Text

Supplemental Information Regarding Application for License Amendment to Adopt NFPA 805, Performance Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition)
	ML14051A499
Person / Time
Site:	Beaver Valley
Issue date:	02/14/2014
From:	Emily Larson; FirstEnergy Nuclear Operating Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	L-14-064, TAC MF3301, TAC MF3302
	Download: ML14051A499 (303)
	v • d • e

FENOC- %P.O.

Beaver Valley Power Station Box 4 FirstEnergy Nuclear OperatingCompany Eric A. Larson 724-682-5234 Site Vice President Fax: 724-643-8069 February 14, 2014 L-14-064 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Beaver Valley Power Station, Units No. 1 and 2 BVPS-1 Docket No. 50-334, License No. DPR-66 BVPS-2 Docket No. 50-412, License No. NPF-73 Supplemental Information Regarding Application for License Amendment to Adopt NFPA 805, "Performance Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition)" (TAC Nos. MF3301. MF3302)

By letter dated December 23, 2013 (Agencywide Documents Access and Management System Accession Number ML14002A086), FirstEnergy Nuclear Operating Company submitted an application for license amendment to adopt NFPA 805 as the licensing basis for fire protection programs at the Beaver Valley Power Station (BVPS). In support of the application for license amendment, an analysis of the adequacy of the internal events probabilistic risk assessment (PRA) for BVPS is enclosed.

There are no regulatory commitments established in this letter or its enclosure. If there are any questions or if additional information is required, please contact Mr. Thomas A. Lentz, Manager - Fleet Licensing, at 330-315-6810.

I declare under penalty of perjury that the foregoing is true and correct. Executed on February ji__, 2014.

Sincerely, Eric A. Larson

Enclosure:

Beaver Valley Power Station Units 1 and 2 - Internal Events PRA Quality cc: Director - NRC Office of Enforcement (w/o Enclosure)

NRC Regional Administrator - Region I (w/o Enclosure)

NRC Resident Inspector (w/o Enclosure)

NRC Project Manager (w/o Enclosure)

Director - State of Pennsylvania BRP/DEP (w/o Enclosure)

Site Representative - State of Pennsylvania BRP/DEP (w/o Enclosure)

IV(

Enclosure L-14-064 Beaver Valley Power Station Units 1 and 2 Internal Events PRA Quality (301 pages follow)

Beaver Valley Power Station Units I and 2 Internal Events PRA Quality Page 1 of 301

The Level 1 and Level 2 Probabilistic Risk Assessment (PRA) analyses for Beaver Valley Power Station (BVPS) Units 1 and 2 were originally developed in response to Generic Letter 88-20, Individual Plant Examination for Severe Accident Vulnerabilities -

10 CFR 50.54(f).

The BVPS-1 Individual Plant Examination (IPE) and the Individual Plant Examination of External Events (IPEEE) were submitted to the Nuclear Regulatory Commission (NRC) in October 1992 and June 1995, respectively. Since the inception of these studies, the BVPS-1 PRA model has evolved and has been updated many times. The following table provides a summary of the BVPS-1 PRA model revision history.

Date Revision BVPS-1 PRA Model Chanae 10/1992 0 Individual Plant Examination (IPE) NRC submittal 06/1995 1 Individual Plant Examination - External Events (IPEEE) NRC submittal 06/1998 2 Integrated Level 1 and Level 2 models 09/2003 3 WOG NEI 00-02 Peer Review with Category A/B F&Os addressed 06/2006 4 HRA [Human Reliability Analysis] Calculator, replacement steam generators, atmospheric containment conversion, and extended power uprate model 12/2010 5 RG 1.200, R1 (excluding Floods) CCII Compliant Model 01/2013 5a Interim model update to include Internal Flooding, RG 1.200, R1 (including Floods) CCII Compliant Model The BVPS-2 Individual Plant Examination (IPE) and the Individual Plant Examination of External Events (IPEEE) were submitted to the NRC under separate letters in March 1992 and September 1997, respectively. Since the inception of these studies, the BVPS-2 PRA model has evolved and has been updated many times. The following table provides a summary of the BVPS-2 PRA model revision history.

Date Revision BVPS-2 PRA Model Chanae 03/1992 0 Individual Plant Examination (IPE) NRC submittal 09/1997 1 Individual Plant Examination - External Events (IPEEE) NRC submittal 10/1997 2 Integrated Level 1 and Level 2 models 01/2002 3A WOG NEI 00-02 Peer Reviewed 05/2003 3B WOG NEI 00-02 Peer Review with Category A/B F&Os addressed 04/2007 4 HRA [Human Reliability Analysis] Calculator, atmospheric containment conversion, and extended power uprate model 12/2010 5 RG 1.200, R1 (excluding Floods) CCII Compliant Model Page 2 of 301

08/2012 5a Interim model update to include Internal Flooding, RG 1.200, R1 (including Floods) CCII Compliant Model The BVPS-1 and BVPS-2 PRA models, PRA-BV1-AL-R05 (BVI REV5) and PRA-BV2-AL-R05a (BV2REV5A), were the starting points for the Fire PRA. The BVPS PRA models have been subjected to assessments establishing the technical adequacy of the PRA. These assessments are identified and discussed in the paragraphs below.

9 2002 - An independent PRA peer review of the BVPS PRA models (BV1 REV3 and BV2REV3A) was conducted under the auspices of the Westinghouse Owners Group (WOG) in July 2002, following the guidance provided by the Nuclear Energy Institute in NEI 00-02, "Probabilistic Risk Assessment Peer Review Process Guidance,"

Revision A3, March 2000 (NEI 00-02).

2007 - Following the BVPS-1 PRA model revision in 2006 (BVI REV4) and the BVPS-2 PRA model revision in 2007 (BV2REV4) which incorporated necessary updates and changes to address F&Os from the 2002 peer review, a self-assessment of the BVPS PRA models was performed against the American Society of Mechanical Engineers Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications, (ASME-RA-S-2002, and addenda, hereafter referred to as the ASME PRA Standard) using NRC Regulatory Guide (RG) 1.200, Revision 1, January 2007, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk Informed Activities.

o 2007 - As part of the resolution to several F&Os from the 2002 PRA peer review, a change in the Human Reliability Analysis (HRA) methodology was incorporated into the 2006 BVPS-1 and the 2007 BVPS-2 PRA model revisions, so a focused scope peer review of the HRA Technical Elements against the ASME PRA Standard was performed using RG 1.200, Revision 1.

2011 - Due to an upgrade of the internal flooding model following the revision of both BVPS PRA models in 2010 (BV1 REV5 and BV2REV5), a focused scope peer review of the Internal Flood PRA Technical Elements was performed against the applicable requirements of Part 3 of the ASME PRA standard as endorsed in RG 1.200, Revision 2.

Facts and Observations (F&Os) from the various reviews are assigned significance levels of A, B, C, D, or S for the 2002 peer review and 2007 self-assessment; or Finding, Suggestion, or Best Practice for the 2007 HRA peer review and the 2011 Internal Flooding peer review. The F&O significance levels are defined as follows.

2002 Peer Review

" A - Extremely important and necessary to address to assure the technical adequacy of the PRA or the quality of the PRA or the quality of the PRA update process

" B - Important and necessary to address, but may be deferred until the next PRA update Page 3 of 301

" C - Recommended, and considered desirable to maintain maximum flexibility in PRA Applications and consistency in the Industry, but not likely to significantly affect results or conclusions

" D - Editorial or Minor Technical Item, left to the discretion of the host utility

" S - Superior treatment, exceeding requirements for anticipated applications and exceeding what would be found in most PRAs 2007 Self-Assessment

A and B level F&Os represent issues that have the potential to affect the risk results and/or risk insights. B level F&Os also represent documentation issues that are required to meet Capability Category I1. All A and B level F&Os need to be resolved to achieve Capability Category II or higher.

" C and D level F&Os are comments or suggestions to improve documentation or traceability of analyses, but do no impact the supporting requirement grades. A C level F&O may also provide a suggestion on an alternative approach to achieve an objective, but does not imply that the approach used is not sufficient to meet the supporting requirements at the stated grade.

S level F&Os are considered to be superior and do not reflect any shortfall to a requirement.

2007 HRA Focused Peer Review and 2011 Internal Flooding Focused Peer Review

" Finding - Equivalent to the old A and B levels of significance

" Suggestion - In general, equivalent to the old C and D levels of significance

Best Practice - Equivalent to the old Strength (S) level of significance The WOG conducted the Beaver Valley PRA model peer review following the NEI 00-02 process in July 2002. This peer review focused on the Unit 2 PRA model but also provided a cursory review of the Unit 1 PRA model and methodology. The Peer Review Team noted that Unit I uses the same PRA modeling techniques as Unit 2, so when the Unit 1 PRA revision is performed in the future using the same modeling assumptions as Unit 2 (including addressing applicable peer review comments) the Unit 1 PRA model and results should have the same level of confidence and applicability as those of Unit 2.

The significant findings (Category A and B F&Os) from the BVPS PRA peer review were incorporated into the 2003 BVPS-1 Revision 3 (BV1 REV3) and the 2003 BVPS-2 Revision 3B (BV2REV3B) PRA models respectively. A long term solution to one of the PRA peer review findings was to revise the human reliability analysis methodology from the success likelihood index methodology (SLIM) to the EPRI HRA Calculator. The BVPS HRA were revised using the EPRI HRA Calculator and the results were incorporated into the 2006 BVPS-1 Revision 4 (BV1 REV4) and 2007 BVPS-2 Revision 4 (BV2REV4) PRA models respectively. The Revision 4 PRA models included the Page 4 of 301

replacement steam generators for BVPS-1, and the atmospheric containment conversion and extended power uprate to 2900 MWt for both units.

Following the BVPS-1 PRA Model Revision 4 in 2006 and the BVPS-2 PRA Model Revision 4 in 2007, a self-assessment of the BVPS PRA models was conducted in 2007 with the assistance of Westinghouse. Once again this review focused on the BVPS-2 PRA model, but to the extent that the PRA modeling methodologies are equivalent this self-assessment was also applicable to the Unit 1 PRA. This self-assessment was performed to determine if there were any gaps present between the BVPS PRA models and meeting the Capability Category II Supporting Requirements (SR) in the 2005 version of the ASME PRA Standard Addendum B, as endorsed by RG 1.200, Revision 1.

The status of the A and B level F&Os from the 2002 BVPS peer review were also checked, and were found to be resolved when considering the change in methodology to the EPRI HRA Calculator and associated reports that document the HRA inputs and considerations.

In January 2008, Westinghouse provided the final summary report of the BVPS PRA models self-assessment to demonstrate compliance with the ASME PRA Standard and RG 1.200, Revision 1. A total of 73 F&Os were identified in this review, and this assessment provided a starting point for determining where enhancements to the model, sensitivity analyses, or evaluations outside the PRA may be needed for a given application of the PRA to adequately support the integrated decision-making process.

A focused scope peer review was conducted by Westinghouse in October 2007 on the upgraded BVPS HRA methodology (EPRI HRA Calculator) to determine compliance with Addendum B of the ASME PRA Standard and RG 1.200, Revision 1. Because the methodology is the same between Units and the basic analyses differ only in minor details, the review focused on the Unit 2 HRA Report but is also applicable to Unit 1.

Seven new F&Os were prepared to document the specific issues that were identified, all of which were classified as Findings.

In 2010 the BVPS-1 and BVPS-2 Revision 5 PRA models (BV1 REV5 and BV2REV5, respectively) resolved the identified PRA self-assessment F&Os and focused HRA peer review F&Os, with the exception of the 27 F&Os associated with internal flood which required an upgrade of the internal flooding model to comply with the ASME PRA Standard internal flooding methodology.

The BVPS-1 Revision 5 and the BVPS-2 Revision 5 internal flooding PRA models were upgraded to comply with the Capability Category II Supporting Requirements of the combined ASME/ANS PRA standard (RA-Sa-2009), as endorsed by RG 1.200, Revision 2. In June 2011, these upgraded BVPS PRA models underwent a focused PRA peer review on the Internal Flooding portion of the model, which superseded the previous 27 internal flooding F&Os from the 2007 self-assessment and resulted in 17 new F&Os.

The 17 internal flooding PRA F&Os were appropriately resolved in the interim 2013 BVPS-1 Revision 5a (BV1 REV5A) PRA model and the interim 2012 BVPS-2 Revision Page 5 of 301

5a (BV2REV5A) PRA model. These Revision 5a PRA models (documented as PRA-BV1-AL-R05a and PRA-BV2-AL-R05a, respectively) are the current effective reference models at BVPS.

The BVPS-1 Revision 5a PRA model (PRA-BV1-AL-R05a) and BVPS-2 Revision 5a PRA model (PRA-BV2-AL-R05a) have resolved all of the applicable F&Os identified in the 2002 BVPS PRA Peer Review, 2007 BVPS PRA Self-Assessment, 2007 BVPS HRA Focused Peer Review, and the 2011 BVPS Internal Flood PRA Focused Peer Review. These PRA models are considered to be fundamentally compliant with RG 1.200, Revision 1 for the scope of this application, meet Capability Category II or above in the ASME PRA Standard (RA-Sb-2005), and are capable of supporting all risk-informed applications requiring Capability Category I or II.

The Fire PRA model for BVPS-1 was based on the BVPS-1 Revision 5 PRA model, in which all previous F&Os except those related to internal flooding were resolved. Interim Issued Revision 5a PRA has already addressed all internal flooding F&Os. Final Fire PRA will be integrated into the updated working PRA model prior to the implementation of NFPA-805. The Fire PRA model for BVPS-2 was based on the BVPS-2 Revision 5a PRA model in which all F&Os, including those related to internal flooding, are resolved.

Furthermore, BVPS is currently working on a regular update of 5a internal events PRA models, and the final Fire PRA model will be integrated into the latest revision of the PRA models as they are rolled out.

A brief summary of the BVPS final resolutions to the A, B, C, and D level F&Os from the 2002 WOG NEI 00-02 BVPS PRA Peer Review is provided in Table 1-1 Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions, and Table 2-1 Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions.

The resolutions to the 2007 BVPS PRA Self-Assessment F&Os are provided in Table 1-2 Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions, and Table 2-2 Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions.

The resolution to the seven F&Os from the 2007 BVPS HRA Focused Peer Review are provided in Table 1-3 Summary of BVPS-1 HRA Focused Peer Review - Facts and Observations Resolutions, and Table 2-3 Summary of BVPS-2 HRA Focused Peer Review - Facts and Observations Resolutions.

The 2011 BVPS Internal Flood PRA Focused Peer Review F&O resolutions are provided in Table 1-4 Summary of BVPS-1 Internal Flooding Focused Peer Review -

Facts and Observations Resolutions, and Table 2-4 Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions.

Page 6 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN AS-I 0 AS-12 A Y The BV PRA uses the WOG 2000 Additional MAAP uncertainty No impact to Fire seal LOCA in a way that may be cases for BVPS-1 were PRA, because this unacceptable to the NRC for risk performed using pessimistically issue was based applications. MAAP runs are biased values along with setting addressed in the performed to find the core uncovery input parameters to their high or base PRA model times for various sizes of seal LOCA. low limits. These cases were run prior to building the If the best estimate MAAP runs show out to 48-hours or until core Fire PRA.

the core is covered at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , the damage occurred. The success sequence is considered success. The state for the BV1 REV3 PRA result is that all SLOCA sizes except model was redefined as any case the 480 gpm leak have no impact on (including uncertainties) that did CDF, because the core is shown to not go to core damage before 48-remain covered at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . This strict hours. For cases that went to interpretation of the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months mission core damage before 48-hours but time results in a .01 probability of core after 24-hours, additional electric uncovery, even in sequences where power recovery values were SW or AC power is not restored. used, based on NUREG/CR-5496. For cases that lead to This result is significantly more core uncovery before 24-hours, a optimistic than most other plant specific electric power Westinghouse PRAs. The uncertainty recovery model was used. If in the calculation [due to the possible electric power recovery was variation in RCS pressure or seal successful for these cases, the LOCA size from the predicted] is not sequence was also binned to the pursued. success end state.

The MAAP analysis shows time to core uncoverv of areater than 24

' The Supporting Requirement is in reference to NEI 00-02 Element - Subelement.

Page 7 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN hours, but the plant is not yet in a stable configuration. Declaration of success at this point, based only on MAAP results without thorough investigation of MAAP uncertainties (e.g., sensitivities) is a liberal application of the intent of the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months success criteria and may be non-conservative.

Page 8 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN HR-07 HR-10 A Y The BV PRA uses the SLIM As a resolution to this PRA Peer No impact to Fire methodology. The HEP's are grouped Review observation all operator PRA, because this in to 10 categories and then each actions having a Risk issue was category is "calibrated" in terms of 1 to Achievement Worth (RAW) addressed in the 5 other PRA's. The PRA's that were greater than 2 (generally base PRA model used were Oconee (1984), Seabrook accepted as the risk significant prior to building the (1983), Diablo Canyon (1987), TMI threshold) were compared to Fire PRA.

(1985), Fermi (not referenced), South similar actions for all Texas (1988). The categories reflect Westinghouse plants by using each type of error (rule, skill, the WOG/B&WOG PSA knowledge, diagnosis, response). The Comparison Database HRA's on which these are based are (Revisions 2 and 3). Additionally, representative of nuclear plant a smaller subset of these plants procedures, training and operator was also looked at that consisted cognizance typical for mid-1980. of 3-loop plants (since these were assumed to have similar The error rate curves should be operation action completion updated to reflect current operator times based on plant power to performance in the nuclear power heatup volume ratios), plants that industry. The use of 15 year old also used the SLIM process, and reliability data will limit the ability of Indian Point 2, which received a the PRA to support risk based superior finding in their Human applications. Reliability Analysis.

The results of this comparison show that for the operator actions that were compared, the human error rates used in the BVI REV3 PRA model are all within the range of both comparison groups defined above. It is therefore believed that the basic error curves used in the calibration of Page 9 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID RequirementI Level Closed PRA YIN the BV1 REV3 HRA are not grossly out of date, and that the current human error rates used in the PRA model are acceptable as is. Moreover, as a final resolution to this observation, future BVPS PRA models will use the EPRI HRA Calculator, which uses a more current and robust methodology.

This F&O was written against an obsolete HRA PRA model (BV1 REV3) and is considered to be resolved by the updated HRA PRA model incorporated in BV1 REV4, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

HR-1 1 HR-27 A Y The BV HRA does not have a process To identify dependent human No impact to Fire to perform a systematic search for actions, sequences with two or PRA, because this dependent human actions credited on more failed split fractions that issue was individual sequences. One case of have a contribution from human addressed in the dependent HEPs was identified and actions were reviewed. Of the base PRA model treated (OF1 and 0B2). However, it is sequences reviewed the human prior to building the Page 10 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN not known how this was found. Other actions were determined to be Fire PRA.

potential cases of dependent human independent between split actions in SGTR. LOCAs or feed and fractions. Human actions that are bleed sequences were not addressed. modeled in a single top event PRAs typically have one or more of have appropriate dependencies the dependent HEPs. modeled in the event tree logic and rules.

SGTR-OD*CD*WM, or RR*WM SGTR-SL*OD*CD*WM Moreover, as a final resolution to SLOCA -CD*MU this observation, future BVPS Trans- OB*MU PRA models will use the EPRI Trans- OF*OB*MU HRA Calculator, which uses a Init - Start standby CCP

Trip RCP more current and robust methodology to identify human There could potentially be other action dependencies.

combinations that were not identified.

This F&O was written against an Current HRA practices generally obsolete HRA PRA model require a systematic process to (BV1 REV3) and is considered to identify, assess and adjust be resolved by the updated HRA dependencies between multiple PRA model incorporated in human errors in the same sequence, BV1 REV4, which underwent a including those in the initiating events. focused Peer Review in accordance with the guidance in Moreover, there was no process in the Appendix B of NRC RG 1.200, HRA to adjust HEP on the final Rev.1, conducted during the sequences and determine week of October 29, 2007, by combinations of operator errors Westinghouse. The F&Os as a credited on individual sequences. A result from this focused Peer sensitivity study was done, but did not Review, as well as their adjust the HEPs. The cutoff was 4E-9, resolutions are presented in so that many other combinations were Table 1-3.

already below the truncation. It is not Page 11 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N clear how HEPs in the initiating events were treated in the study.

To be consistent with current HRA methods, there must be a systematic process to identify, assess and adjust dependencies between multiple human errors in the same sequence, including those in the initiating events.

AS-07 AS-1 9 B Y For the SGTR event tree one of the Based on the EOP Background No impact to Fire operator actions is to initiate Bleed document for FR-H. 1, steam PRA, because this and Feed (top event OB). The generator dryout is expected to issue was success criteria for OB indicates that occur at 33.1 minutes if all RCP addressed in the the basis for the success criteria remain running during a loss of base PRA model assumes that the operator must have all secondary cooling. If the RCP prior to building the stopped the RCPs prior to OB in order are tripped 5 minutes after the Fire PRA.

to extend the time available to initiate reactor trip, steam generator bleed and feed (referenced EOP FR- dryout is expected to occur at H.1). If the tripping of the RCPs is a 40.9 minutes. This difference of prerequisite for the degree of success less than 8 minutes is not of OB where in the model is this expected to significantly impact dependency accounted for. the human error rates calculated for Top Event OB, since the actions to trip the RCPs, initiate SI and open a PORV are fairly simple actions that can be accomplished within minutes.

Therefore, these actions are all assumed to be accounted for in the human action failure rate.

DA-06 DA-8 B Y The generic MGL data used in the BV A summary of all of the MGL No impact to Fire Unit 2 PRA is referenced, almost parameters used in the top event PRA, because this I exclusively to the PLG generic common cause groupings is now issue was Page 12 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN database. Although the data analysis provided in Appendix C, Table C- addressed in the was updated recently, there is no 7 of the Data Analysis PRA base PRA model discussion in the Data Analysis Notebook. No further Corrective prior to building the Notebook regarding the availability of Actions are required. Fire PRA.

newer data sources, e.g.,

NUREG/CR-5497. There should, at a Updated common cause failure minimum be a discussion of the data from WCAP-16672, based currently available data sources. It is on NUREG/CR-6819, were noted that at least one Beta factor ultimately used in the BV2REV5 from NUREG/CR-5497 is used, but it PRA model and appropriately is not referenced in the data notebook. documented. The methodology for the update was taken from NUREG/CR-5485.

DA-09 DA-1 0 B Y There is very little guidance for or Resolutions to this F&O included No impact to Fire documentation of the process of adding a better reference to the PRA, because this selecting CCF groups. The System methodology used in retaining issue was Analysis Overview and Guidance the common cause groupings, addressed in the Notebook provides some of the high along with a listing of all of the base PRA model level methodology, but there is no common cause groupings used prior to building the discussion in the Data Analysis or in the quantification of the system Fire PRA.

System Notebooks as to the top event models. These are development of the groups that were provided in Section 6 "Common ultimately modeled. In general, the Cause Modeling" and Appendix system notebooks document the CCF A, Table A-1 of the BVPS-1 groups by referring to the Riskman Systems Analysis Overview and output files. This is not very Guidance PRA Notebook, informative. For example, the AC respectively. Additionally, a Electric Power System Notebook summary of all of the MGL provides no discussion of the CCF parameters used in the top event model for the diesel generators. A common cause groupings is now discussion of decoupling the Unit 2 provided in Appendix C, Table C-diesels from the Unit 1 should be 6 of the Data Analysis PRA included. Notebook.

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Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N Furthermore, it is the opinion of the BVPS PRA staff that the details of the common cause groups that were retained in the PRA system models and presented in Appendix C of the BVPS Unit I PRA System Notebooks, under the common cause sections of the RISKMAN System Notebook files are adequately documented and can be found by knowledgeable personnel. Therefore, the practice of referencing this part of the notebook is deemed acceptable.

DA-O DA-7 B Y The test and maintenance Unit 2 emergency diesel No impact to Fire unavailabilities for DG were reviewed, generator unavailability data PRA, because this The following were observed, during refueling outages was issue was collected for 3/99 through 2/02 by addressed in the

1. The DG are used in a cross-tie the system engineer. This data base PRA model situation for either unit. Thus, it is was used in addition to the 2.5% prior to building the possible that the unaffected unit could assumed on-line unavailability, Fire PRA.

be in shutdown and the DG could be for a total Unit 2 emergency in overhaul. The outage time for the diesel generator unavailability of DG (when used as a cross-tie) must 4.4% used in the BV1 REV3 PRA include the OOS time during model update for the AC power shutdown. crosstie.

2. Appendix B of the data document indicates maintenance outage was collected Nov 98 through May 2000.

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Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN This is not long enough to capture the DG overhaul experience.

3. For unit 2, the unit 1 DG are used for the cross-tie. The T&M data must come from unit 1 experience. This information was not found.

DE-04 DE B Y There is no discussion of some flow In response to this observation, No impact on the (Draft characteristics (e.g., spray effects, the work that was completed for submitted BVPS-1 IF-09) pipe whip) in the consideration of the Beaver Valley Unit 1 Risk- Fire PRA, which impacts from flood initiators. Informed In-Service Inspection used the (RI-ISI) Indirect (Spatial) BV1REV5 as its Consequence Evaluation was basis. Internal fire reviewed (8700-DMC-1333, Rev. initiators and flood 0). As a part of this evaluation initiators are process, an assessment of the mutually exclusive postulated indirect (spatial) and have no effect consequences associated with on each other.

piping failures was made in order to further distinguish the piping Furthermore, the segments. The indirect effects BVPS-1 Fire PRA assessment was accomplished working model through an investigation of uses BV1 REV5A I existing plant documentation on as its basis, so this Page 15 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N pipe breaks, flooding, and plant F&O will be layout along with a focused plant resolved when walkthrough. The indirect effects NFPA 805 is that were specifically looked at implemented.

included; pipe whip, jet impingement, sprays, and flooding resulting from pipe breaks or leaks. The results of this indirect effects evaluation did not identify any viable SSC impacts due to flood induced failure mechanisms that were not already addressed in the PRA flooding analysis documentation.

No further flooding impacts were incorporated into the BV1 REV3 PRA.

This F&O was written against an obsolete Internal Flooding PRA model (BV1 REV3) and is considered to be resolved by the updated Internal Flooding PRA model incorporated in BV1 REV5A, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are Page 16 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN presented in Table 1-4.

DE-05 DE B Y A number of flood-specific HEPs are To resolve this PRA Peer Review No impact on the (Draft included in the analysis (e.g., observation at Unit 1, operator submitted BVPS-1 IF-25, ZHEFL1-4). These four HEPs are actions ZHEFL1, ZHEFL2, Fire PRA, which IF-26) evaluated in the HRA Notebook in the ZHEFL3, and ZHEFL4 were used the calculation tables, but no discussion of added to Table 3-1 "Beaver BV1 REV5 as its these actions is included in the HRA Valley Human Actions" and basis. Internal fire documentation, and only ZHEFL1 and discussions of the scenarios now initiators and flood ZHEFL2 appear in the flood appear in Appendix A"Dynamic initiators are documentation in the Appendix C of Action Identifier Sheets mutually exclusive the IE Notebook. and have no effect This F&O was written against an on each other.

obsolete Internal Flooding PRA model (BV1 REV3) and is Furthermore, the considered to be resolved by the BVPS-1 Fire PRA updated Internal Flooding PRA working model model incorporated in uses BV1 REV5A BV1 REV5A, which underwent a as its basis, so this focused Peer Review in F&O will be accordance with the guidance in resolved when Appendix B of NRC RG 1.200, NFPA 805 is Rev. 1, conducted during June 6- implemented.

9 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are I presented in Table 1-4.

Page 17 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN HR-01 HR-4 B Y Miscalibration errors are not This observation is not totally No impact to Fire considered for either independent or correct, since the SSPS model PRA, because this common cause pre-initiator human did include instrument string issue was errors. The PRA assumes that both miscalibration errors in the fault determined to have would be captured in the equipment tree model. Additionally, no effect on the failure data. However, the generic common cause miscalibration BVPS PRA model.

common cause failure database is not errors between trains are verified as having included considered to be rare events miscalibration errors as well. since the On-line Maintenance Therefore, there is a potential Program is developed to misapplication of the generic common alternate work between trains on cause data use since the generic data different weeks. Furthermore, a source may not include the common search in the Corrective Action cause miscalibration. database and EPIX did not reveal any such miscalibration errors between trains at BVPS.

Therefore, this observation was assumed to be resolved by the instrument string miscalibration errors already accounted for in the SSPS model. No further miscalibration errors were incorporated into the BV1 REV3 PRA.

This F&O was written against an obsolete HRA PRA model (BV1 REV3) and is considered to be resolved by the updated HRA PRA model incorporated in BV1 REV4, which underwent a focused Peer Review in accordance with the guidance in Page 18 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN Appendix B of NRC RG 1.200, Rev. 1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

HR-03 HR-2 B Y The BV PRA uses the SLIM While it is true that the FLI is a No impact to Fire methodology to quantify the post linear combination of the PSF PRA, because this initiator human actions. The HRA rankings and weightings product, issue was quantification currently in use was the actual HER is logarithmic as addressed in the completed for the IPE and has not discussed in Section 2.1 of the base PRA model been updated. The SLIM method can HRA notebook. Additionally, as prior to building the only combine the PSFs linearly to shown in Table B-4 "Beaver Fire PRA.

develop the overall FLI for each Valley Unit 1 - Group 2 Human action. Current industry practice Actions Evaluation" between contends that PSFs can have ZHEMU1 and ZHEMU2, where significant non-linearities. For the only major difference is in the example if a particular action is rated timing rankings, there is a poorly for a given PSF and moderately significant difference in the HER in all the others, middle of the road values.

HEPs tend to result even though poor performance in only one PSF may be This PRA Peer Review indicative of poor human reliability observation was dispositioned irrespective of what is going on with by, the resolution of F&O HR-07 the other PSFs. Mosleh of University above, where it was shown that of Maryland has addressed this issue the current human error rates in a refinement of the FLIM method used in the PRA model are (which allows assignment of acceptable as is, and by importance to PSFs) in an update of acknowledging the PRA Peer I Page 19 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN the Calvert Cliffs PRA. The BV PRA Review Team comment on its uses linear compilation of PSFs. The significance on CDF. Moreover, ability to use non-linear compilations, as a final resolution to this if desired would be an enhancement. observation, future BVPS PRA models will use the EPRI HRA Calculator, which uses a more current and robust methodology to identify human action dependencies.

This F&O was written against an obsolete HRA PRA model (BV1 REV3) and is considered to be resolved by the updated HRA PRA model incorporated in BV1 REV4, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

Page 20 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N HR-09 HR-03 B Y There is not enough detail in the HRA This CA is being (was) rolled into No impact to Fire to reproduce the results. The following CA 02-09046-29 to track its PRA, because this information was not available and resolution. issue was does not appear to have been addressed in the retained: This F&O was written against an base PRA model obsolete HRA PRA model prior to building the a) the time lines (BVI REV3) and is considered to Fire PRA.

be resolved by the updated HRA b) discussion of the events chosen for PRA model incorporated in "calibration" from the other PRA's and BV1 REV4, which underwent a the reason why they are applicable, focused Peer Review in accordance with the guidance in c) the basis for choosing 10 Appendix B of NRC RG 1.200, categories of HEP and the basis for Rev.1, conducted during the assigning each BV HEP to a category week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

Page 21 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN HR-13 HR-19 B Y Some discrepancies in the timing CAs 02-09045-18, -19, -20, 02- No impact to Fire were observed in the PRA. 05632-01, and 03-07552-06 are PRA, because this All the timing calculations were based all associated with re-evaluating issue was on hand calculations. Although the operator actions for Revision 4 of addressed in the times seemed reasonable compared the BVPS-1 PRA model using base PRA model to other PRAs, there were some the EPRI HRA Calculator. prior to building the observations. Fire PRA.

This F&O was written against an

1) There was a calculation done for obsolete HRA PRA model steam generator dryout, which (BV1 REV3) and is considered to assumed all the water would be be resolved by the updated HRA exhausted from the SG by 1.1 hours1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . PRA model incorporated in Using 1.1 hours1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months overestimates the BV1 REV4, which underwent a time available to do F&B or restore focused Peer Review in AFW. Effectiveness of decay heat accordance with the guidance in removal will decrease way before all Appendix B of NRC RG 1.200, the water is gone in the SG. Rev. 1, conducted during the week of October 29, 2007, by

2) ZHECC1 - start standby CCP Westinghouse. The F&Os as a provides a time of 30 minutes, based result from this focused Peer on seal failure after loss of seal Review, as well as their cooling. But, after loss of CCW, the resolutions are presented in RCP must be tripped with in 5-10 Table 1-3.

minutes to avoid catastrophic seal failure. The 30 minutes for seal failure after loss of cooling does not apply.

This scenario is for bearing failure after loss of CCW. The timing should be consistent.

3) ZHEIC1 and ZHEIC2 show 70 and 30 minutes based on seal failure after

.1. .1______________ 1 1 loss of seal coolina. The time should .1.

Page 22 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN be consistent and should consider if the Loss of CCW to the RCP bearing must be considered.

4) ZHEMU1 - timing for MU indicates the operator has 1.6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months to act, based on the time it takes to drain the RWST from minimum level "empty".

The number should be coordinated with the boron dilution calculation, which assumes boron dilution times from a RWST level of 140,000 or 360,000 gallons. time allowed for operator diagnosis on the front end must be subtracted from time allowed

5) ZHEOB1 provides 78 minutes for feed and bleed, based on the time for a PORV to lift after loss of AFW.

There is no analysis for this. In most PWR, F&B must be started prior to the time the PORV lifts. Start time for F&B should be based on MAAP analysis.

6) ZHEOCl - states there are 30 minutes to trip RCP after loss of seal cooling. The other parts of the PRA state 5 or 10 minutes. 30 min is a seal failure number, not a bearing failure number. ZHEOCl be based on 5 minutes.

7) ZHEOS6 - timina states 1.3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months Page 23 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN available to start AFW. 1.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months is the time from reactor trip to core uncovery. AFW must be started before 1.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months . Also, ifthere is 1.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months allotted to start AFW, then there is no time for MFW restoration and F&B. The time from reactor trip to core damage must be apportioned to the 3 actions in this sequence.

8) ZHEWA5- 30 minutes to align diesel driven SW pump after LOSP.

This time is based on seal failure due to loss of SW. The DG will fail in 8 minutes ifthere is no SW. The time to align Diesel driven pump is based on failure of the DG, which is 8 minutes.

IE-04 IE-16 B Y Subtier criteria requires that "The For Unit 1, full power operation No impact to Fire initiating event frequency should not began on May 1977. The Unit 1 PRA, because this use data from the initial year of PRA model initiating event data issue was commercial operation." Contrary to collection started on Jan. 1, determined to have this data from 1987 (Beaver Valley 1980. Therefore, no revision of no effect on the initial year of operation) is included in data is needed based on this BVPS PRA model.

the data update. Use of this data, observation.

though conservative, could shift the importance of components.

Page 24 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN IE-05 IE-13 B Y In appendix D of the initiating event The interfacing system's LOCA No impact to Fire notebook, the interfacing systems (ISLOCA) initiating event PRA, because this LOCA frequency is calculated frequency was recalculated issue was referring to two references from 1985. based on NUREG/CR-3862, addressed in the The 2 landmark ISLOCA reports NUREG/CR-5102, NUREG/CR- base PRA model (NUREG/CR-5102 and NSAC-152) 5603, and NSAC-152. The new prior to building the were written in 1992. Although the value used in the BV1 REV3 PRA Fire PRA.

frequency calculated in the Beaver model, with a Monte Carlo Valley PRA does not seem out of the quantification is 1.07E-05 recognized range of values for this events/yr.

frequency, due to the importance of this event for LERF, the compatibility of the method and data used in the PRA should be checked against the later references.

Other inconsistencies in the analysis are:

OST 2.11.16 is performed prior to startup, if it has not been performed in the previous 9 months. The PRA assumes there are 3 shutdowns per year (which is not supported by the historical performance of BV), so assigns a test frequency of 3 months.

The maximum possible test interval for OST 2.11.16 is 26 months [plant ascends to power 8 months from last test for an 18 month run]. The minimum is 9 months. The true average test interval is likely in the 13-20 month ranae. Substitutina this test Page 25 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN interval into the equation would have a significant affect on frequency.

The probability of MOV 8889 being inadvertently open is not considered.

The LHSI lines are interconnected such that if CV 552 and 109 fail, both 132 and 133 will be challenged. This is true for the other injection lines also.

So the valve combination is 3 times higher than shown.

The probability of pipe over pressure is assumed to be the same as pipe rupture. This is not consistent with the two 1992 references listed above.

Page 26 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN IE-08 IE-13 B Y Bayesian updating is used extensively Regarding Bayesian Update with No impact to Fire in data analysis and also in initiating 0 failures, there are indeed PRA, because this event frequency calculations. situations that updating with 0 issue was Although mathematically correct, the failures could cause the posterior determined to have use of Bayesian updating without mean to be significantly lower no effect on the some limitations has been criticized, than the prior mean. A known BVPS PRA model.

with justification, in the past. Under situation is the case of using certain conditions, bayesian updating moment matching. This refers to with zero or 1 failures may reduce a the practice of changing a prior prior mean (with a high error factor) that is presumably a lognormal considerably. Since PRA results and distribution, to a gamma applications depend on, and are distribution by matching the measured mainly by point estimate mean and the standard deviation.

(mean) results, but not by uncertainty After the Gamma distribution is bounds, any evidence that shifts the updated with plant data mean considerably must be rigorously analytically, the resulting gamma justified. distribution is convert back to the lognormal distribution again The BV PRA uses bayesian analysis using the moment matching for virtually all transient initiating method. It is known that in this events. In most cases, the plant practice, if there should be 0 specific data is 0 trips in 11 years. In failures, the resulting posterior general the posterior is lower than the gamma distribution has a mean prior. If the plant specific data was value significantly lower than the used by itself, the is enough data to prior mean.

justify a point estimate of about .05/yr.

The prior for LOSP is .027. The prior The BVPS analysis did not use for SGTR is .0074. The posterior for the moment matching. Instead, LOSP is .025 and for SGTR .0048. In the Bayesian update functionality both these cases, the posterior is provided by RISKMAN was used.

lower than the prior and lower than the There are two classes of priors plant specific data can justify. This is used in the BVPS analysis. The due to the use of Bayesian analysis first class are the lognormal Page 27 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN when too little plant specific data distribution based on parameters exists. from the NUREG study (for LOCA initiators, for example).

Rules for when to use Bayesian Updating a lognormal distribution analysis and when to use generic data with 0 events in about 10 years should be developed to ensure that does not change the mean in failure rates and initiating event most cases (or there is a slight frequencies are not reduced below change in the third significant both the generic values and the plant number).

specific estimates.

A more general type of priors is the industry data. The prior consists of three parts. The first and most important part is the failure and success data for a set of PWR power plants. The second part is the so-called grid, which consists of a set of values for the median (of the assumed prior curve), and a set of values for the range factor (of the assumed prior curve). The selection of median and range factor should be such that the resulting distribution should not skewed toward either end of the median or range factor in the grid (grid is the matrix of median and range factor values). The third part of a prior is the so-called lambdas, which is a set of values for the possible bin values that the distribution can locate. The Page 28 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN lambdas do not affect the posterior mean distribution as long as has sufficient range and sufficient number of values (typically 20 bins are sufficient for a distribution). It should be pointed out that for the industrial data type of prior, updating it with zero failures typically results in a smaller mean value for the posterior then the prior.

However, the decrease is much smaller in magnitude than the moment matching approach, and it should be treated as a normal behavior of the Bayesian analysis (i.e., zero failures always provide information leading to a lower estimate).

In response to this observation, each posterior distribution that was Bayesian updated with zero failures was reexamined to assure that there was no skewing of results on the grid, and that there were no abnormally large values (excessive probabilities) in a single lambda bin. In some cases a few more lambdas were added to actually bring the probability per each lambda lower than 0.1. However, in Page 29 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN these cases the posterior distribution changed little compared to the original set of lambdas (note, the grid was not changed in this response because these were checked in the original analysis and quality was assured). The results of the review did not identify any concerns, so confidence in the Bayesian update results using zero failures based on the discrete probabilistic distribution approach, which is a robust process, was maintained.

Based on the above discussion, no revision of the Unit 1 data are necessary in response to this observation.

L2-03 L2-18 B Y All early SGTR core damage The BV1 REV3 PRA model No impact to Fire sequences with wet SGs are classified assumes that all steam generator PRA, because this as SERF (small early release tube ruptures that are faulted and issue was frequency) vs. LERF without regard to have a depleted RWST or have a addressed in the break location or other sequence loss of all secondary cooling are base PRA model specific conditions such as SG considered to be LERF prior to building the isolation, primary to secondary contributors, even if the tubes are Fire PRA.

pressure equalization, etc. The basis wetted (i.e., no credit for for the use of small release was scrubbing going to SERF instead scrubbing; however, there is no of LERF). It is assumed that documentation supporting this leakage from the RCS will classification. For example, failure to continue indefinitely through the cooldown and depressurize the RCS faulted steam generator and the Page 30 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN may result in lifting the ruptured SG core will uncover after the RWST ASDVs or safety valves, depletes. This LERF definition is Radionuclides, both volatile and non- in agreement with WCAP-1 5955, volatile, entrained in the escaping "Steam Generator Tube Rupture steam result in a release to the PSA Notebook".

environment. Without evaluation, the magnitude of the release to the Subsequently after closing this environment is unknown, and may be F&O, the ASME Standard sufficient to meet LERF classification, recognizes scrubbing during SGTRs as a way to reduce LERF. Ultimately resolved by GAP F&O LE-CI0-01 (see Table 1-2).

MU-02 MU-06 B Y The computer models of the PRA IT has placed restrictions to the No impact to Fire (electronic files for the input and "S:/AII/PRA Engineering" PRA, because this output of the PRA model and its directory. The permissions for issue was sensitivity analyses) should be stored this directory are limited to addressed for the in a controlled manner. The subtier specific design Engineering base PRA model criteria states that "a secure offsite personnel. This will prevent prior to building the storage facility for computer codes, unauthorized personnel from Fire PRA.

inputs, outputs, and models should be accessing PRA reports and used". models. Inaddition, the network is backed up daily, making Discussions with the BV PRA staff retrieval of lost files very easy.

indicate that the PRA model files are kept on CDs and also on a network drive (not a protected drive).

To meet the intent of the subtier criteria, the model files should be also stored with the same philosophy as the paper copies of calculation notes; namely stored by a dedicated Page 31 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. 1Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN organization (preferably outside of the PRA group), in a protected manner and be available for long term retrieval.

Page 32 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. 1 Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN QU-02 QU-08 B Y The original top ten sequences were The BV1 REV3 PRA model now No impact to Fire for total CDF and not just internal. Of includes Top Event CG (LEVEL 1 PRA, because this these three were control building fire, OR LEVEL 2 SEQUENCE issue was one seismic, and four external. The GROUP), in the Containment addressed in the number 1 was ELOCA and number 2 Event Trees (CET & CETLOCA). base PRA model was ISLOCA, both which were the This Top Event bypasses the prior to building the initiating event which leads to Level 2 Top Events when it is set Fire PRA.

guaranteed failure. The remaining four to a guaranteed failure, and will were internal sequences which meant query the Level 2 Top Events something. The number five sequence when it is set to a guaranteed was loss of AC bus "Purple" with success. To quantify only the other failures that lead to core Level 1 CDF, the Split Fraction damage. Sequences 7 and 8 were logic rule for CG1 (1.0) uses the LOIA with loss of heat removal (high NOT NOMELT (-NOMELT) and dry). The number 10 sequence macro. Therefore, all core melt was ATWT (on a turbine trip) with the sequences bypass the Level 2 failure of the operator to manually trip Top Events, and the resultant the reactor, with all subsequent sequences have the Level 2 Spilt operator actions guaranteed failure. Fractions suppressed. When the Since this had limited internal Level 2 Top Events need to be sequences, a larger report was quantified for LERF, the Split reviewed with the objective to see Fraction logic rule for CG1 (1.0) what SBO looked like. The SBO was is changed to SS=F*SS=S, which not on this and in fact the first LOSP can never be true, so the was very low on the list. Then a guaranteed success Split sequence report was reviewed looking Fraction CG2 (0.0) is used and at LOSP only. Sequence #57 was the the Level 2 Top Events get first SBO sequence and #58 was the queried and retained in the second SBO sequence. The only sequences.

difference between these was in the containment tree. With this is was realized that the containment tree was splitting up ("fractionalizing") the Page 33 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN LOSP sequences, as opposed to some other sequences (such as ELOCA) which had one path through the containment tree. It was now realized that in order to analyze the sequences in the same context as previously, there needed to be a run of the event trees where the extra details of the containment tree suppressed. The utility staff ran this and the results and insights were noticeably different than before.

The results of the top ten were significantly different. The ELOCA and VSLOCA stayed the same value but now are sequences 2 and 4 respectively. The number 1 sequence is now loss of instrument air. ATWT on PLMFWA is number three (while the previous ATWT went to 12). Two sequences are control building I flooding.

Page 34 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN QU-03 QU-08 B Y In ATWT, if the operators fail to trip In response to this observation, No impact to Fire the reactor as an immediate action the BV1 REV3 PRA model was PRA, because this (top event OT) then subsequent revised to incorporate giving issue was operator actions RI and OA are failed. credit for the longer term addressed in the I suspect that this sequence has operator action to emergency base PRA model always been this way in the past, but borate, even though the earlier prior to building the with the recent enhancements in the actions to manually trip the Fire PRA.

model, the sequence has risen into reactor or to insert the control the top ten. This leads to an overly rods may have failed.

conservative results in CDF. This appears to be the number 6 in internal The BV1 REV3 PRA model was

(#10 sequence in total CDF). Of the revised by removing the top 50 sequences, 20% are ATWS. emergency boration (Top Event The total CDF for ATWS is a OA) human action dependency noticeable part of the CDF, and would on prior ATWS human actions, not support any future RI ATWS which must be performed applications. immediately; i.e., manual reactor trip (Top Event OT) and manual rod insertion (Top Event RI).

This involved editing the ATWS event tree split fraction logic rules for OAF by removing OT=F +

RI=F, as shown in Table 3.5-3 "ATWS Event Tree Logic Rules" of the Event Tree Analysis Notebook.

The basis for this change was derived from WCAP -15831-P Section 5.1.1.12, where it is assumed that the operator action to emergency borate is independent of the previous Page 35 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN operator actions since itdoes not need to be completed in the same short time period as the operator actions to trip the reactor, or manually drive in the control rods.

