LR-N18-0109, Response to Request for Additional Information, License Amendment Request: Inverter Allowed Outage Time (AOT) Extension

Response to Request for Additional Information, License Amendment Request: Inverter Allowed Outage Time (AOT) Extension

ML18291B038
Person / Time
Site:	Hope Creek
Issue date:	10/17/2018
From:	Carr E Public Service Enterprise Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EPID L-2018-LLA-0101, LAR H18-02, LR-N18-0109
Download: ML18291B038 (16)

Text

PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, New Jersey 08038-0236 10 CFR 50.90 LR-N18-0109 LAR H18-02 ocr 1' 2o1s U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Hope Creek Generating Station Renewed Facility Operating License No. NPF-57 NRC Docket No. 50-354

Subject:

Response to Request for Additional Information, Re: License Amendment Request: Inverter Allowed Outage Time (AOT) Extension

References:

1. PSEG letter to NRC, "License Amendment Request: Inverter Allowed Outage Time (AOT) Extension" dated April 13, 2018 (ADAMS Accession No. ML18103A218)

2. NRC email to PSEG, "Hope Creek AOT Final RAI-from PRA Branch," (EPID L-2018-LLA-0101) dated September 12, 2018 (ADAMS Accession No. ML18263A144)

In the Reference 1 letter, PSEG Nuclear LLC (PSEG) submitted a license amendment request for Hope Creek Generating Station. The proposed amendment would revise Technical Specifications to increase the Alternating Current (AC) Inverters allowed outage time (AOT) from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days. In Reference 2, the Nuclear Regulatory Commission (NRC) requested PSEG to provide additional information in order to evaluate the proposed License Amendment Request to revise Technical Specifications. The response due date was subsequently extended to October 19, 2018 at PSEG's request. to this letter provides a restatement of the RAI questions followed by our responses. PSEG has determined that the information provided in this submittal does not alter the conclusions reached in the 10 CFR 50.92 no significant hazards determination previously submitted. In addition, the information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.

There are no regulatory commitments contained in this letter.

In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," paragraph (b), PSEG is providing a copy of this response, with attachments, to the designated State of New Jersey Official.

OCT l 7 1 0 18 Page 2 LR-N18-0109 Should you have any questions regarding this submittal, please contact Mr. Lee Marabella at 856-339-1208.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on (Date)

Eric Carr Site Vice President Hope Creek Generating Station Attachments:

1. Response to Request for Additional Information - License Amendment Request to Revise Technical Specification 3.8.3.1 Regarding Alternating Current Inverters cc: Administrator, Region I, NRC Mr. J. Kim, Project Manager, NRC NRC Senior Resident Inspector, Hope Creek Mr. P. Mulligan, Chief, NJBNE Hope Creek Commitment Tracking Coordinator Corporate Commitment Tracking Coordinator

LR-N18-0109 Attachment 1 Response to Request for Additional Information - License Amendment Request to Revise Technical Specification 3.8.3.1 Regarding Alternating Current Inverters

LR-N18-0109 By letter dated April 13, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML18103A218), PSEG Nuclear LLC (PSEG) submitted a license amendment request (LAR) [1] regarding the Hope Creek Generating Station. The proposed amendment would revise Technical Specification (TS) 3.8.3.1, Distribution - Operating, to increase the allowed outage time (AOT) for one or both inverters inoperable in one channel from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days.

By email dated September 12, 2018, the NRC staff requested additional information to complete the review of the LAR.

Below is a restatement of the questions followed by our responses.

Question 1 (APLA RAI-1)

Section 3.2.1 and Attachment 2 of the LAR provides a very detailed discussion about the licensees evaluation of the technical adequacy of the full-power internal events (FPIE) PRA to support the proposed amendment. The discussion includes some details that appear unnecessary, e.g. an extensive discussion of a 1999 peer review and results that were superseded by a 2008 full scope peer review. Other details are difficult to interpret, e.g., that the 2008 peer review was performed using the 2007 American Society of Mechanical Engineers (ASME) ASME PRA Standard endorsed in Regulatory Guide (RG) 1.200 Rev. 1 whereas Rev. 1 of RG 1.200 endorses, with qualifications, the ASME RA-Sb-2005 PRA Standard.

