EBRCCOIDXN Power CAB-PC-FOP-EW-EBRCCO 1DXN-1E PMS-EW-EBRCCOl EXN Power CAB-PC-FOP-EW-EBRCCO 1EXN-IE Figure 4-5 displays the initiating event gate for the GTRAN with feedwater initiating event from the baseline internal events model. Figures 4-6 and 4-7 displays the updated logic with all the non-IE cable nonconformance basic events added into the model for each cable in Table 4-3. The cable impacts were ANDed with an IE trigger basic event. The IE trigger basic event is named %CABLE-WFW and is set to '

a 1/year initiating event frequency.

i GENERAL TRANSIENT WfTK UAM FEEIM'ATER

[GTRAtl-WFWl W

GENERAL TRANSIENT PLANTAWMLABtUTY

'MTH UMN FEEDWAtTEH FACTOR l%Gm'^-v/Fwl

-Q* 4 SSE-01W Figure 4-5: GTRAN with Feedwater Logic Before

• This record was final approved on 9/30/2021 6:07:00 PM. (Tfils statement was added by tfie PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 15 of 49 Westinghoiise Non-Proprietary Class 3 Page 15 of 49 LTR-APlOOO-PRA-21-01 Rev. I 09/30/2021

-NP CABLE lt<<W:TS FOR REACTOR TRIP SWTOOEARS (VOCABLES-IE lSGTR.W-¥^

'Q' 4.5s-<linr CCNERM. mANSIENT VnTH UAJN fEEDWAIER TO CABLE FAaflUES

C4V>S4

aBLE&4El CABLE UPACrS FOR FACTOR TRIP 3WTCHCEARS GENERAL TRANSENT WTTVIUWIJ FEEOWATER 006 TO CABLE FAilHOES lrp5cahI55e1 Figure 4-6: GTRAN with Feed water Logic After Part L

1tf 1 P£jW1g<< CIRCUIT CASl£ PfcHS-SW-JDRTSAa 1AW4

- IE POWER CIROnT CABt^

P*1SeW-J0RTSAa2HXN IE jCA8-PC-FOP-E<V-JORTSA01A>:N-lEl 4 3TE-04 1 CA84>>C-FO>>^ W-JDR T SAOZWWEl 4 31E-04 POWER ciRCurr cable PMS-evwDRTSAOiSACS

- tE POWER CIRCUIT CABLE PWS-EW-E&RCC01 AXN IE (cAaPC.FOF-aiVjDR79Afl tex>i.iel jCAB-PC-FOP-EW-ESRCCO < A>>WEl 4-3IE-04 POViSR CIRCUIT CABLE PMS-EWODRTSAOICXN POy/ER CIRCUIT CABLE PMS-^E^CCaiBXt*

• te jCAB-FC-FOP-EW-JO<<TSAO)CXMtel jCAB-FC-FOP-EWEBRCCOiaXH-IEj C3 PO>>T^ CIRCUIT CAflLf P<<S-E//-JCRTSAaiSXM

-IE POWER CIRCUIT CA8US PM5-eW-^LCC01 CXM

->E

}C*a-POFOP-ElV-Jtw TSAfi 10XW-lg 1 A-3'E-aA jCA8-PC-FOP-EW-8RCC01 CXWCl povffiR ciRCLtrr cable PMS-£W-jCRT5A<<2£Xa<

IE POWER ClflCUTT CABLE PLtS-E 10XN-IE lCAB^PC-HiP-EW-JDRTaAl]2EXH4E j A3!EJ1<<

lCABU>C.FOP-EW.ESnCCB1QXN4E[

4.S1E-0A CIRCUIT CASl£ P>>.^£-<<-JDRTSAaif>.N

-IE POWER CIRCUIT CABLE PMS-EW-ESRCC01EXN

-i jCAS.PC-FCP-EWJIMTSAaZFXrHej ICAfrPC-FOP-EW-EERCCC 1EXN-IE l 4 31S-04

• .31E<4 POVVER GRCUtT CABLE prAS-Evy-4SRTSA02OAn

-IE lCA8-PC-FQP-CW-40RTSA02QXH-lEl

• • 31E-QA Figure 4-7: GTRAN with Feedwater Logic After Part 2 This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 16 of 49 Westinghoiise Non-Proprietary Class 3 Page 16 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 4.2 Review of Available Cable Failure Data A review of available generic data sources including NUREG-2169 (Reference 11), NUREG/CR-5461 (Reference 12), IEEE Std-500(Reference 13), and EGG-SSRE-8875 (Reference 23) was performed and is provided in the subsequent subsections for insight on the likelihood of cable failures. Table 4-4 provides a summary of the conclusions of this review. For more information on the estimated failure rates refer to the corresponding report section provided.

Table 4-4: Cable Failure Data Summary Source Applicability Failure Rate (/hour)

Corresponding Report Section NUREG-2169 Power Cables 1.47E-11 4.2.1 NUREG/CR-5461 All (power, control, and Instrumentation) 1.28E-10 4.2.2 IEEE Std-500 Control Cables 1.20E-09 4.2.3.1 IEEE Std-500 Power Cables 8.90E-10 4.2.3.2 IEEE Std-500 Instrumentation Cables 7.10E-09 4.2.3.3 EGG-SSRE-8875 All (power, control, and Instrumentation) 5.35E-09 4.2.4 Based on these insights the cable failure rates from IEEE Std-500 were used to assess the impact of the non-IE cable nonconformances on the at-power internal event PRA. IEEE Std-500 failure rate data was used since it is specific to the different cable types identified. Table 4-5 outlines the failure rates applied for the different cable type. Note that there were no nonconforming control cables identified for impact on PRA equipment, and so that value is not needed.

Table 4-5: Type Code Failure Rates Description Type Code Failure Rate Failure Probability for Basic Events Power Cable Fails CAB-PC-FOP 8.90E-10/hour 2.14E-08 for mitigation events 7.80E-06 for initiator events Instrumentation Cable Fails CAB-IC-FOP 7.10E-09/hour 1.70E-07 for mitigation events 6.22E-05 for initiator events The failure probability for cable mitigation basic events is estimated using a 24-hour mission time. Support system initiating event cable basic events frequency is estimated using a 1-year mission time (8760 hours0.101 days <br />2.433 hours <br />0.0145 weeks <br />0.00333 months <br />).

All the IDS equipment outlined in Table B-1 is normally operating equipment during power operation. In addition to surveillance testing the IDS major components are monitored on a continuous basis to assess whether the system performance is within the acceptable limits to meet the system design functions (Section This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 17 of 49 Westinghouse Non-Proprietary Class 3 Page 17 of 49 LTR-A?

1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 9.2 of Reference 19). Each division contains identical monitoring and protection instrumentation (Section 7.1 of Reference 19).

Each battery bank, including the spare, has a battery monitor system that detects battery open circuit conditions, monitors battery voltage and detects battery ground. The battery monitor provides trouble alarm locally and in the MGR. This information is provided at a summary level. Battery monitors also allow a remote check of the voltage of each battery cell.

In addition to the IDS monitoring, loss of any IDS bus would be self-revealing during at-power operation since a consequential reactor trip is anticipated. Table 7.2.2.5 of the IE Notebook (Reference 20) outlines the review of each bus and the potential consequential trip (e.g., spurious GMT due to loss of power to solenoid, spurious PRHR due to loss of power to solenoid.) Given the available monitoring and that loss of any single bus is self-revealing the use of a 24-hour mission is appropriate for this application.

The switchgears outlined in Table B-2 includes PRA equipment with failure probabilities estimated based on a per demand failure rate (e.g., breaker failure to open.) The failure probability for cable mitigation basic events is still estimated using a 24-hour mission time since the non-IE cable nonconformance is not performing a demand function. This concern is that the cable could negatively impact the reliability of the switchgears. This is related to assumption 6 of Section 8.

4.2.1 NUREG-2169 Insights NUREG-2169 (Reference 11) provides updated fire ignition frequency estimates to the original analyses developed in NUREG/GR-6850 using the most current Fire Events database. Table 4-4 of this NUREG assigns a mean frequency of 7.02E-04/year for the likelihood of cable run (self-ignited cable fires) at-power (Bin 12 ignition source type). This frequency has a 5* percent frequency of 1.29E-05/year and a 95* percent frequency of 2.21E-03/year.

This is a plant wide frequency considering the impact of all cables throughout the plant. Based on input from WIRED outlined in Section 4.2.5 Vogtle Unit 3 has roughly 247,371 feet of cable throughout the plant. The total length of power cables is estimated at 108,777 feet. To estimate the fraction of the length of cable of concern, the estimated length of non-separated cable is ratioed over the total length of all cables.

It is assumed that the length of non-separated cable is no longer than 20' for each cable nonconformance identified (Assumption 1 of Section 8). For this estimate, the total length of power cables was used since they are more susceptible to self-igniting over instrument or control cables.

Based on this insight the following equation was used to estimate a 1.47E-11 /hour failure rate for one non-separated cable failing. Utilizing an upper end based on the 95* percent and lower 5 percent end estimates failure range this value could range from 4.64E-11/ hour to 2.71E-13/hour, hourly faiure rate of one non separated cable failing

^ ^

/

I year \\ /length of one non separated cable\\

=

(Bin 12 mean frequency) rr

rr

\\8760 hours/ \\

total length of cables at plant

/

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 18 of 49 Westinghouse Non-Proprietary Class 3 Page IS of 49 LTR-AP1OOO-PRA-21-011-NP Rev. 1 09/30/2021 OR 1.47E-Vhour = (7.02E-04/year)f-ll^)f^i:^)

V8760/lours Ai08,777 ft /

4.2.2 NUREG/CR-5461 Insights NUREG/CR-5461 (Reference 12) examines effects of aging on cables, connections, and containment electrical penetration assemblies. Table 5 of NUREG/CR-5461 (Reference 12) summarizes the number of cable failures based on licensee event report (LER) reviews from the mid-1980s to 1988. This data collection includes broader range of cables failures than the scope NUREG/CR-2196 that is limited to self-ignited cable fires. Appendix A NUREG/CR-5461 summarizes LER cable failure events included. This list includes instrumentation cable failures, power cable failures, and control cable failures.

The LER search covers a period of about 8 years, but analysis assumes an average of 5 years coverage to account for down time and for plants that came online during the period. A total of 151 events occurred over this time period. The number of plants in operation during this time period was 70 (Section 5.2 of Reference 12).

Based on input from WIRED outlined in Section 4.2.5 Vogtle Unit 3 has roughly 247,371 feet of cable throughout the plant. To estimate the fraction of the length of cable of concern the estimated length non-separated cable is ratioed over the total length of all cables. It is assumed that the length of non-separated cable is no longer than 20' for each cable nonconformance identified (Assumption 1 of Section 8).

Based on this insight the following equation was used to estimate a 1.28E-10/hour failure rate for one non-separated cable failing.

hourly failure rate of one non separated cable failing 1

\\/

1

^ /length of one non separated cable\\

\\years in time period/ \\# of plants in time period / \\8760 hours) \\ total length of cables at plant

/

OR 3.96E-<<Vhour = (151)( '

)

fJ-)

)

V5yearsA70A8760AoursA247,371ft^

4.2.3 IEEE Std-500 Insights IEEE Standard 500(Reference 13) presents reliability data for use in nuclear power generating station reliability calculations. The tables in Section 9.1 of IEEE Standard 500 outline failure rate data for different cable types. Failure rates provided in this report are in per unit for all that cable type. This data collection This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 19 of 49 Westinghouse Non-Proprietary Class 3 Page 19 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 includes broader range of cables failures than the scope NUREG/CR-2196 that is limited to self-ignited cable fires. This report was reviewed to identify cable failure rate information.