QU-04 AS-12 B Y An asymmetry discussion is provided Asymmetries in a PRA model can No impact to Fire in the PRA Quantification Notebook, occur in the system fault trees, PRA, because this section A.3. The write-up includes maintenance alignments, or in issue was general discussion regarding the use the event tree modeling. All addressed inthe of alignments to simulate the various specific system asymmetries due base PRA model modeling asymmetries in the systems to plant differences are prior to building the modeling and the effect on event trees addressed in the system fault Fire PRA.

by partitioning some of the initiating trees. A system example is the event categories with some examples River Water system, where only being provided. Some of these the Aheader can supply an asymmetries are due to modeling emergency source of water to the assumptions and some are due to Auxiliary Feedwater system.

actual plant differences. No specific Specific system asymmetries due discussion is provided to explain what to plant NSA differences are I system asymmetries are due to simple addressed in the maintenance Page 36 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I YIN modeling assumptions and which alignment module of RISKMAN.

ones are due to plant differences. An example of this is the auxiliary feedwater system, in which the turbine driven AFW pump is normally aligned to the A header.

Actual plant data from the Maintenance Rule for train unavailabilities have been utilized when possible to account for maintenance alignment asymmetries. Whenever no specific plant data was available it was assumed that the train alignments were symmetrical.

An example of this is with the Reactor Plant Component Cooling Water system, where each pump is equally assumed to be the running pump. The only exception to this was in the River Water system maintenance alignments, where due to the limitation on RISKMAN it was assumed that the A pump was always the running pump. These differences between the trains are addressed in the BV1 REV3 PRA model top events and by the split fraction rules in the event trees.

In the event trees, potential issues with asymmetries Page 37 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN associated with initiating events have been removed by partitioning some of the initiating event categories. Examples of initiating events partitioned are Large LOCAs, which now models a break in each specific loop (initiating events LLOCAA, LLOCAB, and LLOCAC) using the same probability.

QU-07 QU-15 B Y A review of the non-dominant The specific sequences listed in No impact to Fire sequences was made. The non- the issue description only apply PRA, because this dominant sequences are those that to the Unit 2 BV2REV3A PRA issue was are not normally saved when the model. To ensure that the Unit 1 addressed in the entire model is run. It was necessary sequences are valid, the base PRA model to quantify one initiator at a time to get BV1 REV3 PRA model was prior to building the the cutsets below 4E-1 0. A review of quantified using only the Level 1 Fire PRA.

these cutsets had the following Top Events so that a review of observations: the CDF sequences could be performed to verify that the split

1) SGTR 1.507E-12: IAF

OD16B - fraction logic rules made sense.

how is OD possible when IA is failed? This included looking at non-dominate sequences 5 orders of

2) TTrip 7.26E-1 1: magnitude lower than the total AFI*OF1*OB4*CDF*RRI - ifAF, OF, CDF value.

OB and CD are failed, how can RR be asked in a probabilistic manner. RR should be RRF.

3) TTrip 3.233E-1 1:

SAI *OS6*AF3A*OFF*OBF*CDF*RR1

- How can RR be asked in a probabilistic fashion after failure of all Page 38 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N that?

4) TTrip 8.34E-12 AF1*MFF*OBI*CDF*RR1 - same question about RR?

5) TTrip 1.1649E-12:

PR7*HH2A*OR3A*MU2: If HH2A is failed, how can MU2 succeed? Does not MU2 use the HHSI pumps?

6) TLMFW 1.2559E-12:

AF1*OF1*OB1*HH1: Why is OF1 in the tree for Loss MFW? Why is OB1 in the same sequence as HH1. If OB1 fails, there is no initiation of HHSI, so why is HH1 included?

QU-09 QU-31 B Y This element asks whether the As a resolution to this PRA Peer No impact to Fire sequence results by sequence, Review observation a ballpark PRA, because this sequence types, and total was comparison was made utilizing issue was reviewed and compared to similar the WOG PSA Model and addressed in the plants to assure reasonableness and Results Comparison Database, base PRA model identify any exceptions. A review of Revision 3. Items compared prior to building the the PRA documentation did not reveal included; initiating event Fire PRA.

a comparison of the current PRA frequencies and their conditional revision results to results of similar CDF, component failure rates, plants. human error rates, and success criteria. While, this review was not detailed no outliers were identified, and the conditional CDF from LOSP initiators was comparable with North Anna, a I nearly identical plant. During the I Page 39 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN next PRA model update a more thorough comparison will be made utilizing the most recent WOG PSA Model and Results Comparison Database, and the findings documented.

Ultimately resolved by GAP F&O F&O IE-C10-01 (see Table 1-2).

QU-10 QU-30 B Y The initiating event frequency for This PRA Peer Review Fact & No impact to Fire interfacing system LOCA (i.e., initiator Observation was written against PRA, because this VSX) was quantified using point the Unit 2 BV2REV3A PRA issue was estimates (result of 2.2E-7) and using model. For Unit 1, the BVI REV3 addressed in the Riskman's Monte Carlo algorithm PRA model recalculated the base PRA model (result 3.OE-7). The difference is interfacing system's LOCA prior to building the explainable based on data (ISLOCA) initiating event Fire PRA.

dependence between valve failures. frequency based on NUREG/CR-3862, NUREG/CR-5102, But the event tree quantification used NUREG/CR-5603, and NSAC-the lower, point estimate result. The 152. The new initiating event 3.0E-7 Monte Carlo result should be frequency value used in the used in the quantification. BV1REV3 PRA model is 1.07E-05 events/yr, which was performed using a Monte Carlo I quantification.

Page 40 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA IYN I ST-02 ST-1 0 B Y The internal flooding analysis was In response to this observation, No impact on the done for the IPE and has not been the work that was completed for submitted BVPS-1 updated since then. All flood barriers the Beaver Valley Unit 1 Risk- Fire PRA, which were treated deterministically and Informed In-Service Inspection used the assumed to succeed. The sub-criteria (RI-ISI) Indirect (Spatial) BV1 REV5 as its for this element suggests that flood Consequence Evaluation (8700- basis. Internal fire propagation pathways should include DMC-1 333, Rev. 0), as well as, initiators and flood failure of doors, floor drains, and other several updated flooding initiators are flood barriers. analyses performed after the IPE mutually exclusive submittal were reviewed. The and have no effect results of this review determined on each other.

that the flooding analyses did consider the potential of flood Furthermore, the barrier failures due to the flood BVPS-1 Fire PRA water static head on the door working model latching mechanisms and uses BV1 REV5A likelihood that floor drains were as its basis, so this inadequate. Itwas concluded F&O will be that the IPE flooding analysis resolved when assumptions regarding the NFPA 805 is propagation of floodwaters did implemented.

consider flood barrier failures, and therefore, they remain valid.

No further flooding impacts were incorporated into the BV1REV3 PRA..

This F&O was written against an obsolete Internal Flooding PRA model (BV1 REV3) and is considered to be resolved by the updated Internal Flooding PRA model incorporated in Page 41 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN BV1 REV5A, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-4.

SY-01 SY-12 B Y Loss CCP/CCR results in a loss of With multiple high temperature No impact to Fire seal water heat exchanger cooling alarms coming in at more than PRA, because this (discharges directly to the charging 100 OF prior to reaching this issue was pump suction) as well as loss of non- temperature, there would be determined to have Regenerative heat exchanger cooling plenty of time available to no effect on the (discharges to the VCT). The result is operators to perform mitigating BVPS PRA model.

a potential common mode failure of all actions. Moreover, a loss of charging pumps due to an increasing NPSH would only impact the charging pump inlet temperature, running charging pump, since the coupled with the loss of CCP/CCR, standby pump does not this results in an RCP seal LOCA. automatically start, unless a Riskman macro RWSTSO (VCT Safety Injection Signal is present, swap-over to RWST) contains logic to in which case the suction would include the failure of the components automatically swap over to the required to perform this action, but the RWST. The third pump would operator action is not included. Given only be manually aligned and the uncertainty of the time to charging started following the failure of the pump failure, the operator action may first two normally aligned pumps.

dominate the mechanical component Therefore, this observation was failures. not considered to be a valid common cause failure mechanism of the charging/HHSI pumps, so the operator action I Page 42 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N was not included in the BV1 REV3 PRA model.

SY-02 SY-3 B Y The degree of documentation in the Split fraction definitions were No impact to Fire systems analysis should provide developed by using the PRA, because this enough detail that the systems dependency matrices located in issue was analysis can be duplicated with Appendix B of the Level 1 Event addressed in the minimal effort. A review of the Tree Analysis PRA Notebook. base PRA model Auxiliary Feedwater System Notebook Split fractions and truth tables for prior to building the (Book 2, Tab 2) and the Main Top Events AG, AL, AM, HC, HH, Fire PRA.

Feedwater System (Book 3, Tab 6) HL, HM, HR, LA, LB, LC, LL, LM, revealed that the Split Fraction LO, LP, LQ, OP, OR, VA, VB, definition / truth tables are not VC, VL and XL are found in the documented and the Common Cause Split Fraction sections of the assumptions are not documented. RISKMAN System Notebook files There is no discussion as to where in Appendix C. Common cause these assumptions came from or the failure inputs, assessment definition of the split fractions utilized methodology and data update I Page 43 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN in the Systems Analysis. The summaries are located in absence of this information could Appendix C of the Data Analysis result in the inability to reproduce the Notebook. Top Events AG, AL, Systems Analysis for verification of AM, HC, HH, HL, HM, HR, LC, results or future applications. LL, LM, LO, LP, LQ, OR, VA, VB, VC, VL and XL Common Cause failures are found in the common cause sections of the RISKMAN System Notebook files in Appendix C.

SY-03 SY-1 5 B Y Some initiator dependent component The LHSI mini-flow valves MOV- No impact to Fire failure modes do not appear to be 1 SI-885AIB/C/D are NSA open at PRA, because this modeled. For example, the S18890 Unit 1, so a failure to open is not issue was MOVs are included in the model for applicable to the PRA model. determined to have fail to open to prevent LHSI pump The MOV transfer closed failures no effect on the overheating during low flow are included in the LA/LB Top BVPS PRA model.

conditions. For this specific example, Events. This is a slightly large LOCAs should only consider conservative assumption for the transfer open as a flow diversion; large LOCA, when the RCS failure to open is not applicable. For pressure is low and mini-flow is small LOCAs, the failure to open is not required, but is not a correctly modeled, but transfer closed significant contributor to the should also be included. For medium failure probability. Also, a failure LOCAs, the need to open or close the to close is not considered to be a S18890's may require additional valid flow diversion path for large thermal hydraulic analyses. Other LOCAs since the 3" mini-flow system designs susceptible to initiator lines are less than 1/3 of the specific failure modes include systems diameter of the 10" injection with pumps which have mini-flow lines. These valves are required which return to the pump's suction. to close on SI recirculation, which Systems like this may require operator is included in Top Events VANB.

action to stop these pumps if It is concluded that the LHSI I downstream pressure prevents mini-flow valves are properly I Page 44 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN adequate flow to prevent pump modeled in the BV1 REV3 PRA overheating, model.

The AFW mini-flow recirculation valves are controlled in auto and do not require any operator actions to open or close; therefore, this is not an issue for the Unit 1 AFW system.

SY-06 SY-6 B Y Assumptions concerning non-modeled The failures of non-modeled No impact to Fire failure modes, or support systems due support systems are accounted PRA, because this to low frequency sequences need to for in the initiating event issue was be reconsidered with respect to frequencies. Also, as was addressed in the specific applications. For example, originally assumed in the base PRA model condenser hotwell level is assumed to previous PRA models, these prior to building the always be adequate due to supporting systems for Support Fire PRA.

redundancy of sources (i.e., via steam Systems are considered dumps, or makeup); however, some of available for mitigating system these sources may not be available functions (e.g., condenser is during online T/M. available to support the MFW system) following the initiating Also many of these done when the event. Additionally, even though CDF was in the 2E-4 range. Now that the CDF has reduced through the CDF is in 8E-6 range many of these years, the individual system items may no longer be insignificant in function probabilities have not the current model. generally changed much.

Guidance was also added to the System Analysis and Overview Notebook to include assumptions concerning non-modeled failure modes, or support systems.

Page 45 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN SY-16 SY-13 B Y The sequence modeling credits Using the BVPS-1 Cycle 16 BOL No impact to Fire RWST refill for LOCA's and SGTR. boron requirement of 1195 ppm PRA, because this The RAW worths of the split fractions for shutdown (k=0.99) with all issue was indicate that without RWST, CDF rods in and hot zero power from addressed in the would be 3.8E-5. RWST refill is WCAP-15995, Rev.1 as the base PRA model modeled in split fractions WM and minimum required boron prior to building the MU. concentration, the expected Fire PRA.

RWST boron concentration after The minimum make up rate is 150 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of dilution would be gpm. The actual makeup rate [if this 1208 ppm. This value assumes procedure was used] may be up to that 400 gpm of river water is 400 gpm. The initial water source for delivered to the spent fuel pool RWST refill is the boric acid blenders. during the first 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months following This system has a 7,000 gallon tank at RWST depletion, with 120 gpm 7,000 ppm boron. This system does makeup for the remaining hours, not have sufficient volume nor flow as identified in the MAAP rate to match the times and volumes success criteria calculation needed for safe shutdown in the (FAI/03-18) for required RWST sequences modeled. The ultimate makeup rates using the spent source of water is unborated river fuel pool during LOCAs.

water. To provide enough input to the Therefore, makeup to the RWST RWST, the flow path is into the Fuel via the spent fuel pool, with river Pool and then from the fuel pool to the water makeup to the spent fuel RWST. pool is considered to be successful, since minimum The Miscellaneous Notebook shutdown boron requirements documentation states "The current will take longer than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to BV2REV3A PRA model assumes that achieve.

400 gpm is required for makeup to the RWST during the entire mission time." A precaution was also added to Boron dilution of the fuel pool is BVPS-1 OM Procedure 1OM-calculated, but not boron dilution of 7.4.Q "Makeup To The Refueling the core. The observation is that if Water Storacje Tank," that if a Page 46 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I

_YN unborated water was used to make-up significant volume of river water for the times required, boron dilution is added to the Spent Fuel Pool, could occur in the core, thus negating boric acid addition to the Spent the RWST make up function. Due to Fuel Pool may be required to the fact that RWST cause significant maintain adequate shutdown core damage reduction, the ability to margin.

use RWST make-up should have a more substantial analytical basis.

This observation is worse for unit 2 than unit 1, because of the smaller RWST volume. The minimum core boron concentration for hot zero power at BOL is 771 ppm. For most of the sequences where RWST make-up is used, the reactor is assumed to be depressurized and cooled down

[LOCA's and SGTR]. For the purpose of this F&O, it is assumed necessary to maintain a 1500 ppm boron concentration. The RWST switchover is 140,000 gallons for unit 1 and 360,000 gallons for unit 2. Times to boron dilution (in the RWST) is shown below:

Unit 1 dilution to 771 ppm at 150 gpm

= 15h Unit 1 dilution to 771 ppm at 400 gpm

= 5h Unit 1 dilution to 1500 ppm at 150 gpm = 4.5h Unit 1 dilution to 1500 ppm at 400 Page 47 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN gpm = 1.7h Unit 2 dilution to 771 ppm at 150 gpm

= 38 h Unit 2 dilution to 771 ppm at 400 gpm

= 14h Unit 2 dilution to 1500 ppm at 150 gpm = 11.5h Unit 2 dilution to 1500 ppm at 400 gpm = 4.3h Only one of these conditions can meet a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months mission time.

Considering that RWST make-up is used to lower CDF and LERF to the extent it does, the technical basis should be stronger. The calculation must match the conditions of the sequences for which it is used, must use a representative flow rate, and must consider the uncertainties in the inputs and the outcome.

SY-17 SY-21 B Y Service Water success criteria This concern is not applicable to No impact to Fire appears to have no supporting the Unit 1 River Water System. PRA, because this analysis as to 1 service water cooling BVPS-1 UFSAR Section 9.9.2 issue was pump could provide sufficient flow. specially described that each determined to have Additionally, there appears to be some river water pump is able to no effect on the HEP for some manual operator action deliver approximately 9,000 gpm BVPS PRA model.

to start standby pumps under some and is designed to supply the circumstances. No success criteria for quantity of water needed for the the time available for these actions essential safety-related cooling was found. requirements for all unit I operating conditions. I Page 48 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN TH-02 TH-8 B Y The Beaver Valley Unit 2 Ventilation Calculation 8700-DMC-3467, No impact to Fire and Room Cooling Analysis Notebook Rev. 1, was developed to show PRA, because this Table 7 lists that for item 10, Control the heatup of the common issue was Building, Operators add portable fans; control room following a loss of addressed in the not included in risk model. It appears BVl HVAC due to a fire. The base PRA model from Figure A-9 "Temperature as a results of this calculation are also prior to building the Function of Time in Control Room with applicable for the PRA evaluation Fire PRA.

No Ventilation-Fan Added in 10 of a loss of all control room Minutes," that without the addition of cooling, and are provided below.

the fans the temperature in the Main Control Room would impact It takes longer than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to instrument qualification. Though this reach a room ambient appears to be an important operator temperature of 115*F, using an action that justified not adding MCR initial room temperature of 75*F, HVAC to the model, there is no calculated heat loads, and taking operator action to add fans for MCR credit for the Unit 2's HVAC. This cooling within 10 minutes. conclusion is based on the assumption that a homogenous Additional investigation into the MCR mixture of air exists between the heatup calculation 12241-US(B)-211 control room volumes. In order revealed that two different values to keep this assumption valid, the were used for the MCR heat load. operators must immediately Page C-4 uses a MCR heatup value (within 10 minutes) open all of of 156,861 BTU/hr (-46000W) and the common doorways between page IPE-4 uses 74665W. The trend the control rooms, following the shown on Figure C-3 is the more loss of Unit l's HVAC. The expected MCR room heatup, rather accomplishment of this action is than the temperature spike seen on not considered to be unrealistic, IPE-9. since human nature would drive the operators to keep cool, as they begin to feel uncomfortable.

It is also recommended that at least one portable fan be set up Page 49 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN at an open common doorway, so that it is blowing the cooler air into Unit l's control room. This would assist the natural buoyancy driven air flow between the units and provide a constant air recirculation path, which would further ensure that a homogeneous mixture exists.

The time to accomplish this action to set up a portable fan is not calculated, but it is expected that 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months would suffice.

Therefore, based on these results, a loss of Unit 1 control room HVAC does not need to be modeled in the Unit I PRA.

AS-01 AS-12 C Y Beaver Valley is using a modified As a resolution to this PRA Peer No impact to Fire version of the WOG 2000 seal LOCA Review observation, sensitivity PRA, because this model, which is derived from the BNL analyses were performed on the issue was "best estimate" model, with Beaver BVPS Unit 1 MAAP RCP seal addressed in the Valley specific MAAP runs for time to LOCA cases to investigate the base PRA model core uncovery. The time of the start of impact of varying the timing of prior to building the excessive leakage is 30 minutes in the increased RCP seal leakage Fire PRA.

this model. The NRC has not from 30 to 13 minutes on the accepted this from licensing resultant time to core damage.

submittals. Since Beaver Valley is The conclusion from these planning some extensive AOT sensitivities was that the change submittals in the future, this will have in onset of the increased RCP to be addressed. seal LOCA leakage from 30 minutes to the minimum time of 1 13 minutes would not lead to Page 50 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN significantly earlier times to core damage.

Ultimately resolved based on WCAP-15603, Rev. 1-A, NRC Approved, May 2003, Seal LOCA start time is 13 min.

AS-04 AS-07 C Y AMSAC is a mitigation system that In response to this PRA Peer No impact to Fire only appears in the ATWS tree. Review observation, the PRA, because this Actually AMSAC is a redundant start GENTRANS Event Tree (see issue was of AFW and turbine trip that is useful Figure D-4a) was modified to addressed in the in mitigation even when SSPS has include Top Event PL (Power base PRA model failed but the reactor trip has been Level <40 %) and Top Event AS prior to building the successful. Additionally AMSAC is (ATWS Mitigating System Fire PRA.

only model as a system point estimate Actuation Circuitry) before asking of 1E-2 (see F&O SY-20). This could Auxiliary Feedwater in Top Event affect/reduce the system/equipment AF. The split fraction logic rules importance of SSPS, AFW and and macros were also modified Turbine Trip to credit the use of AMSAC for providing a diverse method of starting the AFW pumps (see Tables 3.4-3 & 3.4-4). Section 3.4 "General Transient/Small LOCA Event Trees" and Tables 3.4-1 and 3.4-2 were also revised to account for these new top events in the GENTRANS Event Tree.

With respect to the AMSAC top event being quantified using a I point estimate value instead of a I Page 51 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN fault tree analysis, it was not deemed necessary to pursue a detailed fault tree analysis at this time. The point estimate value of 1.OE-02/demand used in the BVPS PRA models is taken from WCAP -11993 (Reference 1) and is conservative with respect to unavailabilities of a one signal train and the design criteria applied to AMSAC by the Westinghouse Owner's Group.

Additionally, the more recent WCAP-15831-P (Reference 14) also uses this point estimate value, as has other studies, as an appropriate value to use. A detailed fault tree would probably result in a lower AMSAC unavailability value, but this is not expected to have a significant impact on the core damage frequency, due to the already low significance of SSPS failures in non-ATWS sequences.

Page 52 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. 1 Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA I YIN AS-09 AS-18 C Y The SGTR event tree assumes that The concerns of this PRA Peer No impact to Fire the actuation of PORVs (should be Review observation are PRA, because this PORV due to definition of B&F unfounded, since the timing of issue was success criteria) will result in the CIB the CIB initiation following bleed- determined to have (8 psig) actuation. A review of the and-feed scenarios during a no effect on the MAAP runs (Success Criteria, SGTR will not impact the NPSH BVPS PRA model.

Attachment A, Appendix F, Table 3) of the HHSI pumps. This CA was indicates that CIB occurs for cases in dispositioned by examining the which OB (B&F) is successful for MAAP SGTR accident sequence cases in which AFW is failed and it summary files as summarized occurs in approximately 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The below:

QSS is assumed to be actuated given the CIB signal. The water injected to For the SGTR cases with a loss the containment sump is necessary of secondary cooling, the HHSI for NPSH success. It isn't clear what pumps will initially be taking will happen in the case that CIB does suction from the RWST, either not occur until 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months into the due to an SI signal being scenario and what effect this may generated or to the bleed-and-have on the NPSH concerns. feed initiation. After about 6 minutes following the initiating of bleed-and-feed, the containment sump would begin to fill when the PRT rupture disc blows. During this time there will be RCS mass and energy released inside of the containment from the open PORVs, which will slowly start to increase the containment pressure and also be providing inventory directly into the containment sump.

After approximately 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months a Page 53 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID RequirementI Level Closed PRA YIN I

CIB occurs, and QS will start and also begin to add RWST inventory into the sump, so that when the RS pumps start about 210 seconds later there should be sufficient inventory in the sump to provide adequate NPSH to the RS pumps. However, if a sufficient amount of water is not collected in the containment sump after this time, the recirculating spray pumps must be manually turned off and then turned back on when NPSH is sufficient. Operator actions to first turn off and then to turn on the RS pumps are modeled in Top Events SM and OR.

Success of these actions ensures that the RS pumps will be available when the RWST reaches the low-level setpoint and SI Recirculation is initiated.

At this time the HHSI pumps could be piggybacked onto the RS pumps if the LHSI pump trains were unavailable, and adequate NPSH would be provided.

Prior to this CIB signal being generated, the QS and RS will not start. However, the HHSI Page 54 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN pumps will continue to take suction from the RWST until the low level SI Recirculation setpoint is reached. At this time even without a CIB initiation, approximately 296,000 gallons of RWST water would have been directed into the containment sump though the opened PORVs, so that ifthe HHSI pumps are piggybacked onto the LHSI/RS pumps, adequate NPSH would also be provided.

DA-03 DA-03 C Y The documentation of the CCF MGL The resolution to this F&O was to No impact to Fire parameters is presented in Appendix put shading and bold text in PRA, because this C of the Data Analysis Notebook. The Table C-5 for the MGL issue was final compilation of the MGL distributions that were developed addressed in the parameters is presented in Table C-6. based on a plant specific base PRA model The results are presented as "Plant- analysis, so that they are more prior to building the Specific" distributions, but this table is easily identified. This table was Fire PRA.

in fact a mix of parameters developed also renamed to Table C-5 based on plant specific event Beaver Valley Unit 1 - Common screening, in some cases Bayesian Cause MGL Distributions.

updating, and in other cases generic data. With some difficulty, the reviewer could trace back through the documentation to determine the actual Page 55 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN source of the MGL parameter, but a naming convention that identifies the parameter as plant specific, or generic would be helpful. As a minimum, generic data could be presented in a separate table from the parameters generated based on plant specific analysis.

DA-04 DA-5 C Y The data notebook describes several The BV1 REV3 PRA model does No impact to Fire sources for the generic component not use any automatic PRA, because this failure distributions for the BV Unit 2 recirculation check valves in the issue was model. Column 6 provides the model. Therefore, this is not an determined to have disposition of the 6 sources of issue at Unit 1. no effect on the information. Item f-1994 STP data BVPS PRA model.

was used to derive the failure rate distribution for the automatic recirculation check valve failure to open and was cloned from ZTVCOS using PLG generic check valve database distributions. Then the data from STP of 0 in 704 demands was used. It is not clear what this database variable was used for and if it is currently being used. The discussion does not indicate why was no information used from the BV plant history in this update process.

Page 56 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN DA-05 DA-03 C Y Table C-6 lists the Beta factor for The disposition of this PRA Peer No impact to Fire battery failure fails to operate Review observation was to PRA, because this (ZBBCHR) as a point estimate of include a discussion on the issue was 1.26E-2. The source of this value is availability of newer data sources addressed in the not documented in the Data Analysis and justification as to why they base PRA model Notebook. A review of the EP System were not used, to Section 3.6 of prior to building the Notebook found a reference to this this notebook. Although, Fire PRA.

value in an assumption, stating that Appendix C does not specifically the value was taken from NUREG/CR- list the source document 5497. Appendix C of the Data references, they are specifically Analysis Notebook should be self identified in Section 3.6 contained with respect to the source "Calculation of Common Cause of the generic MGL. Appendix C does Factors," and are included in not reference NUREG/CR-5497. Are Section 5 "References" in the all other generic parameters actually Data Analysis PRA Notebook.

from the PLG database or are other Section 3.6 also provides the sources used? Is this the only value basis for using common cause taken from 5497? What was the basis data sources other than the PLG for using one selected value from common cause database.

5497?

DA-1 1 DA-05 C Y A statement needs to be made in the This PRA Peer Review No impact to Fire assumptions to describe the method observation was dispositioned by PRA, because this of assembling the data. The write-up adding a discussion in Section issue was implies that only unit 2 data is 3.3 "Presentation of Plant- addressed in the included in the tables but there Specific Data" of the Data base PRA model appears that some unit 1 pumps may Analysis PRA Notebook to prior to building the have been included. Ifthis is the identify what Unit 2 equipment is Fire PRA.

case, then the text needs to explain included in the development of that Unit 2 equipment is included and the Unit 1 database distributions only the Unit 1 equipment that may be or test and maintenance needed to shutdown Unit 2 is unavailability.

included. I II Page 57 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA

__________I______ YN ___________________

I DE-03 DE-11 C Y The flooding analysis and the IPE Since the documentation for the No impact on the state (briefly) that a plant walkdown flooding walkdown that was submitted BVPS-1 YIN was performed. But there is no performed as part of the IPE Fire PRA, which I documentation of the walkdown, or could not be located, the used the the insights gained from the walkdown that was completed for BV1 REV5 as its walkdown, available for review. The the Beaver Valley Unit 1 Risk- basis. Internal fire walkdown "notebook" would be a Informed In-Service Inspection initiators and flood valuable resource for analyst in future (RI-ISI) Indirect (Spatial) initiators are updates of the PRA. Consequence Evaluation was mutually exclusive credited, as discussed in the and have no effect response to F&O DE-04 above. on each other.

Since this RI-ISI walkdown is documented in a BVPS Furthermore, the calculation and is retrievable, it is BVPS-1 Fire PRA not deemed necessary to working model reproduce it for the PRA uses BV1 REV5A notebooks. as its basis, so this F&O will be This F&O was written against an resolved when obsolete Internal Flooding PRA NFPA 805 is model (BV1 REV3) and is implemented.

considered to be resolved by the updated Internal Flooding PRA model incorporated in BV1 REV5A, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are Page 58 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN presented in Table 1-4.

DE-06 SY C Y Some of the flood frequencies are This F&O was written against an No impact on the based on a document (PLG-0624) that obsolete Internal Flooding PRA submitted BVPS-1 is dated 1988. The next update model (BV1 REV3) and is Fire PRA, which should include consideration of more considered to be resolved by the used the recent flood data sources. updated Internal Flooding PRA BV1 REV5 as its model incorporated in basis. Internal fire BV1 REV5A, which underwent a initiators and flood focused Peer Review in initiators are accordance with the guidance in mutually exclusive Appendix B of NRC RG 1.200, and have no effect Rev. 1, conducted during June 6- on each other.

9 2011, by the PWR Owners Group. The F&Os as a result Furthermore, the from this focused Peer Review, BVPS-1 Fire PRA as well as their resolutions are working model presented in Table 1-4. uses BV1REV5A as its basis, so this F&O will be resolved when NFPA 805 is I implemented.

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Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N DE-07 SY C Y The PRA documentation should This F&O was written against an No impact on the include a discussion of the potential obsolete Internal Flooding PRA submitted BVPS-1 impact of floods on systems that are model (BV1 REV3) and is Fire PRA, which shared between the two units. considered to be resolved by the used the Although this impact is expected to be updated Internal Flooding PRA BV1 REV5 as its minimal, one example is the potential model incorporated in basis. Internal fire impact on the electric power crosstie BV1 REV5A, which underwent a initiators and flood to Unit 1 availability due to floods in focused Peer Review in initiators are the service water intake structure. Is accordance with the guidance in mutually exclusive the Unit 1 diesel dependence on Appendix B of NRC RG 1.200, and have no effect service water correctly accounted for Rev. 1, conducted during June 6- on each other.

when the flood impacts the availability 9 2011, by the PWR Owners of the Unit 1 service water system? Group. The F&Os as a result Furthermore, the from this focused Peer Review, BVPS-1 Fire PRA as well as their resolutions are working model presented in Table 1-4. uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is I_ implemented.

HR-02 HR-06 C Y A generic error of omission term from This F&O was written against an No impact to Fire the PLG database (ZHEO1A) was obsolete HRA PRA model PRA, because this used for all misalignment HEPs (BV1 REV3) and is considered to issue was without regard for procedural or be resolved by the updated HRA addressed in the operational failure barriers such as PRA model incorporated in base PRA model independent verification, peer checks, BVl REV4, which underwent a prior to building the walkdowns, etc. However, plant focused Peer Review in Fire PRA.

specific data was used for test and accordance with the guidance in maintenance frequencies. Therefore, Appendix B of NRC RG 1.200, the overall misalignment errors were a Rev.1, conducted during the hybrid of generic and plant specific week of October 29, 2007, by data. This was used for systems Westinghouse. The F&Os as a Page 60 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN which are important to CDF (e.g., AF, result from this focused Peer SI). Review, as well as their resolutions are presented in Table 1-3.

HR-10 HR-18 C Y The number of operators interviewed This PRA Peer Review No impact to Fire for the performance shaping factors observation was dispositioned by PRA, because this was stated to be 3 operators, 3 acknowledging that, while issue was training staff and 3 PRA staff. This is a technically only 3 operators were addressed in the low number of operators for the FLIM interviewed, the training staff base PRA model method to succeed. Having the PRA personnel were former operators prior to building the staff fill out the PSF forms dilutes the that still held a senior reactor Fire PRA.

operator input to the process. operators license at the time of the interview. Therefore, a total of six licensed personnel were used in developing the PSFs.

Additionally, as a final resolution to this observation, future BVPS PRA models will use the EPRI HRA Calculator, which uses a more current and robust methodology to identify human action dependencies.

This F&O was written against an obsolete HRA PRA model (BV1REV3) and is considered to be resolved by the updated HRA PRA model incorporated in Page 61 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N BV1 REV4, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

IE-01 IE-04 C Y In section 3.3 of the Initiating Events In response to this observation, No impact to Fire Notebook, there is a discussion about Section 3.3 of the Initiating PRA, because this the justification for the exclusion of Events Analysis PRA Notebook issue was Random RCP Seal LOCAs as a was revised to add further addressed in the separate IE that is based on the RCP clarification based on the floating base PRA model floating ring seals and the assumption ring seals (per Reference 15) as prior to building the of limited leak flow. The justification to why random RCP seal LOCAs Fire PRA.

provided to account for assuming this were eliminated from the Beaver is a discussion by FENOC with Valley PRA model. Additionally, Westinghouse. No documentation of this Section was revised to this discussion is provided and no provide justification as to why a further technical justification is given random RCP seal failure at as to why random seal failure should Beaver Valley that resulted in a have the frequency and be included in reactor trip would be captured Category GI/QG9 under RTRIP. under the RTRIP initiating event frequency.

IE-02 IE-13 C Y In the discussion of the process used In response to this observation, No impact to Fire for Initiating Event frequency update, Section 2.3 of the Initiating PRA, because this BWR data and other NSSS vendor Events Analysis PRA Notebook issue was PWRs are excluded from the update was revised to provide a brief addressed in the without sufficient documentation. explanation for why BWR and base PRA model Page 62 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN other PWR NSSS vendor data prior to building the were excluded from the BVPS Fire PRA.

initiating event frequency update.

IE-03 IE-10 C Y The Support System Faults that are In response to this observation No impact to Fire used as Initiating Events are assigned Tables Al and Al0 in the PRA, because this a Code Designator. The System Initiating Events Analysis PRA issue was Codes and Top Events for these Notebook was revised to include addressed in the designators are not explained. The a cross-reference from the base PRA model System Notebook does not clearly initiating event "Code Designator" prior to building the explain how the System is considered to the applicable PRA System Fire PRA.

to cause an Initiating Event in the Notebook. In addition, Table A2 Model. of this notebook provides a failure modes and effects analysis of the key BVPS Unit 1 support systems and why they were considered for initiating events, so it was not judged to be necessary to duplicate this information in the System Notebooks. It was not the intent of the PRA System Notebooks to be stand-alone documents, but rather to be supplemented by the I PRA analysis notebooks. I Page 63 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N IE-06 IE-16 C Y Plant trip trends in the recent years In response to this observation, No impact to Fire are showing a general decrease in Figure 3-1 was generated to PRA, because this trips/year. A simple trend analysis present a plan trip trend issue was (like a histogram) showing number of histogram and Section 3.2 of the addressed in the trips versus years for each unit should Initiating Events PRA Notebook base PRA model be considered as a subsection in the was revised to include a prior to building the initiating events section. This would discussion of the plant trip trend Fire PRA.

possibly allow better estimation of analysis performed for BVPS plant specific transient event Unit 1.

frequency. Currently, there appears to be no analysis to show whether there is a positive or negative trend (or a lack of it). Also, a trend analysis fits well with the concept of plant-specific nature of analysis in question.

For example, consider a plant with 10 years of trip data; the first 5 years each have 5 trips/year; the last 5 years have 1 trip per year. This would result in an average of 3 events per year over a ten-year period. Now consider another plant where the two numbers are interchanged; it has 1 event per year for the first five years and 5 events per year for the next five years. The overall average is still 3 events per year. In both cases, there are definite trends; the first plant should actually use a frequency of 1 trip per year; the second plant should use 5 trips per year. In any case, neither plant should use 3 trips per year.

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Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N IE-07 IE-03 C Y There was not enough information in In response to this observation, No impact to Fire the initiating event report to reproduce Table Al 2 was generated in PRA, because this the results. Appendix A of the Initiating issue was Events Analysis PRA Notebook addressed in the

1. The prior distributions were not to show the set of input data base PRA model available. used in the creation of each first prior to building the stage (prior) distribution identified Fire PRA.

2. the screening of the WCAP IE in Table A4, as well as, the report was not available resultant RISKMAN distribution parameters for the mean,

3. The derivation of prior means was median, 5th and the 95th not available. percentiles. This data was input into the RISKMAN Data Module, using the 'First Stage of Two Stage' distribution option to create the resultant prior distributions. The derivation of how RISKMAN generates these prior distributions using this option is contained in the RISKMAN Software Users Manual, and does not need to be reproduced in this notebook.

Additionally, there was no screening of the Westinghouse WCAP-1 5210 initiating event data since each individual utility performed a thorough review of their plant's trip events to ensure that the data was valid.

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Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN

[2-02 [2-08 C Y Most containment phenomena are Ultimately resolved by GAP F&O No impact to Fire either excluded via generic, or plant LE-F2-01 (see Table 1-2) PRA, because this specific analyses, or are modeled as a issue was point estimate. Other issues such as addressed in the whether the containment is inerted are base PRA model more directly quantified. For example, prior to building the the LI/L2 interface directly quantifies Fire PRA.

those end states when the sprays are operating; operation of the sprays is considered to de-inert containment.

[2-04 [2-21 C Y Top Event 10 - Containment Failure Ultimately resolved by GAP F&O No impact to Fire Prior to Vessel Breach (Cl) states that LE-D6-01 (see Table 1-2) PRA, because this because the Beaver Valley Unit 2 issue was containment normally operates at addressed in the subatmospheric conditions, the base PRA model existence of large pre-existing leaks is prior to building the believed to be negligible. Current L2 Fire PRA.

analysis would not support containment conversion application.

MU-01 MU-04 C Y Plant changes that may impact the Ultimately resolved by procedure No impact to Fire PRA model are documented, and NOBP-CC-6001 and Design PRA, because this resolved via Risk Evaluation Review Interface Evaluation (DIE) issue was (RER) forms. Continuing training is process that evaluates changes addressed in the used to educate engineering (includes for PRA impact. base PRA model procedure writers) on when an RER is prior to building the required vs. direct procedural Fire PRA.

guidance. The update process could be improved by adding a similar review process into other plant I change procedures I I Page 66 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN MU-03 MU-1 1 C Y When the PRA model is updated for Ultimately resolved by procedure No impact to Fire plant modifications or for decreases in NOBP-CC-6001, Section 7 lists PRA, because this CDF all areas of applications should RI-applications that need issue was be evaluated. Certain applications updated following a new ERM addressed in the can be adversely impacted by (Effective Reference Model). base PRA model decreases in CDF. For example, prior to building the credit taken for examining segments Fire PRA.

in a RI-ISI program could decrease with a decrease in CDF (or even an unrelated CDF increase, depending on changes to the risk profile.)

Additionally more than just the change in CDF needs to be evaluated. The risk profile may change drastically without a corresponding change in the CDF. For example CDF due to one IE may go up by 30% in conjunction with another change in CDF due to a different IE decreasing by 25%. This would cause only a 5% change in CDF but significant changes to the risk profile.

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Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N QU-01 QU-07 C Y PRA Peer Review Subtler Criteria for As resolution to this PRA Peer No impact to Fire this sub-element describes the need Review observation it should be PRA, because this for documentation of the limitations of noted that the RISKMAN model issue was simplified models. This is used for purposes for risk addressed in the documentation could not be found for sensitivities (e.g., SDP findings) base PRA model Beaver Valley Unit 2. and risk-informed applications, prior to building the as such, there are no simplified Fire PRA.

model used for these purposes and hence nothing to document.

Additionally, the intent of the PRA Notebooks was to document the development process and results of the RISKMAN PRA model, not to document the Safety Monitor model or its process that currently uses pre-solved sequence, or to document other risk-informed sensitivities and programs. Moreover, future versions of the Safety Monitor for RISKMAN users are to incorporate a full requantification of the sequences in place of pre-solved sequences.

QU-05 QU-23 C Y RISKMAN allows the user to apply a In general, the BV1 REV3 PRA No impact to Fire cutoff at the system (i.e., top event) model update did not use any PRA, because this level. This cutoff is applied prior to the truncation limits (i.e., a value of issue was event tree quantification. In general, 0) for cutset generation. addressed in the no truncation (i.e., a value of 0) is However, when the cutsets base PRA model used in the systems cutset generation. exceeded the quantification prior to building the But non-zero values are used for a limits, very low non-zero values Fire PRA.

handful of top events. Of these most were used. This was only I Page 68 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I YIN I use very low cutoffs (<1E-12). The present in a handful of top one exception to this (as best this events.

reviewer could determine) is the quantification of Top Event WC where The one exception to this is the a cutoff of 5E-7 was used. Top Event quantification of Top Event WC WC is an intermediate top used to where a cutoff of 7E-7 was used.

quantify Top Event WA and WB. Split Top Event WC is an intermediate Fraction WC1 has an unavailability of top used to quantify Top Events about 3E-9. WA and WB. The 7E-7 cutoff was used for the cutset The SW system notebook discusses generation with elevated the system level cutoff and when it is common cause failure rates for used. However, the potential pump and fan starts and run quantitative impacts associated with basic events. The failure rates the truncated results are not are reset to best estimate values discussed. prior to the quantification of split fractions. This is done so that the cutoff is high enough to stay below the Riskman cutset limitation, but allows the cutsets to contain the higher order cutsets that will allow analysis of degraded boundary conditions (i.e., split fractions).

Split Fraction WC2B (DC Purple fails) has an unavailability of about 9.6914E-6, and only accounts for the probabilistic failure of the A header since DP=F causes a guaranteed failure of the B header. When this value is comDared to the Page 69 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN Split Fraction WA1 (all support available) value of 1.0493E-5 (generated using a 1E-1 2 truncation limit), it can be shown that only about 8% of the expected unavailability is lost due to the higher truncation limits used in Top Event WC.

Furthermore, truncation limits will not be required in RISKMAN version 6, which uses binary decision diagrams to generate Split Fractions values directly without cutsets.

Ultimately resolved by quantifying the split fractions using the BDD methodology, starting with the revision 4 PRA model.

SY-04 SY-27 C Y It would be desirable to reference the Ultimately resolved in Revision 5 No impact to Fire success criteria source in the system PRA model System Notebooks, PRA, because this notebook. Success criteria are Section 3 "SYSTEM SUCCESS issue was specified in the "Success Criteria" CRITERIA" addressed in the notebook, and the reviewers found it base PRA model difficult to flip from one source to prior to building the another, especially when using the Fire PRA.

electronic documentation CD.

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Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN SY-05 SY-12 C Y The system notebooks do not Ultimately resolved in Revision 5 No impact to Fire specifically discuss the dependencies PRA model System Notebooks, PRA, because this that may be present regarding HVAC / Section 4 "SUPPORT issue was room cooling. However, review of the SYSTEMS" addressed in the HVAC notebook identified the various base PRA model spatial locations that may require prior to building the HVAC and indicated the various Fire PRA.

analyses that have been completed to either require HVAC dependencies or not.

SY-07 SY-26 C Y The Beaver Valley Unit 2 system Ultimately resolved by GAP F&O No impact to Fire notebooks have no indication of F&O SY-Cl-02 (see Table 1-2). PRA, because this system engineering reviews. These issue was reviews help ensure that systems are addressed in the model in accordance with day-to-day base PRA model plant operations and additionally prior to building the expand the PRA knowledge of the Fire PRA.

I system engineers.

SY-08 SY-01 C Y The guidance did not provide for more The split fraction definitions were No impact to Fire complete description of the actual developed using the dependency PRA, because this boundary conditions used in the matrices located in Appendix B of issue was system analysis. It did talk about the Level 1 Event Tree Analysis addressed in the support, but the actual details are not PRA Notebook. Split fractions base PRA model required (i.e. what AC bus is needed for Top Events are found in the prior to building the for which pump for that boundary Split Fraction sections of the Fire PRA.

condition for the split fraction). As a RISKMAN System Notebook files result most of the notebooks do not in Appendix C. Common cause give a good description of what each failure inputs, assessment split fraction means and its usage. methodology and data update The only place this appears to be summaries are located in actually documented is the description Appendix C of the Data Analysis on the split fraction in the RISKMAN Notebook.

split fraction. II Page 71 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN SY-09 (sic SY-14) C Y System Diagrams contained in Hard copy of 11x17 with markups No impact to Fire System Notebooks do not have of plant drawings are provided in PRA, because this explanation of color highlighting, the System Notebook. issue was Figures are difficult to read and many Components modeled in the PRA addressed in the component lDs are not legible. are highlighted in PINK, while the base PRA model flow paths are highlighted in prior to building the There also does not appear to be a YELLOW. Fire PRA.

discussion of 'Operating experience for the system' required in the Operating experience for the guidance document. system is subsumed in the system engineers review.

SY-10 (sic SY-14) C Y The Fault Trees for IA, IC have Resolved in Revision 5 PRA No impact to Fire Transfer Gates and page numbering models that have Fault Trees PRA, because this that is confusing. IA page 6 transfers redrawn so Top Gate is on page issue was to page 7 but page 7 top gate 1. addressed in the transfers to page 1. In IC, page 1 is a base PRA model transfer from page 5 which is the Top NOTE: The Fire PRA FTs are not prior to building the Event IC. This is confusing and is organized due to addition of Fire PRA. Also, easily fixed. NFPA 805 basic events, this is a documentation-only issue.

SY-12 SY-17 C Y The Service cooling water system Ultimately resolved by GAP F&O No impact to Fire notebook assumption #7 has 10 F&O SY-B7-01 (see Table 1-2). PRA, because this minutes to trip the RCP's on loss of issue was cooling. However, in the addressed in the Miscellaneous system notebook, top base PRA model event OC has 5 minutes to trip the prior to building the RCP's. Note, this time might be Fire PRA.

important in quantifying an HEP. I Page 72 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID RequirementI Level Closed PRA YIN SY-13 SY-13 C Y Several systems appeared to be The AFW pump macros were No impact to Fire modeled as point estimate only, revised in the BV1 REV3 PRA PRA, because this AMSAC and the Switchyard. This is model to include credit for issue was acceptable, per the peer review AMSAC to start the AFW pumps addressed in the guidance, but consideration could be (in addition to the SSPS signal), base PRA model given to adding some detail to these given that the signal is generated prior to building the models. during non-ATWS events. Fire PRA.

The Switchyard (Top Event OG) was modeled as a single basic event. However, it used a lognormal distribution to quantify Monte Carlo values in addition to the point estimate value.

Furthermore, the PRA model already addressed transient induced LOSP events due to failures of the USST/SSST and Switchyard breakers in the normal bus top events.

The current methods to address the AMSAC and Switchyard failure probabilities are deemed acceptable as is.

SY-1 5 SY-1 0 C Y HVAC support analysis appears to As a resolution to this PRA Peer No impact to Fire only consider 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months versus 24 Review observation Table 3 in PRA, because this hours. The analysis was extended to the Ventilation and Room issue was 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months based upon the fact that the Cooling Analysis Notebook was addressed in the curves were essentially flat after 8 revised to show the expected base PRA model hours. Some of the curves are straight area temperature at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to building the and increasing and not flat and following the loss of ventilation. Fire PRA.

constant. I I Page 73 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID RequirementI Level Closed PRA Y/N AS-05 AS-1 7 D Y The success criteria for top event TT Ultimately resolved in Revision 5 No impact to Fire is missing from Table 3.3-2 of the PRA model Level 1 Accident PRA, because this Event Tree Notebook although it is Sequence Analysis Notebooks, issue was described on page 58 of the notebook. Table 3.3-2 & Table 3.4-2. addressed in the base PRA model prior to building the Fire PRA.

AS-06 AS-1 7 D Y The success criteria for top event NM Top Event NM is a switch to No impact to Fire is missing from Table 3.3-6 of the query if early core damage has PRA, because this Event Tree Notebook although it is occurred during the SI injection issue was described on page 67 of the notebook. phase, and does not have any addressed in the success criteria per se, so is not base PRA model included in the Success Criteria prior to building the Tables. Fire PRA.

DE-01 DE-01 D Y The guidance for including spatial Ultimately resolved in Revision 5 No impact to Fire information in the system notebooks PRA model Systems Analysis PRA, because this could not be found in the system Overview and Guidance issue was notebook guidance document. Notebooks, Section 5 "SPATIAL addressed in the However, it appears that most, if not CONSIDERATIONS" base PRA model all, the system notebooks did have a prior to building the section on spatial considerations for Fire PRA.

flooding, fire and seismic.

SY-1 1 SY-1 5 D Y The AC power system calculation Ultimately resolved in Revision 5 No impact to Fire notebook, has top event OG which PRA model Data Analysis PRA, because this has a split fraction for generic loss of Notebooks, Tables A-1 and A-2. issue was power after a plant trip. The basic addressed in the event report for this was missing from base PRA model the system notebook, but the system prior to building the notebook listed a database variable Fire PRA.

"OG1X" used. This variable could not be found in the data notebook. It was in the RISKMAN model with no references from where it came from. It I I Page 74 of 301

Table 1-1. Summary of BVPS-1 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN was determined that it came from the PLG-0500 revision 1, 1989.

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Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IE- IE-A6 B Y There is no documentation of interviews Documentation of interviews with A6- of plant personnel (e.g., operations, system engineering plant personnel to 01 maintenance, engineering, safety determine if potential system analysis) to determine if potential descriptions have been overlooked is No impact to initiating events have been overlooked, located in the Unit-1 PRA Notebook Fire PRA, This is required to meet capability Systems Analysis Overview and because this category II Guidance, Appendix B. Review of the issue was initiating events section in the system addressed in notebooks was also included as the base PRA review of the system description by model prior to system engineers. System engineers building the were asked to identify from a list of Fire PRA.

the current initiating events if there are any top events whose failure could result in a potential initiating event (plant/reactor trip), which may have been overlooked. No additional potential initiating events were brought up. Also, review of AOPs (e.g., 1OM-53C.4.1.28.1) can be credited I Page 76 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I IE- IE-C8 C Y All the relevant combinations of events The Initiating Events section of the No impact to C8- involving the annual frequency of one system notebooks now contain a Fire PRA, 01 component failure combined with the description of the development of the because this unavailability (or failure during the repair support system initiating events, issue was time of the first component) of other Except as noted, the mission time for addressed in components are not available in the normally running equipment is the base PRA support system notebooks. The support changed from 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to 8760 hours0.101 days 2.433 hours 0.0145 weeks 0.00333 months model prior to system notebooks list which initiators times the plant availability factor. building the are developed from the fault trees and Portions of the system fault tree logic Fire PRA.

provide a diagram of the fault tree, which is not used to quantify support however there is no narrative system initiating event frequency is explanation of how these fault trees are also noted.

modified and what assumptions are used to develop the support system initiator frequencies. RISKMAN reports, provided as System Notebook appendices, list the details of the system IE models (i.e. cutsets, modified basic event equations, etc.), however there is no discussion of which component failures were considered, what mission time assumptions are used, or description of the development of the system IE models. Therefore it is difficult to determine if all relevant combinations of events have been considered.

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Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IE- IE-C9 B Y Plant-specific information used in the The Recovery Considerations section No impact to C9- assessment and quantification of of the System Notebooks now Fire PRA, 01 recovery actions included in the support documents the operator actions that because this system initiating event analysis is not were modified in the quantification of issue was included in the support system the system initiating event frequency. addressed in notebooks. Analysis of the recovery No new recovery actions are credited the base PRA actions should be consistent with the in the analysis of initiating event model prior to applicable requirements in the Human frequency. building the Reliability Analysis Fire PRA.

IE- IE-Cl 0 B Y There is no comparison of the initiating In the Initiating Events Analysis No impact to C1 0- event analysis with generic data Notebook, Table A6 demonstrates a Fire PRA, 01 sources or explanation of differences to comparison of initiating event because this provide a reasonableness check of the frequencies for the Westinghouse 3- issue was results. loop PWR. The industrial events are addressed in from WOG Rev 7 PSA comparison the base PRA database. Comparably Beaver Valley model prior to 1 to other Westinghouse 3-loop PWR building the plants has most initiating events Fire PRA.

frequencies close to order of magnitude. Some differences in plant frequency include Loss of Emergency Switchgear HVAC (BVX) with a much lower frequency then the other plants and MLOCA. The reason for difference in HVAC is due to the high detail of the ventilation and room cooling analysis, as well as several ventilation sources available in the area (i.e., normal fans, emergency I Page 78 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA I YIN L fans, and portable fans). MLOCA initiating event frequency has been updated for PRA-BV1-AL-R05 to a new methodology based on NUREG-1829 (April 2008) and lowering the effective break size therefore lowering the frequency. The WOG Rev 7 of other Westinghouse 3-loop PWRs was developed before the methodology of NUREG-1829 was used. Blank gaps in Table A6 do not have data for that plant from the WOG database.

DA- DA-C4 B Y A clear basis for the identification of Documentation of this is now included No impact to C4- events as failures is not included in the in Section 3.3 of the Unit 1 Data Fire PRA, 01 Data Analysis Notebook. This basis Analysis Notebook. because this could be used to distinguish between issue was those degraded states for which a addressed in failure, as modeled in the PRA, would the base PRA have occurred during the mission and model prior to those for which a failure would not have building the occurred (e.g., slow pick-up to rated Fire PRA.

speed).

It could not be determined from the Data Analysis Notebook if any failures were screened out or if the maintenance rule MPFFs are used as the data source.

DA- DA-C5 B Y There is no listing or description in the For Beaver Valley Unit 1, repeated No impact to C5- Data Analysis Notebook of repeated plant specific component failures Fire PRA, 01 component failures that were counted occurring within a short time interval because this a L as a single failure. were counted as a sinale failure V

issue was Page 79 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N during implementation of the addressed in Repeated component failures occurring Maintenance Rule. PRA data is taken the base PRA within a short time interval should be from Maintenance Rule sources and model prior to counted as a single failure if there is a therefore meets the requirements of building the single, repetitive problem that causes the ASME PRA standard." Fire PRA.

the failures. In addition only one demand should be counted.

DA- DA-C8 B Y Plant records should be used and Maintenance Rule plant specific No impact to C8- documented to determine the time that unavailability data is incorporated into Fire PRA, 01 components are configured in their the PRA model. Documentation of because this standby status. This is required to this can be found in the Presentation issue was change SR DA-C8 from Capability of Plant-Specific Data section of the addressed in Category I to III Data Analysis notebook under sub- the base PRA section Component Maintenance model prior to Data and is evidenced by the Prior building the Maintenance Data of Appendix B." Fire PRA.

DA- DA-C10 B Y Decompose failure modes into sub- Component failure modes have been No impact to C1 0- elements and count demands/failures handled appropriately to meet this Fire PRA, 01 individually in the sub-elements. Supporting Requirement at the CC-Il because this level. Failures of sub-elements of a issue was component that are modeled explicitly addressed in in the PRA are associated with the the base PRA sub-element and not the component model prior to itself. Documentation of this can be building the found in the Presentation of Plant- Fire PRA.

Specific Data section of the Data Analysis Notebook under sub-section Component Failure Event Allocation and is evidenced by the data in Table A-I. I Page 80 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN HR- HR-B1, HR- B Y This F&O is a carry-over from the peer As outlined in HRA Notebook Section No impact to B1- D2 review (F&O HR-2). A generic 2.2, testing and maintenance Fire PRA, 01 error of omission term from the PLG procedures were evaluated to identify because this database (ZHEO1A) was used for all potential misalignments. These issue was misalignment HEPs without regard for potential misalignments were addressed in procedural or operational failure barriers evaluated using the EPRI HRA the base PRA such as independent verification, peer Calculator 4.1.1 to develop specific model prior to checks, walkdowns, etc. However, HEPs for each potential misalignment building the plant specific data was used for test and as documented in HRA Notebook Fire PRA.

maintenance frequencies. Therefore, Table 3.5.

the overall misalignment errors were a hybrid of generic and plant specific data. This was used for systems which are important to CDF (e.g., Auxiliary Feedwater, Safety Injection).

HR- HR-D3 B Y While the discussion in the system Procedure quality has been No impact to D3- notebooks (AFW and QS/RS notebooks incorporated into human error Fire PRA, 01 were reviewed) references the probability assessments, because this procedures, no documentation of quality Documentation of this can be found issue was of those procedures or administrative throughout the HRA Notebook, addressed in controls was found. particularly the Dynamic Actions the base PRA section and tables of Section 3." model prior to building the I_ Fire PRA.

HR- HR-12 B Y The BV HRA does document a process Section 2.3 of the Unit 1 HRA No impact to 12- to perform a systematic search for notebook has been created to Fire PRA, 01 dependent human actions credited on document the process employing the because this individual sequences. It is clear from the EPRI HRA calculator that is used to issue was human action identifier sheets complete the dependency analysis addressed in documented in the BVPS-2 HRA evaluation. The results of the human the base PRA Page 81 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N notebook that such an evaluation has action dependency analysis model prior to been performed, but there is no presented in Appendix F show that building the evidence of the process documented in the dependency contributions to the Fire PRA.

the HRA notebook. split fraction values are insignificant.

The largest change identified is for split fraction CDC which has a value of 1.40E-2 and a dependency contribution of 6.41 E-4 or a 4.6%

To be consistent with current HRA increase due to dependencies. This methods, there must be a systematic increase in the split fraction CDC process to identify, assess and adjust value due to operator action dependencies between multiple human dependencies would lead to a 0.34%

errors in the same sequence, including increase in the core damage those in the initiating events. frequency. This level of change is considered insignificant to the overall results, and did not reveal any new dependencies that were not already analyzed and accounted for.

Furthermore, these results confirm the success of using the Event Sequence Diagrams during development of the IPE to identify dependencies between operator actions, and account for these dependencies in the development of the HEPs 4.

HR- HR-I1, The HRA notebook sporadically A new Assumptions section has been No impact to 13- HR-13, discusses assumptions and added to the Unit 1 HRA notebook. Fire PRA, 01 AS-C3, uncertainties. Per the Clarification to All major assumptions and sources of because this regulatory Guide 1.200 Revision 1, uncertainty are listed in this location. issue was IE-D3, there is an increased importance in the addressed in IF-F3, industry to identify assumptions and the base PRA LE-F3, uncertainties in the PRA model. In model prior to LE-G4, reviewing the HRA notebook, it is building the L

Page 82 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation 1BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I SC-C1, difficult to locate the assumptions and Fire PRA.

SC-C3, uncertainties.

QU-F4 HR- HR-I1, HR-12 C Y The Beaver Valley Unit 2 system and The BVPS Units 1 & 2 PRA and No impact to I1- data notebooks have been updated and System notebooks were formally Fire PRA, 01 exist in draft form, but there is no record reviewed and signed off as part of the because this of formal review and approval, update process. issue was Furthermore, only a subset of the total addressed in PRA notebooks have been updated for the base PRA this revision of the PRA. model prior to building the Fire PRA.

HR- HR-12 C Y There is no evidence in the HRA or During the Extended Power Uprate No impact to 12- Success Criteria notebooks that an evaluation, plant operations did Fire PRA, 02 operator review of the HRA has been review the operator actions and because this performed. timings. These reviews are issue was documented in FENOC Letters L addressed in 003 and L-06-018. Furthermore, the base PRA several operator action scenarios model prior to were evaluated using the plant building the simulator. Fire PRA.

IF- IF-Ala B Y It is not clear from the documentation This F&O was written against an No impact on Ala- that a comprehensive assessment has obsolete Internal Flooding PRA model the submitted 01 been conducted to finalize the (BV1 REV4) and is considered to be BVPS-1 Fire combined rooms including propagation, resolved by the updated Internal PRA, which barriers, etc. The IF assessment is Flooding PRA model incorporated in used the based on large flood areas but there is BV1 REV5A, which underwent a BV1REV5 as no description of the process used to focused Peer Review in accordance its basis.

define those areas with respect to flood with the guidance in Appendix B of Internal fire propagation and barriers. NRC RG 1.200, Rev.1, conducted initiators and during June 6-9, 2011, by the PWR flood initiators I Owners Group. The F&Os as a result are mutually Page 83 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-A3 B Y There is no evidence in the IF Notebook This F&O was written against an No impact on A3- that it represents the current as-built-as obsolete Internal Flooding PRA model the submitted 01 operated plant (circa 2007). Rev4 (BV1 REV4) and is considered to be BVPS-1 Fire documentation in another document resolved by the updated Internal PRA, which may include the information to show Flooding PRA model incorporated in used the that the IF assessment is current, but it BV1 REV5A, which underwent a BV1REV5 as is not in this Notebook, IF-A3-01 was focused Peer Review in accordance its basis.

written as a B level F&O to provide with the guidance in Appendix B of Internal fire documentation that the IF assessment NRC RG 1.200, Rev.1, conducted initiators and still represents the as-built as operated during June 6-9, 2011, by the PWR flood initiators plant in 2007, This probably also Owners Group. The F&Os as a result are mutually applies to other PRA elements from the from this focused Peer Review, as exclusive and ASME PRA Standard (e.g., SY, SC, well as their resolutions are presented have no effect HR, etc.) and should be addressed in Table 1-4. on each other.

generically for the BVPS PRA. This would facilitate future reviews and Furthermore, development of PRA applications, the BVPS-1 I I_Fire PRA Page 84 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N working model uses BV1REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-B1 B Y The ASME PRA Standard states "for This F&O was written against an No impact on B1- each flood area, identify the potential obsolete Internal Flooding PRA model the submitted 01 sources of flooding." Section C3.1 (BV1 REV4) and is considered to be BVPS-1 Fire identifies flood sources in each area but resolved by the updated Internal PRA, which clear documentation of each source in Flooding PRA model incorporated in used the an area is lacking. The Standard BV1 REV5A, which underwent a BV1REV5 as expects a more systematic approach for focused Peer Review in accordance its basis.

identifying potential flood sources and with the guidance in Appendix B of Internal fire then later screening them. The IF NRC RG 1.200, Rev.1, conducted initiators and assessment here includes initial during June 6-9, 2011, by the PWR flood initiators screening without written justification. It Owners Group. The F&Os as a result are mutually is suggested that a complete discussion from this focused Peer Review, as exclusive and of potential sources be documented and well as their resolutions are presented have no effect the basis for screening potential in Table 1-4. on each other.

sources.

Furthermore, I_ I_the BVPS-1 Page 85 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions on BVPS-1 Final Resolution Impact to Fire PRA Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

I 4.

Section C3.1 states that major flood This F&O was written against an No impact on sources were reviewed to identify obsolete Internal Flooding PRA model the submitted potential flood locations. The ASME (BV1 REV4) and is considered to be BVPS-1 Fire standard suggests that first you identify resolved by the updated Internal PRA, which flooding areas then identified all Flooding PRA model incorporated in used the flooding sources in that area. This BV1 REV5A, which underwent a BV1REV5 as method used for BVPS may have lead focused Peer Review in accordance its basis.

to overlooking other sources of flooding with the guidance in Appendix B of Internal fire within each area. NRC RG 1.200, Rev.1, conducted initiators and during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1REV5A as its basis, so I I I I I-this F&O will be Page 86 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N resolved when NFPA 805 is implemented.

IF- IF-B2, B Y The SR B-2 of the PRA Standard This F&O was written against an No impact on B2- IF-B3 requires "For each source of flooding, obsolete Internal Flooding PRA model the submitted 01 identify the flooding mechanisms that (BV1 REV4) and is considered to be BVPS-1 Fire would result in a fluid release including resolved by the updated Internal PRA, which failure models, human-induced Flooding PRA model incorporated in used the mechanisms, and other events resulting BV1 REV5A, which underwent a BV1REV5 as in a release into the flood area." In focused Peer Review in accordance its basis.

addition, SR B-3 requires "For each with the guidance in Appendix B of Internal fire source and its identified failure NRC RG 1.200, Rev.1, conducted initiators and mechanism, identify the characteristic of during June 6-9, 2011, by the PWR flood initiators release and the capacity of the source." Owners Group. The F&Os as a result are mutually Section C3.1 of the IF Notebook does from this focused Peer Review, as exclusive and not provide enough detail to judge well as their resolutions are presented have no effect whether these requirement is met. One in Table 1-4. on each other.

example is that although a few human error induced floods (e.g., testing or Furthermore, maintenance errors) were considered, the BVPS-1 there is no evidence of a systematic Fire PRA assessment of potential test and working model maintenance errors. uses BV1REV5A as Page 87 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA W/N its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-C2b B Y Section C3.1 does not have enough This F&O was written against an No impact on C2b- detail to show that the capacity of the obsolete Internal Flooding PRA model the submitted 01 drains and the amount of water retained (BV1 REV4) and is considered to be BVPS-1 Fire by the sumps, berms, dikes, and curbs resolved by the updated Internal PRA, which was estimated. The reviewer notes that Flooding PRA model incorporated in used the it is likely that this was performed but BV1 REV5A, which underwent a BV1REV5 as there is no record of the assessment. focused Peer Review in accordance its basis.

The capacity of drains and the amount with the guidance in Appendix B of Internal fire of water retained by sumps, etc. should NRC RG 1.200, Rev.1, conducted initiators and be documented in the IF Notebook. during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model Page 88 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

Page 89 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation ID Requirement Level Closed YIN

=

IF- IF-C3 B Y The PRA Standard states "for each This F&O was written against an No impact on C3- SSCs identified in IF-C2c identify the obsolete Internal Flooding PRA model the submitted 01 susceptibility of each SSC in the flood (BV1 REV4) and is considered to be BVPS-1 Fire area to flood-induced failure resolved by the updated Internal PRA, which mechanism". Also, the SR-C3a states, Flooding PRA model incorporated in used the "to determine susceptibility of SSC to BV1 REV5A, which underwent a BV1REV5 as flood-induced failure mechanism, take focused Peer Review in accordance its basis.

credit for the operability of SSC with the guidance in Appendix B of Internal fire identified in IF-C2c with respect to NRC RG 1.200, Rev.1, conducted initiators and internal flood impact only if supported during June 6-9, 2011, by the PWR flood initiators by an appropriate combination of: 1) Owners Group. The F&Os as a result are mutually test or operational data, 2) engineering from this focused Peer Review, as exclusive and analysis, and 3) expert judgment." It is well as their resolutions are presented have no effect likely that flood-induced failure in Table 1-4. on each other.

mechanisms were considered in the IF assessment but are not identified in the Furthermore, IF Notebook. Section C3.1 does not the BVPS-1 provide enough detail on the impact of Fire PRA the flood on SSCs. working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

Page 90 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/NIA IF- IF-C3a, IF- B Y The IF-C3b SR requires that all This F&O was written against an No impact on C3b- C3b potential mechanisms that can create obsolete Internal Flooding PRA model the submitted 01 interconnections between flooding (BV1 REV4) and is considered to be BVPS-1 Fire areas be considered for CCII and that resolved by the updated Internal PRA, which barrier unavailability also be considered Flooding PRA model incorporated in used the for CCIII. There is no evidence in the BV1 REV5A, which underwent a BV1REV5 as Appendix C of the Initiating Events focused Peer Review in accordance its basis.

Notebook that any mechanism other with the guidance in Appendix B of Internal fire than open obvious pathways (e.g., NRC RG 1.200, Rev.1, conducted initiators and vents in doors, tunnels, etc.) were during June 6-9, 2011, by the PWR flood initiators considered. This may be just a Owners Group. The F&Os as a result are mutually documentation issue for CCII. from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect Also, the RI-ISI program did a in Table 1-4. on each other.

comprehensive assessment of flooding potential for various break locations. A Furthermore, comparison should be performed the BVPS-1 between the RI-ISI flooding assessment Fire PRA and the PRA IF assessment to ensure working model consistency. uses BV1 REV5A as its basis, so this F&O will be Note that upgrading to CCIII requires resolved when the additional consideration of barrier NFPA 805 is unavailability, for example due to implemented.

maintenance activities or maintenance implemented.

unavailability.

IF- IF-C3c B Y Develop engineering calculations for This F&O was written against an No impact on C3c- ALL flooding scenarios, not just the obsolete Internal Flooding PRA model the submitted 01 "worst case" scenarios. This is likely just (BVI REV4) and is considered to be BVPS-1 Fire a documentation issue, but since it is resolved by the updated Internal PRA, which missing from the IF Notebook, SR IF- Flooding PRA model incorporated in used the C3c is not met. BV1 REV5A, which underwent a BV1REV5 as Page 91 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA W/N focused Peer Review in accordance its basis.

with the guidance in Appendix B of Internal fire NRC RG 1.200, Rev.1, conducted initiators and during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-C4, B Y The operator actions credited in the IF This F&O was written against an No impact on C4- IF-C6, flooding assessment are based on obsolete Internal Flooding PRA model the submitted 01 IF-C8 detailed HRA assessments for two (BV1 REV4) and is considered to be BVPS-1 Fire Page 92 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N operator actions. Cues, procedures, resolved by the updated Internal PRA, which etc. are detailed in the HRA Flooding PRA model incorporated in used the assessment. It is not clear if these BV1 REV5A, which underwent a BV1REV5 as actions are also applied to scenarios focused Peer Review in accordance its basis.

other than those used to quantify the with the guidance in Appendix B of Internal fire HEP in the HRA Notebook. In addition, NRC RG 1.200, Rev.1, conducted initiators and there are a number of other instances in during June 6-9, 2011, by the PWR flood initiators which the operators are assumed to be Owners Group. The F&Os as a result are mutually highly reliable. There is also no from this focused Peer Review, as exclusive and indication that these are validated by well as their resolutions are presented have no effect operator interviews. Cleaner in Table 1-4. on each other.

documentation of the operator actions that are credited (as well as those not Furthermore, credited), and their basis, should be the BVPS-1 completed to assist in future reviews Fire PRA and for risk applications in which the working model performance of operators is important. uses Also a clear linkage between the IF and BVIREV5A as HRA Notebooks should be documented its basis, so for the basis of the important HRA input this F&O will be and some of the operator actions to resolved when screen scenarios is based on highly NFPA 805 is reliable operator actions. implemented.

IF- IF-C4 B Y SR-IF-C4 requires the development of This F&O was written against an No impact on C4- flood scenarios by examining the obsolete Internal Flooding PRA model the submitted 02 equipment and relevant plant features (BV1 REV4) and is considered to be BVPS-1 Fire in the flood area and area in potential resolved by the updated Internal PRA, which propagation paths, taking credit for Flooding PRA model incorporated in used the appropriate flood mitigation systems or BV1 REV5A, which underwent a BV1REV5 as operator actions, and identifying focused Peer Review in accordance its basis.

susceptible SSCs. No flood scenarios with the guidance in Appendix B of Internal fire are developed in the IF Notebook. NRC RG 1.200, Rev.1, conducted initiators and I during June 6-9, 2011, by the PWR flood initiators Page 93 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-C5, B Y The screening methodology This F&O was written against an No impact on C5- IF-C5a, documented in Section C3.1 does not obsolete Internal Flooding PRA model the submitted 01 IF-C7, follow the systematic methodology (BV1 REV4) and is considered to be BVPS-1 Fire IF-D7 described inthe Standard. For the IF resolved by the updated Internal PRA, which assessment, the screening is performed Flooding PRA model incorporated in used the at the source and location level and, in BV1 REV5A, which underwent a BV1REV5 as some cases, without adequate basis as focused Peer Review in accordance its basis.

discussed in a previous F&O (IF-B1- with the guidance in Appendix Bof Internal fire 01). The method used in the IFflooding NRC RG 1.200, Rev.1, conducted initiators and assessment may be technically during June 6-9, 2011, by the PWR flood initiators adequate, ifthe basis is better Owners Group. The F&Os as a result are mutually documented, even though it does not from this focused Peer Review, as exclusive and meet the Standard SRs for C-5, C5a well as their resolutions are presented have no effect and C7. in Table 1-4. on each other.

Furthermore, I_ I the BVPS-1 Page 94 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N Fire PRA working model uses BV1REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-D1 B Y The FENOC response to DE-06 from This F&O was written against an No impact on D1- the OG Peer Review is incomplete. obsolete Internal Flooding PRA model the submitted 01 The F&O is concerned about the (BV1 REV4) and is considered to be BVPS-1 Fire vintage of the data used to estimate resolved by the updated Internal PRA, which pipe break frequencies and the FENOC Flooding PRA model incorporated in used the response talks about walkdowns. BV1 REV5A, which underwent a BV1REV5 as focused Peer Review in accordance its basis.

with the guidance in Appendix B of Internal fire NRC RG 1.200, Rev.1, conducted initiators and during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when Page 95 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN NFPA 805 is implemented.

IF- IF-D5, B Y The IF pipe and tank break frequencies This F&O was written against an No impact on D5- IF-D5a used in the IF assessment are based on obsolete Internal Flooding PRA model the submitted 01 1988 and 1990 data. The prior pipe (BV1REV4) and is considered to be BVPS-1 Fire break frequencies should be updated to resolved by the updated Internal PRA, which reflect more recent experience and Flooding PRA model incorporated in used the should include plant specific BV1 REV5A, which underwent a BV1REV5 as experience. In estimating pipe break focused Peer Review in accordance its basis.

frequencies, it is recommended that with the guidance in Appendix B of Internal fire experience with safety related vs. BOP NRC RG 1.200, Rev.1, conducted initiators and piping be considered along with active during June 6-9, 2011, by the PWR flood initiators pipe degradation mechanisms. Credit Owners Group. The F&Os as a result are mutually for condition monitoring programs from this focused Peer Review, as exclusive and should also be applied where well as their resolutions are presented have no effect applicable, in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1REV5A as its basis, so this F&O will be resolved when NFPA 805 is I implemented.

Page 96 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N IF- IF-El B Y The Standard states "for each flood This F&O was written against an No impact on El- scenario, review the accident obsolete Internal Flooding PRA model the submitted 01 sequences for the associated plant- (BV1 REV4) and is considered to be BVPS-1 Fire initiating event group to confirm resolved by the updated Internal PRA, which applicability of other accident Flooding PRA model incorporated in used the sequences model." A spot check was BV1 REV5A, which underwent a BV1 REV5 as made to provide reasonable confidence focused Peer Review in accordance its basis.

that the overall results are correct. with the guidance in Appendix B of Internal fire However, there is no record that EACH NRC RG 1.200, Rev.1, conducted initiators and scenario was reviewed. during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

Page 97 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IF- IF-Fl, B Y The Internal Flooding documentation This F&O was written against an No impact on Fl- SY-A4 does not include the results of the obsolete Internal Flooding PRA model the submitted 01 walkdowns performed during the (BV1 REV4) and is considered to be BVPS-1 Fire original assessment. FENOC response resolved by the updated Internal PRA, which to OG Peer Review F&O DE-4 indicates Flooding PRA model incorporated in used the that the RI-ISI walkdowns are BV1 REV5A, which underwent a BV1REV5 as documented and cover the issues focused Peer Review in accordance its basis.

required for an Internal Flooding with the guidance in Appendix B of Internal fire walkdown. To facilitate future NRC RG 1.200, Rev.1, conducted initiators and maintenance and reviews of the internal during June 6-9, 2011, by the PWR flood initiators flooding assessments, the use of the Owners Group. The F&Os as a result are mutually RI-ISI walkdowns for internal flooding from this focused Peer Review, as exclusive and should be documented in the Internal well as their resolutions are presented have no effect Flooding Notebook and a direct in Table 1-4. on each other.

reference to a retrievable copy the RI-ISI walkdowns should also be included. Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is I implemented.

Page 98 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA IF- IF-F2 B Y The documentation of the processes to This F&O was written against an No impact on F2- identify flood areas, sources, pathways, obsolete Internal Flooding PRA model the submitted 01 scenarios, etc. are not clearly (BV1 REV4) and is considered to be BVPS-1 Fire documented. For example, the rules resolved by the updated Internal PRA, which used to screen out sources and areas Flooding PRA model incorporated in used the are not defined and the bases for BV1 REV5A, which underwent a BV1REV5 as eliminating or justifying propagation focused Peer Review in accordance its basis.

pathways is either not clearly defined or with the guidance in Appendix B of Internal fire not provided at all. NRC RG 1.200, Rev.1, conducted initiators and during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1REV5A as its basis, so this F&O will be resolved when NFPA 805 is I implemented.

Page 99 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N IF- IF-F2 B Y The IF Notebook states that the annual This F&O was written against an No impact on F2- frequency of a flood scenario in location obsolete Internal Flooding PRA model the submitted 02 X is Rx = Fi*fx,i*fs,x*fp,x and the (BV1 REV4) and is considered to be BVPS-1 Fire quantify scenarios in which recover resolved by the updated Internal PRA, which actions can be included is Sx=Rx (Dx + Flooding PRA model incorporated in used the lx). However, the frequency is never BV1 REV5A, which underwent a BV1 REV5 as quantified using these equations. This focused Peer Review in accordance its basis.

is confusing for a reviewer - what is the with the guidance in Appendix B of Internal fire purpose of these statements if they are NRC RG 1.200, Rev.1, conducted initiators and not used? or if they are used, an during June 6-9, 2011, by the PWR flood initiators explanation is needed. Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is I implemented.

Page 100 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N IF- IF-Alb, IF- C Y Although it is apparent that dual unit This F&O was written against an No impact on Al- Bla, IF-C4a, impacts for internal flooding were obsolete Internal Flooding PRA model the submitted 01 IF-D4 considered, the details are buried in the (BV1 REV4) and is considered to be BVPS-1 Fire individual assessments. To assist resolved by the updated Internal PRA, which future reviews and the development of Flooding PRA model incorporated in used the risk informed applications, it is BV1 REV5A, which underwent a BV1 REV5 as recommended that a separate section focused Peer Review in accordance its basis.

of the Internal Flooding documentation with the guidance in Appendix B of Internal fire be created to summarize the search for NRC RG 1.200, Rev.1, conducted initiators and and results of an assessment of dual during June 6-9, 2011, by the PWR flood initiators unit internal flooding impacts. Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-A4, B Y The OG Peer Review F&O DE-3 This F&O was written against an No impact on A4- documented the lack of documentation obsolete Internal Flooding PRA model the submitted 01 of a walkdown for internal flooding and (BV1 REV4) and is considered to be BVPS-1 Fire other PRA purposes. The F&O resolved by the updated Internal PRA, which response by FENOC is incorrect and Flooding PRA model incorporated in used the does not address the F&O. As a result, BV1 REV5A, which underwent a BV1REV5 as A.

the walkdown documentation is still not focused Peer Review in accordance its basis.

Page 101 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I identified. The walkdown needs to be with the guidance in Appendix B of Internal fire documented and reviewed from the NRC RG 1.200, Rev.1, conducted initiators and perspective of internal floods in order to during June 6-9, 2011, by the PWR flood initiators assign a CC to several of the SRs for Owners Group. The F&Os as a result are mutually Internal Flooding, from this focused Peer Review, as exclusive and IF-C9, well as their resolutions are presented have no effect IF-D4 It is noted that in response to OG F&O in Table 1-4. on each other.

DE-04, FENOC used the RI-ISI Furthermore, documentation in place of the original the BVPS-1 walkdown documentation. Based on the Fire PRA scope of the RI-ISI walkdowns, this is Fing P oA considered to be an acceptable working model substitute for the Internal Flooding uses assessment since the same BV1 REV5A as considerations are being investigated its basis, so (e.g., drain locations, equipment this F&O will be elevations, etc.). However, a resolved when retrievable walkdown document needs NFPA 805 is to be identified in the IF Notebook. implemented.

IF- IF-D1, C Y The IF assessment does not rely on This F&O was written against an No impact on D1- IF-D3, grouping of lEs, sources, locations, etc. obsolete Internal Flooding PRA model the submitted a a - a Page 102 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N 02 IFD3a The screening methodology discussed (BVI REV4) and is considered to be BVPS-1 Fire in the IFNotebook and assessed under resolved by the updated Internal PRA, which the IF-C-xx SRs methodology resulted Flooding PRA model incorporated in used the in only a handful of flooding events to BV1 REV5A, which underwent a BV1REV5 as be considered. These were individually focused Peer Review in accordance its basis.

assessed in the overall PRA with the guidance in Appendix B of Internal fire quantification using RISKMAN. The NRC RG 1.200, Rev.1, conducted initiators and methodology used may be technically during June 6-9, 2011, by the PWR flood initiators adequate in spite of not meeting the Owners Group. The F&Os as a result are mutually ASME Standard SRs for grouping ifit from this focused Peer Review, as exclusive and can be justified that only a handful of well as their resolutions are presented have no effect events are important. in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-D4 C Y The PRA documentation should include This F&O was written against an No impact on D4- a discussion of the potential impact of obsolete Internal Flooding PRA model the submitted 01 floods on systems that are shared (BVI REV4) and is considered to be BVPS-1 Fire between the two units. This impact is resolved by the updated Internal PRA, which expected to be minimal. One example Flooding PRA model incorporated in used the is the potential impact on the electric BV1 REV5A, which underwent a BV1REV5 as power crosstie to Unit 1 availability due focused Peer Review in accordance its basis.

to floods in the service water intake with the guidance in Appendix B of Internal fire structure. Is the Unit 1 diesel NRC RG 1.200, Rev.1, conducted initiators and Page 103 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N dependence on service water correctly during June 6-9, 2011, by the PWR flood initiators accounted for when the flood impacts Owners Group. The F&Os as a result are mutually the availability of the Unit 1 service from this focused Peer Review, as exclusive and water system? well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-D5 C Y The IEF for pipe breaks is based on a This F&O was written against an No impact on D5- generic 80% capacity factor. There are obsolete Internal Flooding PRA model the submitted 02 two issues with this method: a) current (BV1 REV4) and is considered to be BVPS-1 Fire capacity factors are typically greater resolved by the updated Internal PRA, which than 80% so that the IEFs are slightly Flooding PRA model incorporated in used the lower, and b) the method is inconsistent BV1 REV5A, which underwent a BV1REV5 as with the method used to calculate other focused Peer Review in accordance its basis.

IEFs. It is recommended that the with the guidance in Appendix B of Internal fire calculation for IF IEF be revised to be NRC RG 1.200, Rev.1, conducted initiators and consistent with the method used for during June 6-9, 2011, by the PWR flood initiators other IEFs. Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

I Furthermore, Page 104 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN the BVPS-1 Fire PRA working model uses BVI REV5A as its basis, so this F&O will be resolved when NFPA 805 is I _implemented.

IF- IF-D6 C Y The IF flooding assessment uses This F&O was written against an No impact on D6- screening criteria to limit the operator obsolete Internal Flooding PRA model the submitted 01 induced floods during maintenance (BV1 REV4) and is considered to be BVPS-1 Fire (e.g., due to operator errors such as resolved by the updated Intemal PRA, which inadvertently opening isolation valves Flooding PRA model incorporated in used the which maintenance is occurring). One BV1 REV5A, which underwent a BV1REV5 as of the screening criteria is whether the focused Peer Review in accordance its basis.

maintenance activity is performed with the guidance in Appendix B of Internal fire during power operation or at shutdown. NRC RG 1.200, Rev.1, conducted initiators and The application of these criteria to during June 6-9, 2011, by the PWR flood initiators potential floods should be re-assessed Owners Group. The F&Os as a result are mutually in light of recent practices to perform from this focused Peer Review, as exclusive and more maintenance at power to shorten well as their resolutions are presented have no effect the shutdown periods. It is expected in Table 1-4. on each other.

that this will have a small to negligible impact on the IF assessment and is Furthermore, therefore assigned a Level C. the BVPS-1 Fire PRA working model uses BV1REV5A as its basis, so this F&O will be Page 105 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N resolved when NFPA 805 is implemented.

IF- IF-E5 C Y There are a number of operator actions This F&O was written against an No impact on E5- credited in the IF assessment that are obsolete Internal Flooding PRA model the submitted 01 used to screen potential flooding events (BV1 REV4) and is considered to be BVPS-1 Fire based on the operators ability to resolved by the updated Internal PRA, which diagnose the pipe break and isolate the Flooding PRA model incorporated in used the leak thereby preventing the flood. BV1 REV5A, which underwent a BV1REV5 as However, these operator actions are focused Peer Review in accordance its basis.

based on judgment. For others, one of with the guidance in Appendix B of Internal fire the two HEPs that are analyzed is used NRC RG 1.200, Rev.1, conducted initiators and based on judgment. Examples include: during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect

1) In Section C4.3.6 it is stated that in Table 1-4. on each other, operator will receive sump alarms and be alert to the loss of RWST tank level Furthermore,

... the possibility that the operators do the BVPS-1 not locally isolate the tank ... is Fire PRA estimated as 6.7E-03 from ZHEFL2. working model Page 106 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N

2) In Section C3.2.1 it is stated that a uses flood from the fan room should be BV1 REV5A as detected quickly since this room is next its basis, so to the control room. The control this F&O will be building sump high-level alarm would resolved when alert operators. Failure of the air NFPA 805 is conditioning would also alert operators. implemented.

It is recommended that a better basis for these operator actions be developed to ensure consistency with the remainder of the PRA.\

IF- IF-E5a C Y Several operator actions in the IF This F&O was written against an No impact on E5a- assessment use the HEPs documented obsolete Internal Flooding PRA model the submitted 01 by detailed analysis for ZHEFL1 and 2. (BV1 REV4) and is considered to be BVPS-1 Fire These assume that the cues, resolved by the updated Internal PRA, which procedures steps, action, timing, etc. Flooding PRA model incorporated in used the are similar enough to that for ZHEFL1 BV1 REV5A, which underwent a BV1REV5 as or 2 but this is not documented in the IF focused Peer Review in accordance its basis.

Notebook or the HR Notebook. To be with the guidance in Appendix B of Internal fire consistent with the operator action NRC RG 1.200, Rev.1, conducted initiators and assessments for the remainder of the during June 6-9, 2011, by the PWR flood initiators PRA, it is recommended that better Owners Group. The F&Os as a result are mutually documentation be developed to support from this focused Peer Review, as exclusive and the use of ZHEFL1 or 2 for these well as their resolutions are presented have no effect operator actions, or new HEPs be in Table 1-4. on each other.

developed as appropriate.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as Page 107 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA I Y/N its basis, so this F&O will be resolved when NFPA 805 is implemented.

IF- IF-F1 C Y If the current IF methodology is This F&O was written against an No impact on Fl- retained, a comparison of the current obsolete Internal Flooding PRA model the submitted 02 methodology to the ASME Standard is (BV1 REV4) and is considered to be BVPS-1 Fire recommended to facilitate future resolved by the updated Internal PRA, which reviews. Flooding PRA model incorporated in used the BVl REV5A, which underwent a BV1 REV5 as focused Peer Review in accordance its basis.

with the guidance in Appendix B of Internal fire NRC RG 1.200, Rev.1, conducted initiators and during June 6-9, 2011, by the PWR flood initiators Owners Group. The F&Os as a result are mutually from this focused Peer Review, as exclusive and well as their resolutions are presented have no effect in Table 1-4. on each other.

Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so Page 108 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN this F&O will be resolved when NFPA 805 is implemented.

LE- LE-C2a, LE- B Y SR LE-C2a is assigned a capability The Level 2 LERF Analysis Notebook No impact to C2a- C2b, LE-C3, category I because BVPS 2 does not Section 2.5 "General Discussion of Fire PRA, 01 LE-C6 use operator actions post core damage. Level 2 Operator Actions" discusses because this This is considered conservative operator actions considered for this issue was treatment of operator actions following model. addressed in the onset of core damage. To meet the base PRA capability category III for this SR, BVPS WCAP-16657-P suggests seven model prior to 2 level 2 analysis must contain realistic potential operator actions (OA) for building the operator actions, based on SAMGs, inclusion in a Level 2 PRA model. Fire PRA.

EOPs, etc. such as WCAP-16657-P. Each of these actions along with two others were reviewed specifically for Beaver Valley Unit 1. The Level 2 OA to restore feedwater to a dry steam generator was added to the PRA model.

LE- LE-C2b B Y Only recovery of AC power after UTAF Section 2.5 of the Level 2 LERF No impact to C2b- is discussed in the Level 2 notebook. It Analysis Notebook discusses the use Fire PRA, 01 is concluded that not enough time exists of Level 2 Operator Actions for because this to assign a high success probability, recovery; specifically recovery of issue was No other recoveries are discussed. feedwater to a dry steam generator is addressed in included in the CET Top Event OL. the base PRA AC electric power recovery is included model prior to in the Level 1 Top Event RE building the I Fire PRA.

Page 109 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N LE- LE-C9a, LE- B Y Level 2 and LERF analysis stopped at A discussion has been added to No impact to C9a- C9b containment failure and continued Section "General Modeling Fire PRA, 01 operation of equipment and operator Assumptions and Criteria for Level 2 because this actions were not modeled. Operation of Analysis" in the Level 2 LERF issue was mitigating systems after containment Analysis Notebook to justify the addressed in failure is not modeled either. Justify the significance of the containment spray the base PRA lack of credit of equipment survivability, system operability on LERF mitigation model prior to following containment failure. Details building the of equipment survivability can also be Fire PRA.

found in Appendix A, Sections A. 1.7 and A.1.10.

LE- LE-Cl0 B Y SGTR and containment bypass did not A discussion has been added to the No impact to C10- take credit for scrubbing. WCAP-16657 Level 2 LERF Analysis Notebook Fire PRA, 01 suggests that scrubbing for tube rupture Section 3.3 "Containment Event because this events can be credited by an operator Tree," Top Event OL to credit SGTR issue was action restart auxiliary feedwater to the scrubbing and the basis for the addressed in ruptured steam generator. decontamination factor. the base PRA model prior to building the I _ Fire PRA.

LE- LE-D5 B Y Beaver Valley Thermal Induced SGTR The PI-SGTR and TI-SGTR methods No impact to D5- is based on a 1995 Fauske and are included in Appendix F of the Fire PRA, 01 Associates report and Westinghouse Level 2 LERF Analysis Notebook. because this Calculation CN-RRA-02-38. Recent issue was investigations suggest that these results addressed in may be too optimistic. A more the base PRA reasonable approach may be model prior to implementing WCAP 16341, "Simplified building the LERF Model," and characterizing the Fire PRA.

uncertainties based on that latest EPRI, I__I _ IIPWROG, and NRC interactions.

LE- LE-D5 B Y The Cl analysis for BV2REV3b is based Following the Beaver Valley Unit 1 No impact to D6- on a sub-atmospheric containment. Atmospheric Containment Conversion Fire PRA, Page 110 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N 01 BV2 has been converted to atmospheric modification, the containment still because this so this analysis must be revisited, normally operates at slightly sub- issue was BV1REV4 does account for the atmospheric conditions. A discussion addressed in atmospheric containment conversion in has been added in Section the base PRA the Containment Isolation notebook. "Condensed Plant Damage State model prior to The results of a similar assessment for Matrix for Beaver Valley Unit 1" to building the BV-2 need to be incorporated in the outline the Beaver Valley Unit 1 Fire PRA.

LERF notebook. containment change from sub-atmospheric to atmospheric and the impact on the Level 2 analysis.

LE- LE-E4 B Y The BV2 LERF model is quantified The Level 2 phenomena split fraction No impact to E4- using RISKMAN. Only point-estimates distributions are included in Table 3- Fire PRA, 01 for each top event are used and there 26 of the Level 2 LERF Analysis because this are no uncertainty estimates or Notebook. This table contains Beaver issue was uncertainty propagation. Valley Unit 1 plant specific Level 2 addressed in phenomena distributions along with the base PRA the mean, median, 5th%ile, and the model prior to 95th%ile. A discussion on how these building the distributions were developed is Fire PRA.

provided in Section 3.4 of this notebook.

LE- LE-F2 B Y The PRA Peer Review Team suggested The LERF uncertainty analysis was No impact to F2- in F&O L2-02 using uncertainty analysis performed as part of the quantification Fire PRA, 01 for the LERF top events to ensure that process using Monte Carlo sampling because this future applications are not affected by of the Level 2 split fraction issue was use of point estimates. distributions. The result of this addressed in analysis is provided in the BVPS-1 the base PRA Page 111 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation 1BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA This F&O was entered into the BVPS Quantification Notebook, Revision 5, model prior to Corrective Action Program as CA 02- Section 1.5.6 "Results of Containment building the 09043-26 (Reference 16) to track and Performance Analysis." Fire PRA.

resolve the issues. The suggested PRA Peer Review Team resolution to this observation was not addressed in the BV2REV3B PRA model update, but will be evaluated sometime later in a future PRA model update.

This update has not yet been completed. At the time, it was a "C" level F&O but the PRA standard raises the requirements for PRA quality and this F&O is now a "B" level.

LE- LE-G5 B Y Limitations of the LERF analysis are Section "Limitations of the Level 2 No impact to G5- identified throughout the BV2 Level 2 Model" has been added to the Level 2 Fire PRA, 01 notebook. However, they need to be LERF Analysis Notebook to include because this gathered into a single location to limitations of the Level 2 analysis. issue was facilitate future usage. addressed in the base PRA model prior to building the Fire PRA.

LE- LE-B3 C Y In Section 2.1 of the LERF Notebook, it Level 2 LERF Analysis Notebook No impact to B3- is stated that MAAP, STCP, and Section 2.1 "Guidelines on Grouping Fire PRA, 01 MELCOR are used to characterize the Core Damage Sequences into Plant because this timing of important events. There is no Damage States Based on Their issue was evidence that STCP and MELCOR are Accident Progression Attributes" has addressed in ever used. been updated to include a discussion the base PRA of the codes used and their applicable model prior to analyses. building the I I_Fire PRA.

Page 112 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN LE- LE-D3 C Y The LERF assessment for ISLOCA is The ISLOCA analysis is reported in No impact to D3- self contained in the Appendix D of the the Initiating Event Notebook. The Fire PRA, 02 Initiating Event Analysis notebook. Level 2 LERF Analysis notebook because this There is no reference to the ISLOCA contains a pointer to the ISLOCA issue was assessment in the LERF notebook. It is analysis in Section 1.2 addressed in not readily apparent from reading the "Interrelationship with Other Parts of the base PRA LERF notebook that an ISLOCA PRA." model prior to assessment was done. building the Fire PRA.