A previous staff review described in Hope Creek Generating Station - Issuance of Amendment RE: Technical Specification Change for Permanent Extension to Type A and Type C Containment Leak Rate Test Frequencies (ADAMS Accession No. ML17291A209) indicated

that, an independent full-scope peer review of the internal events and internal flooding PRA model was performed in 2008 against the requirements set forth in the 2005 version of the ASME PRA standard and the qualifications provided in the staff's endorsement of that standard in RG 1.200, Revision 1. The peer review was performed against the CC II Supporting Requirements. Following PRA model revisions arising from the peer review, the licensee performed a self-assessment of the Hope Creek [full-power internal events] FPIE PRA model in 2011 to determine if there were any gaps present between the Hope Creek FPIE PRA model and the CC II Supporting Requirements in the 2009 version of the ASME/American Nuclear Society.

Section 3.2.1 of the LAR further added that more recently [t]he Full Power Internal Events and Flooding PRA was the subject of a Facts and Observations (F&Os) closure review completed by the BWR Owners Group in August 2017 [15]. At this time, there are no F&Os that are considered open.

Please confirm that the above summary of the internal events PRA reviews is current and correct or provide correction and clarification.

2

LR-N18-0109

Response

The above summary of PRA reviews is accurate, with one minor correction.

Upon review of the FPIE models documented history, it was determined that the evaluation supporting Hope Creek Generating Station - Issuance of Amendment RE: Technical Specification Change for Permanent Extension to Type A and Type C Containment Leak Rate Test Frequencies was incorrect in stating that the 2008 peer review was performed against the RA-Sb-2005 [2] standard. The peer review report [3] identifies RA-Sc-2007 [4] as the standard used in the review teams evaluation.

However, it is noted that RA-Sc-2007 is a very minor revision to the ASME Standard, comprising the addition of a non-mandatory appendix clarifying the distinction between PRA maintenance and upgrades as well as some front matter errata. No changes to the Supporting Requirements or any other technical items are identified, rendering it functionally equivalent to RA-Sb-2005. Therefore, the conclusions of the 2008 peer review would have been the same under RA-Sb-2005 as RA-Sc-2007.

While preparing this RAI response, the PSEG team noted that the gap assessment of differences between the 2008 peer reviewed model and the current model has not been explicitly reviewed by an independent team. Therefore, PSEG concluded that this should be performed and reported to the NRC as part of the discussion of PRA technical adequacy. Since there are no SR differences between RA-Sb-2005 and RA-Sc-2007, the gap assessment provided below directly follows guidance in NEI 05-04 [5].

1. Overview of High Level Requirement and Supporting Requirement Changes (NEI 05-04 Section 3.3)

In general, the changes to the ASME/ANS PRA standard high level requirements (HLRs) and SRs in the transition from Addendum B (ASME RA-Sb-2005) through Revision 1, Addendum A (ASME/ANS-RA-Sa-2009) were minor and include the following:

Incorporation into the ASME/ANS PRA Standard issues that were identified by the NRC in RG 1.200, Revision 1 [6],

Renumbering of the ASME/ANS PRA Standard HLRs and SRs to remove deleted SRs and SRs ending with a letter (for example, SR QU-A2a); as listed in Appendix F of NEI 05-04, Revision 3, Changes in the cross-references updated to the new tables, and Corrections of typographical and grammar errors, and changes in wording.

However, there were a few examples of changes to either the ASME/ANS PRA standard or the RG 1.200, Revision 2 that would require re-evaluation of the PRA against the ASME/ANS PRA Standard requirements. These are discussed in the following sections.

2. Supporting Requirements Requiring Re-evaluation (NEI 05-04 Section 3.3.1)

SRs that require re-evaluation are those SRs that have changed significantly, including those with new issues identified in RG 1.200, Revision 2; these SRs are provided in Table 1.