Note that this report includes failure rates in term of per hour and per cycle. Only the per hour failure rates are used in this application. It is noted in Section D.9.5.1 of the IEEE Standard 500(Reference 13) that for cables hours of operation have more meaning than per cycles. The per cycle failure rates are provided in term of per 1000 circuit feet units. For this application, the concern is that non-IE cable nonconformances can have a negative impact on the reliability of its associated IDS panel or safety related switchgear. The IDS panels outlined in Table B-1 are all normally operating equipment during power operation. They also have continuous monitoring available, and loss of any single bus is self-revealing. The use of a 24-hour mission time is appropriate for this application for the IDS panels.

The switchgears outlined in Table B-2 include PRA equipment with failure probabilities estimated based on demand failure rates (e.g., breaker failure to open.) The failure probability for cable mitigation basic events is still estimated using a 24-hour mission time since the non-IE cable nonconformance is not performing a demand function. The concern is that the cable could negatively impact the reliability of the switchgears and is related to assumption 6 of Section 8.

4.2.3.1 Control Cables Subsection 9.1.2 of IEEE Standard 500(Reference 13) provides a recommended rate of 4.79E-06/hr per plant for control cables for all failure modes. A lower end value (10% confidence interval) of 1.32E-06/hr and a high end value (90% confidence interval) of 170E-06/hr is also presented. Note that there are no non-IE cable nonconformances associated with control cables identified. This section is retained for comparison purposes for available cable failure rate data only.

Based on input from WIRED outlined in Section 4.2.5 Vogtle Unit 3 has roughly 79,911 feet of control cable throughout the plant. To estimate the fraction of cable of concern, the estimated length non-separated cable is ratioed over the total length of control cable. It is assumed that the length of non-separated cable is no longer than 20' for each cable nonconformance identified (Assumption 1 of Section 8).

The following equation was used to estimate a 1.20E-09/hour failure rate for one non separated cable failing. Utilizing the upper and lower end estimates failure range this value could range from 3.30E-10/

hour to 4.25E-08/hour.

hourly failure rate of one non separated cable failing

/ length of one non -

separated cable \\

=

(Plant failure rate for control cables) z Vtotal length of control cables at plant /

uotal length of control cables at plant >

OR L.20E-°^/hour = (4.79E-°^//iour) p.)

This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon Its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 20 of 49 Westinghouse Non-Proprietary Class 3 Page 20 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 4.2.3.2 Power Cables Subsection 9.1.1 of IEEE Standard 500(Reference 13) provides a recommended rate of 4.84E-06/hr per plant for power cables for all failure modes. A lower end value (10% confidence interval) of 0.17E-06/hr and a high end value (90% confidence interval) of 175E-06/hr is also presented.

Based on input from WIRED outlined in Section 4.2.5 Vogtle Unit 3 has roughly 108,777 feet of power cable throughout the plant. To estimate the fraction of cable of concern, the estimated length non-separated cable is ratioed over the total length of power cables. It is assumed that the length of non-separated cable is no longer than 20' for each cable nonconformance identified (Assumption 1 of Section 8).

The following equation was used to estimate a 8.90E-10/hour failure rate for one non separated cable failing. Utilizing the upper and lower end estimates failure range this value could range from 3.13E-11/hour to 3.22E-08/hour.

hourly failure rate of one non separated cable failing

^

/length of one non -

separated cablex

=

(Plant failure rate for power cables) I

)

Vtotal length of power cables at plant /

OR 06//,ni/r3 I a08,777 ft 4.2.3.3 Instrumentational Cables 8.90E ^°/hour = (4.84E °^/hour) f,

^ )

Vl08,777fty Subsection 9.1.3 of IEEE Standard 500(Reference 13) provides a recommended rate of 20.83E-06/hr per plant for instrumentation cables for all failure modes. Note that NUREG-2169 (Reference 11) uses the term signal cables. Signal cables transmit information, and this term can be used interchangeable with the term instrumentation cables. A lower end value (10% confidence interval) of 2.00E-06/hr and a high end value (90 % confidence interval) of 200E-06/hr is also presented.

Based on input from WIRED outlined in Section 4.2.5 Vogtle Unit 3 has roughly 58,683 feet of instrumentation cable throughout the plant. To estimate the fraction of cable of concern, the estimated length non-separated cable is ratioed over the total length of instrumentation cables. It is assumed that the length of non-separated cable is no longer than 20' for each cable nonconformance identified (Assumption 1 of Section 8 ).

The following equation was used to estimate a 7.10E-09/hour failure rate for one non separated cable failing. Utilizing the upper and lower end estimates failure range this value could range from 6.82E-08/hour to 6.82E-10/hour.

' This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 21 of 49 Westinghouse Non-Proprietary Class 3 Page 21 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 hourly failure rate of one non separated cable failing roi

4. ^ I

4. r I

x/

length of one non separated cable

\\

=

(Plant failure rate for signal cables)

)

\\total length of instrumentation cables at plant /

OR 7.10E->>Vhour=(20.83E->>VW)(5^)

4.2.4 EGG-SSRE-8875 Insights EGG-SSRE-8875 (Reference 23) is a generic component failure database developed for light water and liquid sodium reactor PRAs. Table 4 of EGG-SSRE-8875 provides a recommended value for failure rates per hour of copper cables, per circuit for all failure modes. From this table, a 1.07E-7 hour per circuit failure rate is provided.

To estimate the fraction of cable of concern, the estimated length of non-separated cable is ratioed over the average length of cables. The failure rate from Reference 23 is in per hour, per circuit units. The average length of cables is used since total circuit lengths is not provided in the WIRED output. This should be conservative for this application since the total circuit length could be longer than an individual cable.

Based on input from WIRED outlined in Section 4.2.5 the average length of each cables is roughly 400 ft long. This was estimated by averaging the sum total of "Estimated Length" column in the "WIRED" tab of the wired_cable_schedule.xlsx attachment (see Section 13.) This value was used to estimate the fraction of cable of concern. It is assumed that the length of non-separated cable is no longer than 20' for each cable nonconformance identified (Assumption 1 of Section 8). The estimated length of non-separated cable is ratioed over the average length of each cable to estimate the fraction of the circuit for a given cable nonconformance.

The following equation was used to estimate a 5.35E-09/hour failure rate for one non separated cable failing.

hourly failure rate of one non separated cable failing

^

/length of one non -

separated cablex

=

{Plant failure rate for cables)

V average lenth of cable

/

OR 5.35E-0Vhour =

(1.07E-°/hour)

\\400 ft /

4.2.5 Vogtle Unit 3 Cables Based on input from WIRED Vogtle Unit 3 has roughly 7,681,406 feet of cable throughout the plant. The wired_cable_schedule.xlsx attachment (see Section 13) includes a copy of the output from WIRED. The plant cable length estimate includes safety related and non-safety related control cables, instrumentation cables, and power cables. The cable schedule list was trimmed to include cable lengths for cables associated with equipment contained in the DRAP and RTNSS programs. This was performed by directly connecting

^ This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 22 of 49 Westinghouse Non-Proprietary Class 3 Page 22 of 49 LTR-A?

1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 to the equipment using the From Equipment and To Equipment columns in the WIRED Cable Schedule with direct matches between the component ID in WIRED and the From Equipment or To Equipment.

Although this process does not select cables without a direct match, this results in a lower total cable length result. This is conservative for this application since it results in a higher cable failure rate for this application. The DRAP and RTNSS equipment list was developed from Table 3 of Reference 18.

In order to use a total population of cable commensurate with the population of failures collected for IEEE Std-500, the DRAP and RTNSS equipment list was used to align closer to the safety related and defense in depth (DID) equipment that cable failures would generate a LER report or event report for a currently operating PWR. The DRAP designation applies to components that represent a significant contribution to the PRA. This includes safety-related and non-safety-related equipment outlined in Table I and Table 2 of Reference 18. The RTNSS designation applies to non-safety systems and components that may have a significant role in accident or consequence mitigation. This includes non-safety-related equipment outlined in Table 3 of Reference 18.

It is assumed that the length of non-separated cable is no longer than 20' for each cable nonconformance identified (Assumption 1 of Section 8). The cable lengths from Table 4-6 were used to estimate the fraction of the cable of concern (control, instrumentation, power or all) documented in the prior sections. The fraction was based on the category which represented the reference data.

Table 4-6: Vogtle Cable Lengths for DRAP and RTNSS Equipment List Type of Cable Length (ft)

Total Control Cables 79,911 Total Instrumentation Cables 58,683 Total Power Cables 108,777 All Cables 247,371 4.3 Common Cause Failure (CCF) Modes For this application no known generic data source is available for common cause factors specifically for cable failures; however, generic common cause data can be applied to provide a bounding assessment of these potential cable failures. Table 4-7 is an extraction from Table 7.3-3 of the Data Notebook (Reference 4). The value in this table is from Table 5.0-1 of WCAP-16672-P (Reference 10). This table shows the recommended generic common cause factors for components with no operating data. For this treatment only the factor for a group size of 2 is shown. For simplification, only one common cause event was used for each type of type code addressed using a beta factor approach.

Table 4-7: Common Cause Factor Value Source 5.04E-02 WCAP-I6672-P, TABLE 5.0-1 (Reference 10) for a group of size of 2 This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 23 of 49 Westinghouse Non-Proprietary Class 3 Page 23 of 49 LTR-APIOOO-PRA-21-011-NP Rev. 1 09/30/2021 The following equation is from NUREG/CR-5485 (Reference 14) Table A-1 for estimating CCF probability for a beta factor method.

Q2 =

The factor used is the CCF factor from Table 4-7. Qt is the total failure probability for the corresponding component. The independent failure probability (typed code

• mission time) is utilized for Qt.

For each type code with a failure rate assigned from Table 4-5 and for each system group a common cause basic event was added to the model at the same level as its corresponding independent failure basic event was added. This was done for all instrument circuit and power circuit cables outlined in Table B-1, Table B-2, and Table 4-3. The system group assigned is IDS for the IDS panels, ECS for the RCP switchgears, and RPS for the reactor trip switchgears. The CAFTA equation field was used to calculate the failure probability of the CCF event to utilize the cable type codes and existing variables for CCF factors within the baseline internal event model. Table 4-8 outlines the common cause basic events added into the model.

Table 4-8: CCF Basic Events Basic Event Name Description Equation Probability CCFM-IDS-CAB-IC-FOP Common Cause of all IDS Instrument Circuit Cables

'CAB-IC-FOP'*'@MT'*5.04E-02 8.59E-09 CCFM-IDS-CAB-IC-FOP-IE Common Cause of all IDS Instrument Circuit Cables -

IE

'CAB-IC-FOP'*'@MT 1 Y'*5.04E-02 3.13E-06 CCFM-ECS-CAB-IC-FOP Common Cause of all ECS Instrument Circuit Cables

'CAB-IC-FOP*'@MT'*5.04E-02 8.59E-09 CCFM-IDS-CAB-PC-FOP Common Cause of all IDS Power Circuit Cable Fails

'CAB-PC-FOP*'@MT'*5.04E-02 1.08E-09 CCFM-IDS-CAB-PC-FOP-IE Common Cause of all IDS Power Circuit Cable Fails -

IE

'CAB-PC-FOP*'@MT1Y'*5.04E-02 3.93E-07 CCFM-RPS-CAB-PC-FOP-IE Common Cause of all RPS Power Circuit Cable Fails -

IE

• CAB-PC-FOP*'@MT1Y'*5.04E-02 3.93E-07 Figure 4-8 provides an example of updated logic for the mitigation cable basic events for IDSA-DS-1 with the common cause factor for instrument circuit cables added (CCFM-IDS-CAB-IC-FOP). The same modification was made to add in the "-IE" common cause BE to the logic for the SSIE cable BEs. Note the only difference between the SSIE CCF event and the mitigation CCF event is the mission time applied to calculate the probability (1 year vs. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />).

