L-MT-17-043, Expedited Seismic Evaluation Process (ESEP) - Augmented Approach to Post-Fukushima Near-Term Task Force (NTTF) 2.1 - Commitment Completion

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Expedited Seismic Evaluation Process (ESEP) - Augmented Approach to Post-Fukushima Near-Term Task Force (NTTF) 2.1 - Commitment Completion
ML17166A050
Person / Time
Site: Monticello Xcel Energy icon.png
Issue date: 06/14/2017
From: Gardner P
Northern States Power Company, Minnesota, Xcel Energy
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
L-MT-17-043
Download: ML17166A050 (4)


Text

2807 West County Road 75 Monticello, MN 55362 800.895.4999 xcelenergy.com June 14, 2017 L-MT-17-043 10 CFR 50.54(f)

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 Monticello Nuclear Generating Plant: Expedited Seismic Evaluation Process (ESEP) -

Augmented Approach to Post-Fukushima Near-Term Task Force (NTTF) 2.1 -

Commitment Completion

References:

1) NRC Letter, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 12, 2012. (ADAMS Accession No. ML12056A046)
2) Letter from K. Fili (NSPM) to Document Control Desk (NRC),

Monticello Nuclear Generating Plant: Expedited Seismic Evaluation Process (ESEP) - Augmented Approach to Post-Fukushima Near-Term Task Force (NTTF) 2.1, L-MT-14-093, dated December 23, 2014. (ADAMS Accession No. ML14357A280)

3) Email from S. Wyman (NRC) to J. Fields (NSPM), Monticello ESEP Report Clarifications, dated April 8, 2015. (ADAMS Accession No. ML16109A151)
4) Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

Monticello Nuclear Generating Plant: Expedited Seismic Evaluation Process (ESEP) - Augmented Approach to Post-Fukushima Near-Term Task Force (NTTF) 2.1 - Response to Requests for Additional Information, L-MT-15-030, dated May 22, 2015. (ADAMS Accession No. ML15142A862)

Document Control Desk Page 2

5) Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

Monticello Nuclear Generating Plant: Expedited Seismic Evaluation Process (ESEP) - Augmented Approach to Post-Fukushima Near-Term Task Force (NTTF) 2.1 - Proposed Resolution for Components Requiring Action, L-MT-16-025, dated July 22, 2016. (ADAMS Accession No. ML16204A159)

6) Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

High Frequency Supplement to Seismic Hazard Screening Report, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident, L-MT-17-025, dated April 11, 2017. (ADAMS Accession No. ML17101A598)

On March 12, 2012, the NRC issued Reference 1 to request seismic profile information associated with Near-Term Task Force (NTTF) Recommendation 2.1 from all NRC power reactor licensees.

In Reference 2, Northern States Power Company, a Minnesota corporation (NSPM),

d/b/a Xcel Energy, the licensee for Monticello Nuclear Generating Plant (MNGP),

responded to the NRC and provided an Expedited Seismic Evaluation Process (ESEP) report. The results indicated that additional action (e.g. evaluation, modification, or other action) was required to assure that sufficient seismic margin is available for a small set of plant equipment.

On April 8, 2015, the NRC sent an email (Reference 3) that contained requests for additional information (RAIs) related to the ESEP report provided in Reference 2. On May 22, 2015 (Reference 4), NSPM responded to the NRC requested information in Reference 3. As part of the response to the NRC, NSPM provided corrections to the ESEP report and provided two regulatory commitments; one commitment to identify the proposed resolution and the time frame for completion of the resolution and a second commitment to report to the NRC when the resolution was completed.

On July 22, 2016 (Reference 5), NSPM provided the response to fulfill the first commitment.

The purpose of this letter is to provide the response for the second commitment.

Specifically, NSPM committed to perform the following:

A letter will be provided to the NRC summarizing the HCLPF [High Confidence of a Low Probability of Failure] results of each component and confirming the resolution of each component.

Document Control Desk Page 3 Reference 5 identified that the following components would be replaced in the 2017 refueling outage (RFO) for MNGP. Each component would be replaced with a device that has a greater seismic capacity than the currently installed component. Each replaced component and its respective HCLPF value is listed below. In each case, the value exceeds the required HCLPF value of 0.19 g.

Component - HCLPF value Component - HCLPF value

  • dPIS-13 0.43 g
  • PS-13-87B - 1.19 g
  • dPIS-13 0.43 g
  • PS-13-87C - 1.19 g
  • PS-13-87A - 1.19 g
  • PS-13-87D - 1.19 g During the MNGP 2017 RFO, NSPM completed the replacement of the components identified in Reference 5. Based on completion of this scope of work, the commitment made in Reference 4 is complete and no further action remains.

In addition, the NRC contacted NSPM on April 24, 2017 and discussed the results of Reference 6. Based on this discussion, the NRC requested further justification for excluding relay 13A-K26 from consideration in Reference 6. Below is the requested additional justification:

Relay 13A-K26 is used by the Reactor Core Isolation Cooling (RCIC) system Auto-Isolation Signal as a permissive to open the steam line isolation valves to the RCIC turbine. This relay is normally in a deenergized state with normally closed contacts.

The RCIC steam line isolation valves are left in a normally open position. Since the steam line isolation valves are open, the Auto-Isolation Signal will be in a reset state.

Assuming contact chatter on relay 13A-K26 occurs coincident with a seismic event, the chatter will not affect the RCIC system performance as 13A-K26 is not energized and the RCIC steam isolation valves will already be open and thus able to perform their function.

Based on this information, contact chatter in relay 13A-K26 was determined to not negatively affect the stations response to a seismic event.

Please contact John Fields, Fukushima Response Licensing, at 763-271-6707, if additional information or clarification is required.

Summary of Commitments This letter makes no new commitments and no revisions to existing commitments. This letter closes a commitment made in Reference 4.

Document Control Desk Page4 I declare under penalty of perjury that the foregoing is true and correct.

Executed on June L_i, 2017.

cc: Administrator, Region Ill, USNRC Project Manager, Monticello Nuclear Generating Plant, USNRC Resident Inspector, Monticello Nuclear Generating Plant, USNRC