ML20120A027

NRR E-mail Capture - Request for Additional Information Monticello Long Term Steam Dryer Inspection Plan

ML20120A027
Person / Time
Site:	Monticello
Issue date:	04/28/2020
From:	Robert Kuntz NRC/NRR/DORL/LPL3
To:	Kivi J Northern States Power Company, Minnesota
References
L-2019-LLL-0035
Download: ML20120A027 (3)

Text

From: Kuntz, Robert Sent: Tuesday, April 28, 2020 2:20 PM To: Kivi, Jeffrey L.

Subject:

Request for Additional Information RE: Monticello Long Term Steam Dryer Inspection Plan (EPID: L-2019-LLL-0035)

Mr. Kivi, By letter dated November 20, 2019, Northern States Power Corporation (NSPM) provided the Monticello Nuclear Generating Plant Long-Term Replacement Steam Dryer Inspection Plan. The NRC staff has determined that additional information is required for the NRC staff to complete its review. The following is the NRC staffs request for additional information (RAI). During a teleconference for the staff to provide clarification on the following RAI, it was agreed that a response would be provided by June 12, 2020.

Robert Kuntz Senior Project Manager NRC/NRR/DORL/LPL3 (301)415-3733 REQUEST FOR ADDITIONAL INFORMATION MONTICELLO NUCLEAR GENERATING PLANT LONG TERM STEAM DRYER INSPECTION PLAN (EPID: L-2019-LLL-0035)

Background

Monticello Nuclear Generating Plant (MNGP) Renewed Facility Operating License Condition (License Condition) 2.C.15.(h) requires that:

At the end of the second refueling outage, following the implementation of the EPU

[extended power uprate], the licensee shall submit a long-term steam dryer inspection plan based on industry operating experience along with the baseline inspection results for NRC review and approval.

License Condition 2.C.15 requires, in part, that:

The license conditions described above shall expire (1) upon satisfaction of the requirements in Paragraphs 15(f) and 15(g), provided that a visual inspection of the steam dryer does not reveal any new unacceptable flaw(s) or unacceptable flaw growth that is due to fatigue, and (2) upon satisfaction of the requirements specified in Paragraph 15(h).

By letter dated November 20, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19324F851), Northern States Power Corporation (NSPM) provided the MNGP Long-Term Replacement Steam Dryer Inspection Plan. The inspection plan was submitted pursuant to MNGP License Condition 2.C.15.(h).

RAI 1

The November 20, 2019 letter stated that during the 2019 inspection, one location was identified having two relevant indications and that the flaws were evaluated to be acceptable for the next two refueling cycles prior to the next visual examination. By letter dated August 9, 2019 (ADAMS Accession No. ML19221B714) NSPM provided the results of the 2019 steam dryer inspection. Table 1 provided in Attachment 1 to the August 9, 2019 letter, identified relevant indications in one location (RSD-ID-C1-S1, stiffener welds).

Request

a. Were the relevant indications determined to be fatigue crack(s) or intergranular stress corrosion crack(s)? Provide the basis for that determination.

b. What repair measure or approach is planned to ensure acceptability of the indications beyond the 2 cycles that have been determined to be acceptable?

RAI-2

The November 20, 2019 letter stated that:

The proposed inspection plan includes inspection of the various locations over ten-year periods. This frequency is consistent with the re-inspection frequency of BWRVIP-139 and Westinghouse recommendations.

Over the ten-year periods, the plan requires inspection of:

• All inspection locations in accordance with LTR-A&SA-12-8, Revision 1.

• All flaws found during inspections (re-inspections) in accordance with BWRVIP-139-1A re-inspection recommendations.

• The maximum stress location in accordance with Westinghouse recommendations (Reference 4).

Reference 4 has not been provided to support the long term steam dryer inspection plan.

Request Provide the information from Reference 4 that is included in the long term steam dryer inspection plan.

Hearing Identifier: NRR_DRMA Email Number: 554 Mail Envelope Properties (MN2PR09MB59487E68E8B47318BD392B6299AC0)

Subject:

Request for Additional Information RE: Monticello Long Term Steam Dryer Inspection Plan (EPID: L-2019-LLL-0035)

Sent Date: 4/28/2020 2:19:38 PM Received Date: 4/28/2020 2:19:00 PM From: Kuntz, Robert Created By: Robert.Kuntz@nrc.gov Recipients:

"Kivi, Jeffrey L." <Jeffrey.Kivi@xenuclear.com>

Tracking Status: None Post Office: MN2PR09MB5948.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 3598 4/28/2020 2:19:00 PM Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: