L-MT-18-053, Thirty Day Report of Changes in the Emergency Core Cooling System Evaluation Models Pursuant to 10 CFR 50.46

From kanterella
Jump to navigation Jump to search
Thirty Day Report of Changes in the Emergency Core Cooling System Evaluation Models Pursuant to 10 CFR 50.46
ML18271A138
Person / Time
Site: Monticello Xcel Energy icon.png
Issue date: 09/28/2018
From: Church C
Northern States Power Co, Xcel Energy
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
L-MT-18-053
Download: ML18271A138 (4)


Text

2807 West County Road 75 Monticello, MN 55362

~ Xcel Energy*

RES PONS I B LE BY NATURE 800.895.4999 xcelenergy.com September 28, 2018 L-MT-18-053 10 CFR 50.46 (a)(3)(ii)

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket No. 50-263 Renewed Facility Operating License No. DPR-22 Thirty Day Report of Changes in the Emergency Core Cooling System Evaluation Models Pursuant to 10 CFR 50.46 Pursuant to 10 CFR 50.46(a)(3)(ii), the Northern States Power Company, a Minnesota corporation (NSPM), doing business as Xcel Energy, is providing this 30 day report concerning changes or errors identified in the Emergency Core Cooling System (ECCS) evaluation for the Monticello Nuclear Generating Plant (MNGP).

This thirty-day report is being made due to recent issuance of a notification letter from Framatome for changes or errors to the current, Analysis of Record (AOR). These changes exceeded the 50°F threshold in 10 CFR 50.46(a)(3)(i) for a significant increase in PCT.

Provided within Enclosure 1 is a summary of the changes or errors identified in the Framatome's 10 CFR 50.46 PCT Reporting Estimates for MNGP. This error pertains only to the ATRIUM 10XM fuel.

The adjusted licensing basis PCT is 2090°F for the ATRIUM' 10XM fuel. This PCT is 110°F below the 2200°F acceptance criterion of 10 CFR 50.46(b)(1). This provides sufficient margin to justify taking no further action.

Should you have questions regarding this letter, please contact Mr. David Gerads at (763) 295-1046.

Summary of Commitments

/~///'tt~

es no new commitments and no revisions to existing commitments.

Christopher R. Church Site Vice President, Monticello Nuclear Generating Plant Northern States Power Company - Minnesota Enclosure (1)

Cc: Administrator, Region Ill, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC

ENCLOSURE 1 Monticello Nuclear Generating Plant Table 1 Summary of Monticello LOCA Changes and Errors Involving Changes in Peak Cladding Temperature (PCT) for Atrium 10XM Fuel

TABLE 1 -

SUMMARY

OF MONTICELLO LOCA CHANGES AND ERRORS INVOLVING CHANGES IN PEAK CLADDING TEMPERATURE (PCT) FOR ATRIUM 10XM FUEL Licensing Basis Applicable Analysis or Error/Change Description Ref.

PCT(°F) 10XM ANP-3558P Revision 0, Monticello LOCA MAPLHGR Limits for EPU/EFW with ATRIUM 10XM Fuel and Revised ECCS Parameters 2-1 2034 MSIV closure The impact of this MSIV closure change was estimated for the Monticello 2-2 +51 LOCA break spectrum and exposure-dependent MAPLHGR analyses.

Updated steam dryer information A review of the steam dryer related inputs identified a need to update the 2-3 +5 input for the dryer region.

Sum of absolute value of changes since the last 10 CFR 50.46 report (Reference 2-4). 5 Sum of absolute value of changes since last AOR (Reference 2-1). 56 Algebraic sum of changes since the last 10 CFR 50.46 report (Reference 2-4). +5 Algebraic sum of changes since last AOR (Reference 2-1). +56 Current Adjusted Peak Cladding Temperature 2090 References 2-1. ANP-3558P Revision 0, "Monticello LOCA MAPLHGR Limits for EPU/EFW with ATRIUM 10XM Fuel and Revised ECCS Parameters," January 2017.

2-2. FS1-0032297, Revision 1.0, "Monticello 10 CFR 50.46 PCT Reporting for ATRIUM 10XM Fuel Through May 2017," May 2017.

2-3. FS1-0039467, Revision 1.0, "Monticello 10 CFR 50.46 PCT Reporting Estimates for ATRIUM 10XM Fuel between August 2017 and August 2018," August 2018.

2-4. L-MT-17-086, 2017, letter from C. Church (Xcel Energy) to USNRC, "2017 Annual Report of Changes in Emergency Core Cooling System Evaluation Models Pursuant to 10 CFR 50.46," December 15, 2017.