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U, S. Nuclear Regulatory Ccmmission ND-21-0843 Enclosure 3 Page 24 of 49 WestinghoLise Non-Proprietary Class 3 Page 24 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 iCAB^C^OP-lCm^W-ODlAZhii 1 70E-07 lC.a&4C-f0P-a^SA-£W-03tNa>ll 1.rOE-07 Instrument Circuit Cable ID3A-eW-DK1AZN FAILS fCAB-lC-FOP-IDSA-EW-DSILZNl 170E-07 Figure 4-8: IDS-BUS-FOP-DSl/A Updated Logic with CCF 4.3.1 CCF Insights While there is no definitive statement to this effect in any document, all indications from the available references is that CCF of cables is not credible. The following excerpt is from NUREG/CR-5485 (Reference 14 Section 1.2.)

"CCFs result from the coexistence of two main factors: a susceptibility for components to fail or become unavailable due to a particular root cause of failure, and a coupling factor (or coupling mechanism) that creates the condition for multiple components to be affected by the same cause."

Furthermore, in Section 4.3 of NUREG/CR-6268 (Reference 26) includes one other important part of a common cause definition by excluding a specific condition. That is, "The equipment failures are not caused by the failure of equipment outside the established component boundary, such as cooling water or AC power. These failures are dependent but are not CCF events." Application of these directions precludes the failure of supporting equipment that can cause the failure of multiple components or trains, e.g., IE DC or AC power.

This record was final approved on 9/30/2021 6:07:00 PM, (This statement was added by the PRiME system upon its vaiidation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 25 of 49 Westinghouse Non-Proprietary Class 3 Page 25 of 49 LTR-A?

1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 As a contrast to noncredible CCF, here is an example, from Section 1.2 of NUREG/CR-5485 Reference 14, of the identification of a credible identification of CCF:

"An example is the case where two relief valves fail to open at the required pressure due to set points being set too high, as a result of an incorrect procedure. Each of these two valves fail to fulfill their safety function due to an incorrect setpoint. What makes the two valves fail together, however, is a common calibration procedure, and perhaps a contributor is common maintenance personnel. These commonalities are the coupling factors of the failure event in this case. It is obvious that each component fails because of its susceptibility to the conditions created by the root cause, and the role of the coupling factor is to make those conditions common to several components."

In this example there is a clear root cause, the incorrect procedure, and a clear coupling mechanism, namely being susceptible to an incorrect calibration.

At Vogtle common cause between the cables is not credible. This is because while the incorrect spacing may serve as either the root cause, or the coupling mechanism, the other feature required for common cause is absent from U.S. plant experience. Each situation will be discussed in the context of U.S. nuclear operating history for equipment cables.

In the case at Vogtle the notable condition as the root cause is the lack of spatial separation between the cables. This condition was determined from NRC inspection. However, the existence of this root cause does not make a common cause event or create a condition for which a common cause event can occur. This is because there is no coupling mechanism between the different cables in the system that do not already exist for two different cables spaced at a conforming distance. Therefore, the incorrect spatial separation as the root cause does not create a unique vulnerability not already experienced by cabling that is correctly spaced.

Conversely, if the lack of spatial separation is the coupling mechanism, then what is the root cause for a potential common cause event. One can think of cabinet fire, flooding, spray, etc. but these threats are already present for existing cables and cable routing in the U.S. nuclear fleet.

Historically, passive components have not been modeled for common cause. Cabling and piping are two key classes of plant component types that have never been modeled for common cause or have common cause events been found for them. See CCF Parameter Estimations 2015, U.S. Nuclear Regulatory Commission (Reference 22). Also, the ASME-ANS PRA Standard, which was endorsed by the U.S. NRC does not list cables for common cause modeling (Reference 24) under supporting requirement SY-B3 as an example.

As additional input, the U.S. NRC has been involved with sponsoring research on cable condition monitoring, aging degradation, environmental qualification, and testing practices for electric cables, and cable accessories used in U.S. nuclear power plants. Brookhaven National Laboratory wrote a report sponsored by the NRC addressing these issues in NUREG/CR-7000 (Reference 27).

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon Its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 26 of 49 Westinghoiise Non-Proprietary Class 3 Page 26 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 This NUREG addresses many facets of the performance and degradation of electric cables. The following text is extracted from the foreword of Reference 27.

"The Office of Nuclear Regulatory Research (RES) sponsored the research reported herein to evaluate the various aging mechanisms and failure modes associated with electrical cables along with condition monitoring techniques that may be useful for monitoring degradation of power, control, and instrumentation cables."

Noticeably absent from the report is any discussion of common cause or common mode failure, or anything similar, in reference to the experience in the industry regarding the degradation or failure of electric cables.

The report provides discussion and analysis of failure modes for power, I&C cables, connectors, and cable splices, but there is no discussion of any common cause failure mode.

Environmental effects could affect multiple cables, and these types of incidents have been brought to the attention of licensees in NRC Information Notice 2002-12 (Reference 28) and in Generic Letter 2007-01 (Reference 29.) Generic Letter 2007-01 (Reference 29) acknowledged that cable insulation degradation due to continuous wetting or submergence could affect multiple underground power cable circuits at a plant.

However, these mechanisms were never declared as common cause mechanisms for failure. In any event, the cable situation under discussion for Vogtle has no association with wetting or submergence.

Thus, based on existing documentation, reports, standards, and PRA conventional practice, common cause failures of passive cables are not modeled, and should not be considered as credible contributors to risk at Vogtle. Despite this conclusion, this assessment did include CCF (as discussed at the beginning of this section), which is a conservative treatment given the evidence.

4.3.2 CCF Data Insights Given the discussion in section 4.3.1, the selection of a CCF value is challenging. As noted in section 4.3, a generic value from WCAP-16672-P (Reference 10) for a group of 2 was selected. As a check, other approaches were also considered.

Estimates of CCF parameters are also provided in Reference 22. This reference has no data specifically related to CCF affecting cables. Surrogate data are therefore needed. To ensure that realism in modeling CCF mechanisms is preserved, it is reasonable to first identify the passive components included in Reference 22, since cables are passive components themselves. It could be argued that the fact that cable CCF data is not provided in Reference 22 and in fact cannot be found anywhere in the literature that it is less likely than CCF for the passive components where such data is provided (i.e., that the CCF data for the passive components that are provided in Reference 22 bounds the possible value of CCF data for cables).

Two categories of Reference 22 apply: 1) strainers and filters (Section 2.6), and 2) heat exchangers (Section 2.7). Table 4-9 below summarizes CCF values for these two categories, taken from Reference 22.

I The focus is on parameters calculated using the alpha factor method, since this method has the advantage of providing uncertainty parameters.

" This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon Its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 27 of 49 Westinghouse Non-Proprietary Class 3 Page 27 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 The table provides CCF parameters of pooled data. This selection is made because it is the most encompassing category, capturing various CCF mechanisms (design causes, environmental stress, human causes, etc.).

The table focuses on the a2 parameter. For this investigation, there is no knowledge of the number of cable divisions that could be affected, and furthermore, the alpha factors all sum to 1, so in effect, the a2 parameter is an appropriate representative value for the overall CCF probability.

For a representative and somewhat conservative calculation that investigates the adverse impacts of CCF mechanisms, it is recommended to use the a2 parameter of the Heat Exchanger category, as it has the highest value.

Table 4-9. CCF Parameters Representative of Passive Components Category a2 parameter (mean value)

Beta distribution "a" parameter Beta distribution "b" parameter Source Section from Reference 22 Strainers and filters 2.21E-02 4.345E-01 1.925E+01 Section 2.6.1 Heat exchangers 2.72E-02 6.049E-01 2.162E+01 Section 2.7.1 The anticipated conservatism in the a2 parameter of the Heat Exchanger category when applied to cabling is confirmed by further comparison with the a2 parameter of breakers. Based on a review of Reference 3, which defines the boundary of components whose reliability data are to be used in PRAs, AC and DC circuit breakers are the only types of equipment in which any significant amount of cabling is included in component boundaries. This is based on the fact that these breakers include within their component boundaries overcurrent protection hardware. Section 3.2.1 of Reference 25 indicates that: "This additional application hardware is generally located external to the circuit breaker and merely utilizes the remote operating features of the breaker [...] It includes all sensing devices, cabling, and components necessary to process the signals and provide control signals to the individual breaker". Therefore, the CCF mechanisms pertaining to breakers embed potential CCF mechanisms associated with cabling, if any.

Furthermore, considering that 1) cabling is only one of the components of breakers, and 2) these other components are more susceptible to CCF mechanisms (for example, maintenance activities, which raise the risk of human-induced CCFs, are in general performed on the breakers themselves and not on cabling), it follows that the contribution of cabling can be expected to be a marginal fraction of the CCF probability of breakers.

Table 4-10 shows the a2 parameter for DC power breakers and 480V AC breakers given in Reference 22.

4160V AC and 6.9 KVA breakers are also included for completeness.

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon Its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 28 of 49 Westinghouse Non-Proprietary Class 3 Page 28 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 Table 4-10. CCF Parameters for Breakers Category and failure mode o2 parameter (mean value)

Source Section from Reference 22 480V AC breaker spurious operation 1.36E-02 Section 2.13.1.3 480V AC breaker failure to open/close 2.13E-02 Section 2.13.1.4 DC power breaker spurious operation 2.25E-02 Section 2.14.3.3 DC power breaker failure to open/close 1.73E-02 Section 2.14.3.4 4160V and 6.9 kVA power breakers spurious operation 2.75E-02 Section 2.13.2.3 4160V and 6.9 kVA power breakers failure to open/close 1.66E-02 Section 2.13.2.4 Table 4-10 shows that the a2 parameter is in all cases less than the 2.72E-02 value found for heat exchangers, except for the spurious operation affecting 4160V and 6.9kVA breakers, which has a slightly greater value of 2.75E-02. But given the discussion above on the marginal contribution of cabling to the CCF of breakers, it follows that the actual a2 parameter of cabling, if it could be more precisely ascertained, would be only a fraction of that value. On that basis, the 2.72E-02 value is conservative.

The values discussed above are all in the same range as the value from Reference 10, and so the selection of that value for this assessment is considered to be reasonable.

5 RISK ASSESSMENT RESULTS For this risk assessment, the modified model outlined in Section 4 was quantified to gain an understanding of the PRA model's sensitivity to the impact of the nonconforming cable separation issue. Two sensitivity studies are performed to support this risk assessment. Case 1 assumes that only independent failures (no CCF) of the cables. Case 2 includes the independent failures of cables and common cause contribution of cable failures (with CCF).

Table 5-1 outlines the risk result of the two risk assessment cases in comparison to the baseline risk. The results for Case 1 and 2 were achieved utilizing the baseline internal event at-power model attached to Reference 2. Core Damage Frequency (CDF) and Large Early Release Frequency (LERF) results were generated using the same truncation limits and quantification files/configurations as the baseline internal event at-power model for CDF per Reference 2 and for LERF per Reference 3. The resulting cutset files are electronically attached as outlined in Section 13.