Qu- QU-F4, QU- A Y The Revision 3B Quantification Documentation of a more rigorous No impact to F4- E4, IE-D3 notebook Section 5 states that the PRA uncertainty analysis for the Beaver Fire PRA, 01 notebooks..."include an estimation of Valley Unit 1 PRA model is presented because this the uncertainty introduced by the data in Section 5 of the Quantification issue was used to quantify the PRA model...This Notebook addressed in uncertainty estimation does not, the base PRA however, reflect possible effects on the Westinghouse has provided support model prior to results from other sources of for the BVPS-1 Revision 5 uncertainty building the uncertainty. Such sources may include analysis that is documented in Fire PRA.

such things as: optimism or pessimism "Transmittal of the Beaver Valley in definitions of sequence, component, Power Station Unit 1 PRA Notebook or human action success criteria; Uncertainty Analysis," LTR-RAM-II-limitations in sequence models due to 10-052, December 21, 2010.

simplifications (for example, not modeling available systems or equipment) made to facilitate quantification; uncertainty in defining human response within the emergency procedures...; degree of completeness in selection of initiating events; assumptions regarding phenomenology or structures, systems, and components (SSC) behavior under accident conditions... While it is difficult to Page 113 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA I YIN quantify the effects of such sources of uncertainty, it is important to recognize and evaluate them because there may be specific PRA applications where their effects may have a significant influence on the results.

QU-F4 requires that these sources of uncertainty be characterized regardless of the difficulty of the evaluation. By Beaver Valley's own admission (above),

it is important to recognize and evaluate them because there may be specific PRA applications where their effects may have a significant influence on the results.

Furthermore, the documentation provided in Chapter 5 of the Quantification notebook makes a start at identifying the sources of model uncertainty. PWROG guidance suggests the number of identified sources of uncertainty typically is on the order of 50 items. it is also suggested the BVPS perform a more rigorous search to complete a fairly complete list of sources of uncertainty.

Page 114 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N QU- QU-B9 B Y Component boundary conditions are not A table of component boundaries was No impact to B9- well defined. The Data Analysis added to section A.4 of the Unit 1 Fire PRA, 01 Notebook, as well as several system PRA Data Analysis Notebook. because this notebooks (AFW & SWS) were issue was reviewed and there is no discussion of addressed in component boundary (a pump fail to the base PRA start, for example.. .does the component model prior to boundary include the local circuitry?). building the There are assumptions made regarding Fire PRA.

system boundaries, but no discussion of component boundaries. As a result, module definitions can not be determined.

QU- QU-F4, QU- B Y A detailed description of the RISKMAN Documentation of the RISKMAN No impact to F4- F5 quantification process is provided. software quantification limitations are Fire PRA, 02 However, the Revision 3B presented in Appendix A, Section because this Quantification notebook does not A.1.1 "RISKMAN Software issue was discuss limitations in the methodology. Limitations" of the Quantification addressed in Notebook the base PRA model prior to building the Fire PRA.

QU- QU-D5a B Y Significant contributors to CDF have Documentation of the significant No impact to D5a- been identified, but there is no contributors to CDF, including Fire PRA, 01 identification of SSCs and operator initiating events, accident sequences, because this actions that contribute to initiating event basic events (containing common issue was frequencies and event mitigation cause failures), components, addressed in systems, and operator actions are the base PRA included in Section 3 "Results" of the model prior to Quantification notebook. The System building the Notebooks also provide information Fire PRA.

on SSC and operator action (i.e., I Page 115 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N basic event) contribution to initiating event frequencies and event mitigation, in the cutset listing reports.

QU- QU-F6 B Y Beaver Valley does list important The definition of significant accident No impact to F6- operator action basic events; however, sequences is provided in Section 3.1 Fire PRA, 01 there is no documented definition of of the Quantification Notebook. because this "significant". The Revision 3B Section 3.1.4 provides the definition of issue was Quantification notebook lists top significant systems. The top 10 basic addressed in accident sequences but provides no events, components, and operator the base PRA definition of whether they are actions ranked by Birnbaum model prior to "significant" or not. The only discussion importance are also considered building the is that there is "no single sequence significant. Fire PRA.

makes up a large fraction of the CDF".

The Revision 3B Quantification notebook states the following definition for important systems: "The system rankings for determining High Importance is based on having an F-V Importance greater than 5.OE-02 or a RAW greater than 10, while the Low Importance is based on having an F V Importance less than 5.OE-03 and a RAW less than 2. Medium Importance systems are comprised of everything else in between these importance measures." This definition agrees with the Regulatory Guide 1.200 definition I for "significant contributors." However, I Page 116 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation 1BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN there is no documented justification (no reference to a standard definition, such as R.G. 1.200 or the EPRI PRA Applications Guide).

QU- QU-D5b C Y The BVPS-2 system importance Documentation of the basic event and No impact to D5- rankings are based on component component importances are provided Fire PRA, 02 importances; however there is no in Section 3.1.3 "Basic Event and because this specific discussion of component or Component Importance Rankings," of issue was basic event importances (excluding the Quantification Notebook. A addressed in operator actions). complete listing of CDF importance the base PRA measures for all basic events and model prior to components is provided in the linked building the files "CDF Basic Event Fire PRA.

Importance.xls" and "BV1REV5 CDF I Component Importance.xls." I SC- SC-A5 B Y This SR requires that for sequences in A discussion has been added in the No impact to A5- which stable plant conditions would not medium LOCA Top Event MU to Fire PRA, 01 be achieved by 24 hr using the modeled address containment flooding and because this plant equipment and human actions, supply of make water. Containment issue was PERFORM additional evaluation or flooding is a severe accident addressed in modeling by using an appropriate mitigating strategy used to flood up to the base PRA technique. the lower head of the RPV to model prior to significantly delay, and possibly building the prevent vessel failure. The Fire PRA.

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Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA I YIN _

consequences of containment flooding have been addressed in BVPS-1 SAMG CA-5, "Containment Water Level and Volume," to determine when water levels are jeopardizing vital equipment and monitoring capabilities. A review of Figures 1 & 2 and Table 6 of this document reveals that no significant core damage mitigating equipment or instrumentation would be impacted, even if 3 RWST volumes are injected.

There is an unlimited supply of makeup water via the Ohio River.

The MU top event for medium LOCA Furthermore, if a significant volume of and Small LOCA/General Transient river water is added to the Spent Fuel uses RWST makeup as part of the Pool, makeup procedure 1OM-7.4.Q success path when recirculation has recommends the addition of boric acid failed. While a mission time of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to the Spent Fuel Pool to maintain is assumed, the plant is not at a safe adequate shutdown margin.

stable state because another action is Therefore, at BVPS actions to add required for long term success. The makeup to the RWST and use the RWST refill results in additional water to HHSI pumps in SI injection mode for the containment which eventually will continued RCS makeup are result in the design basis flooding level determined to result in a safe stable being exceeded and the potential for plant condition. This would be true for subsequent loss of instrumentation and all accidents identified in the F&O control. The impact of continued RWST (i.e., medium LOCA, small LOCA, makeup and injection into containment General Transient, SGTR, and needs to be discussed in relation to the ISLOCA).

achievement of a safe stable state I I where no additional operator actions Page 118 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA IY/N I are required.

A similar situation exists for SGTR and ISLOCA where RWST refill is being used to maintain core cooling, but the justification for mission time of only 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is not apparent given that the plant is not in a safe stable state by traditional definitions.

~4. .t I SC- SC-C2 B Y No discussion of the limitations of the Section "MAAP-DBA Limitations" has No impact to C2- MAAP code for Success Criteria are been added to the Success Criteria Fire PRA, 01 provided in the Success Criteria Analysis Notebook to identify the because this Notebook. Two known limitations are limitations of the MAAP-DBA code. issue was the use of MAAP for early phase large addressed in LOCAs and the use of MAAP for SG the base PRA dryout assessments without model prior to benchmarking to design basis codes building the (e.g., bleed and feed initiation). It was Fire PRA.

observed in the Success Criteria Notebook that MAAP runs were made to justify only 1 accumulator (but that 2 of 2 intact accumulators appear to have been actually used as stated to be used in Section 3.1 of the Notebook). It is recommended that a discussion of MAAP limitations (similar to that provided in the EPRI assessment for MAAP 3) be documented or referenced I A. I in the Success Criteria Notebook. I =

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Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N _

SC- SC-A5 C Y The success criteria for top event WM A discussion has been added to the No impact to A5- for the SGTR states that 400 gpm Success Criteria Analysis Notebook in Fire PRA, 02 makeup to the RWST is sufficient to Section 3.5 "Steam Generator Tube because this maintain HHSI for RCS inventory Rupture" Top Event WM to address issue was control at full RCS pressure despite RWST makeup. addressed in leakage through a ruptured SG tube. the base PRA model prior to The maximum RCS inventory loss building the through a single SGTR is on the order Fire PRA.

of 600 gpm if the primary side is at normal operating pressure and the secondary side of the SG is not depressurized. This is in excess of the 400 gpm makeup and therefore appears to invalidate the success criteria as stated. Also, ifcontinued HHSI at full system pressure is required, SG overfill is likely to occur and the SG will be depressurized and the leakage through the ruptured tube I will even be higher.

SC- SC-B1 C Y Reviewer Note R7 for TH states that Section "MAAP-DBA Limitations" has No impact to B1- MAAP limitations were observed and been added to the Success Criteria Fire PRA, 01 MAAP was not used for Large LOCA Analysis Notebook to identify the because this early success criteria such as limitations of the MAAP-DBA code. issue was accumulators. It was observed in the addressed in Success Criteria Notebook that MAAP the base PRA runs were made to justify only 1 model prior to accumulator but that 2 of 2 intact building the accumulators was stated to be used in Fire PRA.

Section 3.1 of the Notebook. This may be confusing for future use because no discussion of MAAP limitations is I Page 120 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN presented in the Appendix containing the MAAP analyses (e.g., at page C-8 of the U2 Success Criteria Notebook).

SC- SC-B5 C Y The ASME PRA requirement for SC-B5 Attachment D has been added to the No impact to B5- includes the possibility of comparison to Success Criteria Analysis Notebook to Fire PRA, 01 check the reasonableness of the compare the Beaver Valley Unit 1 because this success criteria. It is recommended results with North Anna Unit 1. issue was that such as effort be undertaken, Furthermore, the Beaver Valley PRA addressed in possibly as a PWROG or EPRI effort. model success criteria developed the base PRA using MAAP were compared with the model prior to NUREG-1953 Surry success criteria building the (a similar plant), which used the Fire PRA.

MELCOR computer code and were found to be in good agreement.

SC- SC-Cl, SY- C Y The ASME PRA Standard for SC-Cl Section "System Success Criteria" No impact to C1- C1 requires that Success Criteria be has been added to the Success Fire PRA, 02 documented in a manner that facilitates Criteria Analysis Notebook to show because this applications, upgrades, and peer where the system specific success issue was reviews. The current state of the BVPS criteria are contained in each system addressed in PRA Success Criteria is that the notebook. the base PRA accident sequence success criteria are model prior to Page 121 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Require m en t Level Closed PRA Y/N gathered in the Success Criteria This was believed to be the best place building the Notebook, but other success criteria are to locate support system success Fire PRA.

scattered about though the PRA. criteria.

Examples include the SW success criteria and ISLOCA success criteria for U1. It is recommended that FENOC consider gathering all success criteria in the Success Criteria Notebook to facilitate future usage.

SC- SC-B1 S Y CCIII of the standard requires that plant No response required for F&O SC-B1- No impact to B1- specific analyses be used to determine 02. Fire PRA, 02 success criteria with plant specific because this analyses. The large number of MAAP was identified analyses for success criteria meet this as a strength of requirement and the BVPS U1 and U2 the model.

PRAs are considered to be exemplary in this respect.

SY- SY-A14, SY- B Y The DRAFT Revision 4 System Instances of excluded failure modes No impact to A14- A12, SY-Cl notebooks (AFW, SWS, CCS, CCP, and contributors to unavailability for Fire PRA, 01 MFW were reviewed) discuss failure the applicable systems were reviewed because this modes and contributors to system and compiled into a single location in issue was unavailability and unreliability that are their respective System Notebooks. addressed in excluded from the systems analysis. When warranted, justification for the the base PRA However, the SY-A14 criteria does not excluded failure mode or unavailability model prior to appear to have been applied contributor was made more thorough. building the consistently throughout the analysis. This information is located in the Fire PRA.

The only exceptions found where the Excluded Failure Modes and SY-A14 criteria are explicitly met is in Unavailability Contributors section of the CCS notebook, Section 14, c, the notebooks.

Assumption #2, and the AFW notebook Section 14, c, Assumption #3. Insome instances, such as the CCP notebook Section 14, c, Assumption #1, there II Page 122 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA was no explanation given for why the contributor was not modeled.

SY- SY-Ci B IY In providing the response to peer review The Common Cause section of the No impact to Cl- F&O DA-09, which deals with providing System Notebooks now reference the Fire PRA, 01 documentation of the CCF groupings, Common Cause Modeling section, because this Beaver Valley noted that the Systems Table A-I, and Table 1 of the issue was Analysis Overview and Guidance Systems Analysis Overview and addressed in notebook provides the process used to Guidance Notebook to thoroughly the base PRA identify CCF groupings. The response document the methodology and model prior to further suggests details of the common grouping of the common cause building the cause groups that were retained in the modeled in the PRA. Fire PRA.

PRA system models and presented in Appendix C of the BVPS Unit 2 PRA System Notebooks, under the common cause sections of the RISKMAN System Notebook files are adequately documented and can be found by knowledgeable personnel.

S Page 123 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA I Y/N I The reviewer agrees that one can review Appendix C of the Systems notebooks and see what the CCF groupings are and how the CCF probabilities were generated. The reviewer also agrees that high level guidance is provided in the Systems Analysis Overview and Guidance notebook. However, it appears a link between the two documents is missing.

For example, the guidance states

'When identical, nondiverse, and active components are used to provide redundancy, they should be considered for assignment to common cause groups, one group for each identical redundant component". When the Systems notebook Appendix C is reviewed, the components contained in the CCF group is clearly identified, but there is no documentation that states that those components are "identical, and/or non-diverse" or used to provide redundancy.

Further examination of other sections System notebooks (such as Section 3 "System Success Criteria", or Section 6 "Operating Features" would lead a reviewer to find this type of information.

But this documentation is not always I Page 124 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N intuitively obvious and makes peer review difficult at times.

SY- SY-Al 1 C Y The system notebooks do not An additional response has been No impact to All- specifically discuss the dependencies added to the evaluations of the areas Fire PRA, 01 that may be present regarding HVAC / that are represented by the actual top because this room cooling. However, review of the event equipment whether the HVAC issue was HVAC notebook identified the various dependency is required or not and is addressed in spatial locations that may require HVAC located in Support Systems section in the base PRA and indicated the various analyses that the system notebooks. model prior to have been completed to either require building the HVAC dependencies or not. Fire PRA.

SY- SY-B1 C Y At the time of the BVPS Unit 2 common Up-to-date generic MGL CCF data No impact to B1- cause MGL data update during has been updated in PRA-BV1-AL- Fire PRA, 01 Revision 3, the NRC update to R05 using WCAP-16672-P (Section because this NUREG/CR-5497 was still not 3.6 and Table C-5 in the Data issue was available. As such, a decision was Analysis Notebook). In June 2008, addressed in made during the update process to Westinghouse issued WCAP-16672-P the base PRA keep the existing generic MGL data, which covers 1980 - 2003 in order to model prior to which is almost exclusively based on provide guidance to address the building the the PLG generic database dated circa concerns that were raised regarding Fire PRA.

1989. There is no documentation to the consistency and correctness of illustrate that the Beaver Valley the CCF events included in the NRC considered NUREG/CR-5497 during the CCF database. The WCAP data Revision 4 PRA update. source contains CCF parameter estimates for the majority of risk-significant components whose performance are potentially applicable to PWROG utilities only in the U.S.

1 designed by either Westinghouse or Page 125 of 301

Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Require m en t Level Closed PRA YIN Combustion Engineering. The parameter estimates for failure modes of significant components that are generally included in the PRA are provided for the Alpha factors that are converted to the Multiple Greek Letter approach (MGL) by the method in NUREG/CR-5485 and to allow for quantifying CCF probabilities.

Sy- SY-B7 C Y The Service cooling water system The Miscellaneous Top Events No impact to B7- notebook assumption #7 lists 10 Notebook, Top Event OC models the Fire PRA, 01 minutes to trip the RCPs on loss of operator actions to trip the RCPs because this cooling. However, in the Miscellaneous during situations that exist for greater issue was system notebook, top event OC has 5 than 5 minutes, in which either CCR is addressed in minutes to trip the RCPs. Note, this time lost to the RCPs and seal injection is the base PRA might be important in quantifying HEP maintained, or both RCP seal model prior to for RCP trip. injection and thermal barrier cooling building the are lost. Both of these conditions Fire PRA.

would be covered in the abnormal operating procedure 1OM-53C.4.1.6.8 "Abnormal RCP Operation", and RCP parameters would be monitored to identify situations that warrant an immediate RCP shutdown.

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Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN If either of these conditions exist for greater than 5 minutes, the human reliability analysis for operator actions OPROC1 (loss of CCR) and OPROC2 (Loss of RCP seal Cooling) assume that the operators would trip the RCPs at 5 minutes, and that the RCPs seals would be damaged in 13 minutes if they were not tripped, leading to a 480 gpm per RCP seal LOCA. These timing assumptions and consequences are based on BVPS AOPs and WCAP-16141.

SY- SY-Cl C Y The Beaver Valley Unit 2 system System Engineers reviewed the No impact to Cl- notebooks have no indication of system system notebooks for PRA-BV1 -AL- Fire PRA, 02 engineering reviews. These reviews R05, in which they had to present because this help ensure that systems are model in comments and provide input for the issue was accordance with day-to-day plant top event system review. System addressed in operations and additionally expand the Engineering comments have been the base PRA PSA knowledge of the system incorporated into BVPS-1 PRA model prior to engineers, corresponding system notebooks. A building the table that contains the comments is Fire PRA.

located in Appendix B in the System 1 Analysis Overview for BVPS-1.

SY- SY-B5, SY- D Y The system notebooks do not An additional response has been No impact to B5- B6, SY-B10, specifically discuss the dependencies added to the evaluations of the areas Fire PRA, 01 SY-B11 that may be present regarding HVAC I that are represented by the actual top because this room cooling. However, review of the event equipment whether the HVAC issue was HVAC notebook identified the various dependency is required or not and is addressed in spatial locations that may require HVAC located in Support Systems section in the base PRA and indicated the various analyses that the system notebooks. model prior to have been completed to either require building the

______________ _____________ A. A.

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Table 1-2. Summary of BVPS-1 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA HVAC dependencies or not. Since this &O is essentially the Fire PRA.

same as F&O SY-Al 1-01, it was also I_ I I resolved by it Page 128 of 301

Table 1-3. Summary of BVPS-1 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N HR- HR-D5, Finding Y BVPS does not have a written Section 2.2 of the HRA Notebook No impact to Fire PR- process for evaluating dependencies documents the methodology and PRA, because 001 between multiple HEPs occurring in a evaluation of the pre-initiator HEPs. A this issue was single accident and does not provide summary of the EPRI HRA Calculator addressed in the a summary of HEPs that were results can be found in Table 3.5 base PRA model explicitly evaluated for dependencies which supplements the detailed prior to building and the associated levels of calculations documented in Appendix the Fire PRA.

dependencies and joint HEPS. The E. Section 2.3 documents the BVPS HRA notebooks do not have a methodology developed to evaluate single summary table of the the dependency between multiple preinitiator human actions and the HEPs.

HR-G7, documentation of the evaluation of HR-H3, pre-initiator human actions in the Section 2.3 of the HRA notebook has system notebooks, which make it been created to document the difficult to identify which actions were process employing the EPRI HRA actually evaluated, calculator that is used to complete the dependency analysis evaluation (See F&O HR-12-01 in Section 6).

HR-I1, HR-12(d)3 HR- HR-G6, HR- Finding Y BVPS does not appear to have An internal consistency check for pre- No impact to Fire PR- 12 evaluated their HEPs for internal initiator HEPs is documented in PRA, because 002 consistency consistent with the Section 3.4 of the Unit 1 HRA this issue was requirements of HR-G6 and does not notebook. addressed in the have a documented process to do so. base PRA model The original post-initiator HRA was prior to building developed using the SLIM/FLIM the Fire PRA.

process, and as such were grouped with respect to similar performance shaping factors and weights (e.g.,

actions where time and preceding actions are most important were Page 129 of 301

Table 1-3. Summary of BVPS-1 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN grouped together) to have internal consistency during the HEP development. As a final check of overall consistency, the HEPs from each group were then compared with those of other groups to determine if the differences in the HEPs were warranted by the differences in the scenarios and PSF ratings.

The BV1 REV4 PRA model revised the HRA methodology from the SLIM/FLIM process to the EPRI HRA Calculator. The HRA Calculator is a software program that is designed to implement consistency within the field of human action analysis by creating a standard methodology for quantification and documentation of HEPs in the context of the PRA. After this conversion was complete, the resulting HEP values were then compared to the previous BV1 REV3 SLIM/FLIM HRA model (see Table 3-4 of the HRA Notebook, Revision 1 drafted for BV1 REV4), to verify consistency in overall trends between events.

Since these BV1 REV3 PRA Model SLIM/FLIM HEPs were compared to the BV1REV4 PRA Model HRA Calculator HEPs to check their Page 130 of 301

Table 1-3. Summary of BVPS-1 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA reasonableness, there is a de facto consistency check in the HEPs.

HR- HR-D2, HR- Finding Y The method for quantifying pre- Pre-initiators are now quantified using No impact to Fire PR- D3, HR-D4, initiator misalignment errors as the THERP methodology as PRA, because 003 HR-I1, HR-12 described on page 8 of the "Beaver presented in the EPRI HRA this issue was Valley Power Station Unit 2 PRA Calculator. This is documented in addressed in the Notebook - Human Reliability Sections 2.2 & 3.4 and Table 3-5 of base PRA model Analysis," Revision 2, dated 10/01/07, the HRA Notebook. The pre-initiator prior to building relies on the use of a generic Error of human error probabilities were the Fire PRA.

Omission rate that does not reflect determined using BVPS operator any detailed assessment of the HEPs. input and BVPS specific procedures The process also does not consider and processes. The process now the quality of plant-specific written considers the plant specific written procedures, administrative controls or procedures, administration controls, the man-machine interface and does and man-machine interface.

not include an explicit assessment of the potential for recovery that A list of the pre-initiator HFEs and specifically delineates which their probabilities was added to procedures and processes influence Section 3 in Table 3 5.

the potential for identification and recovery. Furthermore, the method for quantifying post-maintenance miscalibrations relies on a single generic error of omission rate.

A complication in reviewing the pre-initiator Human Failure Events (HFEs)

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Table 1-3. Summary of BVPS-1 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA I Y/N I was that the HRA notebook does not include a list of the pre-initiator HFEs or their probabilities. The system notebooks provide evidence of the search for and identification of misalignments but they do not present a list of such events or their probabilities.

_____________________ & I Page 132 of 301

Table 1-3. Summary of BVPS-1 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA W/N HR- HR-C2 Finding Y Post-maintenance misalignments Section 2.2 and Appendix C of the No impact to Fire PR- were excluded for normally operating HRA Notebook document the review PRA, because 004 system based on the assumption that of BVPS procedures (OSTs, BVTs, this issue was misalignments on normally operating and MSPs) to identify potential addressed in the systems would be quickly detected misalignments. Section 2.2 and base PRA model and corrected. Post-maintenance Appendix D of the HRA Notebook prior to building unavailabilities were included for documents the review of historical the Fire PRA.

standby systems as appropriate, event data for misalignment However, nowhere in the HRA identification. A search of the BVPS notebook or the system notebooks 1&2 Corrective Action Program (CAP) that were reviewed was there any was performed to identify pre-indication that BVPS had performed a initiators that have occurred at BVPS.

review of their operating/maintenance A review was also performed with the data to look for post-maintenance BVPS operator.

misalignments.

HR- HR-13 Finding Y The BVPS HRA is documented in the Section 7 of the Unit 1 HRA notebook No impact to Fire PR- "Beaver Valley Power Station Unit 2 was added to document HRA PRA, because 005 PRA Notebook - Human Reliability assumptions. this issue was Analysis", Revision 2, dated 10/01/07. addressed in the This notebook does not have an base PRA model explicit assumptions section to identify prior to building and characterize assumptions. A the Fire PRA.

review of this notebook revealed assumptions scattered throughout the text.

HR- HR-F2 Finding Y In reviewing the set of post-initiator The present BV1 REV5 value for HFE No impact to Fire PR- HFEs in Table 3-1, It was noted that ZHEMA2 is 258 minutes = 4.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months PRA, because 006 for the HFE ZHEMA2, the specified (based on MAAP Run Ul_SB02) this issue was time window, 13.26 hours3.009259e-4 days 0.00722 hours 4.298942e-5 weeks 9.893e-6 months , was not which is consistently stated in both addressed in the consistent with the information Table 3-1 and Appendix B of this base PRA model provided in the "Success Criteria/ notebook. prior to building Basis of Timing" for that HFE. A the Fire PRA.

review of the referenced MAAP case II Page 133 of 301

Table 1-3. Summary of BVPS-1 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN indicates that the 13.26 hours3.009259e-4 days 0.00722 hours 4.298942e-5 weeks 9.893e-6 months is the appropriate timing. Furthermore, continued review of table 3-1 indicated that this seemed to be an isolated event.

HR- HR-B1 Finding Y In general, BVPS excludes virtually all ASME/CNRM Inquiry 09-56 states No impact to Fire PR- miscalibration events based on the that miscalibrations are included in PRA, because 007 assumption that events related to the Common Cause Failure (CCF) this issue was instrument miscalibrations are events for the NRC CCF Database. addressed in the captured in the equipment failure rate Since BVPS includes miscalibrations base PRA model data and the On-line Maintenance in the CCF events, it would be double prior to building program precludes common-cause counting to also include them as pre- the Fire PRA.

miscalibration by scheduling work on initiators. As a result, it is believed opposite trains in different weeks. that BVPS's current treatment of Post-maintenance misalignments miscalibrations as part of the CCF were excluded for normally operating events and not pre-initiators meets system based on the assumption that Capability Category II (instead of misalignments on normally operating Capability Category I).

systems would be quickly detected and corrected. While these rules An exception to this is the SSPS seem reasonable, they are applied to model, which did include instrument classes of maintenance and test string miscalibration errors in the fault activities to screen them from further tree model.

consideration. This is sufficient for Capability Category I but not for A search of the Corrective Action Capability Category 1I. database in April 2010 did not reveal any such miscalibration errors between trains at Beaver Valley Unit 1 to date.

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Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN IFPP- IFPP-B1, Finding Y The documentation This F&O was entered into the BVPS This issue remains Bl-01 IFSO-B1, generally does not facilitate Notification System as BV1 Notification open in the BVPS-1 IFSN-B1, peer review. The technical #600689090, Task 17, to track and Fire PRA model which IFEV-B1, aspects of the analysis are resolve the issues. As a resolution to uses the BVI REV5 IFQU-B1 documented in a manner this IFPRA Peer Review finding, Section model as its basis; that cannot be readily 2 of the documentation was revised in however there is no understood by individuals order to facilitate the Peer Review impact to the Fire PRA outside the staff. The process. Figure 2-1 provides an because internal fire ordering of the overview of the ASME/ANS PRA initiators and flood documentation is Standard requirements and their initiators are mutually significantly different from relationships to the analysis and exclusive and have no the standard; a detailed information contained in the various effect on each other.

graphical roadmap of the sections/appendices/tables of the report.

analysis process would This documentation mapping is Furthermore, the enable peer reviewers to consistent with that presented in the BVPS-1 Fire PRA relate the order of the EPRI Final Report 1019194, Guidelines working model uses documentation to the for Performance of Internal Flooding BV1 REV5A as its standard. Probabilistic Risk Assessment basis, so this F&O will be resolved when NFPA 805 is I_ implemented.

IFPP- IFPP-B2 Finding Y The process described the This F&O was entered into the BVPS This issue remains B2-01 identification of site Notification System as BV1 Notification open in the BVPS-1 buildings and flood areas, #600689090, Task 6, to track and Fire PRA model which but the documentation does resolve the issues. As a resolution to uses the BV1 REV5 not clearly establish the this IFPRA Peer Review finding, the model as its basis; basis for the set of buildings intent of Table 3-1 was clarified prior to however there is no considered in the analysis. Section 3.1 (Identify Flood Areas) to impact to the Fire PRA The references to source plainly indicate the table represents a because internal fire material are not sufficiently complete list of plant initiators and flood specific to allow replication buildings/structures based on initiators are mutually of the process. The referenced materials and that it includes exclusive and have no documentation will be the preliminary building screening. effect on each other.

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Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review- Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N easier to follow if the basis for the selection of buildings Furthermore, the considered in the analysis is BVPS-1 Fire PRA enhanced. There is working model uses reference to review of plant BV1 REV5A as its documentation including the basis, so this F&O will fire analysis, but no be resolved when statement that the list of NFPA 805 is buildings in Table 3-1 is the implemented.

complete list of buildings.

IFPP- IFPP-B3 Finding Y The process used to This F&O was entered into the BVPS This issue remains B3-01 determine the plant Notification System as BV1 Notification open in the BVPS-1 partitioning requires some #600689090, Task 7, to track and Fire PRA model which level of assumptions resolve the issues. As a resolution to uses the BV1 REV5 concerning how the plant this IFPRA Peer Review finding, plant model as its basis; partitions are established, partitioning assumptions were however there is no The current plant documented in Section 3.5. impact to the Fire PRA partitioning has no because internal fire discussion of the initiators and flood uncertainties and initiators are mutually assumptions associated exclusive and have no with the plant design effect on each other.

features used to create flood areas. Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is I implemented.

Page 136 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N IFSO- IFSO-A4 Finding Y The potential flooding This F&O was entered into the BVPS This issue remains A4-01 effects is not listed within Notification System as BV1 Notification open in the BVPS-1 any of the tables #600689090, Task 3, to track and Fire PRA model which documenting the potential resolve the issues. As a resolution to uses the BV1 REV5 flooding sources. The this IFPRA Peer Review finding, Section model as its basis; ASME/ANS standard 4.2 (Flood Source Failure Mechanisms however there is no requires the inclusion of the and Failure Modes Summary) was impact to the Fire PRA potential flooding added to specifically address: a) a because internal fire mechanisms when discussion of failure modes and initiators and flood describing the flood sources mechanisms associated with each flood initiators are mutually used in the model. source with direct reference to latter exclusive and have no documentation sections for further effect on each other.

discussion, and b) the EPRI methodology which embeds failures of Furthermore, the all piping system components as part of BVPS-1 Fire PRA the piping segment failures averaged on working model uses a per linear foot basis. Furthermore, BV1 REV5A as its Section 4.3 was added to address any basis, so this F&O will flood source identification assumptions be resolved when with direct reference to latter NFPA 805 is documentation sections for further implemented.

discussion. I Page 137 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN IFSO- IFSO-A5 Finding Y This supporting requirement This F&O was entered into the BVPS This issue remains A5-01 identifies information used Notification System as BV1 Notification open in the BVPS-1 to characterize the flooding #600689090, Task 5, to track and Fire PRA model which sources. Most of the resolve the issues. As a resolution to uses the BV1 REV5 information is provided in this IFPRA Peer Review finding, all model as its basis; Sections 4 and 7 of the normal operating flooding sources however there is no internal flooding PRA documented in the analysis (Table 4-1. impact to the Fire PRA reports. The information Water Sources) have updated system because internal fire identified by this SR was not flow information (including normal initiators and flood provided in its entirety. For operating temperatures) based on initiators are mutually example, system available information provided in the exclusive and have no temperatures are not references noted in the table. effect on each other.

captured in the documentation and some Furthermore, the systems (primarily oil) pump BVPS-1 Fire PRA HP and RPM are captured working model uses but not the flow rates. BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IFSO- IFSO-B3 Finding Y No clear documentation This F&O was entered into the BVPS This issue remains B3-01 was provided of related Notification System as BV1 Notification open in the BVPS-1 assumptions for the #600689090, Task 4, to track and Fire PRA model which identification of flood resolve the issues. As a resolution to uses the BV1 REV5 sources. The sources of this IFPRA Peer Review finding, Section model as its basis; model uncertainty are 12.4.5 contains a review of the impact of however there is no documented in Section 12 all assumptions mapped to uncertainty impact to the Fire PRA of the internal flooding PRA along with sensitivity analysis that was because internal fire reports, 2294706-R-001, evaluated. Table 12-7 contains a cross initiators and flood Rev. 0 and 2294706-R-002, reference of all the assumptions in the initiators are mutually Rev. 0, but it could not be development of the BVPS-1 internal exclusive and have no determined how these flooding notebook related to the effect on each other.

Page 138 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed sources of model frequency uncertainties in Table 12-2.

uncertainty were connected Furthermore, the to the various assumptions. BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IFSN- IFSN-A1 Finding Y The description of the This F&O was entered into the BVPS This issue remains Al-01 propagation paths is not Notification System as BV1 Notification open in the BVPS-1 complete. Table E-1 #600689090, Task 14, to track and Fire PRA model which identifies the "source" resolve the issues. As a resolution to uses the BV1 REV5 location and the next this IFPRA Peer Review finding, Section model as its basis; locations to which it water 7.3 was augmented to clearly explain however there is no can propagate. To with an example, the differences in impact to the Fire PRA determine the complete Table E-1 and E-2 due to subsuming of because internal fire propagation path, these flood propagation paths, and a separate initiators and flood source/next pairs can be column was added to Table E-2 to initiators are mutually combined until the water indicate all of the flood propagation exclusive and have no reaches the accumulation pathways that were subsumed for each effect on each other.

point (no "next" location). documented flooding scenario so that it However, the scenario will be clear that all pathways have been Furthermore, the descriptions in Table E-2 do accounted. BVPS-1 Fire PRA not consistently account for working model uses the propagation paths BV1 REV5A as its identified in Table E-1. For basis, so this F&O will example, scenario PA3C be resolved when FWLP-3 propagates to NFPA 805 is

_______ & ______________ I A.

several locations per Table imDlemented.

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Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N E-2 (PA-3C, PA-3, PA-31, PA-3H) but Table E-1 indicates that PA-3 can propagate to PA-S2, PA-S6, PA-3G, PA-3A, PA-3B, PA-3C, PA-3H, PA-31; several of these are not accounted for in the propagate path in Table E-2. If the missing locations are not possible due to plant features, that should be stated to complete the accounting.

Other examples of this deficiency were observed (PA4-FWLP-1, PT1-FWLP-1 from Unit 2, and PA1A-FWLP-1, FA1A-FWMP-1 from Unit 1). The propagation paths must account for the various possible flow paths.

Combinations presented in the documentation that are not considered bring into question the completeness of the analysis.

IFSN- IFSN-B2, Finding Y The process to identify This F&O was entered into the BVPS This issue remains B2-01 IFSN-A5, scenarios lacks several of Notification System as BV1 Notification open in the BVPS-1 Page 140 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions BVPS-1 Final Resolution Impact to Fire PRA IYN F&O Supporting. Significance Status Fact & Observation ID Requirement Level Closed IFSN-A6 the suggested areas that #600689090, Task 15, to track and Fire PRA model which should be included resolve the issues. As a resolution to uses the BV1 REV5 (recognizing that the SR list this IFPRA Peer Review finding, a model as its basis; is NOT a required set). The graphical depiction of the overall flood however there is no propagation pathways scenario development was provided as impact to the Fire PRA description is not complete Figure 7-1 in Section 7. because internal fire in that it does not include all initiators and flood potential propagation paths initiators are mutually identified in Table E-1 of the exclusive and have no PRA reports. The impacted effect on each other.

(failed) SSCs for each scenario are not clearly Furthermore, the referenced (identified as BVPS-1 Fire PRA needing to be "addressed" working model uses in a REMARKS column in BV1 REV5A as its Table E-2). Assumptions basis, so this F&O will used in the scenario be resolved when discussions are incomplete. NFPA 805 is Scenario screening is not implemented.

clearly documented. The documentation has many weaknesses in capturing the suggested types of information to adequately document this topic.

Page 141 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N IFSN- IFSN-B3, Finding Y The use of the Excel VBA This F&O was entered into the BVPS This issue remains B3-01 IFSN-A4 code to predict flow rates Notification System as BV1 Notification open in the BVPS-1 and failures of equipment #600689090, Task 8, to track and Fire PRA model which has provided a great deal of resolve the issues. As a resolution to uses the BV1 REV5 realistic insight to plant flood this IFPRA Peer Review finding, Section model as its basis; response. Section 9.0 of the 9.5 (Summary of Assumptions) was however there is no internal flooding PRA expanded to include Microsoft EXCEL impact to the Fire PRA reports does not explicitly VBA program specific assumptions and because internal fire discuss all assumptions documentation pointers to flooding initiators and flood regarding the use of scenario specific assumptions. initiators are mutually equations to predict flood exclusive and have no heights, and the scenarios effect on each other.

modeled in Appendix Hof the PRA reports have some Furthermore, the assumptions applied to BVPS-1 Fire PRA each analysis. working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is 1 implemented.

Page 142 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review- Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN I

IFEV- IFEV-A7 Suggestion Y Maintenance and human- This F&O was entered into the BVPS This issue remains A7-01 induced errors causing a Notification System as BV1 Notification open in the BVPS-1 flooding event can be #600689090, Task 9, to track and Fire PRA model which important to the overall resolve the issues. As a resolution to uses the BV1 REV5 plant risk. A more detailed this IFPRA Peer Review suggestion, an model as its basis; analysis of those activities Operating Manual (OM) procedure however there is no within the plant that could review of at-power open maintenance impact to the Fire PRA lead to a system breach was produced as Table 7-4 that because internal fire potential should be evaluates systems 15, 26, 28, 29, 30, initiators and flood analyzed. Maintenance 31, and 33 for potential actions on initiators are mutually activities which could equipment that could cause human- exclusive and have no potentially breach induced flooding scenarios. Some of effect on each other.

pressurized systems could the systems are indirectly reviewed lead to internal flooding based on other systems. The OM Furthermore, the events. By not evaluating all procedures for the condenser waterbox, BVPS-1 Fire PRA potential online CCR heat exchangers, and CCT heat working model uses maintenance activities for exchangers are based on a frequency BV1 REV5A as its the potential breaches, the that is based on SAP work order record basis, so this F&O will flood-induced risk queries. The screening categories for be resolved when associated with these the open maintenance and human- NFPA 805 is activities could be induced review are shown in Table 7-5. implemented.

underestimated. I I Page 143 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN IFEV- IFEV-B2 Suggestion Y Documentation of the This F&O was entered into the BVPS This issue remains B2-01 process that identifies Notification System as BV1 Notification open in the BVPS-1 applicable flood-induced #600689090, Task 18, to track and Fire PRA model which initiating events is required resolve the issues. As a resolution to uses the BV1 REV5 to satisfy this SR. The flood this IFPRA Peer Review suggestion and model as its basis; scenario frequencies are as part of an expanded analysis to however there is no provided in Tables 8-10, F- address probabilistic pipe failure during impact to the Fire PRA 1, and J-1 of the intemal the 24 Hours after an initiator and because internal fire flooding analysis reports system-based initiators, Section 8.1.3 initiators and flood (2294706-R-001, Rev. 0 and Tables 8-11 and 8-12 illustrate the initiators are mutually and 2294706-R-002, Rev. scope of flooding elements (pipe, exclusive and have no 0). The associated HEPs for expansion joints) contained within the effect on each other.

isolating the flood and existing internal events model.

adjustment factors used to Furthermore, the refine the flood frequencies BVPS-1 Fire PRA are also provided in Table working model uses F-i. A qualitative screening BV1 REV5A as its value of 1.OE-12 was used. basis, so this F&O will The process does not be resolved when clearly identify the NFPA 805 is relationship of the implemented.

information provided in the various tables. I IFEV- IFEV-B3 Finding Y The different values that go This F&O was entered into the BVPS This issue remains B3-01 into the calculation of the Notification System as BV1 Notification open in the BVPS-1 internal flooding initiating #600689090, Task 10, to track and Fire PRA model which event frequency are subject resolve the issues. As a resolution to uses the BV1 REV5 to uncertainties. These this IFPRA Peer Review finding, Section model as its basis; uncertainties need to be 12.4.5 contains a summary of the review however there is no well documented to address of the impact of all assumptions mapped impact to the Fire PRA all of the model impacts. to uncertainty along with sensitivity because internal fire analysis that was evaluated. Table 12-7 initiators and flood

~.I. I .1 Page 144 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Require m en t Level Closed Y/N The current flooding contains a cross reference of all the initiators are mutually frequency calculations use assumptions in the development of the exclusive and have no factors to determine the BVPS-1 internal flooding notebook effect on each other.

actual initiating event related to the frequency uncertainties in frequency used within the Table 12-2. Furthermore, the model. The pipe lengths, BVPS-1 Fire PRA location factors, directional working model uses factors, and operator action BV1 REV5A as its failures all have some levels basis, so this F&O will of assumptions and be resolved when uncertainties associated NFPA 805 is with them. These need to implemented.

be addressed in order to meet the SR.

Page 145 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N IFQU- IFQU-A5 Finding Y It appears that no inter-HEP This F&O was entered into the BVPS This issue remains A5-01 dependency analysis Notification System as BV1 Notification open in the BVPS-1 (between flood and non- #600689090, Task 16, to track and Fire PRA model which flood HEPs) was performed. resolve the issues. As a resolution to uses the BV1 REV5 Dependency between HEPs this IFPRA Peer Review finding, Section model as its basis; can significantly increase 10.4.6 (Dependencies between Human however there is no the probabilities of Interactions) was expanded to reiterate impact to the Fire PRA combinations of HEPs. Section 10.4.3 (Screening and Detailed because internal fire However, Section 10.4 of Analysis) discussion on the multiplier initiators and flood the internal flooding PRA factor applied to HEPs included in the initiators are mutually reports states Internal Events PRA based on such exclusive and have no "Dependencies between the factors as the location of the action, the effect on each other.

flood mitigation human timing of the action, and stress, etc. and actions and the non-flood to include a discussion of the Riskman Furthermore, the human actions modeled in modeling analysis approach in which BVPS-1 Fire PRA the remaining part of the human actions included are evaluated working model uses PRA model were judged to conditionally based on the success or BV1 REV5A as its be minimal due to the failure status of the preceding human basis, so this F&O will significant difference in the action(s). As such, dependencies be resolved when nature of the actions (e.g., among the human failure events in the NFPA 805 is flood mitigation actions Internal Events model (i.e., non-flood implemented.

require field investigation by human actions) were fully accounted.

the auxiliary operators, etc.)

and separation in time, etc.,

and as such no additional dependency treatment was considered needed." An evaluation of the HEP combinations should be documented to demonstrate S S S this conclusion. -

Page 146 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN IFQU- IFQU-A7 Finding Y Performance of the internal This F&O was entered into the BVPS This issue remains A7-01 flood events quantification Notification System as BV1 Notification open in the BVPS-1 should be consistent with #600689090, Task 12, to track and Fire PRA model which the quantification of the resolve the issues. As a resolution to uses the BV1 REV5 internal events PRA. The this IFPRA Peer Review finding, model as its basis; quantification of the internal analysis and discussion has been however there is no flooding requires that provided for performance of impact to the Fire PRA applicable requirements quantification with the applicable because internal fire from the Internal Events requirements. QU-B3 requirements initiators and flood Quantification section be have been documented in Section initiators are mutually met. The current section on 12.4.4, Truncation Evaluation. The QU- exclusive and have no Internal Flooding does not B7 requirements have been effect on each other.

include a discussion of the documented in Section 12.5.3, Mutually topics addressed in Section Exclusive Events. QU-Cl & QU-C2 Furthermore, the 2-2.7 of the ASME/ANS requirements have been documented in BVPS-1 Fire PRA Combined PRA Standard. Section 12.5.4, HFE Dependency. QU- working model uses D1 & QU-D2 requirements have been BV1 REV5A as its documented in Section 12.5.5 basis, so this F&O will Significant CDF Sequences and be resolved when Accident Category (for CDF) and NFPA 805 is Section 12.5.8 Significant LERF implemented.

Sequences and Accident Category (for LERF). QU-D4 requirements have been documented in Section 12.5.2 Internal Flooding Comparison Between Plants and Table 12-5. QU-D6 requirements have been documented in Sections 12.5.5 - 12.5.7, and 12.3 for significant contributions to CDF. QU-D7 requirements have been documented in Section 12.5.6 for system importance that is based on importance for components and basic events.

Page 147 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N IFQU- IFQU-A9 Finding Y The loss of the CCR heat This F&O was entered into the BVPS This issue remains A9-01 exchangers in the PRA Notification System as BV1 Notification open in the BVPS-1 models have made an #600689090, Task 19, to track and Fire PRA model which optimistic assumption resolve the issues. As a resolution to uses the BV1 REV5 regarding the survivability of this IFPRA Peer Review finding, a model as its basis; cooling to the heat BVPS Nuclear Engineering Analysis however there is no exchangers following a calculation was performed on this impact to the Fire PRA system breach (see specific Valve Pit assumption. The because internal fire scenario VP1-FWLL-1). Use calculation verified and demonstrated initiators and flood of this assumption allowed a that once the Valve Pit floods (in less initiators are mutually potentially more severe than 30 seconds), there is adequate exclusive and have no scenario to be represented flow to all the necessary heat exchanger effect on each other.

by a less severe scenario, loads, so only the ruptured header The assumption was that should be considered failed. Since the Furthermore, the the vacuum at the inlet to "A" RW pump is modeled and is the BVPS-1 Fire PRA the CCR heat exchangers strongest pump in the current Proto working model uses would prevent sufficient loss Flow model, the "A" RW break is BV1 REV5A as its of cooling water from a conservative and was hence used in this basis, so this F&O will break in the piping calculation. Results of the calculation be resolved when downstream of the river are documented in Section 8.4 NFPA 805 is water (RW) check valve in assumption 2. implemented.

the valve pit from failing both trains of RW. This assumption appears to be non-conservative.

IFQU- IFQU-A10 Suggestion Y Internal flooding contribution This F&O was entered into the BVPS This issue remains Al 0- to LERF should be Notification System as BV1 Notification open in the BVPS-1 01 documented in some way #600689090, Task 11, to track and Fire PRA model which so that the apparent resolve the issues. As a resolution to uses the BV1 REV5 impacts on LERF from the this IFPRA Peer Review suggestion, model as its basis; flooding events could be Section 12.5.8 contains a review of however there is no reviewed. The discussion internal flooding LERF sequences and impact to the Fire PRA I concerning the impacts on accident categories which describes because internal fire Page 148 of 301

Table 1-4. Summary of BVPS-1 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-1 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN [

LERF for internal flooding impacts that are evaluated in internal initiators and flood events could be improved to flooding LERF analysis. initiators are mutually discuss flooding impact on exclusive and have no the different features used effect on each other.

to mitigate releases. Furthermore, the BVPS-1 Fire PRA working model uses BV1 REV5A as its basis, so this F&O will be resolved when NFPA 805 is implemented.

