L-MT-18-020, Supplement to License Amendment Request: Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Control

Supplement to License Amendment Request: Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Control

ML18114A401
Person / Time
Site:	Monticello
Issue date:	04/24/2018
From:	Church C Northern States Power Company, Minnesota, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EPID L-2017-LLA-0434, L-MT-18-020
Download: ML18114A401 (7)

Text

2807 West County Road 75 Monticello, MN 55362 fl, Xcel Energy*

RESPONSIBL E BY NATUR E 800.895.4999 xcelenergy.com April 24, 2018 L-MT-18-020 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket Number 50-263 Renewed Facility Operating License No. DPR-22 Supplement to License Amendment Request: Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (EPID L-2017-LLA-0434)

References:

1. NSPM Letter (L-MT-17-083) to NRC Document Control Desk, License Amendment Request: Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program, dated December 19, 2017 (ADAMS Accession No. ML17353A189)

2. Nuclear Energy Institute (NEI) 04-10, Risk-Informed Technical Specification Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies, Revision 1, dated April 2007 (ADAMS Accession No. ML071360456)

3. Technical Specifications Task Force (TSTF) Standard Technical Specifications (STS) Change TSTF-425, "Relocate Surveillance Frequencies to Licensee Control - [Risk Informed Technical Specifications Task Force] RITSTF Initiative 5b," Revision 3, dated March 18, 2009 (ADAMS Accession No. ML090850642)

Pursuant to 10 CFR 50.90, Northern States Power Company, a Minnesota corporation (NSPM), doing business as Xcel Energy, requested to amend renewed Facility Operating License DPR-22 for the Monticello Nuclear Generating Plant (MNGP) in Reference 1. The proposed amendment would modify the MNGP Technical Specifications (TS) by relocating specific surveillance frequencies to a licensee-controlled program with implementation of NEI 04-10, Risk-Informed Technical

Document Control Desk Page 2 Specification Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies," (Reference 2). The changes were consistent with NRG-approved lndustry/TSTF STS change TSTF-425, "Relocate Surveillance Frequencies to Licensee Control - [Risk Informed Technical Specifications Task Force] RITSTF Initiative 5b,"

Revision 3 (Reference 3).

After submittal of Reference 1, it was determined that errors existed in Attachment 2 of the license amendment request (LAR), which described the Probabilistic Risk Assessment (PRA) technical adequacy. Specifically, the errors were in Table 2-1 and involved the incorrect listing of Supporting Requirements (SRs) for two of the open Fire PRA Facts & Observations (F&Os). This supplement corrects the SRs of the two F&Os.

The enclosure to this letter describes the errors and identifies the correct SRs for the two F&Os. The attachment to the enclosure contains page replacements for the corrected SRs.

The information provided in this letter does not alter the evaluations performed in accordance with 10 CFR 50.92 in Reference 1. In accordance with 10 CFR 50.91, NSPM is notifying the State of Minnesota of this supplement to the LAR by transmitting a copy of the letter and enclosure to the designated State Official.

Please contact Sara Scott, Licensing Manager, at 612-330-6698, if additional information or clarification is required.

Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

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

-11,/4 Executed on April 24, 2018.

Christopher R. Church Site Vice President, Monticello Nuclear Generating Plant Northern States Power Company - Minnesota Enclosure cc: Administrator, Region Ill, USNRC Project Manager, Monticello Nuclear Generating Plant, USNRC Resident Inspector, Monticello Nuclear Generating Plant, USNRC State of Minnesota

L-MT-18-020 NSPM Enclosure ENCLOSURE Supplement to License Amendment Request: Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program

1.0 BACKGROUND

Pursuant to 10 CFR 50.90, Northern States Power Company, a Minnesota corporation (NSPM), doing business as Xcel Energy, requested to amend renewed Facility Operating License DPR-22 for the Monticello Nuclear Generating Plant (MNGP) in Reference 1. The proposed amendment would modify the MNGP Technical Specifications (TS) by relocating specific surveillance frequencies to a licensee-controlled program with implementation of NEI 04-10, Risk-Informed Technical Specification Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies, (Reference 2). The changes were consistent with NRC-approved Industry/TSTF STS change TSTF-425, "Relocate Surveillance Frequencies to Licensee Control - [Risk Informed Technical Specifications Task Force] RITSTF Initiative 5b,"

Revision 3 (Reference 3).

After submittal of Reference 1, it was determined that errors existed in Attachment 2 of the license amendment request (LAR), which described the Probabilistic Risk Assessment (PRA) technical adequacy. Specifically, the errors were in Table 2-1 and involved the incorrect listing of Supporting Requirements (SRs) for two of the open Fire PRA Facts & Observations (F&Os). This supplement corrects the SRs of the two F&Os.

The attachment to the enclosure contains page replacements for the corrected SRs.

2.0 DESCRIPTION

OF SUPPLEMENT Reference 1, Attachment 2, Table 2-1, lists each open Fire PRA F&O by identifier along with the associated SRs, a description of the peer review finding (F&O), a discussion of the resolution, and the impact of the F&O on the TSTF-425 application. The SRs listed for two of the F&Os in Table 2-1 were in error. These F&Os and the associated errors were:

F&O 4 An incorrect SR (SR FSS-C8) was inadvertently copied into the SR column instead of the relevant SRs (SRs FSS-C5 and FSS-D9) for the F&O. The proper SRs to reference are FSS-C5 and FSS-D9. These SRs address different issues than the quoted SR FSS-C8.

F&O FO Three of five SRs were erroneously not listed for F&O-2. The SRs not listed were FSS-H4, FSS-H5, and FSS-H9. The FSS-H SRs all pertain to documentation requirements.