3

LR-N18-0109 Table 1 SUPPORTING REQUIREMENTS REQUIRING GAP ASSESSMENT RE-EVALUATION ASME/ANS RG 1.200, Rev. 1 to Rev. 2 Gap RA-Sa-2009 NEI 05-04, Revision 3, Table 3-2 Assessment Re-evaluation and Supporting Comments Capability Category (CC)

Requirement Meets: The HCGS HRA models characterize the uncertainty in the estimates of the human error RG 1.200, Revision, 2 provides probabilities (HEPs) consistent with the HR-D6 clarification that should be quantification approach and use mean evaluated. values in the quantification of the PRA results. Uncertainty cases are also provided using the 50th and 95th percentiles of the HEPs.

CC I, II, III: The HCGS HRA models use the EPRI HRA calculator, which includes a discussion of the specific scenario to RG 1.200, Revision 2, provided evaluate; the (d) degree of clarity of the clarification to items (d) and (g) of cues/indications in supporting the HR-G3 the SR. Some of the RG 1.200, detection, diagnosis, and decision-Revision 1 wording remains, while making give the plant clarification and some additional clarification is scenario-specific context of the event, provided.

and (g) complexity of detection, diagnosis, and decision-making and executing the required response.

Meets: The HCGS PRA models only take credit for repairing the emergency diesel generators (EDGs) in the electric RG 1.200, Rev. 1, included a new power recovery (EPR) model. This EPR SR - DA-08. The recommended New DA SR model uses a convolution methodology new SR is included in RG 1.200, to calculate the probability of recovering Rev. 2, as DA-D9 (with the offsite power or repairing an EDG in time renumbering).

to prevent core damage as a function of the accident sequence in which the SSE failure appears.

Meets: The HCGS PRA models provide estimates of the individual sequences in a manner consistent with the estimation of CDF and LERF to identify significant QU-A2 Need to ensure QU-A2 evaluates accident sequences and confirm that the LERF results.

logic is appropriately reflected. These estimates are accomplished by quantifying the individual accident sequences.

4

LR-N18-0109 Table 1 SUPPORTING REQUIREMENTS REQUIRING GAP ASSESSMENT RE-EVALUATION ASME/ANS RG 1.200, Rev. 1 to Rev. 2 Gap RA-Sa-2009 NEI 05-04, Revision 3, Table 3-2 Assessment Re-evaluation and Supporting Comments Capability Category (CC)

Requirement CCII: The HCGS PRA models are quantified using PRAQuant. UNCERT is used to determine the mean CDF and QU-A3 Need to ensure QU-A3 evaluates LERF to be estimated by correlating LERF results.

event probabilities. When propagating uncertainty distributions, the CDF and LERF are estimated.

Meets: Both RG 1.200, Rev. 1, Table A-1. "Staff Position on ASME RA-S-2002, ASME RA-Sa-2003, and ASME RA-Sb-2005," and RG 1.200, Rev. 2, Table A-2. "Staff Position on RG 1.200, Rev. 2, provides ASME/ANS RA-Sa-2009 Part 2, clarification that should be Technical and Peer Review QU-B5 evaluated. Need to verify breaking Requirements for At-Power Internal logic loops does not result in Events" have "No objection" to undue conservatism. SR QU85. Furthermore, the HCGS PRA model logical loops are broken in a manner that still permits each dependency to be accounted for when quantified using event trees with conditional split fractions.

Meets: The CAFTA event tree linking quantification process that is used by the HCGS PRA models account for system successes in addition to system failures in the evaluation of accident sequences QU-B6 Need to ensure QU-B6 evaluates to the extent needed for realistic LERF results. estimation of CDF and LERF. This accounting is accomplished by using numerical quantification of success probability. Since the event trees are linked, all "successes" are transferred between event trees.

CCII: The HCGS PRA models take into account the "state of knowledge" correlation between selected parameter QU-E3 Need to ensure QU-E3 evaluates distributions, propagate these LERF results. uncertainties through a Monte Carlo quantification using UNCERT, and calculate the estimated CDF and LERF distributions.