IFQU- IFQU-B2, Finding Y The process used for This F&O was entered into the BVPS This issue remains B2-01 IFQU-B1 quantification documents Notification System as BV1 Notification open in the BVPS-1 the calculation, screening, #600689090, Task 13, to track and Fire PRA model which scenarios deleted and resolve the issues. As a resolution to uses the BV1 REV5 walkdowns. However, there this IFPRA Peer Review finding, the model as its basis; is not enough supporting requirements listed in HLR- however there is no documentation of the QU-D have been completed in the impact to the Fire PRA quantification process internal flooding notebook Section 12.5 because internal fire specifically concerning the Results and Insights. initiators and flood PRA Standard requirements initiators are mutually listed in HLR-QU-D. The SR exclusive and have no requires that documentation effect on each other.

must be consistent with the requirements described in Furthermore, the HLR-QU-D. These BVPS-1 Fire PRA requirements are not working model uses discussed at any point in BV1 REV5A as its the internal flooding PRA basis, so this F&O will reports. be resolved when NFPA 805 is I implemented.

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Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I YIN AS-10 AS-12 A Y The BV PRA uses the WOG 2000 seal LOCA Additional MAAP No impact to Fire in a way that may be unacceptable to the uncertainty cases for PRA, because this NRC for risk based applications. MAAP runs BVPS-2 were performed issue was are performed to find the core uncovery times using pessimistically addressed in the for various sizes of seal LOCA. If the best biased values along with base PRA model estimate MAAP runs show the core is setting input parameters prior to building the covered at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , the sequence is to their high or low limits. Fire PRA.

considered success. The result is that all These cases were run out SLOCA sizes except the 480 gpm leak have to 48-hours or until core no impact on CDF, because the core is damage occurred. The shown to remain covered at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . This success state for the strict interpretation of the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months mission BV2REV3B PRA model time results in a .01 probability of core was redefined as any uncovery, even in sequences where SW or case (including AC power is not restored. uncertainties) that did not go to core damage before This result is significantly more optimistic than 48-hours. For cases that most other Westinghouse PRAs. The went to core damage uncertainty in the calculation [due to the before 48-hours but after possible variation in RCS pressure or seal 20-hours, additional LOCA size from the predicted] is not pursued. electric power recovery values were used, based The MAAP analysis shows time to core on NUREG/CR-5496. For uncovery of greater than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , but the cases that lead to core plant is not yet in a stable configuration. uncovery before 20-hours, Declaration of success at this point, based a plant specific electric only on MAAP results without thorough power recovery model investigation of MAAP uncertainties (e.g., was used. If electric sensitivities) is a liberal application of the power recovery was intent of the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months success criteria and may successful for these be non-conservative. cases, the sequence was The Supporting Requirement is in reference to NEI 00-02 Element - Subelement.

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Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN also binned to the success end state.

DA-07 DA-04 A Y The random independent failure probabilities As a resolution to this No impact to Fire are based on bayesian update of plant PRA Peer Review PRA, because this specific data. The plant specific data is based observation, the success issue was on the time interval 1987 to 2001, for unit 2 data (demands and hours addressed in the only. The processed data is presented in a of operation) for all Unit 2 base PRA model tabular form. Several questions are raised components that used prior to building the when this data is reviewed: Bayesian updating of their Fire PRA.

failure rates were checked

1. The data collection effort gets data before against the Maintenance the institution of the maintenance rule. The Rule estimated success reporting rules and accuracy of the pre-1994 data, and were revised as data should be justified to be the same as the needed if discrepancies post 1994 data collection effort. were found. Additionally,

2. The number of demands for several all RISKMAN failure data components is very high. For example, there distributions that were were 2331 DG demands. This means that Bayesian updated in the each DG was started 89 times per year, BV2REV3A PRA model which is almost 2 per week. were revised in the

3. The run time for the first hour for the DG's BV2REV3B PRA model is 2331 hr, which means each DG ran for one using the results of review hour each time it was started. That leaves no for estimated demands time for the 931 hours0.0108 days 0.259 hours 0.00154 weeks 3.542455e-4 months of extended run time. and hours of operation.

The demands and run time do not match. All Top Events were

4. The RHR pumps have 371 demand to requantified in the start. This means each pump is started 14 BV2REV3B PRA model times per year. Since they are not operated using these revised during power operation, this number seems component failure rates, very high. which were then used to

5. The MD AFW pump has 707 demands, requantify the CDF and which is 27 demands per year. LERF.

6. ZTPMOR and ZTPMSR are events for generic motor driven pump. There are no The specific observations recorded failures in 1.4E+6 hr. This identified in the PRA Peer Page 151 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I_ I I YIN I I performance is far better than industry Review Fact &

average. Without proper back-up information, Observation DA-07 are it is suspect. addressed below:

7. The TD AFW pump has 224 starts, which is 17 starts per year. 1. The data collection effort gets data before the institution of the maintenance rule. The reporting rules and accuracy of the pre-1994 data should be justified to be the same as the post 1994 data collection effort.

Response: Both the pre and post Maintenance Rule failure data were reviewed to the extent possible with the information available at the time to see if they met the requirements to be considered a PRA failure.

This PRA failure definition has remained unchanged throughout the PRA model updating process, and is not based solely on the Maintenance Rule definition, so it was unaffected by the implementation of the Maintenance Rule.

2. The number of L a a a ________________________________________________ a Page 152 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I II YIN I I__

demands for several components is very high.

For example, there were 2331 DG demands. This means that each DG was started 89 times per year, which is almost 2 per week.

Response: The DG start demands (ZTDGSS) was revised to 440 in the BV2REV3B PRA model.

This value is based on the Maintenance Rule estimated OST starts (50) per DG (2) per 3 year period, during 13.2 year of operation, or about 16 starts per year for each DG. Using a two-stage Bayesian process with 0 failures in 440 demands resulted in a mean failure rate of 2.78E-03 per start, as opposed to the 8.42E-04 value used in the BV2REV3A PRA model.

3. The run time for the first hour for the DG's is 2331hr, which means each DG ran for one hour each time it was started.

That leaves no time for Page 153 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I_ It IYIN I I the 931 hours0.0108 days 0.259 hours 0.00154 weeks 3.542455e-4 months of extended run time. The demands and run time do not match.

Response: According to the System Engineer, each Unit 2 emergency DG is run for about a total of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months each time that the OST is performed.

Therefore, using the revised start demand value of 440 in the 13.2 year update period, the operating hours for failures during the first hour (ZTDGS1) and operating hours for failures after the first hour (ZTDGS2) both used 440 hours0.00509 days 0.122 hours 7.275132e-4 weeks 1.6742e-4 months during the Bayesian update process for the BV2REV3B PRA model.

4. The RHR pumps have 371 demand to start. This means each pump is started 14 times per year.

Since they are not operated during power operation, this number seems very high.

Response: The RHR Page 154 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA

- I I _I YIN I pump start demands (ZTPMAS) was revised to 168 in the BV2REV3B PRA model. This value is based on 13.2 year of operation comprised of historical IPE data (11/87 through 12/88), the BV2REV2 PRA model update data (1/89 through 12/96), and the Maintenance Rule estimates for the 1/97 through 12/00 period, or about 6 starts per year for each RHR pump. Using a two-stage Bayesian process with 0 failures in 168 demands resulted in a mean failure rate of 1.89E-03 per start, as opposed to the 1.38E-03 value used in the BV2REV3A PRA model.

5. The MD AFW pump has 707 demands, which is 27 demands per year.

Response: The motor driven AFW pump start demands (ZTPMDS) was revised to 460 in the BV2REV3B PRA model.

This value is based on Page 155 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I I YIN I IY 13.2 year of operation comprised of historical IPE data (11/87 through 12/88), the BV2REV2 PRA model update data (1/89 through 12/96), and the Maintenance Rule estimates for the 1/97 through 12/00 period, or about 17 starts per year for each motor driven AFW pump. Using a two-stage Bayesian process with 0 failures in 460 demands resulted in a mean failure rate of 1.26E-03 per start, as opposed to the 1.02E-03 value used in the BV2REV3A PRA model.

6. ZTPMOR and ZTPMSR are events for generic motor driven pump. There are no recorded failures in 1.4E+6 hr. This performance is far better than industry average.

Without proper back-up information, it is suspect.

Response: Database variable ZTPMOR is only used for the main feedwater DumDs. A L a _______________ a ________________________________________________ a .1.

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Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed YN JI _ _ _ _ _ _ _ _ I_ _ _ _ _

PRA thorough search of the I Y/N available failure data from I MWRs, NPRDS, and EPIX were reviewed for these pumps. Although these data sources did list failures for these pumps, they consisted of mechanical pump seal leaks, oil leaks, and packing leaks. Itwas further noted that these leaks only degraded the pumps and did not result in any failures. Therefore, theses leaks were not counted as failures in the PRA model. However, the pumps were taken off line to repair them after discovery, which was accounted for in the PRA model pump unavailability due to maintenance activities.

Database variable ZTPMSR is used for the small standby pumps. A thorough search of the available failure data from MWRs, NPRDS, and EPIX were reviewed for these pumps. Although these data sources did list Page 157 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA

_ __ _ Y/N I failures for these pumps, they consisted of mechanical pump seal leaks, oil leaks, flange leaks, excessive oil consumption, and high pump vibrations. It was further noted that these only degraded the pumps and did not result in any failures. Therefore, theses were not counted as failures in the PRA model. However, the pumps were taken off line to repair them after discovery, which was accounted for in the PRA model pump unavailability due to maintenance activities if tracked by the Maintenance Rule or by using generic standby pump unavailability if they were not.

7. The TD AFW pump has 224 starts, which is 17 starts per year.

Response: The turbine driven AFW pump start demands (ZTPTSS) was revised to 156 in the L J .1 .1 BV2REV3B PRA model.

Page 158 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN This value is based on 13.2 year of operation comprised of historical IPE data (11/87 through 12/88), the BV2REV2 PRA model update data (1/89 through 12/96), and the Maintenance Rule estimates for the 1/97 through 12/00 period, or about 12 starts per year for each turbine driven AFW pump. Using a two-stage Bayesian process with 1 failure in 156 demands resulted in a mean failure rate of 1.50E-02 per start, as opposed to the 1.14E-02 value used in the BV2REV3A PRA model.

HR-07 HR-10 A Y The BV PRA uses the SLIM methodology. As a resolution to this No impact to Fire The HEP's are grouped in to 10 categories PRA Peer Review PRA, because this and then each category is "calibrated" in observation all operator issue was terms of 1 to 5 other PRA's. The PRA's that actions having a Risk addressed in the were used were Oconee (1984), Seabrook Achievement Worth base PRA model (1983), Diablo Canyon (1987), TMI (1985), (RAW) greater than 2 prior to building the Fermi (not referenced), South Texas (1988). (generally accepted as the Fire PRA.

The categories reflect each type of error (rule, risk significant threshold) skill, knowledge, diagnosis, response). The were compared to similar HRA's on which these are based are actions for all representative of nuclear plant procedures, Westinghouse plants by training and operator cognizance typical for using the WOG/B&WOG mid-1 980. PSA Comparison I Database (Revisions 2 1 Page 159 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I_ I Y/N I I The error rate curves should be updated to and 3). Additionally, a reflect current operator performance in the smaller subset of these nuclear power industry. The use of 15 year plants was also looked at.

old reliability data will limit the ability of the These consisted of; PRA to support risk based applications. Westinghouse 3-loop plants (since these were assumed to have similar operation action completion times based on plant power to heatup volume ratios), plants that also used the SLIM process, and Indian Point 2, which received a superior finding in their Human Reliability Analysis peer review. The results of this comparison show that the human error rates used in the BV2REV3A PRA model are all within the range of both comparison groups defined above, except for human action OPRCD3 (operator fails to cooldown and depressurize during a SGTR). However, the BV2REV3A value is of the same order of magnitude as most of the other plants reviewed and is not considered to be an outliner. It is therefore believed that the basic Page 160 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. I Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA

_ ___I j _ _ _ _ _ YN_

I error curves used in the calibration of the I YIN BV2REV3A HRA are not grossly out of date, and that the current human error rates used in the PRA model are acceptable as is.

Moreover, as a final resolution to this observation, future updates of the BVPS PRA models will use the EPRI HRA Calculator, which uses a more current and robust methodology. The BV2REV3B PRA model was not changed as a result of this observation.

This F&O was written against an obsolete HRA PRA model (BV2REV3B) and is considered to be resolved by the updated HRA PRA model incorporated in BV2REV4, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinqhouse. The Page 161 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-1 3.

HR-11 HR-27 A Y The BV HRA does not have a process to In the initial development No impact to Fire perform a systematic search for dependent of the IPE HRA, an effort PRA, because this human actions credited on individual was made to eliminate the issue was sequences. One case of dependent HEPs dependency between addressed in the was identified and treated (OF1 and 0B2). human actions by base PRA model However, it is not known how this was found. adjusting the split fraction prior to building the Other potential cases of dependent human value of the second Fire PRA.

actions in SGTR. LOCAs or feed and bleed dependent action, given sequences were not addressed. PRAs that the first action failed.

typically have one or more of the dependent For example, if the HEPs. operators failed to manually reestablish Main SGTR-OD*CD*WM, or RR*WM Feedwater following the SGTR-SL*OD*CD*WM failure of Auxiliary SLOCA -CD*MU Feedwater, the human Trans- OB*MU error rate for Trans- OF*OB*MU implementing Bleed and Init - Start standby CCP

Trip RCP Feed cooling later in the accident progression was There could potentially be other combinations adjusted upwards. If the that were not identified. dependent actions were required to take place in Current HRA practices generally require a the same period of time systematic process to identify, assess and during the accident adjust dependencies between multiple human progression, the second errors in the same sequence, including those dependent action was in the initiating events. assigned to be a guaranteed failure. For Moreover, there was no process in the HRA example, if the operators to adiust HEP on the final sequences and failed to cooldown and Page 162 of 301

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_ YIN

_I I determine combinations of operator errors depressurize the RCS by credited on individual sequences. A using the secondary sensitivity study was done, but did not adjust coolant system, no credit the HEPs. The cutoff was 4E-9, so that many was given to the operators other combinations were already below the to depressurize the RCS truncation. It is not clear how HEPs in the using the Pressurizer initiating events were treated in the study. PORVs. However, as a resolution to this PRA To be consistent with current HRA methods, Peer Review observation there must be a systematic process to a method was established identify, assess and adjust dependencies to verify that all dependent between multiple human errors in the same operator actions were sequence, including those in the initiating captured by reviewing events. sequences with two or more failed split fractions that have a contribution from human actions. Of the sequences reviewed, the human actions were either previously adjusted during the IPE HRA, or were determined to be independent between split fractions. This independence was based on the actions not being conducted by the same set of operators (e.g.,

control room Reactor Operator action vs. local Auxiliary Plant Operator action), or different procedures being used separated by sufficient time in the accident Page 163 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impactto Fire ID Requirement 1 Level Closed PRA IYINI IIN progression (e.g., actions to makeup to the RWST given SI recirculation failures, following operator actions to align a spare Service Water pump earlier in the accident sequence progression).

Human actions that are modeled in a single top event have appropriate dependencies modeled in the fault trees. Moreover, as a final resolution to this observation, future updates of the BVPS PRA models will use the EPRI HRA Calculator, which uses a more current and robust methodology. The BV2REV3B PRA model was not changed as a result of this observation.

This F&O was written against an obsolete HRA PRA model (BV2REV3B) and is considered to be resolved by the updated HRA PRA model incorporated in BV2REV4, which underwent a focused Peer Review in accordance with the quidance in ADDendix B of Page 164 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

TH-01 TH-08 A Y The Beaver Valley Unit 2 Ventilation and A new room heatup No impact to Fire Room Cooling Analysis Notebook describes analysis was performed PRA, because this the HVAC requirements for the South for the Safeguards issue was Safeguards Equipment Room. This analysis Building using realistic addressed in the is described as the basis for not requiring time-dependent DBA heat base PRA model room cooling in the PRA model. loads, based on MAAP prior to building the generated success Fire PRA.

The heat load for this area is only listed as a criteria. The results of this number (24898W or 85034BTU/hr) with no analysis were reviewed description of equipment assumed operating and compared to the EQ or other conditions considered. The heat temperature limits to see if load for this analysis is referenced to the necessary Calculation Number 12241-US(B)-210, "Loss components to mitigate of Ventilation Study for Several core damage or Buildings/Areas Outside Containment." containment failures Again this calculation determines the heat would be functional at the source in the South Safeguards Room as time that they were 85034 BTU/hr by reference to another required to function (up to calculation and lacks any description of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ). It was assumed equipment running etc. The concluded that all PRA referenced calculation was 12241-B-215-0, modeled equipment "Heat Gains, Heat Sinks and Beginning located within the Temperature for Emergency Switchgear, Safeguards Building CV&RCA, Diesel Gen. Bldg., Safeguards would be available to I Bldg and Auxiliary Bldg for Loss of Ventilation perform its PRA function I Page 165 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I_ II YIN I_ I Analysis." The objective of this calculation during a loss of all was to "...calculate the rate of increase of ventilation for up to 24 ambient temperature during a loss of hours. Therefore, it was ventilation [caused by a fire in the Cable determined that the Tunnel] in the areas listed..." In the Heat Safeguards Building Gains to Areas section of this calculation the ventilation system is not South Safeguards Area states "since the required for support of the plant is not experiencing accident conditions, PRA modeled equipment the load used for normal plant operation. located within the area, However, since this analysis occurs and the BV2REV3A PRA assuming a fire, the auxiliary feedwater pump modeling assumptions is in operation." The heat load in this area is regarding this remain calculated as valid. The BV2REV3B MDAFWP(68700)+Electrical(16334)=85034 PRA model was not BTU/hr. An additional reference for this heat changed as a result of this load is to calculation 12241-B-62B, Rev. 0, observation.

dated 8-13-85. This final calculation, "Safeguards Area Ventilation - Loads and Air Rates," describes the accident heat load for the South Safeguards Area as 210,136 BTU/hr and the heat load from one MDAFWP and electrical as 68,700 and 15,398 BTU/hr respectively.

It appears from this research that the heat load values for this area are only for a single operating MDAFWP while the room additionally contains the TDAFWP, the Train A QSS Pump, and the Train A SIS Pump. It appears the values in previous calculations were misapplied and that the correct heat load during an accident situation has not been correctly analyzed for this area.

As stated in 12241 -B-62B, "Single failure Page 166 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N cannot be applied in determining which components are operating since the worst case environment must be calculated.

Therefore, all equipment must be assumed to be operating ifthe equipment function is required."

AS-07 I AS-1 9 B Y For the SGTR event tree one of the operator As resolution to this No impact to Fire actions is to initiate Bleed and Feed (top observation, existing PRA, because this event OB). The success criteria for OB documents were issue was indicates that the basis for the success reviewed. Based on the determined to criteria assumes that the operator must have EOP Background have no effect on stopped the RCPs prior to OB in order to document for FR-H. 1, the BVPS PRA extend the time available to initiate bleed and steam generator dryout is model.

feed (referenced EOP FR-H. 1). If the tripping expected to occur at 33.1 of the RCPs is a prerequisite for the degree minutes if all RCPs of success of OB where in the model is this remain running during a dependency accounted for. loss of all secondary cooling. If the RCPs are tripped 5 minutes after the reactor trip, steam generator dryout is expected to occur at 40.9 minutes. This difference of less than 8 minutes is not expected to significantly impact the human error rates calculated for Top Event OB, since the actions to trip the RCPs, initiate SI and open a PORV are fairly simple actions that can be accomplished within minutes.

Therefore, these actions Page 167 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN are all assumed to be accounted for in the current human action failure rate, so the HER was not revised in the BV2REV3B PRA model.

DA-02 DA-03 B Y Table A-1 indicates that the period of time for As a resolution to this No impact to Fire the data collection was approximately 13 PRA Peer Review PRA, because this years. The table indicates that this data is for observation, the success issue was Unit 2. However, when the estimated data (demands and hours addressed in the average demands per year were computed it of operation) that was base PRA model was not clear how this information was used in the Bayesian prior to building the derived based on the expected demands per updating of the Fire PRA.

year. In some cases the number of component failure rates extrapolated demands per time period do not for Unit 2 was revisited match what would be the expected number of and checked against the demands. Maintenance Rule estimated success data, provided by the System Engineers. The Maintenance Rule data was based on a 3-year frequency, so the demands and hours of operation were adjusted for the 13.2 years used for the Bayesian update.

When there was a large discrepancy between the demands or hours of operation that were used in the BV2REV3A PRA model data update and those based on the Maintenance Rule data.

Page 168 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I _I_ YIN I the demands or hours of operation used for Bayesian updating were revised to use those solely estimated from the Maintenance Rule data.

When there was only a minor discrepancy between the two, the total success data used for Bayesian updating was based on the values from the IPE (11/87 through 12/88), the BV2REV2 PRA model data update (1/89 through 12/96), and the Maintenance Rule estimates for the 1/97 through 12/00 period.

This helped to preserve any historical success data that may have been different from the test frequencies used by the System Engineers in estimating the Maintenance Rule demands and hours of operation. However, either way, all failure data distributions that were Bayesian updated in the BV2REV3A PRA model were revised in the BV2REV3B PRA model Page 169 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N using these new estimated demands and hours of operation. This process and the results are documented in Appendix A (PLG Report:

Summary of Plant Data December 2002 Update) and Appendix E (BV2 Component Failure and Success Data: From 11/17/87 - 12/31/00) of BVPS-2 Data Analysis PRA Notebook, Revision 1.

DA-06 DA-08 B Y The generic MGL data used in the BV Unit 2 The following wording was No impact to Fire PRA is referenced, almost exclusively to the added to Revision 1 of the PRA, because this PLG generic database. Although the data Data Analysis PRA issue was analysis was updated recently, there is no Notebook to document the addressed in the discussion in the Data Analysis Notebook justification for using base PRA model regarding the availability of newer data existing dated data in prior to building the sources, e.g., NUREG/CR-5497. There developing the common Fire PRA.

should, at a minimum be a discussion of the cause failure parameters currently available data sources. It is noted for the BV2REV3B PRA that at least one Beta factor from model update.

NUREG/CR-5497 is used, but it is not Additionally, NUREG/CR-referenced in the data notebook. 5497 is now included in the notebook as Reference 15.

InApril 2001, Westinghouse issued WCAP-1 5674 in order to provide guidance to the owner's group utilities for Page 170 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I I Y/N IN improving common cause analyses used in their PRA models. Section 5.5 of the WCAP recommended several generic common cause failure data sources, one of which was NUREG/CR-5497 that was issued in October 1998, along with a CD-ROM disc for utilities to use in developing better common cause MGL parameter estimates.

This NUREG was also to be used in another Westinghouse project to develop a database consisting of a common set of realistic common cause failure events for use among the owners group member utilities.

During this project development it was noted that there were some major discrepancies in the classification of common cause failures between the published NUREG and the CD-ROM. As such, the NRC was to update the coding of their A L 4. 4.

common cause failure Page 171 of 301

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______ _ ___ ____JYIN Level Closed I

PRA events and database, and I YIN Westinghouse was to I provide input and feedback so that there would be consistency between plant-specific PRA models when using the data. However, at the time of the BVPS Unit 2 common cause MGL data update during Revision 3, the NRC update was still not available. As such, a decision was made during the update process to keep the existing generic MGL data, which is almost exclusively based on the PLG generic database (Reference 1), dated circa 1989. Two exceptions to this were for the development of the battery (ZBBATR) and battery charger (ZBBCHR) failure to operate beta factors.

These beta factor parameter estimates were developed using the NUREG/CR-5497 corresponding maximum likelihood estimate (MLE) values.

Page 172 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN Updated common cause failure data from WCAP-16672, based on NUREG/CR-6819, were ultimately used inthe BV2REV5 PRA model and appropriately documented. The methodology for the update was taken from NUREG/CR-5485.

DA-08 DA-04 B Y Acomparison of the failure probabilities for As part of the resolution to No impact to Fire diesel generators and DG output breakers Corrective Action 02- PRA, because this was counter-intuitive. 09037-03, the diesel issue was generator and circuit addressed in the DG FTStart = 8.4E-4 breaker failure base PRA model CB fail to close =1.75E-3 probabilities were revised prior to building the CB fail to open = 8.1E-4 and incorporated into the Fire PRA.

CB-beta =.12 BV2REV3B PRA model.

DG-beta = 7.6E-3.

From these probabilities, we can calculate the following CCF failure probabilities:

CCF 2 DG fail to start = 6.08E-6 CCF 2 CB fail to close = 2.1 E-4 CCF 2 CB fail to open = 9.7E-5 In the process of calculating station blackout frequency, these CCF's should appear in the model.

1. Failure of 2 DG will cause SBO at a single unit.

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Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN

2. Failure of the 2 DG output breakers will cause SBO at a single unit

3. Failure of the 2 bus feed breakers to open will cause SBO at a single unit that is not recoverable by cross-tie.

4. This data implies that the DG's are far more reliable than the circuit breakers and feed breakers which are a much larger contributor to SBO frequency.

DA-09 DA-10 B Y There is very little guidance for or Resolutions to this F&O No impact to Fire documentation of the process of selecting included adding a better PRA, because this CCF groups. The System Analysis Overview reference to the issue was and Guidance Notebook provides some of methodology used in addressed in the the high level methodology, but there is no retaining the common base PRA model discussion in the Data Analysis or System cause groupings, along prior to building the Notebooks as to the development of the with a listing of all of the Fire PRA.

groups that were ultimately modeled. In common cause groupings general, the system notebooks document the used inthe quantification CCF groups by referring to the Riskman of the system top event output files. This is not very informative. For models. These are example, the AC Electric Power System provided in Section 7 Notebook provides no discussion of the CCF "Common Cause model for the diesel generators. A discussion Modeling" and Appendix of decoupling the Unit 2 diesels from the Unit A,Table A-1 of the BVPS-1 should be included. 2 Systems Analysis Overview and Guidance PRA Notebook, respectively. Additionally, a summary of all of the MGL parameters used in the top event common cause groupings is now I provided in Appendix C, Page 174 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN Table C-7 of the Data Analysis PRA Notebook.

Furthermore, it is the opinion of the BVPS PRA staff that the details of the common cause groups that were retained in the PRA system models and presented in Appendix C of the BVPS Unit 2 PRA System Notebooks, under the common cause sections of the RISKMAN System Notebook files are adequately documented and can be found by knowledgeable personnel.

Therefore, the practice of referencing this part of the notebook is deemed acceptable.

DA-10 DA-07 B Y The test and maintenance unavailabilities for As resolution to this No impact to Fire DG were reviewed. The following were observation, the Diesel PRA, because this observed. Generator System issue was Engineer was contacted addressed in the

1. The DG are used in a cross-tie situation for to obtain the historical base PRA model either unit. Thus, it is possible that the diesel generator prior to building the unaffected unit could be in shutdown and the unavailability during plant Fire PRA.

DG could be in overhaul. The outage time for shutdown conditions. For the DG (when used as a cross-tie) must the Unit 1 emergency include the OOS time during shutdown. diesel generators, the shutdown unavailability

2. Appendix B of the data document indicates was based on data maintenance outage was collected Nov 98 obtained from October Page 175 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN through May 2000. This is not long enough to 1997 through September capture the DG overhaul experience. 2001. These values were then combined with the

3. For unit 2, the unit I DG are used for the assumed on-line cross-tie. The T&M data must come from unit maintenance unavailability 1 experience. This information was not found. values to determine the total Unit 1 emergency diesel generator unavailability, which was used in the BV2REV3B electric power cross-tie model.

DE-04 DE B Y There is no discussion of some flow In response to this No impact to Fire (Draft characteristics (e.g., spray effects, pipe whip) observation, the work that PRA. This F&O IF-09) in the consideration of impacts from flood was completed for the was resolved in initiators. Beaver Valley Unit 2 Risk- the submitted Informed In-Service BVPS-2 Fire PRA Inspection (RI-ISI) Indirect model, which used (Spatial) Consequence BV2REV5A as its Evaluation was reviewed, basis.

As a part of this evaluation process, an assessment of the postulated indirect (spatial) consequences associated with piping failures was made in order to further distinguish the piping segments. The indirect effects assessment was accomplished through an investigation of existing plant documentation on I pipe breaks, flooding, and Page 176 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N I plant layout along with a focussed plant walkthrough. The indirect effects that were specifically looked at included; pipe whip, jet impingement, sprays, and flooding resulting from pipe breaks or leaks. The results of this indirect effects evaluation did not identify any viable SSC impacts due to flood induced failure mechanisms that were not already addressed in the PRA flooding analysis documentation. No further flooding impacts were incorporated into the BV2REV3B PRA.

This F&O was written against an obsolete Internal Flooding PRA model (BV2REV3A) and is considered to be resolved by the updated Internal Flooding PRA model incorporated in BV2REV5A, which underwent a focused Peer Review in accordance with the guidance in ApDendix B of NRC RG Page 177 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group.

The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

DE-05 DE B Y A number of flood-specific HEPs are included To resolve this PRA Peer No impact to Fire (Draft in the analysis (e.g., ZHEFL1-4). These four Review observation, PRA. This F&O IF-25, HEPs are evaluated in the HRA Notebook in operator actions ZHEFL1 was resolved in IF-26) the calculation tables, but no discussion of and ZHEFL2 were added the submitted these actions is included in the HRA to Table 3-1 "Beaver BVPS-2 Fire PRA documentation, and only ZHEFL1 and Valley Human Actions" model, which used ZHEFL2 appear in the flood documentation in and discussions of the BV2REV5A as its the Appendix C of the IE Notebook. scenarios now appear in basis.

Appendix A "Dynamic Action Identifier Sheets".

Additionally, operator actions ZHEFL3 and ZHEFL4 are Unit 1 operator actions, and were removed from Table 3.5 "Human Error Rate Distributions" to avoid any confusion.

This F&O was written against an obsolete Internal Flooding PRA model (BV2REV3A) and is considered to be resolved by the updated Internal Flooding PRA I model incorporated in Page 178 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA Y/N BV2REV5A, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group.

The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

HR-01 HR-04 B Y Miscalibration errors are not considered for This observation is not No impact to Fire either independent or common cause pre- totally correct, since the PRA, because this initiator human errors. The PRA assumes SSPS model did include issue was that both would be captured in the equipment instrument string determined to failure data. However, the generic common miscalibration errors in the have no effect on cause failure database is not verified as fault tree model. the BVPS PRA having included miscalibration errors as well. Additionally, common model.

Therefore, there is a potential misapplication cause miscalibration of the generic common cause data use since errors between trains are the generic data source may not include the considered to be rare common cause miscalibration. events since the On-line Maintenance Program is developed to alternate work between trains on different weeks.

Furthermore, a search in the Corrective Action database and EPIX did not reveal any such miscalibration errors between trains at BVPS.

Therefore, this Page 179 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I YIN I observation was assumed to be resolved by the instrument string miscalibration errors already accounted for in the SSPS model. No further miscalibration errors were incorporated into the BV2REV3B PRA.

This F&O was written against an obsolete HRA PRA model (BV2REV3B) and is considered to be resolved by the updated HRA PRA model incorporated in BV2REV4, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

HR-03 HR-02 B Y The BV PRA uses the SLIM methodology to While it is true that the FLI No impact to Fire quantify the post initiator human actions. The is a linear combination of PRA, because this HRA quantification currently in use was the PSF rankings and issue was Page 180 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I I YIN IN completed for the IPE and has not been weightings product, the addressed in the updated. The SLIM method can only combine actual HER is logarithmic base PRA model the PSFs linearly to develop the overall FLI as discussed in Section prior to building the for each action. Current industry practice 2.1 of the HRA Notebook. Fire PRA.

contends that PSFs can have significant non- Additionally, as shown in linearities. For example if a particular action Table B-4 "Beaver Valley is rated poorly for a given PSF and Unit 2" Group 4 Human moderately in all the others, middle of the Actions Evaluation, road HEPs tend to result even though poor between ZHEMU1 and performance in only one PSF may be ZHEMU4, where the only indicative of poor human reliability difference is in the timing irrespective of what is going on with the other rankings, there is a PSFs. Mosleh of University of Maryland has significant difference in addressed this issue in a refinement of the the HER values.

FLIM method (which allows assignment of importance to PSFs) in an update of the This PRA Peer Review Calvert Cliffs PRA. The BV PRA uses linear observation was compilation of PSFs. The ability to use non- dispositioned by the linear compilations, if desired would be an resolution of F&O HR-07 enhancement. above, where it was shown that the current human error rates used in the PRA model are acceptable as is, and by acknowledging the PRA Peer Review Team comment on its significance on CDF.

Moreover, as a final resolution to this observation, future BVPS PRA models will use the EPRI HRA Calculator, which uses a more current I £ a a £ and robust methodology Page 181 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID RequirementI Level Closed PRA Y/N to identify human action dependencies.

This F&O was written against an obsolete HRA PRA model (BV2REV3B) and is considered to be resolved by the updated HRA PRA model incorporated in BV2REV4, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

HR-09 HR-03 B Y There is not enough detail in the HRA to This CA is being (was) No impact to Fire reproduce the results. The following rolled into CA 02-09043- PRA, because this information was not available and does not 30 to track its resolution. issue was appear to have been retained: addressed in the This F&O was written base PRA model a) the time lines against an obsolete HRA prior to building the PRA model (BV2REV3B) Fire PRA.

b) discussion of the events chosen for and is considered to be "calibration" from the other PRA's and the resolved by the updated reason why they are applicable. HRA PRA model I incorporated in BV2REV4, Page 182 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN c) the basis for choosing 10 categories of which underwent a HEP and the basis for assigning each BV focused Peer Review in HEP to a category accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

HR-13 HR-19 B Y Some discrepancies in the timing were These operator actions No impact to Fire observed in the PRA. were reassessed during PRA, because this All the timing calculations were based on the BVPS-2 PRA model issue was hand calculations. Although the times update, addressed in the seemed reasonable compared to other PRAs, when the HRA was base PRA model there were some observations. revised using the EPRI prior to building the HRA Calculator. Fire PRA.

1) There was a calculation done for steam generator dryout, which assumed all the This F&O was written water would be exhausted from the SG by 1.1 against an obsolete HRA hours. Using 1.1 hours1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months overestimates the PRA model (BV2REV3B) time available to do F&B or restore AFW. and is considered to be Effectiveness of decay heat removal will resolved by the updated decrease way before all the water is gone in HRA PRA model the SG. incorporated in BV2REV4, which underwent a

2) ZHECC1 - start standby CCP provides a focused Peer Review in time of 30 minutes, based on seal failure after accordance with the loss of seal cooling. But, after loss of CCW, guidance in Appendix B of the RCP must be tripped with in 5-10 minutes NRC RG 1.200, Rev.1, to avoid catastrophic seal failure. The 30 conducted during the minutes for seal failure after loss of cooling week of October 29, 2007, Page 183 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN does not apply. This scenario is for bearing by Westinghouse. The failure after loss of CCW. The timing should F&Os as a result from this be consistent. focused Peer Review, as well as their resolutions

3) ZHEICl and ZHEIC2 show 70 and 30 are presented in Table 1-minutes based on seal failure after loss of 3.

seal cooling. The time should be consistent and should consider if the Loss of CCW to the RCP bearing must be considered.

4) ZHEMU1 - timing for MU indicates the operator has 1.6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months to act, based on the time it takes to drain the RWST from minimum level "empty". The number should be coordinated with the boron dilution calculation, which assumes boron dilution times from a RWST level of 140,000 or 360,000 gallons. time allowed for operator diagnosis on the front end must be subtracted from time allowed

5) ZHEOB1 provides 78 minutes for feed and bleed, based on the time for a PORV to lift after loss of AFW. There is no analysis for this. In most PWR, F&B must be started prior to the time the PORV lifts. Start time for F&B should be based on MAAP analysis.

6) ZHEOCl - states there are 30 minutes to trip RCP after loss of seal cooling. The other parts of the PRA state 5 or 10 minutes. 30 min is a seal failure number, not a bearing failure number. ZHEOCI be based on 5 minutes.

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Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N

7) ZHEOS6 - timing states 1.3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months available to start AFW. 1.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months is the time from reactor trip to core uncovery. AFW must be started before 1.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months . Also, if there is 1.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months allotted to start AFW, then there is no time for MFW restoration and F&B. The time from reactor trip to core damage must be apportioned to the 3 actions in this sequence.

8) ZHEWA5- 30 minutes to align diesel driven SW pump after LOSP. This time is based on seal failure due to loss of SW. The DG will fail in 8 minutes if there is no SW. The time to align Diesel driven pump is based on failure of the DG, which is 8 minutes.

IE-04 IE-16 B Y Subtier criteria requires that "The initiating The initiating event No impact to Fire event frequency should not use data from the frequencies were PRA, because this initial year of commercial operation." reanalyzed using data issue was Contrary to this data from 1987 (Beaver from January 1, 1989 addressed in the Valley initial year of operation) is included in through May 31, 2001. In base PRA model the data update. Use of this data, though addition, LOCA initiating prior to building the conservative, could shift the importance of event frequencies were Fire PRA.

components. reanalyzed to address aging-related failure mechanisms based on the interim LOCA frequencies from Table 4.1 of the "Technical Work to Support Possible Rulemaking for a Risk-Informed Alternative to 10CFR 50.46 / GDC 35, Revision 1", dated July 2002. The results of this I reanalysis were _ _I Page 185 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN incorporated into the BV2REV3B by updating the initiating event frequencies.

IE-05 IE-13 B Y In appendix D of the initiating event notebook, The interfacing systems No impact to Fire the interfacing systems LOCA frequency is LOCA initiating event PRA, because this calculated referring to two references from frequency was reanalyzed issue was 1985. The 2 landmark ISLOCA reports using the following addressed in the (NUREG/CR-5102 and NSAC-152) were documents: base PRA model written in 1992. Although the frequency prior to building the calculated in the Beaver Valley PRA does not 1. G. Bozoki, P. Kohut, Fire PRA.

seem out of the recognized range of values and R. Fitzpatrick, for this frequency, due to the importance of "Interfacing Systems this event for LERF, the compatibility of the LOCA Pressurized Water method and data used in the PRA should be Reactors," prepared for checked against the later references. U.S. NRC, NUREG/CR-5102, BNL-NUREG-Other inconsistencies in the analysis are: 52135, February 1989.

OST 2.11.16 is performed prior to startup, if it 2. E. T. Burns, K.

has not been performed in the previous 9 Mohammadi, T.P., Mairs, months. The PRA assumes there are 3 V. M. Anderson, and B.

shutdowns per year (which is not supported Hannaman, "ISLOCA by the historical performance of BV), so Evaluation Guidelines,"

assigns a test frequency of 3 months. The prepared for Electric maximum possible test interval for OST Power Research Institute, 2.11.16 is 26 months [plant ascends to power NSAC-154, September 8 months from last test for an 18 month run]. 1991.

The minimum is 9 months. The true average 3. D. A. Wesley, T. R.

test interval is likely in the 13-20 month Kipp, D. K. Nakaki, H.

range. Substituting this test interval into the Hadid-Tamjed, "Pressure-equation would have a significant affect on Dependent Fragilities for frequency. Piping Components -

Pilot Study on Davis-The probability of MOV 8889 being Besse Nuclear Power Page 186 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN inadvertently open is not considered. Station," prepared for U.S.

NRC, NUREG/CR-5603, The LHSI lines are interconnected such that if T191 002465, October CV 552 and 109 fail, both 132 and 133 will be 1990.

challenged. This is true for the other injection lines also. So the valve combinations is 3 The results of this revised times higher than shown. analysis were incorporated into the The probability of pipe over pressure is BV2REV3B by updating assumed to be the same as pipe rupture. the interfacing systems This is not consistent with the two 1992 LOCA initiating event references listed above, frequency.

IE-08 IE-13 B Y Bayesian updating is used extensively in data While there are indeed No impact to Fire analysis and also in initiating event frequency situations that Bayesian PRA, because this calculations. Although mathematically correct, updating with zero failures issue was the use of Bayesian updating without some could cause the posterior addressed in the limitations has been criticized, with mean to be significantly base PRA model justification, in the past. Under certain lower than the prior mean, prior to building the conditions, bayesian updating with zero or 1 these are due to the use Fire PRA.

failures may reduce a prior mean (with a high of using moment error factor) considerably. Since PRA results matching. This refers to and applications depend on, and are the practice of changing a measured mainly by point estimate (mean) prior that is presumably a results, but not by uncertainty bounds, any lognormal distribution, to a evidence that shifts the mean considerably gamma distribution by must be rigorously justified. matching the mean and the standard deviation.

The BV PRA uses bayesian analysis for After the Gamma virtually all transient initiating events. In most distribution is updated cases, the plant specific data is 0 trips in 11 with plant data years. Ingeneral the posterior is lower than analytically, the resulting the prior. Ifthe plant specific data was used gamma distribution is by itself, the is enough data to justify a point convert back to the estimate of about .05/yr. The prior for LOSP lognormal distribution is .027. The prior for SGTR is .0074. The again using the moment Page 187 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA

_I._ II YIN I II posterior for LOSP is .025 and for SGTR matching method. It is

.0048. In both these cases, the posterior is known that in this lower than the prior and lower than the plant practice, ifthere should be specific data can justify. This is due to the zero failures, the resulting use of Bayesian analysis when too little plant posterior gamma specific data exists. distribution has a mean value significantly lower Rules for when to use Bayesian analysis and than the prior mean.

when to use generic data should be The BVPS analysis did developed to ensure that failure rates and not use the moment initiating event frequencies are not reduced matching methodology.

below both the generic values and the plant Instead, the Bayesian specific estimates. update functionality provided by RISKMAN was used. There are two classes of priors used in the BVPS analysis. The first class are the lognormal distributions based on parameters from industry studies (e.g.,

LOCA initiators).

Updating a lognormal distribution with zero events in about 10 years does not change the mean in most cases (or there is a slight change in the third significant number).

The second class, which is a more general type of priors, is the industry data.

These priors consists of Page 188 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA IYIN I I three parts. The first and most important part is the failure and success data for a set of PWR power plants. The second part is the so-called grid, which consists of a set of values for the median (of the assumed prior curve), and a set of values for the range factor (of the assumed prior curve).

The selection of median and range factor should be such that the resulting distribution should not be skewed toward either end of the median or range factor in the grid (grid is the matrix of median and range factor values). The third part of a prior is the so-called lambdas, which is a set of values for the possible bin values that the distribution can locate.

The lambdas do not affect the posterior mean distribution as long as it has sufficient range and sufficient number of values (typically 20 bins are sufficient for a distribution). It should be pointed out that for the Page 189 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I I YIN I_ I industrial data type of prior, updating it with zero failures typically results in a smaller mean value for the posterior then the prior. However, the decrease is much smaller in magnitude than the moment matching approach, and it should be treated as a normal behavior of the Bayesian analysis (i.e., zero failures always provide information leading to a lower estimate).

In response to this observation, each posterior distribution that was Bayesian updated with zero failures was reexamined to assure that there was no skewing of results on the grid, and that there were no abnormally large values (excessive probabilities) in a single lambda bin. In some cases a few more lambdas were added to actually bring the probability per each lambda lower than 0.1.

However, in these cases Page 190 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA I Y/N I the posterior distribution changed little compared to the BV2REV3A original set of lambdas (note, the grid was not changed in this response because these were checked in the original analysis and quality was assured). The results of the review did not identify any concerns, so confidence in the Bayesian update results using zero failures based on the discrete probabilistic distribution approach, which is a robust process, was maintained.

For the BV2REV3B PRA model, since the success time changed from 11 critical years to 9.93 critical years in response to Corrective Action 02-09042-01 (to remove the first year of commercial operation), the posterior mean shifted slightly higher than the original BV2REV3A PRA model analysis.

L2-03 L2-18 B Y All early SGTR core damage sequences with In response to this No impact to Fire I wet SGs are classified as SERF (small early I observation, the I PRA, because this Page 191 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I_ II YIN I I I release frequency) vs. LERF without regard BV2REV3B PRA model issue was to break location or other sequence specific was revised to incorporate addressed in the conditions such as SG isolation, primary to WCAP-1 5955 "Steam base PRA model secondary pressure equalization, etc. The Generator Tube Rupture prior to building the basis for the use of small release was PSA Notebook" Fire PRA.

scrubbing; however, there is no classification of SGTRs documentation supporting this classification. into LERF. In the For example, failure to cooldown and BV2REV3B PRA model depressurize the RCS may result in lifting the update, all steam ruptured SG ASDVs or safety valves. generator tube ruptures Radionuclides, both volatile and non-volatile, that are faulted and have entrained in the escaping steam result in a a depleted RWST, or release to the environment. Without have a loss of all evaluation, the magnitude of the release to secondary cooling and the environment is unknown, and may be consequential challenge sufficient to meet LERF classification. to the steam relief valves are considered to be LERF contributors. For these cases it is assumed that leakage from the RCS will continue indefinitely through a faulted steam generator and the core will uncover after the RWST depletes.

Subsequently after closing this F&O, the ASME Standard recognizes scrubbing during SGTRs as a way to reduce LERF.

Ultimately resolved by GAP F&O LE-Cl0-01 (see Table 2-2).

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Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN MU-02 MU-06 B Y The computer models of the PRA (electronic IT has placed restrictions No impact to Fire files for the input and output of the PRA to the "S:/AII/PRA PRA, because this model and its sensitivity analyses) should be Engineering" directory. issue was stored in a controlled manner. The subtier The permissions for this addressed for the criteria states that "a secure offsite storage directory are limited to base PRA model facility for computer codes, inputs, outputs, specific design prior to building the and models should be used". Engineering personnel. Fire PRA.

This will prevent Discussions with the BV PRA staff indicate unauthorized personnel that the PRA model files are kept on CDs and from accessing PRA also on a network drive (not a protected reports and models. In drive), addition, the network is backed up daily, making To meet the intent of the subtier criteria, the retrieval of lost files very model files should be also stored with the easy.

same philosophy as the paper copies of calculation notes; namely stored by a dedicated organization (preferably outside of the PRA group), in a protected manner and be available for long term retrieval.

QU-02 QU-08 B Y The original top ten sequences were for total In response to this No impact to Fire CDF and not just internal. Of these three observation, a new top PRA, because this were control building fire, one seismic, and event was included in the issue was four external. The number 1 was ELOCA and BV2REV3B PRA model, addressed in the number 2 was ISLOCA, both which were the which contained a switch base PRA model initiating event which leads to guaranteed to bypass the containment prior to building the failure. The remaining four were internal event tree top events. Fire PRA.

sequences which meant something. The This allowed for the Level number five sequence was loss of AC bus 1 (CDF only) sequences "Purple" with other failures that lead to core to be quantified and damage. Sequences 7 and 8 were LOIA with reviewed, while also loss of heat removal (high and dry). The maintaining the ability to number 10 sequence was ATWT (on a provide Level 2 sequence turbine trip) with the failure of the operator to results, when needed.

manually trip the reactor, with all subsequent I I Page 193 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN I operator actions guaranteed failure. Since this had limited internal sequences, a larger report was reviewed with the objective to see what SBO looked like. The SBO was not on this and in fact the first LOSP was very low on the list. Then a sequence report was reviewed looking at LOSP only. Sequence

57 was the first SBO sequence and #58 was the second SBO sequence. The only difference between these was in the containment tree. With this is was realized that the containment tree was splitting up

("fractionalizing") the LOSP sequences, as opposed to some other sequences (such as ELOCA) which had one path through the containment tree. It was now realized that in order to analyze the sequences in the same context as previously, there needed to be a run of the event trees where the extra details of the containment tree suppressed. The utility staff ran this and the results and insights were noticeably different than before.