^ This recxjrd was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRiME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 29 of 49 Westinghouse Non-Proprietary Class 3 Page 29 of 49 LTR-APlOOO-PRA-21-011-NP Rev. 1 09/30/2021 Table 5-1: At-Power Internal Events PRA Risk Results-- Baseline and Risk Assessment Cases CDF^*)

Delta CDF from Baseline^^^

LERF<^^^^>

Delta LERF from Baseline^^^

Basel 3.87E-07 3.72E-08 Case 1 - without CCF 3.94E-7 7.00E-09 3.72E-08 O.OOE+OO Case 2 - with CCF 3.95E-7 8.00E-09 3,74E-08 2.00E-10 Notes:

(1) Per reactor year (2) Baseline CDF result from Table 8.1-1 of Reference 2.

(3) LERF was generated a truncation level of 5E-15 as opposed to IE-16 due to computing memory limitations.

This may be an underestimate as the lower truncation limit of IE-16 would result in the generation of additional cutsets.

(4) Baseline LERF were generated using the internal event model of record attached to Reference 2 with a 5E-15 truncation level.

6 OTHER HAZARD INSIGHTS This risk assessment was limited to the impact on the at-power internal events PRA model. The issues related to the apparent non-1 E cable nonconformances to IEEE 384 spatial separation criteria between Class IE and non-Class IE circuits is anticipated to have no impact on the hazard-specific treatment of IDS equipment in the at-power internal fire, at-power internal flooding, or at-power seismic PRA. The impact on other hazard models would be limited to the potential degraded reliability of IDS equipment in the backbone internal event model.

In the internal fire analysis, IDS equipment is addressed as possible fire ignition sources within a given fire zone. The fire ignition frequencies are generic in nature and do not explicitly account for differences in cable routing withing a cabinet. The impact of a fire event itself on IDS equipment is addressed as loss of the whole IDS equipment function (safety and non-safety). Therefore, I" separation would have no effect on the damage due to fire and there is no impact from this potential nonconformance on the internal fire analysis.

In the internal flooding analysis, the potential nonconformance does not increase the likelihood of a flooding impact on IDS equipment or the RCP switchgear. The equipment is modelled as failed with a probability of 1 if a spray, flood, or high energy break can impact the room in which the cabinets are located, and this 1" separation would have no impact on flood risk.

In the seismic analysis, S-PRA the potential degraded reliability of IDS equipment or RCP switchgear has no impact on the fragility analysis for IDS equipment or RCP switchgears; therefore, there is no impact from this potential nonconformance. Since the seismic modeling is based on the failure of the cabinet and everything in it, 1" separation would have no impact on seismic risk.

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 30 of 49 Westinghouse Non-Proprietary Class 3 Page 30 of 49 LTR-AP1OOO-PRA-21-011-NP Rev. 1 09/30/2021 7

CONSIDERATION OF IMPACT DURING LOW POWER AND SHUTDOWN The insights from at-povs^er PRA are applicable for Modes 1, 2 and 3. Modes 2 and 3 are considered similar to the at-power PRA model with some exceptions. The at-power model would conservatively bound the Mode 3 configuration (no ATWS and potentially lower LOCA frequencies). The impact of these initiating events would also provide more time for operator responses during mode 2 and 3 (Section 7.1.2. of Reference 7).

For Modes 4 and Model 5 with an intact RCS, the plant decay heat removal defenses are not reduced when compared to the at-power level of defenses. For example SGs, PRHR and IRWST injection/ passive recirculation cooling methods are available to support decay heat removal. Therefore, it is acceptable to use the at-power PRA model in lieu of developing quantitative impacts (Section 7.1.2. of Reference 7).

For Mode 5 when the RCS is no longer intact (reactor vessel head vents and/or ADS valves opened) and low modes of operation (6,7, 8) the PRHR heat exchanger and CMTs are isolated. During these modes the strategy to removal decay heat changes to allow boiling and inventory makeup on loss of RNS. Inventory makeup can be provided by RNS gravity injection or IRWST injection. CVS makeup may also be available but the availability to be a long term success path is dependent on the time after reactor shutdown (Section 7.1.2. of Reference 7). RNS cooling, RNS gravity injection, and CVS injection are all non-class IE non-safety related system that can operate without a dependency on the safety related IDS power. Given the multiple lines of defense that are independent from IDS and the longer time window available for recovery typically observed during lower mode operation the risk impact is expected to be minor when compared to the at-power PRA mode insights.

8 KEY ASSUMPTIONS AND UNCERTAINTIES The following is a list of the assumptions and uncertainties pertinent to this application. For a summary of all identified baseline model at-power internal events assumptions and uncertainties see Reference 6. Given that for this application the focus is on ensuring that the impact of non-1 E cable nonconformances is to gain confidence that the risk is not underpredicted only uncertainties that could underpredict the risk impact are recommended for a sensitivity.

1. It is assumed that the length of non-separated cable within a safety related panel/cabinet/switchgear is no longer than 20-foot. This is based on guidance that cable routes will include an additional 10-foot length at equipment connection and when two pieces of equipment ties there could be an additional 20-foot length of cable (Section 2.2.2 of Reference 21.)

o Characterization Assessment: Conservative assumption based on the 20-foot being a maximum length of an individual non IE cable within a panel/switchgear.

2. For the baseline internal event model and this sensitivity the IDS spare battery bank with spare battery charger is not modeled. There are no planned unavailability basic events included for the EPS for Mode 1 operation since the spare components would be place in service (Section 7.4 of Reference 5. Based on the insights from Section 3.3.5 of Reference 9 the types of non IE cable This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commlssjon ND-21-0843 Enclosure 3 Page 31 of 49 Westinghouse Non-Proprietary Class 3 Page 31 of 49 LTR-A?

1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 nonconformances are similar to the other divisions outline in Section 3.3 of Reference 9. The insights if the spare IDS components were in service are expected to the same.

o Characterization Assessment: The non-IE cable nonconformances for the IDS spare equipment is limited to panel IDSS-DF-1 with only 2 Instrument Circuit cables (Section 3.3.5 of Reference 9). No unique insights are expected if the spare battery bank and spare battery charger is in service. Therefore the risk assessment results are not anticipated to be impacted by this source of uncertainty.

3. Five (5) independent non-IE cable nonconformances are assumed for each reactor coolant pump switchgear. Each non-IE cable nonconformance is assumed to be an instrumentation circuit.

Instrumentation circuit cables were selected over power circuit cables based on insights from Section 4.2. This was done to apply a higher failure rate when the exact number and type of cables is unknown. This assumption is related to open item 2 of Section 10.

o Characterization Assessment: This could overestimate or underestimate the impact of switchgear non-IE cable nonconformances. This source of uncertainty is recommended for a sensitivity.

4. There is uncertainty related to cable failure data. Limited generic data source related to cable failure are available. No known generic data source is available specific to this application. The failure data for power cables and instrumentation cables is based on all failure modes from Reference 13.

Based on insights from the deterministic assessments (References 8 and 9) the majority of cable failures are not anticipated to degrade the safety related function of the IDS panels or switchgears.

o Characterization Assessment: This could overestimate or underestimate the impact of s non-IE cable nonconformances. This source of uncertainty is recommended for a sensitivity.

5. For this application no known generic data source is available for common cause factors specifically for cable failures. For simplification only one common cause event was used for each type code addressed using a beta factor approach. The common cause factor is based on a generic common cause factor for components with no operating data available. Based on insights from the deterministic assessments (References 8 and 9) the majority of cable failures are not anticipated to degrade the safety related function of the IDS panels or switchgears. At this time there is no root cause of failure and a coupling factor known to create the condition where common cause would be a concern.

o Characterization Assessment: Based on existing documentation, reports, standards, and PRA conventional practice outlined in Section 4.3.1, common cause failures of passive cables are not modeled, and should not be considered as credible contributors to risk at Vogtle. Despite this conclusion, this assessment did include CCF, which is a conservative treatment given the evidence. The assumed common cause factor could overestimate or underestimate the impact of the non-IE cable nonconformances. This source of uncertainty is recommended for a sensitivity to demonstrate that the risk impact is not underpredicted.

6. The independent failure probabilities for non-IE cable nonconformances is estimated using an hourly failure rate and a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> mission time. Reference 13 includes failure rates in term of per hour and per cycle. Only the per hour failure rates are used in this application. It is noted in Section D.9.5.1 of the IEEE Standard 500(Reference 13) that for cables hours of operation have more This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 32 of 49 Westinghouse Non-Proprietary Class 3 Page 32 of 49 LTR-APlOOO-PRA-21-011-NP Rev. 1 09/30/2021 meaning than per cycles. For the IDS panels given the available of continuous monitoring and that loss of any single bus is self-revealing the use of a 24-hour mission and hourly failure rate is appropriate for this application. The switchgears outlined in Table B-2 include PRA equipment with failure probabilities estimated based on demand failure rates (e.g., breaker failure to open.)

The failure probability for cable mitigation basic events is still estimated using a 24-hour mission time since the non-IE cable nonconformance is not performing a demand function.

o Characterization Assessment: This could overestimate or underestimate the impact of switchgear non-IE cable nonconformances. This source of uncertainty is recommended for a sensitivity to demonstrate that the risk impact is not underpredicted.

7. Vogtle Unit 3 specific cable lengths is estimated from WIRED using the cable schedule list trimmed to include cable lengths for cables associated with equipment contained in the DRAP and RTNSS programs. The DRAP and RTNSS equipment list was used to align closer to the safety related and DID equipment that cable failures would generate a LER report or event report for a currently operating PWR (see Section 4.2.5 for more information).

o Characterization Assessment: Realistic assumption based on the equipment in DRAP and RTNSS is a close alignment to safely related and risk important equipment for a currently operating plant. Note that this assumption is related to the uncertainty related to cable failure data (number 5) that is already recommended for a sensitivity.

8. In general (except as noted in Section 3) no credit is taken in the model when the impact assessment (Reference 8 or 9) circuit analysis concluded that failure of a non-1E cable would not fail the safety related function of a panel or switchgear. That is, failure of a 1E component induced by failure of a non-IE cable is conservatively assumed in all cases.

o Characterization Assessment: Conservative assumption based on the insights summarized below:

I Based on insights from the impact assessment for the IDS cabinets (Reference 9) for circuits with class IE-supplied instrumentation cables, instrumentation circuits, and battery charger power circuits this is conservative treatment to always assumed a non-IE cable fault will fail its associated IDS panel.

I For the reactor trip, this applies to all the rod drive power supply circuits (failure always causes spurious reactor trip) this treatment conservative treatment to always assumed a non-IE cable fault will result in a reactor trip.

I For RCP trip, this applies to all the RCP switchgear cables this treatment conservative treatment to always assumed a non-IE cable fault will always fail the safety related function of the switchgears.

9. The consequential probability that a failure of a non-IE cable will fail it's corresponding IE safety related function is assumed to be 1.0. As there is no generic information available to assess this probability, a failed non-IE cable is assumed to also fail the safety related function of its corresponding panel or switchgear (i.e., that do not have adequate separation) with probability 1.0.

Overall, this assumption is conservative.

o Characterization Assessment: Conservative assumption to assumed failure of a non-IE cable will fail it's corresponding IE safety related function.

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 33 of 49 Westinghouse Non-Proprietary Class 3 Page 33 of 49 LTR-APlOOO-PRA-21-011-NP Rev. 1 09/30/2021 9 ADDITIONAL SENSITIVITY STUDIES Based on the uncertainty characterization assessments in the section above sensitivities are conducted to gain confidence that the risk of the non-IE cable nonconformances is not underpredicted. The following subsections outline the sensitivity studies and results. All sensitivity run performed are based on the Case 2 results (with CCF) from Section 5 as the starting point before modifications for the sensitivity are implemented.