5

LR-N18-0109 Table 1 SUPPORTING REQUIREMENTS REQUIRING GAP ASSESSMENT RE-EVALUATION ASME/ANS RG 1.200, Rev. 1 to Rev. 2 Gap RA-Sa-2009 NEI 05-04, Revision 3, Table 3-2 Assessment Re-evaluation and Supporting Comments Capability Category (CC)

Requirement Revision 1, Addendum A of the Meets: The HCGS PRA models identify ASME/ANS Standard rewords this QU-E4 sources of model uncertainty and their SR. Additionally, RG 1.200, related assumptions, as well as how the Rev. 2, provides clarification to PRA model is affected by these.

remove Note 1.

Flooding SRs:

IFPP-B1, B2, Meets: The HCGS Internal Flooding PRA B3, model documentation is consistent with IFSO-B1, B2, These are new requirements for the SRs. All technical determinations of B3, flooding that expand on the the internal flooding analysis, as well as IFSN-B1, B2, original SRs in the ASME/ANS the methodologies and sources of B3, PRA Standard. uncertainty involved, are documented.

IFEV-B1, B2, Additionally, the uncertainty in CDF and B3, LERF is addressed by using UNCERT.

IFQU-B1, B2, B3.

CCIII: The HCGS Internal Flooding PRA RG 1.200, Rev. 2, provides model included investigation into IFSN-A6 clarification that should be component failure due to flooding, evaluated. induced jet impingement, humidity, condensation, temperature, etc.

3. Supporting Requirements that May Require Re-evaluation (NEI 05-04 Section 3.3.2)

A number of the SRs changed in the ASME/ANS PRA standard as a result of the NRC comments to remove the word "key" with respect to assumptions and sources of (modeling) uncertainty.

The NEI guidance suggests that if the original peer review or self-assessment did evaluate the PRA against these NRC-recommended wording changes, but the SR was assessed as "Not Met", then it may be useful for the gap assessment to include a re-evaluation of these eleven impacted SRs once the methods are modified per the disposition of the applicable F&O. The assessment of these affected SRs is provided in Table 2.

6

LR-N18-0109 Table 2 SUPPORTING REQUIREMENTS AFFECTED BY "KEY" ASSUMPTIONS AND UNCERTAINTY REQUIRING GAP ASSESSMENT RE-EVALUATION ASME/ANS 2009 HCGS Peer RA-Sa-2009 RG 1.200, Rev. 1 to Rev. 2 Gap Review SR Associated F&O Supporting Re-evaluation Capability Category Requirement Meets: Previously assessed as IE-D3 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as AS-C3 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as SC-C3 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as SY-C3 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as HR-I3 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as DA-E3 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as QU-E1 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as QU-E2 Meets None "Meets." No re-evaluation required.

Meets: Previously assessed as QU-F4 Meets None "Meets." No re-evaluation required.

LE-D6 (LE-D5 in N/A None Not applicable to BWRs ASME RA-Sb-2005)

Meets: Previously assessed as LE-G4 Meets None "Meets." No re-evaluation required.

4. SRs Not Requiring Re-evaluation (NEI 05-04 Section 3.3.3)

A number of the SRs changed between Addendum B (ASME RA-Sb-2005) and Revision 1, Addendum A of the ASME/ANS PRA standard (ASME/ANS RA-Sa-2009) do not require re-evaluation during a gap assessment. These include the numbering changes to the SRs and minor editorial changes. NEI 05-04 Rev. 3, Appendix F provides a cross-reference table of the SR numbering changes.

5. Conclusions There were some editorial revisions and clarifications to the internal events PRA standard from the 2005 version to Part 2 (Internal Events) of the 2009 combined standard. The NRC, in RG 1.200, Rev. 2, endorsed this combined standard and did not identify any exceptions. The internal events supporting requirements are essentially the same in the two standards since there are no substantive technical changes to the internal events PRA standard. This, along with the NEI 05-04 Section 3.3 gap assessment provided above for the HCGS internal events PRA model, qualifies the 7

LR-N18-0109 HCGS internal events and internal flooding PRA models as fully compliant with RG 1.200, Rev. 2, at Capability Category II or better. Therefore, the HCGS internal events PRAs based on RG 1.200, Rev. 1 also conform to RG 1.200, Rev. 2, and use of the current HCGS PRA models to perform the inverter allowed outage time risk assessment is justified.