The results of the top ten were significantly different. The ELOCA and VSLOCA stayed the same value but now are sequences 2 and 4 respectively. The number 1 sequence is now loss of instrument air. ATWT on PLMFWA is number three (while the previous ATWT went to 12). Two sequences are control building flooding.

QU-03 QU-08 YB In ATWT, if the operators fail to trip the In response to this No impact to Fire reactor as an immediate action (top event observation, the PRA, because this OT) then subsequent operator actions RI and BV2REV3B PRA model issue was OA are failed. I suspect that this sequence was revised to incorporate addressed in the Page 194 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I IYIN I_ _

has always been this way in the past, but with giving credit for the longer base PRA model the recent enhancements in the model, the term operator action to prior to building the sequence has risen into the top ten. This emergency borate, even Fire PRA.

leads to an overly conservative results in though the earlier actions CDF. This appears to be the number 6 in to manually trip the internal (#10 sequence in total CDF). Of the reactor or to insert the top 50 sequences, 20% are ATWT. The total control rods may have CDF for ATWT is a noticeable part of the failed.

CDF, and would not support any future RI ATWT applications. The BV2REV3B PRA model was revised by removing the emergency boration (Top Event OA) human action dependency on prior ATWS human actions, which must be performed immediately; i.e., manual reactor trip (Top Event OT) and manual rod insertion (Top Event RI).

This involved editing the ATWS event tree split fraction logic rules for OAF by removing OT=F +

RI=F, as shown in Table 3.5-3 "ATWS Event Tree Logic Rules" of the Event Tree Analysis Notebook.

The basis for this change was derived from WCAP -

15831-P Section 5.1.1.12, where it is assumed that the operator action to Page 195 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN emergency borate is independent of the previous operator actions since it does not need to be completed in the same short time period as the operator actions to trip the reactor, or manually drive in the control rods.

QU-04 AS-12 B Y An asymmetry discussion is provided in the As a resolution to this No impact to Fire PRA Quantification Notebook, section A.3. PRA Peer Review PRA, because this The write-up includes general discussion observation the PRA issue was regarding the use of alignments to simulate Quantification Notebook, addressed in the the various modeling asymmetries in the Section A.3 was revised base PRA model systems modeling and the effect on event to address which prior to building the trees by partitioning some of the initiating asymmetries are due to Fire PRA.

event categories with some examples being modeling and which are provided. Some of these asymmetries are due to real plant due to modeling assumptions and some are differences. Asymmetries due to actual plant differences. No specific are also discussed in the discussion is provided to explain what system System Notebooks to asymmetries are due to simple modeling explain where and why assumptions and which ones are due to plant changes were made to differences. reduce or eliminate them from the model and to identify the important ones that remain. Multiple examples can be given of where asymmetries were eliminated by applying initiating events to multiple trains (SW A & B) or multiple similar events such as floods and LOCAs. This helps to Page 196 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impactto Fire ID Requirement 1 Level Closed PRA YIN avoid asymmetries in importance on which train is running, or which piping loop is broken.

Furthermore, risk importance measures are grouped by BVPS system so asymmetries are negated when rating system importance.

Additionally, Risk importance measures of sister components (similar functions) on opposite trains are also conservatively set at the highest importance value to negate asymmetries.

By grouping these risk importance measures it ensures that Risk-Informed applications are not influenced by any PRA asymmetries.

QU-07 QU-15 B Y A review of the non-dominant sequences was In response to this No impact to Fire made. The non-dominant sequences are observation, the split PRA, because this those that are not normally saved when the fraction logic rules were issue was entire model is run. It was necessary to re-examined and addressed in the quantify one initiator at a time to get the compared to the base PRA model cutsets below 4E-1 0. A review of these dependency matrices, prior to building the cutsets had the following observations: The specific concerns Fire PRA.

identified by the peer

1) SGTR 1.507E-12: IAF

OD16B - how is review were reviewed and OID possible when IA is failed? corrected in the Page 197 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN BV2REV3B PRA model

2) TTrip 7.26E-1 1: AF1*OF1*OB4*CDF*RRI - when in error. The ifAF, OF, OB and CD are failed, how can RR BV2REV3B PRA model be asked in a probabilistic manner. RR was then quantified using should be RRF. only the Level 1 Top Events so that a review of

3) TTrip 3.233E-1 1: the CDF sequences could SAl *OS6*AF3A*OFF*OBF*CDF*RR1 - How be performed to verify that can RR be asked in a probabilistic fashion the revised split fraction after failure of all that? logic rules made sense.

This included looking at

4) TTrip 8.34E-12 AF1*MFF*OBI*CDF*RR1 - non-dominant sequences same question about RR? 5 orders of magnitude lower than the total CDF

5) TTrip 1.1649E-12: value. Other concerns PR7*HH2A*OR3A*MU2: If HH2A is failed, identified that were not in how can MU2 succeed? Does not MU2 use error, were determined to the HHSI pumps? have sufficient justification provided in the System

6) TLMFW 1.2559E-12: AF1*OF1*OB1*HH1: Notebooks and Why is OF1 in the tree for Loss MFW? Why is Dependency Matrices.

OB1 in the same sequence as HH1. If OB1 fails, there is no initiation of HHSI, so why is I HH1 included?

QU-09 QU-31 B Y This element asks whether the sequence As an interim resolution to No impact to Fire results by sequence, sequence types, and this PRA Peer Review PRA, because this total was reviewed and compared to similar observation a ballpark issue was plants to assure reasonableness and identify comparison was made addressed in the any exceptions. A review of the PRA utilizing the WOG PSA base PRA model documentation did not reveal a comparison of Model and Results prior to building the the current PRA revision results to results of Comparison Database, Fire PRA.

similar plants. Revision 3. Items compared included; initiating event I frequencies and their I Page 198 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN conditional CDF, component failure rates, human error rates, and success criteria. While, this review was not detailed no outliers were identified, and the conditional CDF from LOSP initiators was comparable with North Anna, a nearly identical plant.

This CA is being (was) rolled into CA 02-09043-30 to track its complete resolution.

Ultimately resolved by GAP F&O F&O IE-C10-01 (see Table 2-2).

QU-10 QU-30 B Y The initiating event frequency for interfacing In response to this No impact to Fire system LOCA (i.e., initiator VSX) was observation, the Monte PRA, because this quantified using point estimates (result of Carlo value generated for issue was 2.2E-7) and using Riskman's Monte Carlo the updated interfacing addressed in the algorithm (result 3.OE-7). The difference is systems LOCA initiating base PRA model explainable based on data dependence event frequency in prior to building the between valve failures, response to CA 02-09042- Fire PRA.

02 previously identified, But the event tree quantification used the was used in the lower, point estimate result. The 3.OE-7 quantification of the Monte Carlo result should be used in the BV2REV3B PRA model.

quantification.

ST-02 ST-10 B Y The internal flooding analysis was done for In response to this No impact to Fire the IPE and has not been updated since then. Iobservation, the work that PRA. This F&O Page 199 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. J Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I _ YIN I All flood barriers were treated was completed for the was resolved in deterministically and assumed to succeed. Beaver Valley Unit 2 Risk- the submitted The sub-criteria for this element suggests that Informed In-Service BVPS-2 Fire PRA flood propagation pathways should include Inspection (RI-ISI) Indirect model, which used failure of doors, floor drains, and other flood (Spatial) Consequence BV2REV5A as its barriers. Evaluation, as well as, basis.

several updated flooding analyses performed after the IPE submittal were reviewed. The results of this review determined that the flooding analyses did consider the potential of flood barrier failures due to the flood water static head on the door latching mechanisms. It was concluded that the IPE flooding analysis assumptions regarding the propagation of flood waters did consider flood barrier failures, and remains valid. No further flooding impacts were incorporated into the BV2REV3B PRA.

This F&O was written against an obsolete Internal Flooding PRA model (BV2REV3A) and is considered to be resolved by the updated Internal Floodinq PRA Page 200 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN model incorporated in BV2REV5A, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group.

The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

SY-01 SY-12 B Y Loss CCP/CCR results in a loss of seal water An evaluation was No impact to Fire heat exchanger cooling (discharges directly performed to see at what PRA, because this to the charging pump suction) as well as loss temperature the available issue was of non-Regenerative heat exchanger cooling NPSH would be lower determined to (discharges to the VCT). The result is a than the required NPSH at have no effect on potential common mode failure of all charging the charging/HHSI pump the BVPS PRA pumps due to an increasing charging pump design flowrate. The model.

inlet temperature, coupled with the loss of results of this evaluation CCP/CCR, this results in an RCP seal LOCA. revealed that the VCT Riskman macro RWSTSO (VCT swap-over to temperature would have RWST) contains logic to include the failure of to increase by more than the components required to perform this 123 OF for this condition to action, but the operator action is not included, be true and result in a loss Given the uncertainty of the time to charging of NPSH. With multiple pump failure, the operator action may high temperature alarms dominate the mechanical component failures, coming in at more than 100 OF prior to reaching this temperature, there would be plenty of time available to operators to I perform mitigating actions. I Page 201 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN Moreover, a loss of NPSH would only impact the running charging pump, since the standby pump does not automatically start, unless a Safety Injection Signal is present, in which case the suction would automatically swap over to the RWST. The third pump would only be manually aligned and started following the failure of the first two normally aligned pumps.

Therefore, this observation was not considered to be a valid common cause failure mechanism of the charging/HHSI pumps, so the operator action was not included in the BV2REV3B PRA model.

SY-02 SY-03 B Y The degree of documentation in the systems The Riskman Split No impact to Fire analysis should provide enough detail that the Fraction and Common PRA, because this systems analysis can be duplicated with Cause Tables are issue was minimal effort. A review of the Auxiliary attached as an Appendix addressed in the Feedwater System Notebook (Book 2, Tab 2) to each of the System base PRA model and the Main Feedwater System (Book 3, Notebooks. These tables prior to building the Tab 6) revealed that the Split Fraction contain the necessary Fire PRA.

definition / truth tables are not documented split fraction and Common and the Common Cause assumptions are not Cause information. This documented. There is no discussion as to action closes this issue.

I where these assumptions came from or the I Page 202 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. 1 Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN definition of the split fractions utilized in the Systems Analysis. The absence of this information could result in the inability to reproduce the Systems Analysis for verification of results or future applications.

SY-03 SY-15 B Y Some initiator dependent component failure The LHSI initiator success No impact to Fire modes do not appear to be modeled. For criteria was reviewed to PRA, because this example, the S18890 MOVs are included in address the specific PRA issue was the model for fail to open to prevent LHSI peer review concerns. determined to pump overheating during low flow conditions. Once such concern was have no effect on For this specific example, large LOCAs that the LHSI fault tree the BVPS PRA should only consider transfer open as a flow modeled the failure to model.

diversion; failure to open is not applicable. open of the mini-flow For small LOCAs, the failure to open is MOVs during a small correctly modeled, but transfer closed should break LOCA, but did not also be included. For medium LOCAs, the model the transfer closed need to open or close the S18890's may failure. Typically the PRA require additional thermal hydraulic analyses. only modeled passive Other system designs susceptible to initiator failures (e.g., transfer specific failure modes include systems with closed) if there were no pumps which have mini-flow which return to active failure modes (e.g.,

the pump's suction. Systems like this may failure to open) modeled, require operator action to stop these pumps if since the active failures downstream pressure prevents adequate flow dominate the components to prevent pump overheating. failure probability (usually by three orders of magnitude). Therefore, this concern was not incorporated into the BV2REV3B PRA model update. Another concern was that the LHSI fault tree always queried the opening of the pump mini-flow valves even though Page 203 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA I I YIN II I/N they would not be required to open during a large break LOCA, and that doing so may provide a flow diversion. To address this concern the BVPS-2 LHSI fluid flow model was reviewed for large LOCAs with and without the mini-flow value opened. It was concluded that the difference in flow delivered to the reactor vessel was less than 75 gpm if the mini-flow valve remained open.

Therefore, this was not determined to be a valid flow diversion path and was not incorporated into the BV2REV3B PRA model. Additionally, while including the mini-flow valve failure to open for large break LOCAs is not required, the Large break LOCA contribution to total CDF is less that 0.1 percent, so it was not considered to be vital to remove it from the BV2REV3A PRA model.

The other Top Event fault trees for systems with mini-flow protected DumDs Page 204 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN were reviewed to ensure that there were no obvious potential for initiator specific success criteria missing form the model. It was found that the Recirculation Spray System Trains C and D also have the same type of mini-flow valve failure modes modeled as the LHSI pumps, so the above justification also applies. All other systems with mini-flow valves were not considered to be dependent on the initiating event.

SY-06 SY-06 B Y Assumptions concerning non-modeled failure As a resolution to this No impact to Fire modes, or support systems due to low PRA Peer Review PRA, because this frequency sequences need to be observation, guidance issue was reconsidered with respect to specific was added to the System addressed in the applications. For example, condenser hotwell Analysis and Overview base PRA model level is assumed to always be adequate due Notebook to include prior to building the to redundancy of sources (i.e., via steam assumptions concerning Fire PRA.

dumps, or makeup); however, some of these non-modeled failure sources may not be available during online modes, or support T/M. systems.

Also many of these done when the CDF was in the 2E-4 range. Now that CDF is in 8E-6 range many of these items may no longer be insignificant in the current model.

SY-16 SY-13 B Y The sequence modeling credits RWST refill An evaluation was No impact to Fire I II _Ifor LOCA's and SGTR. The RAW worths of performed using the PRA, because this Page 205 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I_ I YIN I II the split fractions indicate that without RWST, BVPS Unit 2 Cycle 10 issue was CDF would be 3.8E-5. RWST refill is modeled core design analysis determined to in split fractions WM and MU. (WCAP-15779, Rev. 0) have no effect on boron requirements for the BVPS PRA The minimum make up rate is 150 gpm. The shutdown (k=0.99) at model.

actual makeup rate [if this procedure was beginning of life and hot used] may be up to 400 gpm. The initial water zero power as the source for RWST refill is the boric acid minimum required boron blenders. This system has a 7,000 gallon concentration to prevent tank at 7,000 ppm boron. This system does recriticality. The results not have sufficient volume nor flow rate to of this evaluation match the times and volumes needed for safe determined that the boron shutdown in the sequences modeled. The concentration delivered to ultimate source of water is unborated river the RCS would be above water. To provide enough input to the RWST, the minimum required to the flow path is into the Fuel Pool and then maintain subcriticality for from the fuel pool to the RWST. the entire 24-hour mission time, when using The Miscellaneous Notebook documentation unborated water for states "The current BV2REV3A PRA model makeup to the RWST at assumes that 400 gpm is required for the flowrates determined makeup to the RWST during the entire in the MAAP LOCA mission time." Boron dilution of the fuel pool success criteria analyses.

is calculated, but not boron dilution of the Additional operator core. The observation is that if unborated actions to add boron to water was used to make-up for the times the RWST via the spent required, boron dilution could occur in the fuel pool, to increase the core, thus negating the RWST make up shutdown margin, could function. Due to the fact that RWST cause be implemented, but were significant core damage reduction, the ability not credited in the PRA to use RWST make-up should have a more model. The BV2REV3B substantial analytical basis. PRA model was not changed as a result of this This observation is worse for unit 2 than unit observation.

1, because of the smaller RWST volume. The Page 206 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impactto Fire ID Requirement' Level Closed PRA I

_ I IYIN I minimum core boron concentration for hot A precaution was also zero power at BOL is 771 ppm. For most of added to BVPS-2 OM the sequences where RWST make-up is Procedure 20M-7.4.O used, the reactor is assumed to be "Makeup To The depressurized and cooled down [LOCA's and Refueling Water Storage SGTR]. For the purpose of this F&O, it is Tank," that if a significant assumed necessary to maintain a 1500 ppm volume of river water is boron concentration. The RWST switchover added to the Spent Fuel is 140,000 gallons for unit 1 and 360,000 Pool, boric acid addition to gallons for unit 2. Times to boron dilution (in the Spent Fuel Pool may the RWST) is shown below: be required to maintain adequate shutdown Unit 1 dilution to 771 ppm at 150 gpm = 15h margin.

Unit 1 dilution to 771 ppm at 400 gpm = 5h Unit 1 dilution to 1500 ppm at 150 gpm = 4.5h Unit 1 dilution to 1500 ppm at 400 gpm = 1.7h Unit 2 dilution to 771 ppm at 150 gpm = 38 h Unit 2 dilution to 771 ppm at 400 gpm = 14h Unit 2 dilution to 1500 ppm at 150 gpm =

11.5h Unit 2 dilution to 1500 ppm at 400 gpm = 4.3h Only one of these conditions can meet a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months mission time.

Considering that RWST make-up is used to lower CDF and LERF to the extent it does, the technical basis should be stronger. The calculation must match the conditions of the sequences for which it is used, must use a representative flow rate, and must consider the uncertainties in the inputs and the outcome.

SY-17 SY-21 B Y Service Water success criteria appears to The Service Water No impact to Fire have no supporting analysis as to 1 service System Design Basis PRA, because this Page 207 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN water cooling pump could provide sufficient Document provides the issue was flow. Additionally, there appears to be some basis for one pump addressed in the HEP for some manual operator action to start operation to meet the base PRA model standby pumps under some circumstances. single failure criterion and prior to building the No success criteria for the time available for still provide adequate Fire PRA.

these actions was found. station cooling under accident conditions.

Table 3-1 of the Human Reliability Analysis PRA Notebook gives a summary description of the Service Water human actions analyzed in this study. Also provided in this table are the time windows that are available to the operators in the performance of the task described along with the basis for the timing.

TH-02 TH-08 B Y The Beaver Valley Unit 2 Ventilation and The Unit 2 Ventilation and No impact to Fire Room Cooling Analysis Notebook Table 7 Room Cooling Analysis PRA, because this lists that for item 10, Control Building, Notebook only looked at a issue was Operators add portable fans; not included in loss of ventilation in the determined to risk model. It appears from Figure A-9 Unit 2 side of the Control have no effect on "Temperature as a Function of Time in Building. In reality, the the BVPS PRA Control Room with No Ventilation-Fan Added Unit 1 and Unit 2 Control model.

in 10 Minutes," that without the addition of the Rooms are located within fans the temperature in the Main Control the same building Room would impact instrument qualification, separated by a partial wall Though this appears to be an important (there is no wall above the operator action that justified not adding MCR "egg crate" ceiling), so a HVAC to the model, there is no operator loss of ventilation at one action to add fans for MCR cooling within 10 unit will not result in the Page 208 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I I_Y/N I I minutes. total loss of ventilation to the common Control Additional investigation into the MCR heatup Building. As resolution to calculation 12241-US(B)-21 1 revealed that this observation, a two different values were used for the MCR separate calculation heat load. Page C-4 uses a MCR heatup (8700-DMC-3467, Rev. 1) value of 156,861 BTU/hr (-46000W) and was reviewed, which was page IPE-4 uses 74665W. The trend shown previously performed in on Figure C-3 is the more expected MCR response to an Appendix room heatup, rather than the temperature R Unit 1 Control Room spike seen on IPE-9. Ventilation fire. This calculation combined the Control Room volumes and heat loads, and took credit for the Unit 2 HVAC to cool both Control Room areas. While it was noted that this calculation was performed assuming a loss of Unit 1 HVAC it was determined to be applicable to a loss of Unit 2 HVAC as well, since the HVAC flow rate were similar at each unit. The results of this analysis concluded that during a loss of ventilation at one Unit, the Control Building temperature would remain below the Equipment Qualification limits during a 24-hour mission time, even without setting up portable ventilation fans.

Page 209 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID RequirementI Level Closed PRA YIN This analysis assumed a homogenous mixture of air existed between the Control Rooms, so itwas assumed that the operators would open the common doors between the Control Rooms to aid in cooling. This action was assumed to be a guaranteed success in the PRA model, since both Control Rooms are continuously manned and human nature would drive the operators to do so after they begin to feel uncomfortable. It was determined that this observation did not impact the PRA model, so the recommend changes were not incorporated into the BV2REV3B PRA model.

AS-01 AS-12 C Y Beaver Valley is using a modified version of As a resolution to this No impact to Fire the WOG 2000 seal LOCA model, which is PRA Peer Review PRA, because this derived from the BNL "best estimate" model, observation, sensitivity issue was with Beaver Valley specific MAAP runs for analyses were performed addressed in the time to core uncovery. The time of the start of on the BVPS Unit 1 MAAP base PRA model excessive leakage is 30 minutes in this RCP seal LOCA cases to prior to building the model. The NRC has not accepted this from investigate the impact of Fire PRA.

licensing submittals. Since Beaver Valley is varying the timing of the planning some extensive AOT submittals in increased RCP seal the future, this will have to be addressed. leakage from 30 to 13 Page 210 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN I minutes on the resultant time to core damage. The conclusion from these sensitivities was that the change in onset of the increased RCP seal LOCA leakage from 30 minutes to the minimum time of 13 minutes would not lead to significantly earlier times to core damage. Since the BVPS RCP Seal LOCA models are comparable between Unit 1 and Unit 2, it was concluded that there would be similar insignificant core damage timing impacts at Unit 2.

Therefore, it was concluded that the time to core damage provided in Attachment A, Appendix E, of this notebook for the RCP seal LOCA sequences is sufficient for use in the electric power recovery models.

The e-mail from Fauske &

Associates to FENOC transmitting the results of these BVPS-1 MAAP SBO sensitivity runs is provided in Appendix E of A .1. U .1. _________________________________________________________________________________________

-. J Page 211 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN the BVPS-2 Electric Power Recovery Analysis PRA Notebook.

Ultimately resolved based on WCAP-1 5603, Rev. 1-A, NRC Approved, May 2003, Seal LOCA start time is 13 min.

AS-04 AS-07 C Y AMSAC is a mitigation system that only In response to this PRA No impact to Fire appears in the ATWS tree. Actually AMSAC Peer Review observation, PRA, because this is a redundant start of AFW and turbine trip the GENTRANS Event issue was that is useful in mitigation even when SSPS Tree (see Figure D-4a) addressed in the has failed but the reactor trip has been was modified to include base PRA model successful. Additionally AMSAC is only model Top Event PL (Power prior to building the as a system point estimate of 1E-2 (see F&O Level <40 %)and Top Fire PRA.

SY-20). This could affect/reduce the Event AS (ATWS system/equipment importance of SSPS, AFW Mitigating System and Turbine Trip Actuation Circuitry) before asking Auxiliary Feedwater in Top Event AF. The split fraction logic rules and macros were also modified to credit the use of AMSAC for providing a diverse method of starting the AFW pumps (see Tables 3.4-3 &3.4-4). Section 3.4 "General Transient/Small LOCA Event Trees" and Tables 3.4-1 and 3.4-2 were also revised to account for I these new top events in Page 212 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA

_ _ __ _ __ _ _ __ ___ _ YN_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

I the GENTRANS Event Tree.

I Y/N With respect to the AMSAC top event being quantified using a point estimate value instead of a fault tree analysis, it was not deemed necessary to pursue a detailed fault tree analysis at this time.

The point estimate value of 1.OE-02/demand used in the BVPS PRA models is taken from WCAP -

11993 (Reference 1) and is conservative with respect to unavailabilities of a one signal train and the design criteria applied to AMSAC by the Westinghouse Owner's Group. Additionally, the more recent WCAP-15831-P (Reference 14) also uses this point estimate value, as has other studies, as an appropriate value to use.

A detailed fault tree would probably result in a lower AMSAC unavailability value, but this is not expected to have a siqnificant imDact on the Page 213 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN core damage frequency, due to the already low significance of SSPS failures in non-ATWS

_sequences. I AS-09 AS-18 C Y The SGTR event tree assumes that the The concerns of this PRA No impact to Fire actuation of PORVs (should be PORV due to Peer Review observation PRA, because this definition of B&F success criteria) will result in are unfounded, since the issue was the CIB (8 psig) actuation. A review of the timing of the CIB initiation determined to MAAP runs (Success Criteria, Attachment A, following bleed-and-feed have no effect on Appendix F, Table 3) indicates that CIB scenarios during a SGTR the BVPS PRA occurs for cases in which OB (B&F) is will not impact the NPSH model.

successful for cases in which AFW is failed of the HHSI pumps. This and it occurs in approximately 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The CA was dispositioned by QSS is assumed to be actuated given the examining the MAAP CIB signal. The water injected to the SGTR accident sequence containment sump is necessary for NPSH summary files as success. It isn't clear what will happen in the summarized below:

case that CIB does not occur until 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months into the scenario and what effect this may For the SGTR cases with have on the NPSH concerns. a loss of secondary cooling, the HHSI pumps will initially be taking suction from the RWST, either due to an SI signal being generated or to the bleed-and-feed initiation.

After about 6 minutes following the initiating of bleed-and-feed, the containment sump would begin to fill when the PRT rupture disc blows.

During this time there will I _______________ .1. _____________ ________ _____________________________________________ a be RCS mass and energy Page 214 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA I _I_ YIN I I released inside of the containment from the open PORVs, which will slowly start to increase the containment pressure and also be providing inventory directly into the containment sump.

After approximately 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months a CIB occurs, and QSS will start and also begin to add RWST inventory into the sump, so that when the RSS pumps start about 10 minutes later there should be sufficient inventory in the sump to provide adequate NPSH to the RSS pumps. However, if a sufficient amount of water is not collected in the containment sump after this time, the recirculating spray pumps must be manually turned off and then turned back on when NPSH is sufficient. Operator actions to first turn off and then to turn on the RSS pumps are modeled in Top Events SM and OR.

I I .1.

Success of these actions Page 215 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA

_ _ YIN __I I ensures that the RSS pumps will be available when the RWST reaches the low-level setpoint and SI Recirculation is initiated. At this time the HHSI pumps would be piggybacked onto the RSS pumps, and adequate NPSH would be provided.

Prior to this CIB signal being generated, the QSS and RSS will not start.

However, the HHSI pumps will continue to take suction from the RWST until the low level SI Recirculation setpoint is reached. At this time even without a CIB initiation, approximately 350,000 gallons of RWST water would have been directed into the containment sump though the opened PORVs, so that when the HHSI pumps are piggybacked onto the RSS pumps, adequate NPSH would also be provided.

DA-03 DA-03 C Y The documentation of the CCF MGL The resolution to this F&O No impact to Fire parameters is presented in Appendix C of the] was to put highlighted PRA, because this Page 216 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN Data Analysis Notebook. The final shading and bold text in issue was compilation of the MGL parameters is Table C-6 of the BVPS addressed in the presented in Table C-6. The results are Unit 2 Data Analysis PRA base PRA model presented as "Plant-Specific" distributions, Notebook for the MGL prior to building the but this table is in fact a mix of parameters distributions that were Fire PRA.

developed based on plant specific event developed based on a screening, in some cases Bayesian updating, plant specific analysis, so and in other cases generic data. With some that they are more easily difficulty, the reviewer could trace back identified. This table was through the documentation to determine the also renamed to Table C-actual source of the MGL parameter, but a 6 Beaver Valley Unit 2 -

naming convention that identifies the Common Cause MGL parameter as plant specific, or generic would Distributions, so that it be helpful. As a minimum, generic data could does not imply that all the be presented in a separate table from the MGL distributions are parameters generated based on plant specific plant-specific.

analysis.

DA-04 DA-05 C Y The data notebook describes several sources F&O DA-04 was originally No impact to Fire for the generic component failure distributions assigned as a "B"Level of PRA, because this for the BV Unit 2 model. Column 6 provides Significance in the draft issue was the disposition of the 6 sources of WOG PRA Peer Review addressed in the information. Item f- 994 STP data was used Report, but was base PRA model to derive the failure rate distribution for the downgraded to a "C" in prior to building the automatic recirculation check valve failure to the final report. This Fire PRA.

open and was cloned from ZTVCOS using observation was resolved PLG generic check valve database by adding discussions to distributions. Then the data from STP of 0 in Section 3.5.F "1994 STP 704 demands was used. It is not clear what Data" of the BVPS-2 Data this database variable was used for and if itis Analysis PRA Notebook currently being used. The discussion does as to why and how the not indicate why was no information used database variable for the from the BV plant history in this update automatic recirculation process. check valve failure to open (ZTVARD) was I developed, as well as an Page 217 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN explanation as to why there wasn't any plant specific data included in the update. _

DA-05 DA-03 C Y Table C-6 lists the Beta factor for battery This PRA Peer Review No impact to Fire failure fails to operate (ZBBCHR) as a point observation was PRA, because this estimate of 1.26E-2. The source of this value dispositioned during the issue was is not documented in the Data Analysis resolution of F&O DA-06 addressed in the Notebook. A review of the EP System (CA 02-09042-12). base PRA model Notebook found a reference to this value in Although, Appendix C prior to building the an assumption, stating that the value was does not specifically list Fire PRA.

taken from NUREG/CR-5497. Appendix C of the source document the Data Analysis Notebook should be self references, they are contained with respect to the source of the specifically identified in generic MGL. Appendix C does not Section 3.6 "Calculation of reference NUREG/CR-5497. Are all other Common Cause Factors,"

generic parameters actually from the PLG and are included in database or are other sources used? Is this Section 5 "References" in the only value taken from 5497? What was the Data Analysis PRA the basis for using one selected value from Notebook. Section 3.6 5497? also provides the basis for using common cause data sources other than the PLG common cause database.

DA-1 1 DA-05 C Y A statement needs to be made in the This PRA Peer Review No impact to Fire assumptions to describe the method of observation was PRA, because this assembling the data. The write-up implies dispositioned by adding a issue was that only unit 2 data is included in the tables discussion in Section 3.3 addressed in the but there appears that some unit 1 pumps "Presentation of Plant- base PRA model may have been included. If this is the case, Specific Data" of the Data prior to building the then the text needs to explain that Unit 2 Analysis PRA Notebook to Fire PRA.

equipment is included and only the Unit 1 identify what Unit 1 equipment that may be needed to shutdown equipment is included in Unit 2 is included, the development of the Page 218 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN Unit 2 database distributions or test and maintenance unavailabilities.

DE-02 DE-04 C Y In a limited review of the dependency Most of the concerns of No impact to Fire matrices in Appendix B of the Event Tree this PRA Peer Review PRA, because this Analysis Notebook, it appears that some observation are issue was items maybe missing. unfounded, and are addressed in the attributed to a lack of base PRA model

- There appeared to be no dependencies understanding of how to prior to building the listed for instrument AC inverters 2-3 and 2-4, read the matrices. For Fire PRA.

but it was later noticed that that was covered example, sheet 2 of Table by a footnote in the AC section (2-1 & 2-2 had B-2 "Support-to-Frontline the footnote in both places). System Dependency Table" does list Note 30

- Note 33 does not state the DC power for for the DC dependencies.

RTB shunt coil "B". Likewise, sheet 1 of Table B-1 "Support-to-Support

- No DC power for containment isolation System Dependency valves was listed. Table" identifies vital bus III and vital bus IV as

- No AC dependencies for AC power for failing AMSAC.

instrument AC were identified. Additionally, sheet 2 of Table B-1 lists Note 43 for

- There are no dependencies shown for the AMSAC DC AMSAC, but that maybe appropriate for the dependencies.

level of detail of AMSAC modeling.

However, as the Team observed, Note 33 of Table B-1 "Support-to-Support System Dependency Table" did not state the DC power for RTB "B" shunt coil, so this note was revised to Page 219 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN address this oversight.

Also, Notes 4 and 5 were added to Table B-1 vital bus III and vital bus IV matrices to clarify their DC dependencies, while these same notes already identified the AC dependencies.

DE-03 DE-1 1 C Y The flooding analysis and the IPE state Since the documentation No impact to Fire (briefly) that a plant walkdown was for the flooding walkdown PRA. This F&O performed. But there is no documentation of that was performed as was resolved in the walkdown, or the insights gained from the part of the IPE could not the submitted walkdown, available for review. The be located, the walkdown BVPS-2 Fire PRA walkdown "notebook" would be a valuable that was completed for the model, which used resource for analyst in future updates of the Beaver Valley Unit 2 Risk- BV2REV5A as its PRA. Informed In-Service basis.

Inspection (RI-ISI) Indirect (Spatial) Consequence Evaluation was credited, as discussed in the response to F&O DE-04 above. Since this RI-ISI walkdown is documented in a BVPS calculation and is retrievable, it is not deemed necessary to reproduce it for the PRA notebooks.

This F&O was written against an obsolete Internal Flooding PRA model (BV2REV3A) and is considered to be Page 220 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN resolved by the updated Internal Flooding PRA model incorporated in BV2REV5A, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group.

The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

DE-06 SY C Y Some of the flood frequencies are based on a This F&O was written No impact to Fire document (PLG-0624) that is dated 1988. against an obsolete PRA. This F&O The next update should include consideration Internal Flooding PRA was resolved in of more recent flood data sources. model (BV2REV3A) and the submitted is considered to be BVPS-2 Fire PRA resolved by the updated model, which used Internal Flooding PRA BV2REV5A as its model incorporated in basis.

BV2REV5A, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group.

The F&Os as a result from this focused Peer Review, as well as their resolutions Page 221 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA Y/N are presented in Table 2-4.

DE-07 SY C Y The PRA documentation should include a This F&O was written No impact to Fire discussion of the potential impact of floods on against an obsolete PRA. This F&O systems that are shared between the two Internal Flooding PRA was resolved in units. Although this impact is expected to be model (BV2REV3A) and the submitted minimal, one example is the potential impact is considered to be BVPS-2 Fire PRA on the electric power crosstie to Unit 1 resolved by the updated model, which used availability due to floods in the service water Internal Flooding PRA BV2REV5A as its intake structure. Is the Unit 1 diesel model incorporated in basis.

dependence on service water correctly BV2REV5A, which accounted for when the flood impacts the underwent a focused Peer availability of the Unit 1 service water Review in accordance system? with the guidance in Appendix B of NRC RG 1.200, Rev. 1, conducted during June 6-9 2011, by the PWR Owners Group.

The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

HR-02 HR-06 C Y A generic error of omission term from the This F&O was written No impact to Fire PLG database (ZHEO1A) was used for all against an obsolete HRA PRA, because this misalignment HEPs without regard for PRA model (BV2REV3B) issue was procedural or operational failure barriers such and is considered to be addressed in the as independent verification, peer checks, resolved by the updated base PRA model walkdowns, etc. However, plant specific data HRA PRA model prior to building the was used for test and maintenance incorporated in BV2REV4, Fire PRA.

frequencies. Therefore, the overall which underwent a misalignment errors were a hybrid of generic focused Peer Review in and plant specific data. This was used for accordance with the systems which are important to CDF (e.g., guidance in Appendix B of AF, SI). NRC RG 1.200, Rev.1, Page 222 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

HR-10 HR-18 C Y The number of operators interviewed for the This PRA Peer Review No impact to Fire performance shaping factors was stated to be observation was PRA, because this 3 operators, 3 training staff and 3 PRA staff. dispositioned by issue was This is a low number of operators for the acknowledging that, while addressed in the FLIM method to succeed. Having the PRA technically only 3 base PRA model staff fill out the PSF forms dilutes the operator operators were prior to building the input to the process. interviewed, the training Fire PRA.

staff personnel were former operators that still held a senior reactor operator's license at the time of the interview.

Therefore, a total of six licensed personnel were used in developing the PSFs. Additionally, as a final resolution to this observation, future BVPS PRA models will use the EPRI HRA Calculator, which uses a more current and robust methodology to identify human action dependencies.

This F&O was written I Page 223 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN against an obsolete HRA PRA model (BV2REV3B) and is considered to be resolved by the updated HRA PRA model incorporated in BV2REV4, which underwent a focused Peer Review in accordance with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during the week of October 29, 2007, by Westinghouse. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 1-3.

IE-01 IE-04 C Y In section 3.3 of the Initiating Events In response to this No impact to Fire Notebook, there is a discussion about the observation, Section 3.3 PRA, because this justification for the exclusion of Random RCP of the Initiating Events issue was Seal LOCAs as a separate IE that is based Analysis PRA Notebook addressed in the on the RCP floating ring seals and the was revised to add further base PRA model assumption of limited leak flow. The clarification based on the prior to building the justification provided to account for assuming floating ring seals (per Fire PRA.

this is a discussion by FENOC with Reference 15) as to why Westinghouse. No documentation of this random RCP seal LOCAs discussion is provided and no further were eliminated from the technical justification is given as to why Beaver Valley PRA random seal failure should have the model. Additionally, this frequency and be included in Category Section was revised to G1I/QG9 under RTRIP. provide justification as to why a random RCP seal I failure at Beaver Valley Page 224 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN that resulted in a reactor trip would be captured under the RTRIP initiating event frequency.

IE-02 IE-13 C Y In the discussion of the process used for In response to this No impact to Fire Initiating Event frequency update, BWR data observation, Section 2.3 PRA, because this and other NSSS vendor PWRs are excluded of the Initiating Events issue was from the update without sufficient Analysis PRA Notebook addressed in the documentation. was revised to provide a base PRA model brief explanation for why prior to building the BWR and other PWR Fire PRA.

NSSS vendor data were excluded from the BVPS initiating event frequency update.

IE-03 IE-10 C Y The Support System Faults that are used as In response to this No impact to Fire Initiating Events are assigned a Code observation Tables Al PRA, because this Designator. The System Codes and Top and A9 in the Initiating issue was Events for these designators are not Events Analysis PRA addressed in the explained. The System Notebook does not Notebook were revised to base PRA model clearly explain how the System is considered include a cross-reference prior to building the to cause an Initiating Event in the Model. from the initiating event Fire PRA.

"Code Designator" to the applicable PRA System Notebook. In addition, Table A2 of this notebook provides a failure modes and effects analysis of the key BVPS Unit 2 support systems and why they were considered for initiating events, so it was not judged to be necessary to duplicate this information in the Page 225 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions on System Notebooks. It was not the intent of the PRA System Notebooks to be stand-alone documents, but rather to be supplemented by the PRA analysis notebooks. 4-Plant trip trends in the recent years are In response to this No impact to Fire showing a general decrease in trips/year. A observation, Figure 3-1 PRA, because this simple trend analysis (like a histogram) was generated to present issue was showing number of trips versus years for a plan trip trend histogram addressed in the each unit should be considered as a and Section 3.2 of the base PRA model subsection in the initiating events section. Initiating Events PRA prior to building the This would possibly allow better estimation of Notebook was revised to Fire PRA.

plant specific transient event frequency. include a discussion of the Currently, there appears to be no analysis to plant trip trend analysis show whether there is a positive or negative performed for BVPS Unit trend (or a lack of it). Also, a trend analysis 2.

fits well with the concept of plant-specific nature of analysis in question.

For example, consider a plant with 10 years of trip data; the first 5 years each have 5 trips/year; the last 5 years have 1 trip per year. This would result in an average of 3 events per year over a ten-year period. Now consider another plant where the two numbers are interchanged; it has 1 event per year for the first five years and 5 events per year for the next five years. The overall average is still 3 events per year. In both cases, there are definite trends; the first plant should actually use a frequency of 1 trip per year; the second plant should use 5 trips per year. In any case, neither plant should use 3 Page 226 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impactto Fire ID Requirement' Level Closed PRA YIN

__ trips per year.

IE-07 IE-03 C Y There was not enough information in the In response to this No impact to Fire initiating event report to reproduce the observation, Table Al 1 PRA, because this results. was generated in issue was Appendix A of the addressed in the

1. The prior distributions were not available. Initiating Events Analysis base PRA model PRA Notebook to show prior to building the

2. the screening of the WCAP IE report was the set of input data used Fire PRA.

not available in the creation of each first stage (prior) distribution

3. The derivation of prior means was not identified in Table A4, as available. well as, the resultant RISKMAN distribution parameters for the mean, median, 5th and the 95th percentiles. This data was input into the RISKMAN Data Module, using the "First Stage of Two Stage" distribution option to create the resultant prior distributions. The derivation of how RISKMAN generates these prior distributions using this option is contained in the RISKMAN Software Users Manual, and does not need to be reproduced in this notebook.

Additionally, there was no screening of the Westinqhouse WCAP-Page 227 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA Y/N 15210 initiating event data, since each individual utility performed a through review of their plant's trip events to ensure that the data was valid.

L2-02 1-2-08 C Y Most containment phenomena are either Ultimately resolved by No impact to Fire excluded via generic, or plant specific GAP F&O LE-F2-01 (see PRA, because this analyses, or are modeled as a point estimate. Table 2-2). issue was Other issues such as whether the addressed in the containment is inerted are more directly base PRA model quantified. For example, the L1/L2 interface prior to building the directly quantifies those end states when the Fire PRA.

sprays are operating; operation of the sprays is considered to de-inert containment.

L2-04 L2-21 C Y Top Event 10 - Containment Failure Prior to Ultimately resolved by No impact to Fire Vessel Breach (Cl) states that because the GAP F&O LE-D6-01 (see PRA, because this Beaver Valley Unit 2 containment normally Table 2-2). issue was operates at subatmospheric conditions, the addressed in the existence of large pre-existing leaks is base PRA model believed to be negligible. Current L2 analysis prior to building the would not support containment conversion Fire PRA.

application MU-01 MU-04 C Y Plant changes that may impact the PRA Ultimately resolved by No impact to Fire model are documented, and resolved via Risk procedure NOBP-CC- PRA, because this Evaluation Review (RER) forms. Continuing 6001 and Design issue was training is used to educate engineering Interface Evaluation (DIE) addressed in the (includes procedure writers) on when an RER process that evaluates base PRA model is required vs. direct procedural guidance. changes for PRA impact. prior to building the The update process could be improved by Fire PRA.

adding a similar review process into other I_ I plant change procedures.

MU-03 MU-1 1 C Y When the PRA model is updated for plant Ultimately resolved by No impact to Fire modifications or for decreases in CDF all procedure NOBP-CC- PRA, because this areas of applications should be evaluated. 6001, Section 7 lists RI- issue was Page 228 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN Certain applications can be adversely applications that need addressed in the impacted by decreases in CDF. For updated following a new base PRA model example, credit taken for examining ERM (Effective Reference prior to building the segments in a RI-ISI program could decrease Model). Fire PRA.

with a decrease in CDF (or even an unrelated CDF increase, depending on changes to the risk profile.)

Additionally more than just the change in CDF needs to be evaluated. The risk profile may change drastically without a corresponding change in the CDF. For example CDF due to one IE may go up by 30% in conjunction with another change in CDF due to a different IE decreasing by 25%.

This would cause only a 5% change in CDF but significant changes to the risk profile.

QU-01 QU-07 C Y PRA Peer Review Subtier Criteria for this As resolution to this PRA No impact to Fire sub-element describes the need for Peer Review observation PRA, because this documentation of the limitations of simplified it should be noted that the issue was models. This documentation could not be RISKMAN model is used determined to found for Beaver Valley Unit 2. for purposes for risk have no effect on sensitivities (e.g., SDP the BVPS PRA findings) and risk- model.

informed applications (e.g., BVPS-2 SSPS Slave Relay STI Extension), as such, there are no simplified model used for these purposes and hence nothing to document. Additionally, the intent of the PRA Notebooks was to document the I Page 229 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN development process and results of the RISKMAN PRA model, not to document the Safety Monitor model or its process that currently uses pre-solved sequence, or to document other risk-informed sensitivities and programs. Moreover, future versions of the Safety Monitor for RISKMAN users are to incorporate a full requantification of the sequences in place of pre-solved sequences.

QU-05 QU-23 C Y RISKMAN allows the user to apply a cutoff at This truncation problem is No impact to Fire the system (i.e., top event) level. This cutoff expected to go away PRA, because this is applied prior to the event tree when BVPS updates the issue was quantification. In general, no truncation (i.e., PRA software with the addressed in the a value of 0) is used in the systems cutset RISKMAN version that base PRA model generation. But non-zero values are used for contains binary decision prior to building the a handful of top events. Of these most use diagrams (BDD). The Fire PRA.

very low cutoffs (<1E-12). The one exception BDD software has the to this (as best this reviewer could determine) ability to solve fault trees is the quantification of Top Event WC where a without using cutsets, so cutoff of 5E-7 was used. Top Event WC is an that no truncation values intermediate top used to quantify Top Event are necessary. Therefore, WA and WB. Split Fraction WC1 has an including additional unavailability of about 3E-9. discussions on this topic would not be of any value The SW system notebook discusses the to analysts in future I system level cutoff and when it is used. updates using the BODD I Page 230 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement1 Level Closed PRA YIN However, the potential quantitative impacts methodology.

associated with the truncated results are not discussed. Ultimately resolved by quantifying the split fractions using the BDD methodology, starting with the revision 4 PRA model.

SY-04 SY-27 C Y It would be desirable to reference the Ultimately resolved in No impact to Fire success criteria source in the system Revision 5 PRA model PRA, because this notebook. Success criteria are specified in System Notebooks, issue was the "Success Criteria" notebook, and the Section 3 "SYSTEM addressed in the reviewers found it difficult to flip from one SUCCESS CRITERIA" base PRA model source to another, especially when using the prior to building the electronic documentation CD. Fire PRA.

SY-05 SY-12 C Y The system notebooks do not specifically Ultimately resolved in No impact to Fire discuss the dependencies that may be Revision 5 PRA model PRA, because this present regarding HVAC / room cooling. System Notebooks, issue was However, review of the HVAC notebook Section 4 "SUPPORT addressed in the identified the various spatial locations that SYSTEMS" base PRA model may require HVAC and indicated the various prior to building the analyses that have been completed to either Fire PRA.

require HVAC dependencies or not.

SY-07 SY-26 C Y The Beaver Valley Unit 2 system notebooks Ultimately resolved by No impact to Fire have no indication of system engineering GAP F&O F&O SY-C1-02 PRA, because this reviews. These reviews help ensure that (see Table 2-2). issue was systems are model in accordance with day- addressed in the to-day plant operations and additionally base PRA model expand the PRA knowledge of the system prior to building the engineers. Fire PRA.

SY-08 SY-01 C Y The guidance did not provide for more Boundary conditions were No impact to Fire complete description of the actual boundary developed using the PRA, because this conditions used in the system analysis. It did dependency matrices, issue was talk about support, but the actual details are which are located in addressed in the not required (i.e. what AC bus is needed for Appendix B of the Level 1 base PRA model which pump for that boundary condition for Event Tree Analysis PRA prior to building the Page 231 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN the split fraction). As a result most of the Notebook. Fire PRA.

notebooks do not give a good description of what each split fraction means and its usage.

The only place this appears to be actually documented is the description on the split fraction in the RISKMAN split fraction.

SY-09 (sic SY-14) C Y System Diagrams contained in System Each System Notebook No impact to Fire Notebooks do not have explanation of color has had a note added PRA, because this highlighting. Figures are difficult to read and prior to the links for the issue was many component lDs are not legible. System drawings. This addressed in the note explains the color base PRA model There also does not appear to be a scheme used on the prior to building the discussion of 'Operating experience for the drawings. Some parts of Fire PRA.

system' required in the guidance document. some of the drawings are difficult to read, but using the zoom function does make it easier to read most of the smaller print.