9.1 RCP Switchgear 5 non-IE Cable Nonconformance Assumption This sensitivity assumes a total of 10 non-IE cable nonconformances per each switchgear instead of the five (5) non-IE conformances assumed in risk assessment Case 2. For this sensitivity study, five (5) cables are assumed to be instrumentation cables (aligns with current assumption) and the five (5) additional cables are assumed to be power cables. To perform this sensitivity the additional mitigation basic events outlined in Table 9-1 are added into the model in the same manner as outlined in Section 3 of the report. Each basic event utilizes the power cable type code (CAB-PC-FOP) and a 24-hour mission time. Also included is a common cause basic event for the power cables. This CCF event is named CCFM-ECS-CAB-PC-FOP and utilities the same equation as CCFM-IDS-CAB-PC-FOP from Section 4.3.

Table 9-1: RCP Switchgear Cable Nonconformance Sensitivity-Addition of 5 Power Cables Component Mitigation Basic Events Added to Model Component Mitigation Basic Events Added to Model ECS-ES-31(52)

CAB-PC-FOP-ECS-ES-31(52)-1 ECS-ES-41(52)

C AB-PC-FOP-ECS-ES-41 (52)-1 CAB-PC-FOP-ECS-ES-31(52)-2 C

AB-PC-FOP-ECS-ES-41 (52)-2 CAB-PC-FOP-ECS-ES-31 (52)-3 CAB-PC-FOP-ECS-ES-41 (52)-3 CAB-PC-FOP-ECS-ES-31 (52)-4 C

AB-PC-FOP-ECS-ES-41 (52)-4 CAB-PC-FOP-ECS-ES-31 (52)-5 CAB-PC-FOP-ECS-ES-41 (52)-5 ECS-ES-32(52)

CAB-PC-FOP-ECS-ES-32(52)-1 ECS-ES-42(52)

CAB-PC-FOP-ECS-ES-42(52)-1 CAB-PC-FOP-ECS-ES-32(52)-2 CAB-PC-FOP-ECS-ES-42(52)-2 CAB-PC-FOP-ECS-ES-32(52)-3 CAB-PC-FOP-ECS-ES-42(52)-3 CAB-PC-FOP-ECS-ES-32(52)-4 CAB-PC-FOP-ECS-ES-42(52)-4 CAB-PC-FOP-ECS-ES-32(52)-5 CAB-PC-FOP-ECS-ES-42(52)-5 ECS-ES-51(52)

CAB-PC-FOP-ECS-ES-51 (52)-1 ECS-ES-61(52)

C AB-PC-FOP-ECS-ES-61 (52)-1 CAB-PC-FOP-ECS-ES-51(52)-2 C

AB-PC-FOP-ECS-ES-61 (52)-2 CAB-PC-FOP-ECS-ES-51 (52)-3 C

AB-PC-FOP-ECS-ES-61 (52)-3 CAB-PC-FOP-ECS-ES-51 (52)-4 C

AB-PC-FOP-ECS-ES-61 (52)-4 CAB-PC-FOP-ECS-ES-51 (52)-5 C

AB-PC-FOP-ECS-ES-61(52)-5 ECS-ES-52(52)

CAB-PC-FOP-ECS-ES-52(52)-1 CS-ES-62(52)

CAB-PC-FOP-ECS-ES-62(52)-1 CAB-PC-FOP-ECS-ES-52(52)-2 CAB-PC-FOP-ECS-ES-62(52)-2 CAB-PC-FOP-ECS-ES-52(52)-3 CAB-PC-FOP-ECS-ES-62(52)-3 CAB-PC-FOP-ECS-ES-52(52)-4 CAB-PC-FOP-ECS-ES-62(52)-4 This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 34 of 49 Westinghouse Non-Proprietary Class 3 Page 34 of 49 LTR-A?

1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 Table 9-1: RCP Switchgear Cable Nonconformance Sensitivity-Addition of 5 Power Cables Component Mitigation Basic Events Added to Model Component Mitigation Basic Events Added to Model CAB-PC-FOP-ECS-ES-52(52)-5 CAB-PC-FOP-ECS-ES-62(52)-5 9.2 Independent Cable Failure Data Uncertainty To assess the impact of the uncertainty related to the independent failure rate data for cables the type codes for both power and instrumentation cables was updated to the resulting failure rates when using the high end value (90% confidence interval) from IEEE Standard 500(Reference 13). See sections 4.2.3.2 and 4.2.3.3 for more information on this calculation. For this sensitivity the model was updated to reflect the high end values for the type codes outlined in Table 9-2. Note that impact of this sensitivity is carried through for cable mitigation basic events, cable initiating events, and cable common cause events with the use of the type code.

Table 9-2: Sensitivity 2 Type Code Failure Rates Description Type Code Failure Rate Failure Probability for Basic Events Power Cable Fails CAB-PC-FOP 3.22E-08/hour 7.73E-07 for mitigation events 2.82E-04 for initiator events Instrumentation Cable Fails CAB-IC-FOP 6.82E-08/hour 1.64E-06 for mitigation events 5.97E-04 for initiator events 9.3 Common Cause Failure Probability Uncertainty To assess the impact of the uncertainty related to the cable common cause contribution a sensitivity study was conducted by updating the cable failure common cause factor. No known generic data reference source for cable common cause factors was identified. As an alternative the NRG CCF Parameter Estimations 2015 (Reference 22) update was reviewed to identify alternative CCF factors. Table 9-3 outlines the review of alternative beta factors for this sensitivity from Reference 22. The component type and failure modes were selected based on their relationship to the impacted equipment of the non-IE cable nonconformances.

All of these values are less than the betta factor value of 5.04E-02 from Section 4.3.

• This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commissjon ND-21-0843 Enclosure 3 Page 35 of 49 Westinghouse Non-Proprietary Class 3 Page 35 of 49 LTR-AP1000-PRA.21-011 -NP Rev. 1 09/30/2021 Table 9-3: Alternative CCF Beta Factors Group Report Section from Reference 22 a2 for Group Size of 2 MGL Parameters Generic Demand CCF Distribution 3.1.1 1.95E-02 Batteries 2.14.1 2.52E-03 Battery Chargers 2.14.2 l.lOE-02 DC Power Breaker Failure to Open 2.14.3.1 O.OOE+00 DC Power Breaker Failure Spurious Actuation 2.14.3.3 O.OOE+00 Reactor Trip Breakers 2.15 O.OOE+00 For this sensitivity study a conservative beta factor value of 0.1 was applied. Each CCF basic event from Table 4-8 was updated to the probabilities below. The updated CCF probabilities and equations for this sensitivity are outlined in the Table 9-4.

Table 9-4: CCF Basic Events Sensitivity Basic Event Name Description Equation Probability CCFM-IDS-CAB-IC-FOP Common Cause of all IDS Instrument Circuit Cables

'CAB-IC-FOP'*'@MT'*0.1 1.70E-08 CCFM-IDS-CAB-IC-FOP-IE Common Cause of all IDS Instrument Circuit Cables -

IE

'CAB-IC-FOP'*'@MTl Y'*0.1 6.22E-06 CCFM-ECS-CAB-IC-FOP Common Cause of all ECS Instrument Circuit Cables

• CAB-IC-FOP'*'@Mr*0.1 1.70E-08 CCFM-IDS-CAB-PC-FOP Common Cause of all IDS Power Circuit Cable Fails

'CAB-PC-FOP'*'@MT'*0.1 2.14E-09 CCFM-IDS-CAB-PC-FOP-IE Common Cause of all IDS Power Circuit Cable Fails -

IE

'CAB-PC-FOP'*'@MT 1 Y'*0.1 7.80E-07 CCFM-RPS-CAB-PC-FOP-IE Common Cause of all RPS Power Circuit Cable Fails -

IE

'CAB-PC-FOP'*'@MTI Y'*0.1 7.80E-07 9.4 Mission Time Sensitivity The independent failure probabilities for non-IE cable nonconformance is estimated using an hourly failure rate and a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> mission time. It is noted in Section D.9.5.1 of the IEEE Standard 500(Reference 13)

^ This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 36 of 49 Westinghouse Non-Proprietary Class 3 Page 36 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 that for cables hours of operation have more meaning than per cycles. The per cycle failure rates is provided in terms of per 1000 circuit feet units in the IEEE Std-500(Reference 13). For the IDS panels given the available of continuous monitoring and that loss of any single bus is self-revealing the use of a 24-hour mission is appropriate for this application. The switchgears outlined in Table B-2 includes PRA equipment with failure probabilities estimated based on pre demand failure rates (e.g., breaker failure to open.) To assess the possibility that the use of mission time only could underestimate the impact of switchgear non-IE cable nonconformances the per cycle failure probabilities for this application were also investigated.

The following subsections outline the estimated cable failure probabilities for both power cables and instrumentation cables for per cycle failure rates from Reference 13. In each case for one cycle the per cycle failure rate is lower than the failure probabilities calculated in the section 9.2 sensitivity (90%

confidence interval) from IEEE Standard 500(Reference 13). Insights from the section 9.2 sensitivity would bound any insights using the per cycle failure probabilities for cables outlined in Table 9-5. Since the impact is bounded by the Section 9.2 sensitivity no explicit sensitivity study is performed for this source of uncertainty.

Table 9-5: Per Hour Compared to Per Cycle Failure Probabilities Description Type Code Failure Probability for Basic Events (hourly)

Failure Probability for Basic Events (cycle)

Power Cable Fails CAB-PC-FOP 7.73E-07 4.30E-08 Instrumentation Cable Fails CAB-IC-FOP 1.64E-06 6.92E-08 Notes:

(1) Values from Table 9-2 for 90% confidence interval from Reference 13 for mitigation basic events (24-hour mission time)

(2) Values from Section 9.4.1 and 9.4.2 for 1 cycle.

9.4.1 Power Cables Per Cycle Failure Probability Subsection 9.1.1 of Reference 13 provides a recommended rate of2.15E-06/cycleper 1000 circuit feet plant for power cables for all failure modes. The following equation was used to estimate a 4.30E-08/cycle failure probability for one non separated cable failing.

hourly rate per cycle of one non separated cable failing

= (Plant failure rate for power cables) ^

length of one non separated cable\\

1000 Circuit Feet J

OR 4.30 "Vcycle = (2.15E °^/hour) QOQft)

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 37 of 49 Westinghouse Non-Proprietary Class 3 Page 37 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 9.4.2 Instrumentation Cables Per Cycle Failure Probability Subsection 9.1.3 of Reference 13 provides a recommended rate of 3.46E-06/cycle per 1000 circuit feet plant for instrumentation cables for all failure modes. The following equation was used to estimate a 6.92E-08/cycle failure probability for one non separated cable failing.

hourly rate per cycle of one non separated cable failing

^

^

^

/length of one non separated cable\\

=

(Plant failure rate for power cables)

\\

1000 Circuit Feet

/

OR 20 ft 6.92-oVcycle = i2.15E-°yhour) 9.5 Sensitivities Study Results Table 9-6 provides a comparison of the baseline internal events PRA results compared to the risk assessment results from Section 5 to the sensitivity study results. Sensitivity 1 assesses the impact of assuming 10 non-IE cable nonconformances for the RCP switchgears over the currently assumed 5 non-IE cable nonconformances in the section 5 results. Sensitivity 2 assesses the impact of assuming a higher cable failure rate. Sensitivity 3 assesses the impact of assuming a higher common cause failure probability for cable failures.