The LARs statement in Section 3.2.1 regarding the results of the August 2017 F&O Closure Review is unclear in its reference to open F&Os. This passage should more appropriately read:

The Full Power Internal Events and Flooding PRA was the subject of a Facts and Observations (F&Os) closure review completed by the BWR Owners Group in August 2017 [ref]. At this time, there are no F&Os that are considered open all FPIE Supporting Requirements are met at Capability Category (CC) II.

This wording more precisely communicates the relevancy of the Peer Review results.

Question 2 (APLA RAI-2)

In Section 3.2.1 of the LAR, the licensee states that in November 2010 it completed a full-scope peer review of its then current base Fire PRA. However, the licensee does not provide any details as to which standard the peer review was conducted against or what peer review method was used.

Please provide a discussion summarizing the standard to which the peer review was conducted against and the peer review method that was used.

Response

The peer review was conducted against the ASME/ANS RA-Sa-2009 PRA Standard [7] using the process defined in NEI 07-12 [8] and the clarifications provided by the NRC in Regulatory Guide 1.200, Rev. 2 [9]. It was a full-scope evaluation of all technical elements and Supporting Requirements of the Standard and involved extensive, iterative review of all PRA documentation over the course of several weeks. This process included a week-long onsite meeting to facilitate direct question- and-answer sessions between the PRA development and review teams, as well as a plant walkdown to confirm the treatment of spatial dependencies.

Question 3 (APLA RAI-3)

In the resolution to F&O 5-40, the licensee states that joint human error probabilities (JHEPs) are not risk-significant for the inverters or the reported risk evaluation.

Please characterize the process used to determination that JHEPs are not significant for the risk from inverters and provide any quantitative results.

Response

While there are several JHEPs with a contribution to the change in FPIE CDF and / or LERF, the conclusion of the risk evaluation is not particularly sensitive to these inputs. During the initial analysis supporting the LAR, this conclusion was based on the analysts review of the cutsets 8

LR-N18-0109 contributing to the risk increase. In this response, PSEG develops a quantitative sensitivity analysis. Even assuming a large change in the values of these JHEPs, the calculated values of CDFAVE / ICCDP and LERFAVE / ICLERP are still far below the acceptance limits.

To begin, Table 3-3 through Table 3-5 from the LAR submittal, which summarize these risk metrics, are reproduced as Table 3 through Table 5 below for reference.

Table 3

SUMMARY

OF QUANTIFIED CDF Internal Events Fire Total Case CDF (/yr) CDF(/yr) CDF (/yr)

Base Case MOR 5.91E-06 1.80E-05 2.39E-05 Channel A Inverters OOS 1.02E-05 1.92E-05 2.94E-05 Channel B Inverters OOS 1.13E-05 1.99E-05 3.13E-05 Channel C Inverters OOS 9.95E-06 1.88E-05 2.87E-05 Channel D Inverters OOS 1.02E-05 1.82E-05 2.85E-05 This table is a reproduction of Table 3-3 in Reference [1]

Table 4

SUMMARY

OF QUANTIFIED LERF Internal Events Fire Total Case LERF (/yr) LERF (/yr) LERF (/yr)

Base Case MOR 1.84E-07 2.25E-06 2.44E-06 Channel A Inverters OOS 4.43E-07 2.48E-06 2.92E-06 Channel B Inverters OOS 6.02E-07 2.28E-06 2.88E-06 Channel C Inverters OOS 4.54E-07 2.45E-06 2.90E-06 Channel D Inverters OOS 4.85E-07 2.28E-06 2.77E-06 This table is a reproduction of Table 3-4 in Reference [1]

9

LR-N18-0109 Table 5 COMPARISON OF QUANTITATIVE RESULTS WITH ACCEPTANCE GUIDELINES (TOTAL OF INTERNAL AND EXTERNAL EVENTS)