This is a limitation of the scanner used for this project. In all notebooks however, the drawing number is very easy to read, making retrieval of a larger and more legible drawing very easy. This is a Level 'C' F&O and is considered as a recommendation. The actions defined here are considered appropriate for closure of this F&O.

Operating experience for the system is subsumed Page 232 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN in the system engineer's review.

SY-10 (sic SY-14) C Y The Fault Trees for IA, IC have Transfer Resolved in Revision 5 No impact to Fire Gates and page numbering that is confusing. PRA models that have PRA, because this IA page 6 transfers to page 7 but page 7 top Fault Trees redrawn so issue was gate transfers to age 1. In IC, page 1 is a Top Gate is on page 1. addressed in the transfer from page 5 which is the Top Event base PRA model IC. This is confusing and is easily fixed. NOTE: The BV2REV5A prior to building the FTs are not organized due Fire PRA. Also, to the addition of NFPA this is a 805 basic events, documentation-only issue.

SY-12 SY-17 C Y The Service cooling water system notebook Ultimately resolved by No impact to Fire assumption #7 has 10 minutes to trip the GAP F&O F&O SY-B7-01 PRA, because this RCP's on loss of cooling. However, in the (see Table 2-2). issue was Miscellaneous system notebook, top event addressed in the OC has 5 minutes to trip the RCP's. Note, base PRA model this time might be important in quantifying an prior to building the HEP. Fire PRA.

SY-1 3 SY-1 3 C Y Several systems appeared to be modeled as The AFW pump macros No impact to Fire point estimate only, AMSAC and the were revised in the PRA, because this Switchyard. This is acceptable, per the peer BV2REV3B PRA model to issue was review guidance, but consideration could be include credit for AMSAC addressed in the given to adding some detail to these models. to start the AFW pumps base PRA model (in addition to the SSPS prior to building the signal), given that the Fire PRA.

signal is generated during non-ATWS events.

The Switchyard (Top Event OG) was modeled as a single basic event.

However, it used a lognormal distribution to quantify Monte Carlo Page 233 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN values in addition to the point estimate value.

Furthermore, the PRA model already addressed transient induced LOSP events due to failures of the USST/SSST and Switchyard breakers in the normal bus top events.

The current methods to address the AMSAC and Switchyard failure probabilities are deemed acceptable as is.

SY-15 SY-10 C Y HVAC support analysis appears to only As a resolution to this No impact to Fire consider 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months versus 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The PRA Peer Review PRA, because this analysis was extended to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months based observation Table 6 in the issue was upon the fact that the curves were essentially Ventilation and Room addressed in the flat after 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Some of the curves are Cooling Analysis PRA base PRA model straight and increasing and not flat and Notebook was revised to prior to building the constant. show the expected area Fire PRA.

temperature at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months following the loss of ventilation. Areas that exceed their EQ temperature limits are discussed in the Section 6 and Appendix A of this notebook.

The success criteria for top event "T is Ultimately resolved in No impact to Fire missing from Table 3.3-2 of the Event Tree Revision 5 PRA model PRA, because this Notebook although it is described on page 58 Level 1 Accident issue was of the notebook. Sequence Analysis addressed in the Page 234 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement 1 Level Closed PRA YIN Notebooks, Table 3.3-2 & base PRA model Table 3.4-2. prior to building the Fire PRA.

AS-06 AS-1 7 D Y The success criteria for top event NM is Top Event NM is a switch No impact to Fire missing from Table 3.3-6 of the Event Tree to query if early core PRA, because this Notebook although it is described on page 67 damage has occurred issue was of the notebook. during the SI injection addressed in the phase, and does not have base PRA model any success criteria per prior to building the se, so is not included in Fire PRA.

the Success Criteria Tables.

DA-01 DA-19 D Y Appendix B of the Data Analysis Notebook is Ultimately resolved in No impact to Fire titled incorrectly. It includes reference to Revision 5 PRA model PRA, because this "Common Cause Data Sources" in the title, Data Analysis Notebook, issue was but the appendix contains no CCF renamed Appendix B title addressed in the information, base PRA model prior to building the Fire PRA.

DE-01 DE-01 D Y The guidance for including spatial information Ultimately resolved in No impact to Fire in the system notebooks could not be found Revision 5 PRA model PRA, because this in the system notebook guidance document. Systems Analysis issue was However, it appears that most, ifnot all, the Overview and Guidance addressed in the system notebooks did have a section on Notebooks, Section 5 base PRA model spatial considerations for flooding, fire and "SPATIAL prior to building the seismic. CONSIDERATIONS" Fire PRA.

SY-1 1 SY-15 D Y The AC power system calculation notebook, Ultimately resolved in No impact to Fire has top event OG which has a split fraction Revision 5 PRA model PRA, because this for generic loss of power after a plant trip. Data Analysis Notebooks, issue was The basic event report for this was missing Tables A-1 and A-2. addressed in the from the system notebook, but the system base PRA model notebook listed a database variable "OGIX" prior to building the used. This variable could not be found in the Fire PRA.

data notebook. It was in the RISKMAN model with no references from where it came from. I Page 235 of 301

Table 2-1. Summary of BVPS-2 2002 Internal Events PRA Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement' Level Closed PRA YIN It was determined that it came from the PLG-0500 revision 1, 1989.

Page 236 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N IE- IE-A6 B Y There is no documentation of Documentation of interviews with No impact to Fire A6- interviews of plant personnel (e.g., system engineering plant personnel to PRA, because 01 operations, maintenance, determine if potential system this issue was engineering, safety analysis) to descriptions have been overlooked is addressed in the determine if potential initiating located in Unit-2 PRA Notebook (PRA- base PRA model events have been overlooked. This BV2-AL-R05a) Systems Analysis prior to building is required to meet capability Overview and Guidance, Appendix B. the Fire PRA.

category II Credit was taken for the system review in the notebook PRA System Review as a checklist for relevant combinations of events that might have been unnoticed. Review of the initiating events section in the system notebooks was also included as review of the system description by system engineers. Also, review of AOPs (e.g.,

D5X, 20M-53C.4.2.28.1) can be credited. I Page 237 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Require m en t Level Closed PRA Y/N IE- IE-C8 C Y All the relevant combinations of The Initiating Events section of the No impact to Fire C8- events involving the annual system notebooks now contains a PRA, because 01 frequency of one component failure description of the development of the this issue was combined with the unavailability (or support system initiating events. addressed in the failure during the repair time of the Except as noted, the mission time for base PRA model first component) of other normally running equipment is prior to building components are not available in the changed from 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to 8760 hours0.101 days 2.433 hours 0.0145 weeks 0.00333 months the Fire PRA.

support system notebooks. The times the plant availability factor.

support system notebooks list which Portions of the system fault tree logic initiators are developed from the which is not used to quantify support fault trees and provide a diagram of system initiating event frequency is the fault tree, however there is no also noted.

narrative explanation of how these fault trees are modified and what assumptions are used to develop the support system initiator frequencies.

RISKMAN reports, provided as System Notebook appendices, list the details of the system IE models (i.e. cutsets, modified basic event equations, etc.), however there is no discussion of which component failures were considered, what mission time assumptions are used, or description of the development of the system IE models. Therefore it is difficult to determine if all relevant combinations of events have been considered.

IE- IE-C9 B Y Plant-specific information used in the The Recovery Considerations section No impact to Fire C9- assessment and quantification of of the System Notebooks now PRA, because 01 recovery actions included in the documents the operator actions that this issue was support system initiating event were modified in the quantification of addressed in the Page 238 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N analysis is not included in the the system initiating event frequency. base PRA model support system notebooks. Analysis No new recovery actions are credited prior to building of the recovery actions should be in the analysis of initiating event the Fire PRA.

consistent with the applicable frequency.

requirements in the Human Reliability Analysis IE- IE-C10 B Y There is no comparison of the In the Initiating Events Analysis No impact to Fire C1 0- initiating event analysis with generic Notebook, Table A6 demonstrates a PRA, because 01 data sources or explanation of comparison of initiating event this issue was differences to provide a frequencies for the Westinghouse 3- addressed in the reasonableness check of the results. loop PWR. The industrial events are base PRA model from WOG Rev 7 PSA comparison prior to building database. Comparably Beaver Valley 2 the Fire PRA.

to other Westinghouse 3-loop PWR plants has most initiating events frequencies close to order of magnitude. Some differences in plant frequency include MLOCA with a higher frequency than comparable plants by an order of magnitude and interfacing systems LOCA (VSX) with a frequency one magnitude lower than similar plants. MLOCA initiating event frequency has been updated for PRA-BV2-AL-R05a to a new methodology I Page 239 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N based on NUREG-1 829 (April 2008) and lowering the effective break size therefore lowering the frequency. The WOG Rev 7 of other Westinghouse 3-loop PWRs was developed before the methodology of NUREG-1 829 was used. The lower order of magnitude difference for the initiator, VSX, is due to the difference of the amount of valves that are required. For BV 2, an occurrence would require at least three normally closed valves, which isolate the RCS from low pressure piping, to fail in the open position. Whereas, BV 1 would require at least two normally closed valves in this event and a difference of one order of magnitude for the frequency of the initiator. Blank gaps in Table A6 do not have data for 1 that plant from the WOG database. I DA- DA-C4 B Y A clear basis for the identification of Documentation of this is now included No impact to Fire C4- events as failures is not included in in Section 3.3 of the Unit 2 Data PRA, because 01 the Data Analysis Notebook. This Analysis Notebook (PRA-BV2-AL- this issue was basis could be used to distinguish R05a). addressed in the between those degraded states for base PRA model which a failure, as modeled in the prior to building PRA, would have occurred during the Fire PRA.

the mission and those for which a failure would not have occurred (e.g., slow pick-up to rated speed).

-~J. I I Page 240 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN It could not be determined from the Data Analysis Notebook ifany failures were screened out or if the maintenance rule MPFFs are used as the data source.

DA- DA-C5 B Y There is no listing or description in For Beaver Valley Unit 2, repeated No impact to Fire C5- the Data Analysis Notebook of plant specific component failures PRA, because 01 repeated component failures that occurring within a short time interval this issue was were counted as a single failure. were counted as a single failure during addressed in the implementation of the Maintenance base PRA model Repeated component failures Rule. PRA data is taken from prior to building occurring within a short time interval Maintenance Rule sources and the Fire PRA.

should be counted as a single failure therefore meets the requirements of ifthere is a single, repetitive problem the ASME PRA standard."

that causes the failures. In addition only one demand should be counted.

DA- DA-C8 B Y Plant records should be used and Maintenance Rule plant specific No impact to Fire C8- documented to determine the time unavailability data is incorporated into PRA, because 01 that components are configured in the PRA model. Documentation of this this issue was their standby status. This is required can be found in the Presentation of addressed in the to change SR DA-C8 from Capability Plant-Specific Data section of the Data base PRA model Category I to III Analysis notebook under sub-section prior to building Component Maintenance Data and is the Fire PRA.

evidenced by the Prior Maintenance Data of Appendix B."

DA- DA-C10 B Y Decompose failure modes into sub- Component failure modes have been No impact to Fire C10- elements and count handled appropriately to meet this PRA, because 01 demands/failures individually in the Supporting Requirement at the CC-Il this issue was sub-elements. level. Failures of sub-elements of a addressed in the component that are modeled explicitly base PRA model in the PRA are associated with the prior to building sub-element and not the component the Fire PRA.

I__ I_ I_ I Iitself. Documentation of this can be I Page 241 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N found in the Presentation of Plant-Specific Data section of the Data Analysis Notebook (PRA-BV2-AL-R05a) under sub-section Component Failure Event Allocation and is evidenced by the data in Table A-1.

HR- HR-B1, HR- B Y This F&O is a carry-over from the As outlined in HRA Notebook Section No impact to Fire B1- D2 peer review (F&O HR-2). 2.2, testing and maintenance PRA, because 01 procedures were evaluated to identify this issue was A generic error of omission term potential misalignments. These addressed in the from the PLG database (ZHEO1A) potential misalignments were base PRA model was used for all misalignment HEPs evaluated using the EPRI HRA prior to building without regard for procedural or Calculator 4.1.1 to develop specific the Fire PRA.

operational failure barriers such as HEPs for each potential misalignment independent verification, peer as documented in HRA Notebook checks, walkdowns, etc. However, Table 3.5.

plant specific data was used for test and maintenance frequencies.

Therefore, the overall misalignment errors were a hybrid of generic and plant specific data. This was used for systems which are important to CDF (e.g., Auxiliary Feedwater, Safety Injection).

Page 242 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I HR- HR-D3 B Y While the discussion in the system Procedure quality has been No impact to Fire D3- notebooks (AFW and QS/RS incorporated into human error PRA, because 01 notebooks were reviewed) probability assessments. this issue was references the procedures, no Documentation of this can be found addressed in the documentation of quality of those throughout the HRA Notebook, base PRA model procedures or administrative controls particularly the Dynamic Actions prior to building was found. section and tables of Section 3. the Fire PRA.

HR- HR-12 B Y The BV HRA does document a Section 2.3 of the Unit 2 HRA No impact to Fire 12- process to perform a systematic notebook (PRA-BV2-AL-R05a) has PRA, because 01 search for dependent human actions been created to document that PRA this issue was credited on individual sequences. It Analysis No. PRA-BV2-12-002-R00, addressed in the is clear from the human action "BVPS-2 HRA Dependency Analysis," base PRA model identifier sheets documented in the Revision 0 provides the process used prior to building BVPS-2 HRA notebook that such an for the dependency analysis the Fire PRA.

evaluation has been performed, but evaluation. The results of this human there is no evidence of the process action dependency analysis did not documented in the HRA notebook. reveal any new dependencies that were not already analyzed.

To be consistent with current HRA methods, there must be a systematic process to identify, assess and adjust dependencies between multiple human errors in the same sequence, including those in the I initiating events. I HR- HR-I1, B Y The HRA notebook sporadically A new Assumptions section has been No impact to Fire 13- HR-13, discusses assumptions and added to the Unit 2 HRA notebook PRA, because 01 AS-C3, uncertainties. Per the Clarification to (PRA-BV2-AL-RO5a). All major this issue was regulatory Guide 1.200 Revision 1, assumptions and sources of addressed in the IE-D3, 1 ________ I &

Page 243 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IF-F3, there is an increased importance in uncertainty are listed in this location, base PRA model LE-F3, the industry to identify assumptions prior to building and uncertainties in the PRA model. the Fire PRA.

LE-G4, In reviewing the HRA notebook, it is Sc-c1, difficult to locate the assumptions SC-C3, and uncertainties.

QU-F4 HR- HR-I1, HR-12 C Y The Beaver Valley Unit 2 system The BVPS Units 1 & 2 PRA and No impact to Fire 11- and data notebooks have been System notebooks were formally PRA, because 01 updated and exist in draft form, but reviewed and signed off as part of the this issue was there is no record of formal review update process. addressed in the and approval. Furthermore, only a base PRA model subset of the total PRA notebooks prior to building have been updated for this revision the Fire PRA.

I _ of the PRA.

HR- HR-12 C Y There is no evidence in the HRA or During the Extended Power Uprate No impact to Fire 12- Success Critera notebooks that an evaluation, plant operations did review PRA, because 02 operator review of the HRA has the operator actions and timings. this issue was been performed. These reviews are documented in addressed in the FENOC Letters L-06-003 and L base PRA model 018. Furthermore, several operator prior to building action scenarios were evaluated using the Fire PRA.

the plant simulator.

IF- IF-Ala B Y It is not clear from the This F&O was written against an This F&O was Ala- documentation that a comprehensive obsolete Internal Flooding PRA model resolved in the 01 assessment has been conducted to (BV2REV4) and is considered to be submitted BVPS-finalize the combined rooms resolved by the updated Internal 2 Fire PRA including propagation, barriers, etc. Flooding PRA model incorporated in model, which The IF assessment is based on large BV2REV5A, which underwent a used BV2REV5A flood areas but there is no focused Peer Review in accordance as its basis.

description of the process used to with the guidance in Appendix B of define those areas with respect to NRC RG 1.200, Rev. 1, conducted I flood propagation and barriers, during June 6-9, 2011, by the PWR Page 244 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-A3 B Y There is no evidence in the IF This F&O was written against an This F&O was A3- Notebook that it represents the obsolete Internal Flooding PRA model resolved in the 01 current as-built-as operated plant (BV2REV4) and is considered to be submitted BVPS-(circa 2007). Rev4 documentation resolved by the updated Internal 2 Fire PRA in another document may include the Flooding PRA model incorporated in model, which information to show that the IF BV2REV5A, which underwent a used BV2REV5A assessment is current, but it is not in focused Peer Review in accordance as its basis.

this Notebook, IF-A3-01 was written with the guidance in Appendix B of as a B level F&O to provide NRC RG 1.200, Rev. 1, conducted documentation that the IF during June 6-9, 2011, by the PWR assessment still represents the as- Owners Group. The F&Os as a result built as operated plant in 2007, This from this focused Peer Review, as well probably also applies to other PRA as their resolutions are presented in elements from the ASME PRA Table 2-4.

Standard (e.g., SY, SC, HR, etc.)

and should be addressed generically for the BVPS PRA. This would facilitate future reviews and development of PRA applications.

IF- IF-B1 B Y The ASME PRA Standard states "for This F&O was written against an This F&O was B1- each flood area, identify the potential obsolete Internal Flooding PRA model resolved in the 01 sources of flooding." Section C3.1 (BV2REV4) and is considered to be submitted BVPS-identifies flood sources in each area resolved by the updated Internal 2 Fire PRA but clear documentation of each Flooding PRA model incorporated in model, which source in an area is lacking. The BV2REV5A, which underwent a used BV2REV5A Standard expects a more systematic focused Peer Review in accordance as its basis.

approach for identifying potential with the guidance in Appendix B of flood sources and then later NRC RG 1.200, Rev.1, conducted I screening them. The IF assessment during June 6-9, 2011, by the PWR I Page 245 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN here includes initial screening Owners Group. The F&Os as a result without written justification. It is from this focused Peer Review, as well suggested that a complete as their resolutions are presented in discussion of potential sources be Table 2-4.

documented and the basis for screening potential sources.

IF- IF-B1 B Y Section C3.1 states that major flood This F&O was written against an This F&O was B1- sources were reviewed to identify obsolete Internal Flooding PRA model resolved in the 02 potential flood locations. The ASME (BV2REV4) and is considered to be submitted BVPS-standard suggests that first you resolved by the updated Internal 2 Fire PRA identify flooding areas then identified Flooding PRA model incorporated in model, which all flooding sources in that area. BV2REV5A, which underwent a used BV2REV5A This method used for BVPS may focused Peer Review in accordance as its basis.

have lead to overlooking other with the guidance in Appendix B of sources of flooding within each area. NRC RG 1.200, Rev.1, conducted during June 6-9, 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-B2, B Y The SR B-2 of the PRA Standard This F&O was written against an This F&O was B2- requires "For each source of obsolete Internal Flooding PRA model resolved in the 01 flooding, identify the flooding (BV2REV4) and is considered to be submitted BVPS-mechanisms that would result in a resolved by the updated Internal 2 Fire PRA fluid release including failure models, Flooding PRA model incorporated in model, which human-induced mechanisms, and BV2REV5A, which underwent a used BV2REV5A other events resulting in a release focused Peer Review in accordance as its basis.

into the flood area." In addition, SR with the guidance in Appendix B of Page 246 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IF-B3 B-3 requires "For each source and NRC RG 1.200, Rev. 1, conducted its identified failure mechanism, during June 6-9, 2011, by the PWR identify the characteristic of release Owners Group. The F&Os as a result and the capacity of the source." from this focused Peer Review, as well Section C3.1 of the IFNotebook as their resolutions are presented in does not provide enough detail to Table 2-4.

judge whether these requirement is met. One example is that although a few human error induced floods (e.g., testing or maintenance errors) were considered, there is no evidence of a systematic assessment of potential test and maintenance errors.

Page 247 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IF- IF-C2b B Y Section C3.1 does not have enough This F&O was written against an This F&O was C2b- detail to show that the capacity of obsolete Internal Flooding PRA model resolved in the 01 the drains and the amount of water (BV2REV4) and is considered to be submitted BVPS-retained by the sumps, berms, dikes, resolved by the updated Internal 2 Fire PRA and curbs was estimated. The Flooding PRA model incorporated in model, which reviewer notes that it is likely that BV2REV5A, which underwent a used BV2REV5A this was performed but there is no focused Peer Review in accordance as its basis.

record of the assessment. The with the guidance in Appendix B of capacity of drains and the amount of NRC RG 1.200, Rev.1, conducted water retained by sumps, etc. should during June 6-9, 2011, by the PWR be documented in the IF Notebook. Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in I Table 2-4.

Page 248 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N IF- IF-C3 B Y The PRA Standard states "for each This F&O was written against an This F&O was C3- SSCs identified in IF-C2c identify the obsolete Internal Flooding PRA model resolved in the 01 susceptibility of each SSC in the (BV2REV4) and is considered to be submitted BVPS-flood area to flood-induced failure resolved by the updated Internal 2 Fire PRA mechanism". Also, the SR-C3a Flooding PRA model incorporated in model, which states, "to determine susceptibility of BV2REV5A, which underwent a used BV2REV5A SSC to flood-induced failure focused Peer Review in accordance as its basis.

mechanism, take credit for the with the guidance in Appendix B of operability of SSC identified in IF- NRC RG 1.200, Rev.1, conducted C2c with respect to internal flood during June 6-9, 2011, by the PWR impact only if supported by an Owners Group. The F&Os as a result appropriate combination of: 1) test or from this focused Peer Review, as well operational data, 2) engineering as their resolutions are presented in analysis, and 3) expert judgment." It Table 2-4.

is likely that flood-induced failure mechanisms were considered in the IF assessment but are not identified in the IF Notebook. Section C3.1 does not provide enough detail on the impact of the flood on SSCs.

IF- IF-C3a, IF- B Y The IF-C3b SR requires that all This F&O was written against an This F&O was C3b- C3b potential mechanisms that can obsolete Internal Flooding PRA model resolved in the 01 create interconnections between (BV2REV4) and is considered to be submitted BVPS-flooding areas be considered for resolved by the updated Internal 2 Fire PRA CCII and that barrier unavailability Flooding PRA model incorporated in model, which also be considered for CCIII. There BV2REV5A, which underwent a used BV2REV5A is no evidence in the Appendix C of focused Peer Review in accordance as its basis.

the Initiating Events Notebook that with the guidance in Appendix B of any mechanism other than open NRC RG 1.200, Rev.1, conducted obvious pathways (e.g., vents in during June 6-9, 2011, by the PWR doors, tunnels, etc.) were Owners Group. The F&Os as a result considered. This may be just a from this focused Peer Review, as well Page 249 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N documentation issue for CCII. as their resolutions are presented in Table 2-4.

Also, the RI-ISI program did a comprehensive assessment of flooding potential for various break locations. A comparison should be performed between the RI-ISI flooding assessment and the PRA IF assessment to ensure consistency.

Note that upgrading to CCIII requires the additional consideration of barrier unavailability, for example due to maintenance activities or maintenance unavailability.

IF- IF-C3c B Y Develop engineering calculations for This F&O was written against an This F&O was C3c- ALL flooding scenarios, not just the obsolete Internal Flooding PRA model resolved in the 01 "worst case" scenarios. This is likely (BV2REV4) and is considered to be submitted BVPS-just a documentation issue, but since resolved by the updated Internal 2 Fire PRA it is missing from the IF Notebook, Flooding PRA model incorporated in model, which SR IF-C3c is not met. BV2REV5A, which underwent a used BV2REV5A focused Peer Review in accordance as its basis.

I with the guidance in Appendix B of I Page 250 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N NRC RG 1.200, Rev. 1, conducted during June 6-9, 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-C4, B Y The operator actions credited inthe This F&O was written against an This F&O was C4- IF-C6, IFflooding assessment are based on obsolete Internal Flooding PRA model resolved in the 01 IF-C8 detailed HRA assessments for two (BV2REV4) and is considered to be submitted BVPS-operator actions. Cues, procedures, resolved by the updated Internal 2 Fire PRA etc. are detailed in the HRA Flooding PRA model incorporated in model, which assessment. It is not clear ifthese BV2REV5A, which underwent a used BV2REV5A actions are also applied to scenarios focused Peer Review in accordance as its basis.

other than those used to quantify the with the guidance in Appendix B of HEP in the HRA Notebook. In NRC RG 1.200, Rev.1, conducted addition, there are a number of other during June 6-9, 2011, by the PWR instances inwhich the operators are Owners Group. The F&Os as a result assumed to be highly reliable. There from this focused Peer Review, as well is also no indication that these are as their resolutions are presented in validated by operator interviews. Table 2-4.

Cleaner documentation of the operator actions that are credited (as well as those not credited), and their basis, should be completed to assist in future reviews and for risk applications inwhich the performance of operators is important. Also a clear linkage between the IFand HRA Notebooks should be documented for the basis of the important HRA input and some of the operator actions to screen scenarios is based on highly I Page 251 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I reliable operator actions.

IF- IF-C4 B Y SR-IF-C4 requires the development This F&O was written against an This F&O was C4- of flood scenarios by examining the obsolete Internal Flooding PRA model resolved in the 02 equipment and relevant plant (BV2REV4) and is considered to be submitted BVPS-features in the flood area and area in resolved by the updated Internal 2 Fire PRA potential propagation paths, taking Flooding PRA model incorporated in model, which credit for appropriate flood mitigation BV2REV5A, which underwent a used BV2REV5A systems or operator actions, and focused Peer Review in accordance as its basis.

identifying susceptible SSCs. No with the guidance in Appendix B of flood scenarios are developed in the NRC RG 1.200, Rev.1, conducted IF Notebook. during June 6-9, 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-C5, B Y The screening methodology This F&O was written against an This F&O was C5- IF-C5a, documented in Section C3.1 does obsolete Internal Flooding PRA model resolved in the 01 IF-C7, not follow the systematic (BV2REV4) and is considered to be submitted BVPS-IF-D7 methodology described in the resolved by the updated Internal 2 Fire PRA Standard. For the IFassessment, Flooding PRA model incorporated in model, which the screening is performed at the BV2REV5A, which underwent a used BV2REV5A source and location level and, in focused Peer Review in accordance as its basis.

some cases, without adequate basis with the guidance in Appendix B of as discussed in a previous F&O (IF- NRC RG 1.200, Rev.1, conducted B1-01). The method used in the IF during June 6-9, 2011, by the PWR flooding assessment may be Owners Group. The F&Os as a result technically adequate, ifthe basis is from this focused Peer Review, as well better documented, even though it as their resolutions are presented in does not meet the Standard SRs for Table 2-4.

C-5, C5a and C7. I Page 252 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I IF- IF-D1 B Y The FENOC response to DE-06 from This F&O was written against an This F&O was D1- the OG Peer Review is incomplete, obsolete Internal Flooding PRA model resolved in the 01 The F&O is concerned about the (BV2REV4) and is considered to be submitted BVPS-vintage of the data used to estimate resolved by the updated Internal 2 Fire PRA pipe break frequencies and the Flooding PRA model incorporated in model, which FENOC response talks about BV2REV5A, which underwent a used BV2REV5A walkdowns. focused Peer Review in accordance as its basis.

with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during June 6-9, 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-D5, B Y The IF pipe and tank break This F&O was written against an This F&O was D5- IF-D5a frequencies used in the IF obsolete Internal Flooding PRA model resolved in the 01 assessment are based on 1988 and (BV2REV4) and is considered to be submitted BVPS-1990 data. The prior pipe break resolved by the updated Internal 2 Fire PRA frequencies should be updated to Flooding PRA model incorporated in model, which reflect more recent experience and BV2REV5A, which underwent a used BV2REV5A should include plant specific focused Peer Review in accordance as its basis.

experience. In estimating pipe break with the guidance in Appendix B of frequencies, it is recommended that NRC RG 1.200, Rev.1, conducted experience with safety related vs. during June 6-9, 2011, by the PWR BOP piping be considered along with Owners Group. The F&Os as a result active pipe degradation from this focused Peer Review, as well mechanisms. Credit for condition as their resolutions are presented in monitoring programs should also be Table 2-4.

applied where applicable. I I Page 253 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IF- IF-El B Y The Standard states "for each flood This F&O was written against an This F&O was El- scenario, review the accident obsolete Internal Flooding PRA model resolved in the 01 sequences for the associated plant- (BV2REV4) and is considered to be submitted BVPS-initiating event group to confirm resolved by the updated Internal 2 Fire PRA applicability of other accident Flooding PRA model incorporated in model, which sequences model." A spot check BV2REV5A, which underwent a used BV2REV5A was made to provide reasonable focused Peer Review in accordance as its basis.

confidence that the overall results with the guidance in Appendix B of are correct. However, there is no NRC RG 1.200, Rev.1, conducted record that EACH scenario was during June 6-9, 2011, by the PWR reviewed. Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-Fl, B Y The Internal Flooding documentation This F&O was written against an This F&O was Fl- SY-A4 does not include the results of the obsolete Internal Flooding PRA model resolved in the 01 walkdowns performed during the (BV2REV4) and is considered to be submitted BVPS-original assessment. FENOC resolved by the updated Internal 2 Fire PRA response to OG Peer Review F&O Flooding PRA model incorporated in model, which DE-4 indicates that the RI-ISI BV2REV5A, which underwent a used BV2REV5A walkdowns are documented and focused Peer Review in accordance as its basis.

cover the issues required for an with the guidance in Appendix B of Internal Flooding walkdown. To NRC RG 1.200, Rev.1, conducted facilitate future maintenance and during June 6-9, 2011, by the PWR reviews of the internal flooding Owners Group. The F&Os as a result assessments, the use of the RI-ISI from this focused Peer Review, as well walkdowns for internal flooding as their resolutions are presented in should be documented in the Table 2-4.

Internal Flooding Notebook and a direct reference to a retrievable copy the RI-ISI walkdowns should also be included. I Page 254 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N IF- IF-F2 B Y The documentation of the processes This F&O was written against an This F&O was F2- to identify flood areas, sources, obsolete Internal Flooding PRA model resolved in the 01 pathways, scenarios, etc. are not (BV2REV4) and is considered to be submitted BVPS-clearly documented. For example, resolved by the updated Internal 2 Fire PRA the rules used to screen out sources Flooding PRA model incorporated in model, which and areas are not defined and the BV2REV5A, which underwent a used BV2REV5A bases for eliminating or justifying focused Peer Review in accordance as its basis.

propagation pathways is either not with the guidance in Appendix B of clearly defined or not provided at all. NRC RG 1.200, Rev.1, conducted during June 6-9, 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-F2 B Y The IFNotebook states that the This F&O was written against an This F&O was F2- annual frequency of a flood scenario obsolete Internal Flooding PRA model resolved in the 02 in location X is Rx = Fi*fx,i*fs,x*fp,x (BV2REV4) and is considered to be submitted BVPS-and the quantify scenarios in which resolved by the updated Internal 2 Fire PRA recover actions can be included is Flooding PRA model incorporated in model, which Sx=Rx (Dx + lx). However, the BV2REV5A, which underwent a used BV2REV5A frequency is never quantified using focused Peer Review in accordance as its basis.

these equations. This is confusing with the guidance in Appendix B of for a reviewer - what is the purpose NRC RG 1.200, Rev. 1, conducted of these statements ifthey are not during June 6-9, 2011, by the PWR used? or ifthey are used, an Owners Group. The F&Os as a result explanation is needed. from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

Page 255 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IF- IF-Alb, IF- C Y Although it is apparent that dual unit This F&O was written against an This F&O was Al- Bla, IF-C4a, impacts for internal flooding were obsolete Internal Flooding PRA model resolved in the 01 IF-D4 considered, the details are buried in (BV2REV4) and is considered to be submitted BVPS-the individual assessments. To resolved by the updated Internal 2 Fire PRA assist future reviews and the Flooding PRA model incorporated in model, which development of risk informed BV2REV5A, which underwent a used BV2REV5A applications, it is recommended that focused Peer Review in accordance as its basis.

a separate section of the Internal with the guidance in Appendix B of Flooding documentation be created NRC RG 1.200, Rev.1, conducted to summarize the search for and during June 6-9, 2011, by the PWR results of an assessment of dual unit Owners Group. The F&Os as a result internal flooding impacts. from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

IF- IF-A4, B Y The OG Peer Review F&O DE-3 This F&O was written against an This F&O was A4- documented the lack of obsolete Internal Flooding PRA model resolved in the 01 documentation of a walkdown for (BV2REV4) and is considered to be submitted BVPS-internal flooding and other PRA resolved by the updated Internal 2 Fire PRA purposes. The F&O response by Flooding PRA model incorporated in model, which FENOC is incorrect and does not BV2REV5A, which underwent a used BV2REV5A address the F&O. As a result, the focused Peer Review in accordance as its basis.

walkdown documentation is still not with the guidance in Appendix B of identified. The walkdown needs to NRC RG 1.200, Rev. 1, conducted be documented and reviewed from during June 6-9, 2011, by the PWR the perspective of internal floods in Owners Group. The F&Os as a result order to assign a CC to several of from this focused Peer Review, as well the SRs for Internal Flooding. as their resolutions are presented in IF-C9, Table 2-4.

Page 256 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA W/N IF-D4 It is noted that in response to OG F&O DE-04, FENOC used the RI-ISI documentation in place of the original walkdown documentation.

Based on the scope of the RI-ISI walkdowns, this is considered to be an acceptable substitute for the Internal Flooding assessment since the same considerations are being investigated (e.g., drain locations, equipment elevations, etc.).

However, a retrievable walkdown document needs to be identified in the IF Notebook.

IF- IF-D1, C Y The IF assessment does not rely on This F&O was written against an This F&O was Dt- IF-D3, grouping of IEs, sources, locations, obsolete Internal Flooding PRA model resolved in the 02 IFD3a etc. The screening methodology (BV2REV4) and is considered to be submitted BVPS-discussed in the IF Notebook and resolved by the updated Internal 2 Fire PRA assessed under the IF-C-xx SRs Flooding PRA model incorporated in model, which methodology resulted in only a BV2REV5A, which underwent a used BV2REV5A handful of flooding events to be focused Peer Review in accordance as its basis.

considered. These were individually with the guidance in Appendix B of assessed in the overall PRA NRC RG 1.200, Rev.1, conducted quantification using RISKMAN. The during June 6-9, 2011, by the PWR methodology used may be Owners Group. The F&Os as a result technically adequate in spite of not from this focused Peer Review, as well meeting the ASME Standard SRs for as their resolutions are presented in grouping if it can be justified that Table 2-4.

only a handful of events are important. I I Page 257 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/NIN IF- IF-D4 C Y The PRA documentation should This F&O was written against an This F&O was D4- include a discussion of the potential obsolete Internal Flooding PRA model resolved in the 01 impact of floods on systems that are (BV2REV4) and is considered to be submitted BVPS-shared between the two units. This resolved by the updated Internal 2 Fire PRA impact is expected to be minimal. Flooding PRA model incorporated in model, which One example is the potential impact BV2REV5A, which underwent a used BV2REV5A on the electric power crosstie to Unit focused Peer Review in accordance as its basis.

1 availability due to floods in the with the guidance in Appendix B of service water intake structure. Is the NRC RG 1.200, Rev.1, conducted Unit 1 diesel dependence on service during June 6-9, 2011, by the PWR water correctly accounted for when Owners Group. The F&Os as a result the flood impacts the availability of from this focused Peer Review, as well the Unit 1 service water system? as their resolutions are presented in Table 2-4.

IF- IF-D5 C Y The IEF for pipe breaks is based on This F&O was written against an This F&O was D5- a generic 80-% capacity factor. obsolete Internal Flooding PRA model resolved in the 02 There are two issues with this (BV2REV4) and is considered to be submitted BVPS-method: a) current capacity factors resolved by the updated Internal 2 Fire PRA are typically greater than 80% so Flooding PRA model incorporated in model, which that the IEFs are slightly lower, and BV2REV5A, which underwent a used BV2REV5A b) the method is inconsistent with focused Peer Review in accordance as its basis.

the method used to calculate other with the guidance in Appendix B of IEFs. It is recommended that the NRC RG 1.200, Rev.1, conducted calculation for IF IEF be revised to during June 6-9, 2011, by the PWR be consistent with the method used Owners Group. The F&Os as a result for other IEFs. from this focused Peer Review, as well as their resolutions are presented in I Table 2-4.

Page 258 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN IF- IF-D6 C Y The IF flooding assessment uses This F&O was written against an This F&O was D6- screening criteria to limit the obsolete Internal Flooding PRA model resolved in the 01 operator induced floods during (BV2REV4) and is considered to be submitted BVPS-maintenance (e.g., due to operator resolved by the updated Internal 2 Fire PRA errors such as inadvertently opening Flooding PRA model incorporated in model, which isolation valves which maintenance BV2REV5A, which underwent a used BV2REV5A is occurring). One of the screening focused Peer Review in accordance as its basis.

criteria is whether the maintenance with the guidance in Appendix B of activity is performed during power NRC RG 1.200, Rev.1, conducted operation or at shutdown. The during June 6-9, 2011, by the PWR application of these criteria to Owners Group. The F&Os as a result potential floods should be re- from this focused Peer Review, as well assessed in light of recent practices as their resolutions are presented in to perform more maintenance at Table 2-4.

power to shorten the shutdown periods. It is expected that this will have a small to negligible impact on the IF assessment and is therefore I assigned a Level C. I IF- IF-E5 C Y There are a number of operator This F&O was written against an This F&O was E5- actions credited in the IF obsolete Internal Flooding PRA model resolved in the 01 assessment that are used to screen (BV2REV4) and is considered to be submitted BVPS-potential flooding events based on resolved by the updated Internal 2 Fire PRA the operator's ability to diagnose the Flooding PRA model incorporated in model, which pipe break and isolate the leak BV2REV5A, which underwent a used BV2REV5A thereby preventing the flood. focused Peer Review in accordance as its basis.

However, these operator actions are with the guidance in Appendix B of based on judgment. For others, one NRC RG 1.200, Rev.1, conducted of the two HEPs that are analyzed is during June 6-9, 2011, by the PWR used based on judgment. Examples Owners Group. The F&Os as a result include: from this focused Peer Review, as well as their resolutions are presented in

~.I.

Page 259 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N

1) InSection C4.3.6 it is stated that Table 2-4.

operator will receive sump alarms and be alert to the loss of RWST tank level ... the possibility that the operators do not locally isolate the tank ... is estimated as 6.7E-03 from ZHEFL2.

2) In Section C3.2.1 itis stated that a flood from the fan room should be detected quickly since this room is next to the control room. The control building sump high-level alarm would alert operators. Failure of the air conditioning would also alert operators.

It is recommended that a better basis for these operator actions be developed to ensure consistency with the remainder of the PRA.\

Page 260 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N IF- IF-E5a C Y Several operator actions in the IF This F&O was written against an This F&O was E5a- assessment use the HEPs obsolete Internal Flooding PRA model resolved in the 01 documented by detailed analysis for (BV2REV4) and is considered to be submitted BVPS-ZHEFL1 and 2. These assume that resolved by the updated Internal 2 Fire PRA the cues, procedures steps, action, Flooding PRA model incorporated in model, which timing, etc. are similar enough to that BV2REV5A, which underwent a used BV2REV5A for ZHEFL1 or 2 but this is not focused Peer Review in accordance as its basis.

documented in the IF Notebook or with the guidance in Appendix B of the HR Notebook. To be consistent NRC RG 1.200, Rev.1, conducted with the operator action during June 6-9, 2011, by the PWR assessments for the remainder of Owners Group. The F&Os as a result the PRA, it is recommended that from this focused Peer Review, as well better documentation be developed as their resolutions are presented in to support the use of ZHEFL1 or 2 Table 2-4.

for these operator actions, or new I_ HEPs be developed as appropriate.

IF- IF-F1 C Y If the current IF methodology is This F&O was written against an This F&O was Fl- retained, a comparison of the current obsolete Internal Flooding PRA model resolved in the 02 methodology to the ASME Standard (BV2REV4) and is considered to be submitted BVPS-is recommended to facilitate future resolved by the updated Internal 2 Fire PRA reviews. Flooding PRA model incorporated in model, which BV2REV5A, which underwent a used BV2REV5A focused Peer Review in accordance as its basis.

with the guidance in Appendix B of NRC RG 1.200, Rev.1, conducted during June 6-9, 2011, by the PWR Owners Group. The F&Os as a result from this focused Peer Review, as well as their resolutions are presented in Table 2-4.

Page 261 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN LE- LE-C2a, LE- B Y SR LE-C2a is assigned a capability The Level 2 LERF Analysis Notebook No impact to Fire C2a- C2b, LE-C3, category I because BVPS 2 does not Section 2.5 "General Discussion of PRA, because 01 LE-C6 use operator actions post core Level 2 Operator Actions" discusses this issue was damage. This is considered operator actions considered for this addressed in the conservative treatment of operator model. base PRA model actions following the onset of core prior to building damage. To meet capability WCAP-16657-P suggests seven the Fire PRA.

category III for this SR, BVPS 2 level potential operator actions (OA) for 2 analysis must contain realistic inclusion in a Level 2 PRA model.

operator actions, based on SAMGs, Each of these actions along with two EOPs, etc. such as WCAP-16657-P. others were reviewed specifically for Beaver Valley Unit 2. The Level 2 OA to restore feedwater to a dry steam generator was added to the PRA model.

LE- LE-C2b B Y Only recovery of AC power after Section 2.5 of the Level 2 LERF No impact to Fire C2b- UTAF is discussed in the Level 2 Analysis Notebook discusses the use PRA, because 01 notebook. It is concluded that not of Level 2 Operator Actions for this issue was enough time exists to assign a high recovery; specifically recovery of addressed in the success probability. No other feedwater to a dry steam generator is base PRA model recoveries are discussed. included in the CET Top Event OL. AC prior to building electric power recovery is included in the Fire PRA.

I _ the Level 1 Top Event RE LE- LE-C9a, LE- B Y Level 2 and LERF analysis stopped A discussion has been added to the No impact to Fire C9a- C9b at containment failure and continued Level 2 LERF Analysis PRA Notebook PRA, because 01 operation of equipment and operator Section 2.4 General Modeling this issue was actions were not modeled. Assumptions and Criteria for Level 2 addressed in the Operation of mitigating systems after Analysis to justify the significance of base PRA model containment failure is not modeled the containment spray system on prior to building I either. Justify the lack of credit of LERF mitigation following containment the Fire PRA.

Page 262 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation 1BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN I

equipment survivability, failure. Details of equipment survivability can also be found in Appendix A.

LE- LE-Cl0 B Y SGTR and containment bypass did A discussion has been added to the No impact to Fire C1 0- not take credit for scrubbing. Level 2 LERF Analysis Notebook PRA, because 01 WCAP-16657 suggests that Section 3.3 "Containment Event Tree," this issue was scrubbing for tube rupture events Top Event OL to credit SGTR addressed in the can be credited by an operator scrubbing and the basis for the base PRA model action restart auxiliary feedwater to decontamination factor. prior to building the ruptured steam generator. the Fire PRA.

LE- LE-D5 B Y Beaver Valley Thermal Induced The PI-SGTR and TI-SGTR methods No impact to Fire D5- SGTR is based on a 1995 Fauske are included in Appendix F of the Level PRA, because 01 and Associates report and 2 LERF Analysis Notebook. this issue was Westinghouse Calculation CN-RRA- addressed in the 02-38. Recent investigations base PRA model suggest that these results may be prior to building too optimistic. A more reasonable the Fire PRA.

approach may be implementing WCAP 16341, "Simplified LERF Model," and characterizing the uncertainties based on that latest EPRI, PWROG, and NRC interactions. I Page 263 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N LE- LE-D5 B Y The Cl analysis for BV2REV3b is Following the Beaver Valley Unit 2 No impact to Fire D6- based on a sub-atmospheric Atmospheric Containment Conversion PRA, because 01 containment. BV2 has been modification, the containment still this issue was converted to atmospheric so this normally operates at slightly sub- addressed in the analysis must be revisited, atmospheric conditions. A discussion base PRA model BVI REV4 does account for the has been added in the Level 2 LERF prior to building atmospheric containment conversion Analysis Notebook Section the Fire PRA.

in the Containment Isolation "Condensed Plant Damage State notebook. The results of a similar Matrix for Beaver Valley Unit 2" to assessment for BV-2 need to be outline the Beaver Valley Unit 2 incorporated in the LERF notebook. containment change from sub-atmospheric to atmospheric and the I impact on the Level 2 analysis.

LE- LE-E4 B Y The BV2 LERF model is quantified The Level 2 phenomena split fraction No impact to Fire E4- using RISKMAN. Only point- distributions are included in Table 3-26 PRA, because 01 estimates for each top event are of the Level 2 LERF Analysis this issue was used and there are no uncertainty Notebook. This table contains Beaver addressed in the estimates or uncertainty Valley Unit 2 plant specific Level 2 base PRA model propagation. phenomena distributions along with the prior to building mean, median, 5th%ile, and the the Fire PRA.

95th%ile. A discussion on how these distributions were developed is provided in Section 3.4 of this notebook.

LE- LE-F2 B Y The PRA Peer Review Team The LERF uncertainty analysis was No impact to Fire F2- suggested in F&O L2-02 using performed as part of the quantification PRA, because 01 uncertainty analysis for the LERF top process using Monte Carlo sampling of this issue was events to ensure that future the Level 2 split fraction distributions. addressed in the applications are not affected by use The result of this analysis is provided base PRA model of point estimates. in the BVPS-2 Quantification prior to building Notebook, Revision 5, Section 1.5.6 the Fire PRA.

Page 264 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN This F&O was entered into the "Results of Containment Performance BVPS Corrective Action Program as Analysis."

CA 02-09043-26 (Reference 16) to track and resolve the issues. The suggested PRA Peer Review Team resolution to this observation was not addressed in the BV2REV3B PRA model update, but will be evaluated sometime later in a future PRA model update.

This update has not yet been completed. At the time, it was a "C" level F&O but the PRA standard raises the requirements for PRA quality and this F&O is now a "B" level.

LE- LE-G5 B Y Limitations of the LERF analysis are Section "Limitations of the Level 2 No impact to Fire G5- identified throughout the BV2 Level 2 Model" has been added to the Level 2 PRA, because 01 notebook. However, they need to be LERF Analysis Notebook to include this issue was gathered into a single location to limitations of the Level 2 analysis. addressed in the facilitate future usage. base PRA model prior to building the Fire PRA.

LE- LE-B3 C Y In Section 2.1 of the LERF Level 2 LERF Analysis Notebook No impact to Fire B3- Notebook, it is stated that MAAP, Section 2.1 "Guidelines on Grouping PRA, because 01 STCP, and MELCOR are used to Core Damage Sequences into Plant this issue was characterize the timing of important Damage States Based on Their addressed in the events. There is no evidence that Accident Progression Attributes" has base PRA model STCP and MELCOR are ever used. been updated to include a discussion prior to building of the codes used and their applicable the Fire PRA.