This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 38 of 49 Westinghouse Non-Proprietary Class 3 Page 38 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021 Table 9-6: At-Power Internal Events PRA Risk Results-Baseline, Risk Assessment Cases and Sensitivity Studies CDF<'>

Delta CDF from Baseline^'*

difference from Baseline LERFO)

(3)

Delta LERF from Baseline")

difference from Baseline Baseline'^"'*'

3.87E-07 3.72E-08 Case 1 - without CCF 3.94E-7 7.00E-09 1.81%

3.72E-08 O.OOE+00 0.00%

Case 2 - with CCF 3.95E-7 8.00E-09 2.03%

3.74E-08 2.00E-10 0.54%

Sensitivity 1 -

RCP Switchgear 10 nonconformances 3.95E-7 8.00E-09 2.07%

3.74E-08 2.00E-10 0.54%

Sensitivity 2 -

Cable Failure Rate 3.99E-07 1.20E-08 3.10%

3.96E-08 2.40E-09 6.45%

Sensitivity 3 -

Common Cause 3.95E-07 8.00E-09 2.07%

3.77E-08 5.00E-10 1.34%

Notes:

(1) Per reactor year (2) Baseline CDF result from Table 8.1-1 of Reference 2.

(3) LERF was generated a truncation level of 5E-15 as opposed to lE-16 due to computing memory limitations. This may be an underestimate as the lower truncation limit of lE-16 would result in the generation of additional cutsets.

(4) Baseline LERF were generated using the internal event model of record attached to Reference 2 with a 5E-15 truncation level.

10 OPEN ITEMS

1. Closed - No violation were identified for panel SV3-IDSD-EA-1.

2. The identification of non-IE cable nonconformance and circuit impact assessment review for the reactor coolant pump switchgears (ECS-ES-31(41,51,61) and ECS-ES-32(42,52,62) was not available for this revision of this report.

o In lieu of having cables identified 5 non-IE cable nonconformance are assumed for each reactor coolant pump switchgear. Each non-IE cable nonconformance is assumed to be an instrumentation circuit.

3. Closed -

The identification of non-IE cable nonconformance and circuit impact assessment review in Section 3.3.5 of Reference 9 is complete.

4. Closed - The identification of non-IE cable nonconformance and circuit impact assessment review is compete for the reactor trip switchgears. This is addressed in Section 3.1 of Reference 8.

5. The identification of non-IE cable nonconformances and circuit impact assessment for IDSC-DS-1 was not fully available for this revision of this report. No source cable name identifier is available in Reference 9 for this impact. Cable name is given based on IDS panel. This non-IE cable This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 39 of 49 Westinghouse Non-Proprietary Class 3 Page 39 of 49 LTR-A?

1OOO-PRA-21-011-NP Rev. 1 09/30/2021 nonconformance is assumed to be an instrumentation cable. An instrumentation cable was selected over a power cable based on insights from Section 4.2. This was done to apply a higher failure rate when the exact type of cable is unknown.

11 CONCLUSIONS The risk assessment evaluates the possible risk importance of the identified non-1 E cable nonconformances related to PRA equipment on the Vogtle API000 plant Internal Events PRA Model. Overall, this was a conservative delta-risk estimate, adequate for an SDP determination. The risk impact on CDF (less than lE-8 /year delta risk) and LERF (less than lE-9 /year delta risk) outlined in Table 5-1 concluded a very small risk impact due to the non-IE cable nonconformances.

In addition to the cases outlined in Section 5 sensitivity studies outlined in Section 9 were performed to gain confidence that the risk of the non-IE cable nonconformances is not underpredicted. Uncertainties characterized in Section 8 that could underpredict the risk impact were recommended for a sensitivity.

Qualitative considerations are also provided for other hazards and LPSD in Section 6 and Section 7 respectively.

Table 9-6 presents the results of all of the calculations, showing the change in risk (both absolute and percent increase) associated with the cases discussed in Section 5 and the additional sensitivities discussed in Section 9. Based on these insights it can be concluded that even with conservative treatment of the non-lE cable nonconformances the risk impact is small.

12 REFERENCES

1. IEEE 384-2018, "IEEE Standard Criteria for Independence of Class IE Equipment and Circuits."

2018.

2. SVO-PRA-GSC-322, Revision 0, "API000 Plant At-Power Internal Events PRA, Quantification Notebook."

3. SVO-PRA-GSC-376, Revision 0, "APIOOO Plant At-Power Internal Events PRA, Level 2 Quantification Results Notebook."

4. APP-PRA-GSC-343, Revision 0, "APIOOO Plant At-Power Internal Events PRA, Data Analysis Notebook."

5. APP-PRA-GSC-312, Revision 0, "APIOOO Plant At-Power Internal Events PRA, Electric Power Distribution Systems Notebook."

6. SVO-PRA-GSC-357, Revision 0, "APIOOO Plant At-Power Internal Events PRA, Uncertainties Notebook."

7. SVO-PRA-GSC-383, Revision A, "

APIOOO Plant PRA, Shutdown Defense-In-Depth Risk Monitor Model Notebook."

8. Attachment 3, "Safety Determination Input for IEEE 384 Separation Issues (ESR 50088923)."

This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 40 of 49 Westinghouse Non-Proprietary Class 3 Page 40 of 49 LTR-AP1OOO-PRA-21 -011-NP Rev. 1 09/30/2021

9. Attachment 4, "Safety Determination Input for IEEE 384 Separation Issues within IDS Enclosures."

10. WCAP-16672-P, Revision 1, "Common Cause Failure Parameter Estimates for the PWROG."

11. NUREG-2169, "Nuclear Power Plant Fire Ignition Frequency and Non-Suppression Probability Estimation Using the Updated Fire Events Database," United States Fire Event Experience Through 2009.

12. NUREG/CR-5461, "Aging of Cables, Connections, and Electrical Penetration Assemblies Used in Nuclear Power Plants."

13. IEEE 500, "Guide to the Collection and Presentation of Electrical, Electronic, Sensing Component, and Mechanical Equipment Reliability Data for Nuclear-Power Generating Stations," 1984.

14. NUREG/CR-5485, "Guidelines on Modeling Common-Cause Failures in Probabilistic Risk Assessment."

15. APP-PRA-GSC-317, Revision 0, "APIOOO Plant At-Power Internal Events PRA, Passive Core Cooling and Reactor Coolant Systems Notebook."

16. Not used

17. APP-GW-J4-070, Revision 3, "APIOOO Interface Specification for Reactor Trip Breakers."

18. APP-GW-GLR-241, Revision 0, "Design and Regulatory Requirements and Guidance for DRAP and RTNSS Components."

19. APP-IDS-E8-001, Revision 5, "Class IE DC and UPS System Specification Document."

20. APP-PRA-GSC-340, Revision 0, "APIOOO Plant At-Power Internal Events PRA, Initiating Event Analysis Notebook."

21. APP-GH50-Z0-100, Revision 6, "Westinghouse Integrated Raceway and Electrical Design (WIRED) Software Requirements."

22. "CCF Parameter Estimations 2015U.S. Nuclear Regulatory Commission, "CCF Parameter Estimations, 2015 Update," 10/26/2016.

https://nrcoe.inl.gov/publicdocs/CCF/ccfparamest2015.Ddf.

23. EGG-SSRE-8875, "Generic Component Failure Data Base for Light Water and Liquid Sodium Reactor PRAs, "

Idaho National Engineering Laboratory, February 1990.

24. American Society of Mechanical Engineers (ASME), "Addenda to ASME/ANS RA-S-2008 Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications", ASME/ANS RA-Sa-2009, 2009.

25. NRC web page. Component Boundaries, https://nrcoe.inl.gov/publicdocs/CCF/CompBoundaries.pdf

26. NUREG/CR-6268, Revision 1, "

Common-Cause Failure Database and Analysis System: Event Data Collection, Classification, and Coding."

27. NUREG/CR-7000, "Essential Elements of an Electric Cable Condition Monitoring Program."

This record was final approved on 9/30/2021 6:07:00 PM, (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 41 of 49 Westinghouse Non-Proprietary Class 3 Page 41 of 49 LTR-AP1OOO-PRA-21 -011 -NP Rev. 1 09/30/2021

28. Information Notice 2002-12, "Submerged Safety-Related Electrical Cables," Nuclear Regulatory Commission, March 21,2002.

29. Generic Letter. (GL) 2007-01, "Inaccessible or Underground Power Cables that Disable Accident Mitigation Systems or Cause Plant Transients," Nuclear Regulatory Commission, November 12, 2008.

13

SUMMARY

OF ATTACHMENTS Table 13-1 outlines the electronic attachments that support this analysis.

c Table 13-1: List of Electronic Attachments Attachment No.

Description Prime File Name 2

Safety Determination Input for IEEE 384 Separation Issues (ESR 50088923)

RTS RCPS Safety Determination.docx 3

Safety Determination Input for IEEE 384 Separation Issues within IDS Enclosures IDS Cabinets Safety Determination

.docx 12 Comment Resolution Sheet CommentResolutionForm-LTR-APl OOO-PRA-21-011 Revision 1 DRAFT.xlsx a,c,e

a,c,e

' This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 42 of 49 Westinghouse Non-Proprietary Class 3 Page 42 of 49 LTR-APlOOO-PRA-21-011-NP Rev. 1 09/30/2021 APPENDIX B: NON-IE CABLE NONCONFORMANCE MAPPING TO PRA EQUIPMENT This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 43 of 49 Westinghouse Non-Proprietary Class 3 Page 43 of 49 LTR-APIOOO-PRA-21-011 -NP Rev. 1 09/30/2021 Table B-1: Non-IE Cable Nonconformance Mapping to PRA Equipment for IDS Panel Impacts Coniponent Basic Event Description IEEE Cable Impacts'-'

Basic Events Added For Cable Failure Sensitivity PRA Basic Event Information Impacted Non 1E Cable Type of Cable Mitigation Basic Events Added to Model IE Basic Events Added to Model (if applicable)

Notes 250V DC Distribution Panels^

IDS-BUS-FOP-DSl/A IDS BUS APP-IDSA-DS-1 FAIL TO OPERATE IDSA-EW-DDIAZN Instrumentation CAB-IC-FOP-IDSA-EW-DDIAZN CAB-IC-FOP-IDSA-EW-DDIAZN-IE lDSA-DS-1 IDS-BUS-FOP-DSl/A-lE IDS BUS APP-IDSA-DS-1 FAIL TO OPERATE IDSA-EW-DKIAZN InstiTinientation CAB-IC-FOP-IDSA-EW-DKIAZN CAB-IC-FOP-IDSA-EW-DKIAZN-IE IDSA-EW-DSILZN Instmmentation CAB-IC-FOP-IDSA-EW-DSILZN CAB-IC-FOP-IDSA-EW-DSILZN-IE IDSA-EW-DSINZN Instrumentation CAB-IC-FOP-IDSA-EW-DSINZN CAB-IC-FOP-IDSA-EW-DSINZN-IE IDSB-DS-1 IDS-BUS-FOP-DSl/B IDS BUS APP-IDSB-DS-I FAIL TO OPERATE IDSB-EW-DKIAZN Instnimentation CAB-IC-FOP-IDSB-EW-DKIAZN CAB-IC-FOP-IDSB-EW-DKIAZN-IE Note that IDSB-EW-DKIAZN has 2 different Target SSCs ((IDSB-EW-DFIJZB and IDSB-EW-DSIMZB) but both targets are Instmment Circuit IDS-BUS-FOP-DSl/B-IE IDS BUS APP-IDSB-DS-I FAIL TO OPERATE IDSB-DS-2 1DS-BUS-F0P-DS2/B IDS BUS APP-IDSB-DS-2 FAIL TO OPERATE IDSB-EW-DS2LZN Instmmentation CAB-IC-FOP-IDSB-EW-DS2LZN IDSB-EW-DS2NZN Instrumentation CAB-IC-FOP-IDSB-EW-DS2NZN lDSC-DS-1 IDS-BUS-FOP-DSI/C IDS BUS APP-IDSC-DS-I FAIL TO OPERATE Internal Wires (See Note)

Instnimentation CAB-IC-FOP-IDSC-DS-I CAB-IC-FOP-IDSC-DS-1-IE No source cable name identifier is available in Reference 9 for this impact. Cable name is given based on IDS panel. This is assumed to be an instmment circuit cable (see Open Item 5 of Section 10).