CDFAVE ICCDP LERFAVE ICLERP Acceptance Criteria 1.00E-6 1.00E-7 Channel A Inverters OOS 1.06E-07 9.30E-09 Channel B Inverters OOS 1.41E-07 8.54E-09 Channel C Inverters OOS 9.19E-08 8.93E-09 Channel D Inverters OOS 8.65E-08 6.31E-09 This table is a reproduction of Table 3-5 in Reference [1]

Next, in order to gauge these metrics sensitivity to the JHEP values, the tables below develop a recalculation assuming a doubled contribution from the potentially risk-significant JHEPs for each channel. These are identified as those JHEPs with a Fussell-Vesely importance measure greater than 0.02 in the delterm cutsets (i.e., the change in cutsets between the base case Models of Record and the inverters taken out-of-service, as described in the LAR). Table 6 and Table 7 below list the relevant JHEPs and F-V values and recalculate the resulting CDFs and LERFs assuming these values were doubled.

Doubling the JHEP values is judged to be a significantly conservative sensitivity because of the breadth and depth associated with the model used to quantify them. Regarding breadth, each JHEP consists of several HEPs from both closely- and loosely-related activities. Some JHEPs are derived from HEPs related to high-pressure injection (closely-related, not very diverse),

while other JHEPs are derived from HEPs related to depressurization and suppression pool cooling (not closely-related, but more diverse). The JHEPs span the entirety of the set of HEPs, so applying this conservatism will touch on every aspect of the fault tree model. Regarding depth, while the doubling considered by this sensitivity case is applied to each JHEPs individual value, JHEPs are in actuality the end result of a highly analytical process. Each one incorporates information from multiple underlying independent HEPs, themselves systematically calculated in detail based on a number of performance shaping factors (such as timing, stress, procedure quality, and operator cues), composing them together in a holistic manner via the dependency analysis. Therefore, an imposed increase in a JHEPs final value really represents a host of increases in those underlying parameters. The resulting overall conservatism is the convolution of these many smaller conservatisms.

JHEPs do not appear in the Fire delterm cutsets at all, and therefore the Fire CDFs and Fire LERFs will not change in this sensitivity analysis.

10

LR-N18-0109 Table 6 EFFECT OF DOUBLED RISK-SIGNIFICANT JHEPS (FPIE CDF)

Channel Channel Channel Channel D A B C LAR Base Case MOR 5.91E-06 5.91E-06 5.91E-06 5.91E-06 CDF With Inverters OOS 1.02E-05 1.13E-05 9.95E-06 1.02E-05 FDEPGROUP-XHD246 0.035 Delterm F-V FDEPGROUP-XHD455 0.161 0.152 JHEPs FDEPGROUP-XHD244 0.152 0.143 FDEPGROUP-XHD456 0.139 0.131 Importance FDEPGROUP-XHD421 0.081 0.076 (Assume the contribution Sensitivity of these JHEPs is 1.02E-05 1.15E-05 1.21E-05 1.24E-05 CDF doubled)

(There are no risk-significant JHEPs for Channel A)

Table 7 EFFECT OF DOUBLED RISK-SIGNIFICANT JHEPS (FPIE LERF)

Channel Channel Channel A Channel D B C LAR Base Case MOR 1.84E-07 1.84E-07 1.84E-07 1.84E-07 LERF With Inverters OOS 4.43E-07 6.02E-07 4.54E-07 4.85E-07 FDEPGROUP2-XHD154 0.027 Delterm F-V FDEPGROUP2-XHD169 0.056 JHEPs FDEPGROUP2-XHD182 0.250 0.226 FDEPGROUP2-XHD175 0.083 0.075 Importance FDEPGROUP2-XHD145 0.071 0.064 (Assume the Sensitivity contribution of these 4.50E-07 6.26E-07 5.63E-07 5.95E-07 LERF JHEPs is doubled)

Finally, these new FPIE CDFs and LERFs may now be substituted back into Table 3 through Table 5 to recalculate the new CDFAVE / ICCDPs and LERFAVE / ICLERPs for this sensitivity case. Tables 8 through Table 10 develop these updated values.