I analyses. I Page 265 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N LE- LE-D3 C Y The LERF assessment for ISLOCA The ISLOCA analysis is reported in the No impact to Fire D3- is self contained in the Appendix D Initiating Event Notebook. The Level 2 PRA, because 02 of the Initiating Event Analysis LERF Analysis notebook contains a this issue was notebook. There is no reference to pointer to the ISLOCA analysis in addressed in the the ISLOCA assessment in the Section 1.2 "Interrelationship with base PRA model LERF notebook. It is not readily Other Parts of PRA." prior to building apparent from reading the LERF the Fire PRA.

notebook that an ISLOCA assessment was done. I QU- QU-F4, QU- A Y The Revision 3B Quantification Documentation of a more rigorous No impact to Fire F4- E4, IE-D3 notebook Section 5 states that the uncertainty analysis for the Beaver PRA, because 01 PRA notebooks..."include an Valley Unit 2 Revision 5a PRA model this issue was estimation of the uncertainty is presented in Section 5 and Appendix addressed in the introduced by the data used to B of the Quantification Notebook base PRA model quantify the PRA model...This prior to building uncertainty estimation does not, the Fire PRA.

however, reflect possible effects on the results from other sources of uncertainty. Such sources may include such things as: optimism or pessimism in definitions of sequence, component, or human action success criteria; limitations in sequence models due to simplifications (for example, not modeling available systems or equipment) made to facilitate quantification; uncertainty in defining human response within the emergency procedures...; degree of completeness in selection of initiating events; assumptions regarding phenomenology or Page 266 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN structures, systems, and components (SSC) behavior under accident conditions... While it is difficult to quantify the effects of such sources of uncertainty, it is important to recognize and evaluate them because there may be specific PRA applications where their effects may have a significant influence on the results.

QU-F4 requires that these sources of uncertainty be characterized regardless of the difficulty of the evaluation. By Beaver Valley's own admission (above), it is important to recognize and evaluate them because there may be specific PRA applications where their effects may have a significant influence on the results.

Furthermore, the documentation provided in Chapter 5 of the Quantification notebook makes a start at identifying the sources of model uncertainty. PWROG guidance suggests the number of identified sources of uncertainty typically is on the order of 50 items.

it is also suggested the BVPS perform a more rigorous search to complete a fairly complete list of sources of uncertainty.

Page 267 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N QU- QU-B9 B Y Component boundary conditions are A table of component boundaries was No impact to Fire B9- not well defined. The Data Analysis added to section A.4 of the Unit 2 PRA, because 01 Notebook, as well as several system PRA Data Analysis Notebook (PRA- this issue was notebooks (AFW &SWS) were BV2-AL-R05a). addressed in the reviewed and there is no discussion base PRA model of component boundary (a pump fail prior to building to start, for example.. .does the the Fire PRA.

component boundary include the local circuitry?). There are assumptions made regarding system boundaries, but no discussion of component boundaries. As a result, module definitions can not be determined.

QU- QU-F4, QU- B Y A detailed description of the Documentation of the RISKMAN No impact to Fire F4- F5 RISKMAN quantification process is software quantification limitations are PRA, because 02 provided. However, the Revision 3B presented in Appendix A, Section A.1.1 this issue was Quantification notebook does not "RISKMAN Software Limitations" of the addressed in the discuss limitations inthe Quantification Notebook base PRA model methodology, prior to building the Fire PRA.

QU- QU-D5a B Y Significant contributors to CDF have Documentation of the significant No impact to Fire D5a- been identified, but there is no contributors to CDF, including initiating PRA, because 01 identification of SSCs and operator events, accident sequences, basic this issue was actions that contribute to initiating events (containing common cause addressed in the event frequencies and event failures), components, systems, and base PRA model mitigation operator actions are included in prior to building Section 3 "Results" of the the Fire PRA.

Quantification notebook. The System Notebooks also provide information on SSC and operator action (i.e., basic event) contribution to initiating event I Page 268 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N frequencies and event mitigation, in the cutset listing reports.

QU- QU-F6 B Y Beaver Valley does list important The definition of significant accident No impact to Fire F6- operator action basic events; sequences in provided in Section 3.1 PRA, because 01 however, there is no documented of the Quantification Notebook. this issue was definition of "significant". The Section 3.1.4 provides the definition of addressed in the Revision 3B Quantification notebook significant systems. The top 10 basic base PRA model lists top accident sequences but events, components, and operator prior to building provides no definition of whether actions ranked by Birnbaum the Fire PRA.

they are "significant" or not. The importance are also considered only discussion is that there is "no significant.

single sequence makes up a large fraction of the CDF".

Page 269 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N The Revision 3B Quantification notebook states the following definition for important systems:

"The system rankings for determining High Importance is based on having an F-V Importance greater than 5.OE-02 or a RAW greater than 10, while the Low Importance is based on having an F V Importance less than 5.0E-03 and a RAW less than 2. Medium Importance systems are comprised of everything else in between these importance measures." This definition agrees with the Regulatory Guide 1.200 definition for "significant contributors." However, there is no documented justification (no reference to a standard definition, such as R.G. 1.200 or the EPRI PRA Applications Guide).

QU- QU-D5b C Y The BVPS-2 system importance Documentation of the basic event and No impact to Fire D5- rankings are based on component component importances are provided PRA, because 02 importances; however there is no in Section 3.1.3 "Basic Event and this issue was specific discussion of component or Component Importance Rankings," of addressed in the basic event importances (excluding the Quantification Notebook. A base PRA model operator actions). complete listing CDF importance prior to building measures for all basic events and the Fire PRA.

components are provided in the linked files "CDF Basic Event Importance.xls" and "BV2R5L1 CDF Component 1 Importance.xls." I Page 270 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN Sc- SC-A5 B Y This SR requires that for sequences A discussion has been added in the No impact to Fire A5- in which stable plant conditions medium LOCA Top Event MU to PRA, because 01 would not be achieved by 24 hr address containment flooding and this issue was using the modeled plant equipment supply of make water. Containment addressed in the and human actions, PERFORM flooding is a severe accident mitigating base PRA model additional evaluation or modeling by strategy used to flood up to the lower prior to building using an appropriate technique. head of the RPV to significantly delay, the Fire PRA.

and possibly prevent vessel failure.

The consequences of containment flooding have been addressed in BVPS-2 SAMG CA-5, "Containment Water Level and Volume," to determine when water levels are jeopardizing vital equipment and monitoring capabilities.

A review of Figures 1 & 2 and Table 6 of this document revels that no significant core damage mitigating equipment or instrumentation would be impacted, even if 3 RWST volumes are injected. There is an unlimited supply of makeup water via the Ohio River.

Page 271 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Require m ent Level Closed PRA IYIN I The MU top event for medium LOCA Furthermore, if a significant volume of and Small LOCA/General Transient service water is added to the Spent uses RWST makeup as part of the Fuel Pool, makeup procedure 20M-success path when recirculation has 7.4.0 recommends the addition of failed. While a mission time of 24 boric acid to the Spent Fuel Pool to hours is assumed, the plant is not at maintain adequate shutdown margin.

a safe stable state because another Therefore, at BVPS actions to add action is required for long term makeup to the RWST and use the success. The RWST refill results in HHSI pumps in SI injection mode for additional water to the containment continued RCS makeup are which eventually will result in the determined to result in a safe stable design basis flooding level being plant condition. This would be true for exceeded and the potential for all accidents identified in the F&O (i.e.,

subsequent loss of instrumentation medium LOCA, small LOCA, General and control. The impact of Transient, SGTR, and ISLOCA).

continued RWST makeup and injection into containment needs to be discussed in relation to the achievement of a safe stable state where no additional operator actions are required.

A similar situation exists for SGTR and ISLOCA where RWST refill is being used to maintain core cooling, but the justification for mission time of only 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is not apparent given that the plant is not in a safe stable state by traditional definitions.

Page 272 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N SC- SC-C2 B Y No discussion of the limitations of Section "MAAP-DBA Limitations" has No impact to Fire C2- the MAAP code for Success Criteria been added to the Success Criteria PRA, because 01 are provided in the Success Criteria Analysis Notebook to identify the this issue was Notebook. Two known limitations limitations of the MAAP-DBA code. addressed in the are the use of MAAP for early phase base PRA model large LOCAs and the use of MAAP prior to building for SG dryout assessments without the Fire PRA.

benchmarking to design basis codes (e.g., bleed and feed initiation). It was observed in the Success Criteria Notebook that MAAP runs were made to justify only 1 accumulator (but that 2 of 2 intact accumulators appear to have been actually used as stated to be used in Section 3.1 of the Notebook). It is recommended that a discussion of MAAP limitations (similar to that provided in the EPRI assessment for MAAP 3) be documented or referenced in the Success Criteria Notebook. I SC- SC-A5 C Y The success criteria for top event A discussion has been added to the No impact to Fire A5- WM for the SGTR states that 400 Success Criteria Analysis Notebook in PRA, because 02 gpm makeup to the RWST is Section 3.5 "Steam Generator Tube this issue was sufficient to maintain HHSI for RCS Rupture" Top Event WM to address addressed in the inventory control at full RCS RWST makeup. base PRA model pressure despite leakage through a prior to building ruptured SG tube. the Fire PRA.

Page 273 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N The maximum RCS inventory loss through a single SGTR is on the order of 600 gpm if the primary side is at normal operating pressure and the secondary side of the SG is not depressurized. This is in excess of the 400 gpm makeup and therefore appears to invalidate the success criteria as stated. Also, if continued HHSI at full system pressure is required, SG overfill is likely to occur and the SG will be depressurized and the leakage through the I_ ruptured tube will even be higher.

SC- SC-B1 C Y Reviewer Note R7 for TH states that Section "MAAP-DBA Limitations" has No impact to Fire B1- MAAP limitations were observed and been added to the Success Criteria PRA, because 01 MAAP was not used for Large LOCA Analysis Notebook to identify the this issue was early success criteria such as limitations of the MAAP-DBA code. addressed in the accumulators. It was observed in base PRA model the Success Criteria Notebook that prior to building MAAP runs were made to justify only the Fire PRA.

1 accumulator but that 2 of 2 intact accumulators was stated to be used in Section 3.1 of the Notebook. This may be confusing for future use because no discussion of MAAP limitations is presented in the Appendix containing the MAAP analyses (e.g., at page C-8 of the U2 Success Criteria Notebook). I Page 274 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN Sc- SC-B5 C Y The ASME PRA requirement for SC- Attachment D has been added to the No impact to Fire B5- B5 includes the possibility of Success Criteria Notebook to compare PRA, because 01 comparison to check the the Beaver Valley Unit 2 results with this issue was reasonableness of the success North Anna Unit 1. Furthermore, the addressed in the criteria. It is recommended that such Beaver Valley PRA model success base PRA model as effort be undertaken, possibly as criteria developed using MAAP were prior to building a PWROG or EPRI effort. compared with the NUREG-1953 Surry the Fire PRA.

success criteria (a similar plant), which used the MELCOR computer code and were found to be in good agreement.

SC- SC-Cl, SY- C Y The ASME PRA Standard for SC-Cl Section "System Success Criteria" has No impact to Fire C1- C1 requires that Success Criteria be been added to the Success Criteria PRA, because 02 documented in a manner that Analysis Notebook to show where the this issue was facilitates applications, upgrades, system specific success criteria are addressed in the and peer reviews. The current state contained in each system notebook, base PRA model of the BVPS PRA Success Criteria is prior to building that the accident sequence success This was believed to be the best place the Fire PRA.

criteria are gathered in the Success to locate support system success Criteria Notebook, but other success criteria.

criteria are scattered about though the PRA. Examples include the SW success criteria and ISLOCA success criteria for U1. It is recommended that FENOC consider gathering all success criteria in the Success Criteria Notebook to facilitate future usage. I Page 275 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I

SC- SC-B1 S Y CCIII of the standard requires that No response required for F&O SC-B1- No impact to Fire Bi- plant specific analyses be used to 02. PRA, because 02 determine success criteria with plant this was identified specific analyses. The large number as a strength of of MAAP analyses for success the model.

criteria meet this requirement and the BVPS Ul and U2 PRAs are considered to be exemplary in this respect.

SY- SY-A14, SY- B Y The DRAFT Revision 4 System Instances of excluded failure modes No impact to Fire A14- A12, SY-C1 notebooks (AFW, SWS, CCS, CCP, and contributors to unavailability for the PRA, because 01 MFW were reviewed) discuss failure applicable systems were reviewed and this issue was modes and contributors to system compiled into a single location in their addressed in the unavailability and unreliability that respective System Notebooks. When base PRA model are excluded from the systems warranted, justification for the excluded prior to building analysis. However, the SY-A14 failure mode or unavailability the Fire PRA.

criteria does not appear to have contributor was made more thorough.

been applied consistently throughout This information is located in the the analysis. The only exceptions Excluded Failure Modes and found where the SY-A14 criteria are Unavailability Contributors section of explicitly met is in the CCS the notebooks.

notebook, Section 14, c, Assumption

2, and the AFW notebook Section 14, c, Assumption #3. In some instances, such as the CCP notebook Section 14, c, Assumption

1, there was no explanation given for why the contributor was not modeled. I Page 276 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impactto Fire ID Requirement Level Closed PRA Y/N SY- SY-C1 B Y In providing the response to peer I he Common Cause section ot the No impact to Fire C1- review F&O DA-09, which deals with System Notebooks now references the PRA, because 01 providing documentation of the CCF Common Cause Modeling section, this issue was groupings, Beaver Valley noted that Table A-i, and Table 1 of the Systems addressed in the the Systems Analysis Overview and Analysis Overview and Guidance base PRA model Guidance notebook provides the Notebook to thoroughly document the prior to building process used to identify CCF methodology and grouping of the the Fire PRA.

groupings. The response further common cause modeled in the PRA.

suggests details of the common cause groups that were retained in the PRA system models and presented in Appendix C of the BVPS Unit 2 PRA System Notebooks, under the common cause sections of the RISKMAN System Notebook files are adequately documented and can be found by knowledgeable personnel.

The reviewer agrees that one can review Appendix C of the Systems notebooks and see what the CCF groupings are and how the CCF probabilities were generated. The reviewer also agrees that high level guidance is provided in the Systems Analysis Overview and Guidance notebook. However, it appears a link between the two documents is missing.

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Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N For example, the guidance states "When identical, nondiverse, and active components are used to provide redundancy, they should be considered for assignment to common cause groups, one group for each identical redundant component". When the Systems notebook Appendix C is reviewed, the components contained in the CCF group is clearly identified, but there is no documentation that states that those components are "identical, and/or non-diverse" or used to provide redundancy.

Further examination of other sections System notebooks (such as Section 3 "System Success Criteria",

or Section 6 "Operating Features" would lead a reviewer to find this type of information. But this documentation is not always intuitively obvious and makes peer review difficult at times.

SY- SY-Al 1 C Y The system notebooks do not An additional response has been No impact to Fire All- specifically discuss the added to the evaluations of the areas PRA, because 01 dependencies that may be present that are represented by the actual top this issue was regarding HVAC I room cooling, event equipment whether the HVAC addressed in the However, review of the HVAC dependency is required or not and is base PRA model notebook identified the various located in Support Systems section in prior to building spatial locations that may require the system notebooks. the Fire PRA.

HVAC and indicated the various I Page 278 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I analyses that have been completed to either require HVAC dependencies or not..

SY- SY-B1 C Y At the time of the BVPS Unit 2 Up-to-date generic MGL CCF data has No impact to Fire B1- common cause MGL data update been updated in PRA-BV2-AL-R05 PRA, because 01 during Revision 3, the NRC update using WCAP-16672-P (Section 3.6 and this issue was to NUREG/CR-5497 was still not Table C-5 in the Data Analysis addressed in the available. As such, a decision was Notebook). In June 2008, base PRA model made during the update process to Westinghouse issued WCAP-16672-P prior to building keep the existing generic MGL data, which covers 1980 - 2003 in order to the Fire PRA.

which is almost exclusively based on provide guidance to address the the PLG generic database dated concerns that were raised regarding circa 1989. There is no the consistency and correctness of the documentation to illustrate that the CCF events included in the NRC CCF Beaver Valley considered database. The WCAP data source NUREG/CR-5497 during the contains CCF parameter estimates for Revision 4 PRA update. the majority of risk-significant components whose performance are potentially applicable to PWROG utilities only in the U.S. designed by either Westinghouse or Combustion Engineering. The parameter estimates for failure modes of significant components that are generally included in the PRA are provided for the Alpha factors that are converted to the Multiple Greek Letter approach I (MGL) by the method in NUREG/CR- _I Page 279 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N 5485 and to allow for quantifying CCF probabilities.

-SY- SY-B7 C Y The Service cooling water system The Miscellaneous Top Events No impact to Fire B7- notebook assumption #7 lists 10 Notebook, Top Event OC models the PRA, because 01 minutes to trip the RCPs on loss of operator actions to trip the RCPs this issue was cooling. However, in the during situations that exist for greater addressed in the Miscellaneous system notebook, top than 5 minutes, in which either CCP is base PRA model event OC has 5 minutes to trip the lost to the RCPs, or both RCP seal prior to building RCPs. Note, this time might be injection and thermal barrier cooling the Fire PRA.

important in quantifying HEP for are lost. Both of these conditions RCP trip. would be covered in the abnormal operating procedure 20M-53C.4.2.6.8 "Abnormal RCP Operation", and RCP parameters would be monitored to identify situations that warrant an immediate RCP shutdown.

If either of these conditions exist for greater than 5 minutes, the human reliability analysis for operator actions OPROCI (loss of CCW) and OPROC2 (Loss of RCP seal Cooling) assume that the operators would trip the RCPs at 5 minutes, and that the RCPs seals 1 would be damaged in 13 minutes if Page 280 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N they were not tripped, leading to a 480 gpm per RCP seal LOCA. These timing assumptions and consequences are based on BVPS AOPs and WCAP-16141.

SY- SY-B1 3 C Y There does not appear to be a This F&O only applies to BVPS Unit 2. No impact to Fire B133- detailed room heatup analysis to PRA, because 01 support the evaluation for Area 7 in A detailed BVPS Unit 1 room heatup this issue was the Revision 3B HVAC notebook. analysis of the main steam valve room determined to There are several qualitative following an SBO (8700-DMC-2312, have no effect on arguments in addition to crediting Revision 0, Addendum 2), which the BVPS PRA manual actions for SBO. determined that the steady-state model.

ambient air temperature is expected to be 133 0 F (with roof louvers open). It was judged that the Unit 2 main steam valve room would have a similar steady state ambient air temperature, so a detailed room heatup analysis was not warranted since this temperature is well below the equipment qualification temperature of 348 0 F for the area. Additionally, cooling vests are available for operators to wear while performing any actions located in the main steam valve room.

A subsequent search of Unit 2 calculations, revealed that a room heatup analysis of the Unit 2 main steam valve room following an SBO was performed (10080-DMC-56, Page 281 of 301

Table 2-2. Summary of BVPS-2 RG 1.200 Gap Analysis - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N I

Revision 0, Addendum 1), which determined that the steady-state ambient air temperature is expected to be <120°F (with roof louvers open).

SY- SY-C1 C Y The Beaver Valley Unit 2 system System Engineers reviewed the No impact to Fire C1- notebooks have no indication of system notebooks for PRA-BV2-AL- PRA, because 02 system engineering reviews. These R05, in which they had to present this issue was reviews help ensure that systems comments and provide input for the top addressed in the are model in accordance with day-to- event system review. System base PRA model day plant operations and additionally Engineering comments have been prior to building expand the PSA knowledge of the incorporated into BVPS-2 PRA the Fire PRA.

system engineers, corresponding system notebooks. A table that contains the comments is located inAppendix B in the System Analysis Overview for BVPS-2.

SY- SY-B5, SY- D Y The system notebooks do not An additional response has been No impact to Fire B5- B6, SY-B1i0, specifically discuss the added to the evaluations of the areas PRA, because 01 SY-B11 dependencies that may be present that are represented by the actual top this issue was regarding HVAC / room cooling, event equipment whether the HVAC addressed in the However, review of the HVAC dependency is required or not and is base PRA model notebook identified the various located in Support Systems section in prior to building spatial locations that may require the system notebooks. the Fire PRA.

HVAC and indicated the various analyses that have been completed Since this F&O is essentially the same to either require HVAC as F&O SY-Al 1-01, itwas also dependencies or not. resolved by it Page 282 of 301

Table 2-3. Summary of BVPS-2 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA W/N HR- HR-D5, Finding Y BVPS does not have a written Section 2.2 of the HRA Notebook No impact to Fire PR- process for evaluating dependencies documents the methodology and PRA, because this 001 between multiple HEPs occurring in a evaluation of the pre-initiator HEPs. issue was single accident and does not provide A summary of the EPRI HRA addressed in the a summary of HEPs that were Calculator results can be found in base PRA model explicitly evaluated for dependencies Table 3.5 which supplements the prior to building the and the associated levels of detailed calculations documented in Fire PRA.

dependencies and joint HEPS. The Appendix E.

HR-G7, BVPS HRA notebooks do not have a HR-H3, single summary table of the Section 2.3 of the HRA notebook has preinitiator human actions and the been created to provide a summary documentation of the evaluation of of HEPs that were explicitly pre-initiator human actions in the evaluated for dependencies and to system notebooks, which make it document that PRA Analysis No.

difficult to identify which actions were PRA-BV2-12-002-R00, "BVPS-2 actually evaluated. HRA Dependency Analysis,"

Revision 0 provides the process used for the dependency analysis evaluation (See F&O HR-12-01 in Section 6).

HR-I1, HR-12(d)3 HR- HR-G6, HR- Finding Y BVPS does not appear to have An internal consistency check for No impact to Fire PR- 12 evaluated their HEPs for internal pre-initiator HEPs is documented in PRA, because this 002 consistency consistent with the Section 3.4 of the Unit 2 HRA issue was requirements of HR-G6 and does not notebook (PRA-BV2-AL-R05a). addressed in the have a documented process to do base PRA model so. The original post-initiator HRA was prior to building the developed using the SLIM/FLIM Fire PRA.

process, and as such were grouped with respect to similar performance I shaping factors and weights (e.g.,

Page 283 of 301

Table 2-3. Summary of BVPS-2 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA I YIN I actions where time and preceding actions are most important were grouped together) to have internal consistency during the HEP development. As a final check of overall consistency, the HEPs from each group were then compared with those of other groups to determine if the differences in the HEPs were warranted by the differences in the scenarios and PSF ratings.

The BV2REV4 PRA model revised the HRA methodology from the SLIM/FLIM process to the EPRI HRA Calculator. The HRA Calculator is a software program that is designed to implement consistency within the field of human action analysis by creating a standard methodology for quantification and documentation of HEPs in the context of the PRA.

After this conversion was complete, the resulting HEP values were then compared to the previous BV2REV3B SLIM/FLIM HRA model (see Table 3-4 of the HRA Notebook, Revision 1 drafted for BV2REV4), to verify consistency in overall trends between events.

Since these BV2REV3B PRA Model SLIM/FLIM HEPs were compared to Page 284 of 301

Table 2-3. Summary of BVPS-2 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact& Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA Y/N the BV2REV4 PRA Model HRA Calculator HEPs to check their reasonableness, there is a de facto consistency check in the HEPs.

HR- HR-D2, HR- Finding Y The method for quantifying pre- Pre-initiators are now quantified No impact to Fire PR- D3, HR-D4, initiator misalignment errors as using the THERP methodology as PRA, because this 003 HR-1i, HR-12 described on page 8 of the "Beaver presented in the EPRI HRA issue was Valley Power Station Unit 2 PRA Calculator. This is documented in addressed in the Notebook - Human Reliability Sections 2.2 & 3.4 and Table 3-5 of base PRA model Analysis," Revision 2, dated the HRA Notebook. The pre-initiator prior to building the 10/01/07, relies on the use of a human error probabilities were Fire PRA.

generic Error of Omission rate that determined using BVPS operator does not reflect any detailed input and BVPS specific procedures assessment of the HEPs. The and processes. The process now process also does not consider the considers the plant specific written quality of plant-specific written procedures, administration controls, procedures, administrative controls and man-machine interface.

or the man-machine interface and does not include an explicit A list of the pre-initiator HFEs and assessment of the potential for their probabilities was added to recovery that specifically delineates Section 3 in Table 3 5.

which procedures and processes influence the potential for identification and recovery.

Furthermore, the method for quantifying post-maintenance miscalibrations relies on a single generic error of omission rate.

Page 285 of 301

Table 2-3. Summary of BVPS-2 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN A complication in reviewing the pre-initiator Human Failure Events (HFEs) was that the HRA notebook does not include a list of the pre-initiator HFEs or their probabilities.

The system notebooks provide evidence of the search for and identification of misalignments but they do not present a list of such events or their probabilities.

HR- HR-C2 Finding Y Post-maintenance misalignments Section 2.2 and Appendix C of the No impact to Fire PR- were excluded for normally operating HRA Notebook document the review PRA, because this 004 system based on the assumption that of BVPS procedures (OSTs, BVTs, issue was misalignments on normally operating and MSPs) to identify potential addressed in the systems would be quickly detected misalignments. Section 2.2 and base PRA model and corrected. Post-maintenance Appendix D of the HRA Notebook prior to building the unavailabilities were included for documents the review of historical Fire PRA.

standby systems as appropriate, event data for misalignment However, nowhere in the HRA identification. A search of the BVPS notebook or the system notebooks 1&2 Corrective Action Program that were reviewed was there any (CAP) was performed to identify pre-indication that BVPS had performed initiators that have occurred at a review of their BVPS. A review was also performed operating/maintenance data to look with the BVPS operator I_ for post-maintenance misalignments.

HR- HR-13 Finding Y The BVPS HRA is documented in the Section 7of the Unit 2 HRA notebook No impact to Fire PR- "Beaver Valley Power Station Unit 2 (PRA-BV2-AL-R05a) was added to PRA, because this 005 PRA Notebook - Human Reliability document HRA assumptions. issue was Analysis", Revision 2, dated addressed in the 10/01/07. This notebook does not base PRA model have an explicit assumptions section prior to building the to identify and characterize Fire PRA.

assumptions. A review of this I Page 286 of 301

Table 2-3. Summary of BVPS-2 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA YIN I notebook revealed assumptions scattered throughout the text.

HR- HR-F2 Finding Y In reviewing the set of post-initiator The "Success Criteria/ Basis of No impact to Fire PR- HFEs in Table 3-1, It was noted that Timing" for ZHEMA2 was revised to PRA, because this 006 for the HFE ZHEMA2, the specified reflect the proper timing basis. The issue was time window, 13.26 hours3.009259e-4 days 0.00722 hours 4.298942e-5 weeks 9.893e-6 months , was not present BV2REV5A value for HFE addressed in the consistent with the information ZHEMA2 is 795.6 minutes = 13.26 base PRA model provided in the "Success Criteria/ hours (based on MAAP-DBA Run prior to building the Basis of Timing" for that HFE. A U2_SBO2) which is consistently Fire PRA.

review of the referenced MAAP case stated in both Table 3-1 and indicates that the 13.26 hours3.009259e-4 days 0.00722 hours 4.298942e-5 weeks 9.893e-6 months is the Appendix B of this notebook appropriate timing. Furthermore, continued review of table 3-1 indicated that this seemed to be an isolated event.

HR- HR-B1 Finding Y In general, BVPS excludes virtually ASME/CNRM Inquiry 09-56 states No-impact to Fire PR- all miscalibration events based on that miscalibrations are included in PRA, because this 007 the assumption that events related to the Common Cause Failure (CCF) issue was instrument miscalibrations are events for the NRC CCF Database. addressed in the captured in the equipment failure rate Since BVPS includes miscalibrations base PRA model data and the On-line Maintenance in the CCF events, it would be prior to building the program precludes common-cause double counting to also include them Fire PRA.

miscalibration by scheduling work on as pre-initiators. As a result, it is opposite trains in different weeks. believed that BVPS's current Post-maintenance misalignments treatment of miscalibrations as part were excluded for normally operating of the CCF events and not pre-system based on the assumption that initiators meets Capability Category Page 287 of 301

Table 2-3. Summary of BVPS-2 HRA Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire ID Requirement Level Closed PRA W/N misalignments on normally operating II (instead of Capability Category I).

systems would be quickly detected and corrected. While these rules seem reasonable, they are applied to classes of maintenance and test activities to screen them from further consideration. This is sufficient for An exception to this is the SSPS Capability Category I but not for model, which did include instrument Capability Category II. string miscalibration errors in the fault tree model.

A search of the Corrective Action database in April 2010 did not reveal any such miscalibration errors between trains at Beaver Valley Unit 2 to date.

Page 288 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N IFPP- IFPP-B1, Finding Y The documentation This F&O was entered into the BVPS No impact to Fire PRA, Bl-01 IFSO-B1, generally does not facilitate Notification System as BV2 Notification because this issue was IFSN-B1, peer review. The technical #600689091, Task 17, to track and addressed in the base IFEV-B1, aspects of the analysis are resolve the issues. As a resolution to PRA model prior to IFQU-B1 documented in a manner this IFPRA Peer Review finding, Section building the Fire PRA.

that cannot be readily 2 of the Internal Flooding Analysis understood by individuals Notebook (PRA-BV2-AL-R05a) was outside the staff. The revised in order to facilitate the Peer ordering of the Review process. Figure 2-1 provides an documentation is overview of the ASME/ANS PRA significantly different from Standard requirements and their the standard; a detailed relationships to the analysis and graphical roadmap of the information contained in the various analysis process would sections/appendices/tables of the report.

enable peer reviewers to This documentation mapping is relate the order of the consistent with that presented in the documentation to the EPRI Final Report 1019194, Guidelines standard. for Performance of Internal Flooding I Probabilistic Risk Assessment.

IFPP- IFPP-B2 Finding Y The process described the This F&O was entered into the BVPS No impact to Fire PRA, B2-01 identification of site Notification System as BV2 Notification because this issue was buildings and flood areas, #600689091, Task 6, to track and addressed in the base but the documentation does resolve the issues. As a resolution to PRA model prior to not clearly establish the this IFPRA Peer Review finding, the building the Fire PRA.

basis for the set of buildings intent of Table 3-1 was clarified prior to considered in the analysis. Section 3.1 (Identify Flood Areas) in the The references to source Internal Flooding Analysis Notebook material are not sufficiently (PRA-BV2-AL-RO5a) to plainly indicate specific to allow replication the table represents a complete list of of the process. The plant buildings/structures based on documentation will be easier referenced materials and that it includes to follow if the basis for the the preliminary building screening.

selection of buildings II Page 289 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN considered in the analysis is enhanced. There is reference to review of plant documentation including the fire analysis, but no statement that the list of buildings in Table 3-1 is the complete list of buildings.

IFPP- IFPP-B3 Finding Y The process used to This F&O was entered into the BVPS No impact to Fire PRA, B3-01 determine the plant Notification System as BV2 Notification because this issue was partitioning requires some #600689091, Task 7, to track and addressed in the base level of assumptions resolve the issues. As a resolution to PRA model prior to concerning how the plant this IFPRA Peer Review finding, plant building the Fire PRA.

partitions are established, partitioning assumptions were The current plant documented in Section 3.5 of the partitioning has no Internal Flooding Analysis Notebook discussion of the (PRA-BV2-AL-R05a).

uncertainties and assumptions associated with the plant design features used to create flood areas.

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Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requiremen t Level Closed YIN IFSO- IFSO-A4 Finding Y The potential flooding This F&O was entered into the BVPS No impact to Fire PRA, A4-01 effects is not listed within Notification System as BV2 Notification because this issue was any of the tables #600689091, Task 3, to track and addressed in the base documenting the potential resolve the issues. As a resolution to PRA model prior to flooding sources. The this IFPRA Peer Review finding, Section building the Fire PRA.

ASME/ANS standard 4.1 (Flood Source Failure Mechanisms requires the inclusion of the and Failure Modes Summary) was potential flooding added to the Internal Flooding Analysis mechanisms when Notebook (PRA-BV2-AL-R05a) to describing the flood sources specifically address: a) a discussion of used in the model. failure modes and mechanisms associated with each flood source with direct reference to latter documentation sections for further discussion, and b) the EPRI methodology which embeds failures of all piping system components as part of the piping segment failures averaged on a per linear foot basis.

Furthermore, Section 4.2 was added to address any flood source identification assumptions with direct reference to latter documentation sections for further discussion.

IFSO- IFSO-A5 Finding Y This supporting requirement This F&O was entered into the BVPS No impact to Fire PRA, A5-01 identifies information used Notification System as BV2 Notification because this issue was to characterize the flooding #600689091, Task 5, to track and addressed in the base sources. Most of the resolve the issues. As a resolution to PRA model prior to information is provided in this IFPRA Peer Review finding, all building the Fire PRA.

Sections 4 and 7 of the normal operating flooding sources internal flooding PRA documented in the Internal Flooding reports. The information Analysis Notebook (PRA-BV2-AL-RO5a) identified by this SR was not (Table 4-1. Water Sources) have provided in its entirety. For updated system flow information Page 291 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact &Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N I

example, system (including normal operating temperatures are not temperatures) based on available captured in the information provided in the references documentation and some noted in the table.

systems (primarily oil) pump HP and RPM are captured but not the flow rates.

IFSO- IFSO-B3 Finding Y No clear documentation was This F&O was entered into the BVPS No impact to Fire PRA, B3-01 provided of related Notification System as BV2 Notification because this issue was assumptions for the #600689091, Task 4, to track and addressed in the base identification of flood resolve the issues. As a resolution to PRA model prior to sources. The sources of this IFPRA Peer Review finding, section building the Fire PRA.

model uncertainty are 12.4.5 of the Internal Flooding Analysis documented in Section 12 Notebook (PRA-BV2-AL-R05a) contains of the internal flooding PRA a review of the impact of all assumptions reports, 2294706-R-001, mapped to uncertainty along with Rev. 0 and 2294706-R-002, sensitivity analysis that was evaluated.

Rev. 0, but itcould not be Table 12-7 contains a cross reference of determined how these all the assumptions in the development sources of model of the BVPS-2 internal flooding uncertainty were connected notebook related to the frequency to the various assumptions. uncertainties in Table 12-2.

Page 292 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN IFSN- IFSN-Al Finding Y The description of the This F&O was entered into the BVPS No impact to Fire PRA, Al-01 propagation paths is not Notification System as BV2 Notification because this issue was complete. Table E-1 #600689091, Task 14, to track and addressed in the base identifies the "source" resolve the issues. As a resolution to PRA model prior to location and the next this IFPRA Peer Review finding, Section building the Fire PRA.

locations to which it water 7.3 of the Internal Flooding Analysis can propagate. To Notebook (PRA-BV2-AL-RO5a) was determine the complete augmented to clearly explain with an propagation path, these example the differences in Table E-1 source/next pairs can be and E-2 due to subsuming of flood combined until the water propagation paths, and a separate reaches the accumulation column was added to Table E-2 to point (no "next" location). indicate all of the flood propagation However, the scenario pathways that were subsumed for each descriptions in Table E-2 do documented flooding scenario so that it not consistently account for will be clear that all pathways have been the propagation paths accounted.

identified in Table E-1. For example, scenario PA3C FWLP-3 propagates to several locations per Table E-2 (PA-3C, PA-3, PA-31, PA-3H) but Table E-1 indicates that PA-3 can propagate to PA-S2, PA-S6, PA-3G, PA-3A, PA-3B, PA-3C, PA-3H, PA-31; several of these are not accounted for in the propagate path in Table E-2. If the missing locations are not possible due to plant features, that should be stated to Page 293 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed IY/N I complete the accounting.

Other examples of this deficiency were observed (PA4-FWLP-1, PT1-FWLP-1 from Unit 2, and PA1A-FWLP-1, FA1A-FWMP-1 from Unit 1). The propagation paths must account for the various possible flow paths.

Combination presented in the documentation that are not considered brings into question the completeness of the analysis.

IFSN- IFSN-B2, Finding Y The process to identify This F&O was entered into the BVPS No impact to Fire PRA, B2-01 IFSN-A5, scenarios lacks several of Notification System as BV2 Notification because this issue was Page 294 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed IFSN-A6 the suggested areas that #600689091, Task 15, to track and addressed in the base should be included resolve the issues. As a resolution to PRA model prior to (recognizing that the SR list this IFPRA Peer Review finding, a building the Fire PRA.

is NOT a required set). The graphical depiction of the overall flood propagation pathways scenario development was provided as description is not complete Figure 7-1 in Section 7 of the Internal in that it does not include all Flooding Analysis Notebook (PRA-BV2-potential propagation paths AL-R05a).

identified in Table E-1 of the PRA reports. The impacted (failed) SSCs for each scenario are not clearly referenced (identified as needing to be "addressed" in a REMARKS column in Table E-2). Assumptions used in the scenario discussions are incomplete.

Scenario screening is not clearly documented. The documentation has many weaknesses in capturing the suggested types of information to adequately document this topic.

Page 295 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed W/N IFSN- IFSN-B3, Finding Y The use of the Excel VBA This F&O was entered into the BVPS No impact to Fire PRA, B3-01 IFSN-A4 code to predict flow rates Notification System as BV2 Notification because this issue was and failures of equipment #600689091, Task 8, to track and addressed in the base has provided a great deal of resolve the issues. As a resolution to PRA model prior to realistic insight to plant flood this IFPRA Peer Review finding, Section building the Fire PRA.

response. Section 9.0 of the 9.5 (Summary of Assumptions) of the internal flooding PRA Internal Flooding Analysis Notebook reports does not explicitly (PRA-BV2-AL-R05a) was expanded to discuss all assumptions include Microsoft EXCEL VBA program regarding the use of specific assumptions and documentation equations to predict flood pointers to flooding scenario specific heights, and the scenarios assumptions.

modeled in Appendix H of the PRA reports have some assumptions applied to each analysis.

IFEV- IFEV-A7 Suggestion Y Maintenance and human- This F&O was entered into the BVPS No impact to Fire PRA, A7-01 induced errors causing a Notification System as BV2 Notification because this issue was flooding event can be #600689091, Task 9, to track and addressed in the base important to the overall plant resolve the issues. As a resolution to PRA model prior to risk. A more detailed this IFPRA Peer Review suggestion, an building the Fire PRA.

analysis of those activities Operating Manual (OM) procedure within the plant that could review of at-power open maintenance lead to a system breach was produced as Table 7-4 in the potential should be Internal Flooding Analysis Notebook analyzed. Maintenance (PRA-BV2-AL-RO5a) that evaluates activities which could systems 15, 26, 28, 29, 30, 31, and 33 potentially breach for potential actions on equipment that pressurized systems could could cause human-induced flooding lead to internal flooding scenarios. Some of the systems (i.e.,

events. By not evaluating all 26 and 29) are indirectly reviewed based potential online on other systems. The OM procedures maintenance activities for for the condenser waterbox, CCR heat I Page 296 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed YIN the potential breaches, the exchangers, and CCT heat exchangers flood-induced risk are based on a frequency that is based associated with these on SAP work order record queries. The activities could be screening categories for the open underestimated. maintenance and human-induced review are shown in Table 7-5.

IFEV- IFEV-B2 Suggestion Y Documentation of the This F&O was entered into the BVPS No impact to Fire PRA, B2-01 process that identifies Notification System as BV2 Notification because this issue was applicable flood-induced #600689091, Task 18, to track and addressed in the base initiating events is required resolve the issues. As a resolution to PRA model prior to to satisfy this SR. The flood this IFPRA Peer Review suggestion, building the Fire PRA.

scenario frequencies are and as part of an expanded analysis to provided in Tables 8-10, F- address probabilistic pipe failure during 1, and J-1 of the internal the 24-hour mission time after an flooding analysis reports initiator and for system-based initiators, (2294706-R-001, Rev. 0 Section 8.1.3 and Tables 8-11 and 8-12 and 2294706-R-002, Rev. of the Internal Flooding Analysis 0). The associated HEPs for Notebook (PRA-BV2-AL-R05a) illustrate isolating the flood and the scope of flooding elements (pipe, adjustment factors used to expansion joints) contained within the refine the flood frequencies existing internal events model.

are also provided in Table F-1. A qualitative screening value of 1.OE-12 was used.

The process does not clearly identify the relationship of the information provided in the various tables. I Page 297 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N IFEV- IFEV-B3 Finding Y The different values that go This F&O was entered into the BVPS No impact to Fire PRA, B3-01 into the calculation of the Notification System as BV2 Notification because this issue was internal flooding initiating #600689091, Task 10, to track and addressed in the base event frequency are subject resolve the issues. As a resolution to PRA model prior to to uncertainties. These this IFPRA Peer Review finding, Section building the Fire PRA.

uncertainties need to be 12.4.5 of the Internal Flooding Analysis well documented to address Notebook (PRA-BV2-AL-RO5a) contains all of the model impacts. a summary of the review of the impact of all assumptions mapped to uncertainty The current flooding along with sensitivity analysis that was frequency calculations factors to determine theuse evaluated.

reference ofTable 12-7 all the contains aincross assumptions the actual initiating event development of the BVPS-2 internal frequency used within the flooding notebook related to the model. The pipe lengths, frequency uncertainties in Table 12-2.

location factors, directional factors, and operator action failures all have some levels of assumptions and uncertainties associated with them. These need to be addressed in order to meet the SR. I IFQU- IFQU-A5 Finding Y It appears that no inter-HEP This F&O was entered into the BVPS No impact to Fire PRA, A5-01 dependency analysis Notification System as BV2 Notification because this issue was (between flood and non- #600689091, Task 16, to track and addressed in the base flood HEPs) was performed. resolve the issues. As a resolution to PRA model prior to Dependency between HEPs this IFPRA Peer Review finding, Section building the Fire PRA.

can significantly increase 10.4.6 (Dependencies between Human the probabilities of Interactions) of the Internal Flooding combinations of HEPs. Analysis Notebook (PRA-BV2-AL-R05a)

However, Section 10.4 of was revised to state that an HRA the internal flooding PRA dependency analysis was performed Page 298 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N I reports states (documented in Reference 13.4) and "Dependencies between the that a discussion on the "HFE flood mitigation human Dependencies in Internal Flooding PRA actions and the non-flood Accident Sequences" is provided in the human actions modeled in Human Reliability Analysis PRA the remaining part of the Notebook, Section 2.3.

PRA model were judged to be minimal due to the significant difference in the Section 10.4.6 was also expanded to nature of the actions (e.g., reiterate Section 10.4.3 (Screening and flood mitigation actions Detailed Analysis) discussion on the require field investigation by multiplier factor applied to HEPs the auxiliary operators, etc.) included in the Internal Events PRA and separation in time, etc., based on such factors as the location of and as such no additional the action, the timing of the action, and dependency treatment was stress, etc., and to include a discussion considered needed." An of the Riskman modeling analysis evaluation of the HEP approach which human actions included combinations should be are evaluated conditionally based on the documented to demonstrate success or failure status of the this conclusion, preceding human action(s). As such, dependencies among the human failure events in the Internal Events model (i.e.,

non-flood human actions) were fully accounted.

IFQU- IFQU-A7 Finding Y Performance of the internal This F&O was entered into the BVPS No impact to Fire PRA, A7-01 flood events quantification Notification System as BV2 Notification because this issue was should be consistent with #600689091, Task 12, to track and addressed in the base the quantification of the resolve the issues. As a resolution to PRA model prior to internal events PRA. The this IFPRA Peer Review finding, building the Fire PRA.

quantification of the internal analysis and discussion has been flooding requires that provided for performance of I applicable requirements quantification with the applicable I Page 299 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed Y/N from the Internal Events requirements. QU-B3 requirements Quantification section be have been documented in Section met. The current section on 12.4.4 of the Internal Flooding Analysis Internal Flooding does not Notebook (PRA-BV2-AL-R05a),

include a discussion of the Truncation Evaluation. The QU-B7 topics addressed in Section requirements have been documented in 2-2.7 of the ASME/ANS Section 12.5.3, Mutually Exclusive Combined PRA Standard. Events. QU-Cl & QU-C2 requirements have been documented in Section 12.5.4, HFE Dependency (see References 13.4 and 13.5). QU-D1 &

QU-D2 requirements have been documented in Section 12.5.5 Significant CDF Sequences and Accident Category (for CDF) and Section 12.5.8 Significant LERF Sequences and Accident Category (for LERF). QU-D4 requirements have been documented in Section 12.5.2 Internal Flooding Comparison Between Plants and Table 12-5. QU-D6 requirements have been documented in Sections 12.5.5 - 12.5.7, and 12.3 for significant contributions to CDF. QU-D7 requirements have been documented in Section 12.5.6 for system importance that is based on importance for I components and basic events. I Page 300 of 301

Table 2-4. Summary of BVPS-2 Internal Flooding Focused Peer Review - Facts and Observations Resolutions F&O Supporting. Significance Status Fact & Observation BVPS-2 Final Resolution Impact to Fire PRA ID Requirement Level Closed IFQU- IFQU-A10 Suggestion I YIN Y Internal flooding contribution This F&O was entered into the BVPS INo impact to Fire PRA, Al0- to LERF should be Notification System as BV2 Notification because this issue was 01 documented in some way #600689091, Task 11, to track and addressed in the base so that the apparent impacts resolve the issues. As a resolution to PRA model prior to on LERF from the flooding this IFPRA Peer Review suggestion, building the Fire PRA.

events could be reviewed. Section 12.5.8 of the Internal Flooding The discussion concerning Analysis Notebook (PRA-BV2-AL-R05a) the impacts on LERF for contains a review of internal flooding internal flooding events LERF sequences and accident could be improved to categories which describes impacts that discuss flooding impact on are evaluated in internal flooding LERF the different features used analysis.

to mitigate releases.

IFQU- IFQU-B2, Finding Y The process used for This F&O was entered into the BVPS No impact to Fire PRA, B2-01 IFQU-B1 quantification documents Notification System as BV2 Notification because this issue was the calculation, screening, #600689091, Task 13, to track and addressed in the base scenarios deleted and resolve the issues. As a resolution to PRA model prior to walkdowns. However, there this IFPRA Peer Review finding, the building the Fire PRA.

is not enough supporting requirements listed in HLR-documentation of the QU-D have been completed in the quantification process Internal Flooding Analysis Notebook specifically concerning the (PRA-BV2-AL-RO5a) Section 12.5 PRA Standard requirements Results and Insights.

listed in HLR-QU-D. The SR requires that documentation must be consistent with the requirements described in HLR-QU-D. These requirements are not discussed at any point in the internal flooding PRA I reports.

Page 301 of 301

v t e Letter Sequence Supplement
TAC:MF3301, (Open) TAC:MF3302, (Open)
Initiation Acceptance Supplement Administration Questions 11 May 2015 Answers 27 April 2015 26 June 2015 Results Approval... Other: L-14-181, Online Reference Portal for Review of National Fire Protection Association Standard 805 License Amendment Application, ML14122A106, ML15027A235, ML15203A188
MONTHYEAR2015-01-28 [Table View]

L-14-064, Supplemental Information Regarding Application for License Amendment to Adopt NFPA 805, Performance Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition)

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L-14-064, Supplemental Information Regarding Application for License Amendment to Adopt NFPA 805, Performance Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition)

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