IDS-BUS-FOP-DSl/C-lE IDS BUS APP-IDSC-DS-I FAIL TO OPERATE lDSC-DS-2 1DS-BUS-F0P-DS2/C IDS BUS APP-IDSC-DS-2 FAIL TO OPERATE IDSC-EW-DS2NZN Instrumentation CAB-IC-FOP-IDSC-EW-DS2NZN IDSC-EW-DS2LZN Instmmentation CAB-IC-FOP-IDSC-EW-DS2LZN IDS-BUS-FOP-DSl/D IDS BUS APP-IDSD-DS-I FAIL TO OPERATE IDSD-EW-DKIAZN Instmmentation CAB-IC-FOP-IDSD-EW-DKIAZN CAB-IC-FOP-IDSD-EW-DKIAZN-IE IDS-BUS-FOP-DSl/D-IE IDS BUS APP-IDSD-DS-I FAIL TO OPERATE IDSD-EW-DDIAZN Instmmentation CAB-IC-FOP-IDSD-EW-DDIAZN CAB-IC-FOP-IDSD-EW-DDIAZN-IE IDSD-DS-1 IDSD-EW-DSILZN Instrumentation CAB-IC-FOP-IDSD-EW-DSILZN CAB-IC-FOP-IDSD-EW-DSILZN-IE Note that IDSD-EW-DSILZN has 2 different Target SSCs (IDSD-EW-DSIMZD and Indetenninate) but both targets are Instmment Circuit.

IDSD-EW-DSINZN Instmmentation CAB-IC-FOP-IDSD-EW-DSINZN CAB-IC-FOP-IDSD-EW-DSINZN-IE Note that IDSD-EW-DSINZN has 2 different Target SSCs (IDSD-EW-DSIMZD and Indetenninate) but both targets are Instrument Circuit.

This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 44 of 49 Westiiighouse Non-Proprietary Class 3 Page 44 of 49 LTR-APlOOO-PRA-21-011-NP Rev. I 09/30/2021 Table B-1: Non-IE Cable Nonconformance Mapping to PRA Equipment for IDS Panel Impacts Component 1

Basic Event 1

Description IEEE Cable lmpacts'->

Basic Events Added For Cable Failure Sensitivity PRA Basic Event Information Impacted Non IE Cable Type of Cable Mitigation Basic Events Added to Model IE Basic Events Added to Model (if applicable)

Notes 250V DC MCCV'>

RCS-EW-PLVOOIARZN InstiTimentation CAB-IC-FOP-RCS-EW-PLVOOIARZN IDSA-DK-1 IDS-BUS-FOP-DKl/A IDS BUS APP-IDSA-DK-1 FAIL RCS-EW-PLV003ARZN Instniinentation CAB-IC-FOP-RCS-EW-PLV003ARZN TO OPERATE RCS-EW-PLVOIIARZN Instmmentation CAB-IC-FOP-RCS-EW-PLVOIIARZN RCS-EW-PLV0I3ARZN Instrumentation CAB-IC-FOP-RCS-EW-PLV0I3ARZN IDS-BUS-FOP-DKI/B IDS BUS APP-IDSB-DK-I FAIL TO OPERATE RCS-EW-PLVOOIBRZN Instniinentation CAB-IC-FOP-RCS-EW-PLVOOIBRZN IDSB-DK-1 RCS-EW-PLV003BRZN Instmmentation CAB-IC-FOP-RCS-EW-PLV003BRZN RCS-EW-PLV0I3BRZN Instmmentation CAB-IC-FOP-RCS-EW-PLV0I3BRZN IDS-BUS-FOP-DKl/C IDS BUS APP-IDSC-DK-I FAIL TO OPERATE RCS-EW-PLV002ARZN Instmmentation CAB-IC-FOP-RCS-EW-PLV002ARZN IDSC-DK-I RCS-EW-PLV0I2ARZN Instmmentation CAB-IC-FOP-RCS-EW-PLV0I2ARZN PCS-EW-PLVOOICJYN Instmmentation CAB-IC-FOP-PCS-EW-PLVOOICJYN IDSD-DK-1 IDS-BUS-FOP-DKl/D IDS BUS APP-IDSD-DK-I FAIL TO OPERATE RCS-EW-PLV012BRZN Instmmentation CAB-IC-FOP-RCS-EW-PLV012BRZN Note that RCS-EW-PLV012BRZN has 3 different Target SSCs (Bucket

Controls, PXS-EW-PLV002AHYD, and PXS-EW-PLV002AKZD) but all targets are Class IE Supplied Cable/Instrument cables.

RCS-EW-PLV0()2BRZN Instmmentation CAB-IC-FOP-RCS-EW-PLV002BRZN 120V AC Distribution Panels*'^

IDSA-EA-1 IDS-BUS-FOP-EAl/A IDS BUS APP-IDSA-EA-I FAIL TO OPERATE IDSA-EW-EAIJZN Instmmentation CAB-IC-FOP-IDSA-EW-EAIJZN IDSA-EA-2 IDS-BUS-F0P-EA2/A IDS BUS APP-IDSA-EA-2 FAIL TO OPERATE IDSA-EW-EA2JZN Instmmentation CAB-IC-FOP-IDSA-EW-EA2JZN lDSB-EA-1 IDS-BUS-FOP-EAl/B IDS BUS APP-IDSB-EA-I FAIL TO OPERATE IDSB-EW-EAIJZN Instmmentation CAB-IC-FOP-IDSB-EW-EAIJZN IDSB-EA-2 IDS-BUS-F0P-EA2/B IDS BUS APP-lDSB-EA-2 FAIL TO OPERATE IDSB-EW-EA2JZN Instmmentation CAB-IC-FOP-IDSB-EW-EA2JZN IDSB-EA-3 IDS-BUS-F0P-EA3/B IDS BUS APP-IDSB-EA-3 FAIL TO OPERATE IDSB-EW-EA3JZN Instmmentation CAB-IC-FOP-IDSB-EW-EA3JZN

• • • This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 45 of 49 Westinghouse Non-Proprietary Class 3 Page 45 of 49 LTR-APlOOO-PRA-21-011-NP Rev. I 09/30/2021 Table B-1: Non-IE Cable Nonconformance Mapping to PRA Equipment for IDS Panel Impacts Coniponent Basic Event Description IEEE Cable Impacts^-^

Basic Events Added For Cable Failure Sensitivity PRA Basic Event Information Impacted Non IE Cable Type of Cable Mitigation Basic Events Added to Model IE Basic Events Added to Model (if applicable)

Notes IDSC-EA-1 IDS-BUS-FOP-EAl/C IDS BUS APP-IDSC-EA-1 FAIL TO OPERATE IDSC-EW-EAIJZN Instminentation CAB-IC-FOP-IDSC-EW-EAIJZN Note that IDSC-EW-EAIJZN has 2 different Target SSCs ((DSC-EW-EA4CXC and Indetenninate) but both targets are Instminent Circuit.

IDSC-EA-2 IDS-BUS-FOP-EA2/C IDS BUS APP-IDSC-EA-2 FAIL TO OPERATE IDSC-EW-EA2JZN Instrinnentation CAB-IC-FOP-IDSC-EW-EA2JZN IDSC-EA-3 IDS-BUS-FOP-EA3/C IDS BUS APP-IDSC-EA-3 FAIL TO OPERATE IDSC-EW-EA3JZN Instminentation CAB-IC-FOP-IDSC-EW-EA3JZN IDSD-EA-1 IDS-BUS-FOP-EAl/D IDS BUS APP-IDSD-EA-I FAIL TO OPERATE None Inspection complete no IEEE issue identified.

IDSD-EA-2 IDS-BUS-F0P-EA2/D IDS BUS APP-IDSD-EA-2 FAIL TO OPERATE IDSD-EW-EA2JZN Instminentation CAB-IC-FOP-IDSD-EW-EA2JZN 120V AC Inverters^'^

IDSA-EW-DUILZN Instminentation CAB-IC-FOP-IDSA-EW-DUILZN IDSA-EW-DUIMZN Instminentation CAB-IC-FOP-IDSA-EW-DUIMZN IDSA-DU-1 IDS-INV-FOP-IDS INVERTER APP-IDSA-DU-IDSA-EW-DUINZN Instrumentation CAB-IC-FOP-IDSA-EW-DUINZN DUl/A I FAIL TO OPERATE IDSA-EW-DUIPZN Instminentation CAB-IC-FOP-IDSA-EW-DUIPZN IDSA-EW-DUIQZN Instminentation CAB-IC-FOP-IDSA-EW-DUIQZN IDSA-EW-DUIRZN Instminentation CAB-IC-FOP-IDSA-EW-DUIRZN IDSB-EW-DUINZN Instminentation CAB-IC-FOP-IDSB-EW-DUINZN IDSB-EW-DUILZN Instminentation CAB-IC-FOP-IDSB-EW-DUILZN IDSB-DU-1 IDS-INV-FOP-IDS INVERTER APP-IDSB-DU-IDSB-EW-DUIMZN Instminentation CAB-IC-FOP-IDSB-EW-DUIMZN DUl/B I FAIL TO OPERATE IDSB-EW-DUIQZN Instminentation CAB-IC-FOP-IDSB-EW-DUIQZN IDSB-EW-DUIRZN Instminentation CAB-IC-FOP-IDSB-EW-DUIRZN IDSB-EW-DUIPZN Instminentation CAB-IC-FOP-IDSB-EW-DUIPZN IDSB-DU-2 IDS-INV-F0P-DU2/B IDS INVERTER APP-IDSB-DU-2 FAIL TO OPERATE None Inspection complete no IEEE issue identified.

'** This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission NO-21-0843 Enclosure 3 Page 46 of 49 Westinghouse Non-Proprietary Class 3 Page 46 of 49 LTR-APlOOO-PRA-21-OI 1-NP Rev. 1 09/30/2021 Table B-1: Non-1 C Cable Nonconformance Mapping to PRA Equipment for IDS Panel Impacts Component l Basic Event l

Description IEEE Cable Impacts'-^

Basic Events Added For Cable Failure Sensitivity PRA Basic Event information Impacted Non IE Cable Type of Cable Mitigation Basic Events Added to Model IE Basic Events Added to Model (if applicable)

Notes lDSC-DU-1 IDS-INV-FOP-DUl/C IDS INVERTER APP-IDSC-DU-I FAIL TO OPERATE None Inspection complete no IEEE issue identified.

IDSC-DU-2 IDS-INV-F0P-DU2/C IDS INVERTER APP-IDSC-DU-2 FAIL TO OPERATE None Inspection complete no IEEE issue identified.

IDSD-DU-1 IDS-INV-FOP-DUl/D IDS INVERTER APP-IDSD-DU-I FAIL TO OPERATE None Inspection complete no IEEE issue identified.