Page 1 of 2

L-MT-18-020 NSPM Enclosure The affected pages have been updated and are provided as page replacements in the attachment to this enclosure. The changes are noted for F&O 4-20 and F&O FO-2 with right hand margin revision bars.

The errors are limited to the listing of the SRs in Table 2-1 of Reference 1. The corrections to the listed SRs do not change NSPMs conclusions regarding the PRA technical adequacy. The justifications provided in the TSTF proposal and the safety evaluation prepared by the NRC staff remain applicable to the MNGP and continue to justify the amendment to incorporate the changes to the MNGP TS. Additionally, the changes do not alter the evaluations performed in accordance with 10 CFR 50.92 in Reference 1.

3.0 REFERENCES

1. NSPM Letter (L-MT-17-083) to NRC Document Control Desk, License Amendment Request: Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program, dated December 19, 2017 (ADAMS Accession No. ML17353A189)

2. Nuclear Energy Institute (NEI) 04-10, Risk-Informed Technical Specification Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies, Revision 1, dated April 2007 (ADAMS Accession No. ML071360456)

3. Technical Specifications Task Force (TSTF) Standard Technical Specifications (STS) Change TSTF-425, "Relocate Surveillance Frequencies to Licensee Control - [Risk Informed Technical Specifications Task Force] RITSTF Initiative 5b," Revision 3, dated March 18, 2009 (ADAMS Accession No. ML090850642)

Page 2 of 2

L-MT-18-020 NSPM Enclosure ATTACHMENT Monticello Nuclear Generating Plant Supplement to License Amendment Request:

Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program PAGE REPLACEMENTS FOR PROBABILISTIC RISK ASSESSMENT (PRA)

TECHNICAL ADEQUACY (ATTACHMENT 2 OF ORIGINAL SUBMITTAL)

Replacement Pages for L-MT-17-083, Attachment 2:

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L-MT-17-083 NSPM Table 2-1 MNGP Open Fire PRA Peer Review Findings F&O Number SR Peer Review Finding Resolution Impact on Application cutsets indicate the correct basic event has not been chosen to be flagged. This particular example is not expected to be risk significant.

4. Individual components identified in Table D-1 of the ES notebook as not credited were not failed in the PRM

[e.g.FPAP1AXXXR12-S - CONDENSATE PUMP P-1A FAILS TO RUN (SHORT TERM)]

5. Conversely - Basic events that were not failed in the model, yet were not included in table C-1 as credited [e.g., ABSLPCIAXG -

LPCI MCC FAULT (MCC-133A)]

Finding 4-11 FSS-D4 From 2015 Full Scope Fire PRA Peer Validation studies of the three fire If the assumption of a Review: modeling models used in the fire 20°C ambient PRA were performed. In each case, temperature cannot be An initial ambient temperature of 20°C was the model biases are dispositioned justified for certain plant utilized in the fire modeling calculations for as reasonable for their use based areas, and the risk all MNGP fire zones. This ambient upon Chapter 4 of NUREG-1934. evaluations of specific temperature does not appear to be The F&O closure review team found STI changes could be appropriate for areas that are not the validation studies to be impacted by this temperature controlled such as the Turbine appropriate for cases in which the incorrect assumption, Building, Diesel Generator Building, and ambient temperature is 20°C or less. then sensitivity studies areas of the Reactor Building. Additional justification is required for would be performed on plant areas which may have higher a case by case basis.

ambient temperatures.

Finding 4-20 FSS-C5, From 2015 Full Scope Fire PRA Peer The fire PRA Single Compartment The effect of treatment FSS-D9 Review: Analyses have been updated to of the main control document the analysis associated board sensitive Although the damage criteria for sensitive with the treatment of sensitive electronics is unlikely to electronics is defined in the Single electronics. The F&O closure review impact the STI change Compartment Analysis Notebook 016015- team determined that the methods evaluations. The risk Page 17 of 27

L-MT-17-083 NSPM Table 2-1 MNGP Open Fire PRA Peer Review Findings F&O Number SR Peer Review Finding Resolution Impact on Application CFAST results have sensitivity cases due to ventilation-limited cases for the incorrect application the development of ventilation limited estimating the time to hot gas layer of this method, then conditions. The baseline CFAST results do formation. However, the F&O finding sensitivity studies not result in damage to a generic target closure review team identified issues would be performed on over a 60 minute time interval. The CFAST with the sensitivity case and its a case by case basis.

sensitivity cases that were originally run applicability in certain situations.

with additional ventilation to verify constant Additional justification concerning the exposure damage times would likely result treatment of the ventilation-limited in damage to a generic Thermoplastic (TP) modeling for those areas needs to target when assessed in the heat soak be developed.

model.

Finding FO-2 FSS-D4, From 2017 Focused Scope Fire PRA The various documentation issues This is a documentation FSS-D3, Peer Review: identified in this F&O have been issue and has no FSS-H4, addressed. However, the F&O impacts on quantitative FSS-H5, A number of documentation issues have finding closure review team results. Therefore it will FSS-H9 been identified. These include: determined that additional have no impact on STI information needs to be included in evaluations.

a) There are a number of scenarios that the documentation concerning the appear to credit the thermal heat soak impacts of accumulation of damage method listed in the Fire Modeling Database at low temperature on cables and on (FMDB) but the Hot Gas Layer (HGL) times the impacts of cable size on the heat do not match any scenario listed in Report soak methodology.

016015-RPT-06. An example is Equipment C-18 in tblIgnitionScenarios of the fire modeling database. Scenario 2 and the corresponding comment indicates HGL time is 25 minutes based on heat soak time.

Table J-6 in Section J-6 of Report 016015-RPT-06 does not list any damage times from any ignition source - secondary combustible grouping of 25 minutes. The database should be checked for additional examples and addressed as necessary.

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