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
| 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 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 fl, Xcel Energy*
RESPONSIBL E BY NATUR E
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.
Executed on April 24, 2018.
-11,/4 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 Page 1 of 2 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.
L-MT-18-020 NSPM Enclosure Page 2 of 2 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)
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:
Page 17 of 27 Page 24 of 27 (2 pages to follow)
L-MT-17-083 NSPM
Page 17 of 27
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 -
Finding 4-11 FSS-D4 From 2015 Full Scope Fire PRA Peer Review:
An initial ambient temperature of 20°C was utilized in the fire modeling calculations for all MNGP fire zones. This ambient temperature does not appear to be appropriate for areas that are not temperature controlled such as the Turbine Building, Diesel Generator Building, and areas of the Reactor Building.
Validation studies of the three fire modeling models used in the fire PRA were performed. In each case, the model biases are dispositioned as reasonable for their use based upon Chapter 4 of NUREG-1934.
The F&O closure review team found the validation studies to be appropriate for cases in which the ambient temperature is 20°C or less.
Additional justification is required for plant areas which may have higher ambient temperatures.
If the assumption of a 20°C ambient temperature cannot be justified for certain plant areas, and the risk evaluations of specific STI changes could be impacted by this incorrect assumption, then sensitivity studies would be performed on a case by case basis.
Finding 4-20 FSS-C5, FSS-D9 From 2015 Full Scope Fire PRA Peer Review:
Although the damage criteria for sensitive electronics is defined in the Single Compartment Analysis Notebook 016015-The fire PRA Single Compartment Analyses have been updated to document the analysis associated with the treatment of sensitive electronics. The F&O closure review team determined that the methods The effect of treatment of the main control board sensitive electronics is unlikely to impact the STI change evaluations. The risk
L-MT-17-083 NSPM
Page 24 of 27
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 the development of ventilation limited conditions. The baseline CFAST results do not result in damage to a generic target over a 60 minute time interval. The CFAST sensitivity cases that were originally run with additional ventilation to verify constant exposure damage times would likely result in damage to a generic Thermoplastic (TP) target when assessed in the heat soak model.
ventilation-limited cases for estimating the time to hot gas layer formation. However, the F&O finding closure review team identified issues with the sensitivity case and its applicability in certain situations.
Additional justification concerning the treatment of the ventilation-limited modeling for those areas needs to be developed.
the incorrect application of this method, then sensitivity studies would be performed on a case by case basis.
Finding FO-2 FSS-D4, FSS-D3, FSS-H4, FSS-H5, FSS-H9 From 2017 Focused Scope Fire PRA Peer Review:
A number of documentation issues have been identified. These include:
a) There are a number of scenarios that appear to credit the thermal heat soak method listed in the Fire Modeling Database (FMDB) but the Hot Gas Layer (HGL) times do not match any scenario listed in Report 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.
The various documentation issues identified in this F&O have been addressed. However, the F&O finding closure review team determined that additional information needs to be included in the documentation concerning the impacts of accumulation of damage at low temperature on cables and on the impacts of cable size on the heat soak methodology.
This is a documentation issue and has no impacts on quantitative results. Therefore it will have no impact on STI evaluations.