Battery Chargers' lDSA-DC-1 IDS-BCH-FOP-DCl/A IDS BATTERY CHARGER APP-IDSA-DC-I FAIL TO OPERATE IDSA-EW-DCIAXN Power CAB-PC-FOP-IDSA-EW-DCIAXN CAB-PC-FOP-IDSA-EW-DCIAXN-IE IDS-BCH-FOP-DCl/A-IE IDS BATTERY CHARGER APP-IDSA-DC-I FAIL TO OPERATE IDSA-EW-DCILZN Instrumentation CAB-IC-FOP-IDSA-EW-DCILZN CAB-IC-FOP-IDSA-EW-DCILZN-IE IDSA-EW-DCIMZN Instnimentation CAB-IC-FOP-IDSA-EW-DCIMZN CAB-IC-FOP-IDSA-EW-DCIMZN-IE IDSB-DC-1 IDS-BCH-FOP-DCl/B IDS BATTERY CHARGER APP-IDSB-DC-I FAIL TO OPERATE IDSB-EW-DCIAXN Power Screened - see notes coluinn Screened - see notes column DC Battery Test Circuit cables are not addressed due to the short exposure time. See Section 3.1.2.3 for more infonnation.

IDS-BCH-FOP-DCl/B-IE IDS BATTERY CHARGER APP-IDSB-DC-I FAIL TO OPERATE IDSB-DC-2 IDS-BCH-FOP-DC2/B IDS BATTERY CHARGER APP-IDSB-DC-2 FAIL TO OPERATE IDSB-DC-2-JUMPER Internal Cables 1-3 (See Note)

Power Screened - see notes column DC Battery Test Circuit cables are not addressed due to the short exposure time. See Section 3.1.2.3 for more information.

IDSC-DC-l IDS-BCH-FOP-DCI/C IDS BATTERY CHARGER APP-IDSC-DC-I FAIL TO OPERATE IDSC-EW-DCIAXN Power CAB-PC-FOP-IDSC-EW-DCIAXN CAB-PC-FOP-IDSC-EW-DCIAXN-IE IDS-BCH-FOP-DCl/C-IE IDS BATTERY CHARGER APP-IDSC-DC-1 FAIL TO OPERATE IDSC-DC-2 IDS-BCH-FOP-DC2/C IDS BATTERY CHARGER APP-IDSC-DC-2 FAIL TO OPERATE None Inspection complete no IEEE issue identified.

"* This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 47 of 49 Westinghouse Non-Proprietaiy Class 3 Page 47 of 49 LTR-APIOOO-PRA-21-011-NP Rev. i 09/30/2021 Table B-1: Non-IE Cable Nonconforniance Mapping to PRA Equipment for IDS Panel Impacts Component Basic Event Description IEEE Cable Impacts'^'

Basic Events Added For Cable Failure Sensitivity PRA Basic Event Information Impacted Non IE Cable Type of Cable Mitigation Basic Events Added to Model IE Basic Events Added to Model (if applicable)

Notes IDSD-DC-i IDS-BCH-FOP-DCI/D IDS BATTERY CHARGER APP-IDSD-DC-I FAIL TO OPERATE IDSD-EW-DCIAXN Power CAB-PC-FOP-IDSD-EW-DCIAXN CAB-PC-FOP-IDSD-EW-DCIAXN-IE Note that IDSD-EW-DCIAXN has 2 different Target SSCs (IDSD-EW-DFICXD, Indeterminate) target set are DC Battery and Test Circuit Power Circuit. DC Battery Test Circuit cables are not addressed due to the short exposure time. See Section 2.1.5 for more infonnation. Therefore this is addressed as a DC power circuit cable.

IDS-BCH-FOP-DCI/D-IE IDS BATTERY CHARGER APP-IDSD-DC-I FAIL TO OPERATE IDSD-EW-DCIMZN Instrumentation CAB-IC-FOP-IDSD-EW-DCIMZN CAB-IC-FOP-IDSD-EW-DCIMZN-IE IDSD-EW-DCISZN Instrumentation CAB-IC-FOP-IDSD-EW-DCISZN CAB-IC-FOP-IDSD-EW-DCISZN-IE IDSD-EW-DCILZN Instnnnentation CAB-IC-FOP-IDSD-EW-DCILZN CAB-IC-FOP-IDSD-EW-DCILZN-IE Notes:

(1) Basic Event and description information from Appendix B of Reference 5 for the impacted equipment types across all 4 divisions of IDS.

(2) Impacted Non 1E cable identifiers and corresponding type of circuit from Reference 9 This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 48 of 49 Westinghoiise Non-Proprietary Class 3 Page 48 of 49 LTR-AP1OOO-PRA-21 -0II -NP Rev. 1 09/30/2021 Table B-2: Non-IE Cable N on con form a nee Mapping to PRA Equipment for RCP Switcligear Impacts Component l Basic Event l

Description IEEE Cable Impacts^^)

Basic Events Added For Cable Failure Sensitivity PRA Basic Event Information Impacted Non IE Cable Type of Cable Mitigation Basic Events Added to Model Notes ECS-ES-31(52)

ECS-CBK-FTO-31(52)

ECS CIRCUIT BREAKER APP-ECS-ES-31(52) FAIL TO OPEN ECS-ES-31(52)-1 Instnimentation CAB-IC-FOP-ECS-ES-31 (52)-1 ECS-ES-31(52)-2 Instnnnentation CAB-IC-FOP-ECS-ES-31 (52)-2 ECS-ES-31(52)-3 Instnimentation CAB-IC-FOP-ECS-ES-31(52)-3 ECS-ES-31(52)-4 Instnimentation CAB-IC-FOP-ECS-ES-31 (52)-4 ECS-ES-31(52)-5 Instnimentation CAB-IC-FOP-ECS-ES-31 (52)-5 ECS-ES-32(52)

ECS-CBK-FTO-32(52)

ECS CIRCUIT BREAKER APP-ECS-ES-32(52) FAIL TO OPEN ECS-ES-32(52)-l Instnimentation CAB-IC-FOP-ECS-ES-32(52)-1 ECS-ES-32(52)-2 Instnimentation CAB-IC-FOP-ECS-ES-32(52)-2 ECS-ES-32(52)-3 Instnimentation CAB-IC-FOP-ECS-ES-32(52)-3 ECS-ES-32(52)-4 Instnimentation CAB-IC-FOP-ECS-ES-32(52)-4 ECS-ES-32(52)-5 Instnimentation CAB-IC-FOP-ECS-ES-32(52)-5 ECS-ES-41(52)

ECS-CBK-FTO-41(52)

ECS CIRCUIT BREAKER APP-ECS-ES-41(52) FAIL TO OPEN ECS-ES-41(52)-1 Instnimentation CAB-IC-FOP-ECS-ES-4I(52)-I ECS-ES-41(52)-2 Instnimentation CAB-IC-FOP-ECS-ES-41(52)-2 ECS-ES-41(52)-3 Instnimentation C

AB-IC-FOP-ECS-ES-41 (52)-3 ECS-ES-41(52)-4 Instnnnentation CAB-IC-FOP-ECS-ES-41(52)-4 ECS-ES-41(52)-5 Instnnnentation CAB-IC-FOP-ECS-ES-4I(52)-5 ECS-ES-42(52)

ECS-CBK-FTO-42(52)

ECS CIRCUIT BREAKER APP-ECS-ES-42(52) FAIL TO OPEN ECS-ES-42(52)-l Instnnnentation CAB-IC-FOP-ECS-ES-42(52)-I ECS-ES-42(52)-2 Instnnnentation CAB-IC-FOP-ECS-ES-42(52)-2 ECS-ES-42(52)-3 Instnnnentation CAB-IC-FOP-ECS-ES-42(52)-3 ECS-ES-42(52)-4 Instnimentation CAB-IC-FOP-ECS-ES-42(52)-4 ECS-ES-42(52)-5 Instnnnentation CAB-IC-FOP-ECS-ES-42(52)-5

"* This record was final approved on 9/30/2021 6:07:00 PM. (This statement was added by the PRIME system upon its validation)

U. S. Nuclear Regulatory Commission ND-21-0843 Enclosure 3 Page 49 of 49 Westinghouse Non-Proprietary Class 3 Page 49 of 49 LTR-AP1OOO-PRA-21-011 -NP Rev. 1 09/30/2021 Table B-2: Noii-IE Cable Nonconforniaiice Mapping to PRA Equipment Component l Basic Event l

Description IEEE Cable Impacts^-)

Basic Events Added For Cable Failure Sensitivity PRA Basic Event Information Impacted Non IE Cable Type of Cable Mitigation Basic Events Added to Model Notes ECS-ES-51(52)

ECS-CBK-FTO-51(52)

ECS CIRCUIT BREAKER APP-ECS-ES-51(52) FAIL TO OPEN ECS-ES-51(52)-1 Instmmentation CAB-1C-F0P-ECS-ES-51(52)-1 ECS-ES-51(52)-2 Instrumentation C

AB-lC-FOP-ECS-ES-51(52)-2 ECS-ES-51(52)-3 Instmmentation C

AB-lC-FOP-ECS-ES-51(52)-3 ECS-ES-51(52)-4 Instmmentation CAB-lC-FOP-ECS-ES-51 (52)-4 ECS-ES-51(52)-5 Instrumentation CAB-lC-FOP-ECS-ES-51 (52

)-5 ECS-ES-52(52)

ECS-CBK-FTO-52(52)

ECS CIRCUIT BREAKER APP-ECS-ES-52(52) FAIL TO OPEN ECS-ES-52(52)-l Instmmentation C

AB-IC-FOP-ECS-ES-52(52)-1 ECS-ES-52(52)-2 Instmmentation CAB-lC-FOP-ECS-ES-52(52)-2 ECS-ES-52{52)-3 Instmmentation CAB-lC-FOP-ECS-ES-52(52)-3 ECS-ES-52(52)-4 Instmmentation CAB-lC-FOP-ECS-ES-52(52)-4 ECS-ES-52(52)-5 Instmmentation CAB-lC-FOP-ECS-ES-52(52)-5 ECS-ES-61(52)

ECS-CBK-FTO-61(52)

ECS CIRCUIT BREAKER APP-ECS-ES-61(52) FAIL TO OPEN ECS-ES-61(52)-1 Instmmentation CAB-1C-F0P-ECS-ES-61(52)-1 ECS-ES-61(52)-2 Instmmentation C

AB-lC-FOP-ECS-ES-61 (52)-2 ECS-ES-61(52)-3 Instmmentation C

AB-lC-FOP-ECS-ES-61 (52

)-3 ECS-ES-61(52)-4 Instmmentation CAB-lC-FOP-ECS-ES-61(52)-4 ECS-ES-61(52)-5 Instmmentation CAB-IC-FOP-ECS-ES-61(52)-5 CS-ES-62(52)

ECS-CBK-FTO-62(52)

ECS CIRCUIT BREAKER APP-ECS-ES-62(52) FAIL TO OPEN ECS-ES-62(52)-l Instmmentation CAB-lC-FOP-ECS-ES-62(52)-l ECS-ES-62(52)-2 Instmmentation CAB-lC-FOP-ECS-ES-62(52)-2 ECS-ES-62(52)-3 Instmmentation CAB-lC-FOP-ECS-ES-62(52)-3 ECS-ES-62(52)-4 Instmmentation CAB-lC-FOP-ECS-ES-62(52)-4 ECS-ES-62(52)-5 Instmmentation CAB-lC-FOP-ECS-ES-62(52)-5 Note:

(1) Basic Event and description infonnation from Appendix B of Reference 15 for the ECS breakers which support RCP trip.

(2) Impacted Non IE cable identifiers and corresponding type is assumed for this revision. See open item 2 of Section 10.

• • • This record was final approved on 9/30/2021 6:07:00 PM.

(This statement was added by the PRIME system upon its validation)