11

LR-N18-0109 Table 8

SUMMARY

OF QUANTIFIED CDF -

DOUBLED JHEP SENSITIVITY Internal Events Fire Total Case CDF (/yr) CDF(/yr) CDF (/yr)

Base Case MOR 5.91E-06 1.80E-05 2.39E-05 Channel A Inverters OOS 1.02E-05 1.92E-05 2.94E-05 Channel B Inverters OOS 1.15E-05 1.99E-05 3.14E-05 Channel C Inverters OOS 1.21E-05 1.88E-05 3.09E-05 Channel D Inverters OOS 1.24E-05 1.82E-05 3.06E-05 Table 9

SUMMARY

OF QUANTIFIED LERF -

DOUBLED JHEP SENSITIVITY Internal Events Fire Total Case LERF (/yr) LERF (/yr) LERF (/yr)

Base Case MOR 1.84E-07 2.25E-06 2.44E-06 Channel A Inverters OOS 4.50E-07 2.48E-06 2.93E-06 Channel B Inverters OOS 6.26E-07 2.28E-06 2.91E-06 Channel C Inverters OOS 5.63E-07 2.45E-06 3.01E-06 Channel D Inverters OOS 5.95E-07 2.28E-06 2.87E-06 12

LR-N18-0109 Table 10 COMPARISON OF QUANTITATIVE RESULTS WITH ACCEPTANCE GUIDELINES (TOTAL OF INTERNAL AND EXTERNAL EVENTS) -

DOUBLED JHEP SENSITIVITY CDFAVE ICCDP LERFAVE ICLERP Acceptance Criteria 1.00E-6 1.00E-7 1.06E-07 9.51E-09 Channel A Inverters OOS

(+0%) (+2%)

1.44E-07 9.04E-09 Channel B Inverters OOS

(+2%) (+6%)

1.34E-07 1.11E-08 Channel C Inverters OOS

(+46%) (+24%)

1.28E-07 8.45E-09 Channel D Inverters OOS

(+48%) (+34%)

Even though doubling the JHEPs greatly exaggerates their contribution to the risk metrics, Channels A and B are barely affected, showing at most a 6% change. Channels C and D share several high-importance JHEPs and display an accordingly large increase, ranging from 24 -

48%. However, even this only brings them into rough parity with the other two channels. All metrics remain about an order of magnitude below the RG 1.174 [10] and 1.177 [11] acceptance limits. Therefore, the results are not sensitive to the values of JHEPs and using bounding estimates does not alter the conclusions of the risk evaluation or the acceptability of the inverter allowed outage time extension proposed by the LAR.

References:

[1] PSEG, "LR-N18-0032, License Amendment Request: Inverter Allowed Outage Time (AOT)

Extension," 13 April 2018.

[2] ASME/ANS, "RA-Sb-2005: Addenda to ASME RA-S-2002: Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications".

[3] PSEG, "Hope Creek Generating Station PRA Peer Review Report Using ASME PRA Standard Requirements," March 2009.

[4] ASME/American Nuclear Society, "ASME RA-Sc-2007, Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications," August 2007.

[5] NEI, "NEI 05-04, Process for Performing Internal Events PRA Peer Reviews Using the ASME/ANS PRA Standard, Rev. 3".

[6] USNRC, "Regulatory Guide 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, Revision 1," January 2007.

[7] ASME/American Nuclear Society, "ASME/ANS RA-Sa-2009, Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications," March 2009.

13

LR-N18-0109

[8] NEI, "NEI 07-12, Fire Probabilistic Risk Assessment (FPRA) Peer Review Process Guidelines, Revision 1," June 2010.

[9] USNRC, "Regulatory Guide 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, Revision 2," March 2009.

[10] USNRC, "Regulatory Guide 1.174: An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, Revision 3,"

January 2017.

[11] USNRC, "Regulatory Guide 1.177: An Approach for Plant-Specific, Risk-Informed Decision-Making: Technical Specifications, Rev. 1," May 2011.

14