ML14029A192

Request for Additional Information for the Review of the Callaway Plant, Unit 1, License Renewal Application, Set 30

ML14029A192
Person / Time
Site:	Callaway  (NPF-030)
Issue date:	02/12/2014
From:	Cuadradodejesus S License Renewal Projects Branch 1
To:	Diya F Union Electric Co
References
TAC ME7708
Download: ML14029A192 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Fadi Diya Senior Vice President and Chief Nuclear Officer Union Electric Company P.O. Box 620 Fulton, MO 65251 February 12, 2014

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE CALLAWAY PLANT, UNIT 1, LICENSE RENEWAL APPLICATION, SET 30 (TAC NO. ME7708)

Dear Mr. Diya:

By letter dated December 15, 2011, Union Electric Company (Ameren Missouri) (the applicant) submitted an application pursuant to Title 10 of the Code of Federal Regulations Part 54 (10 CFR Part 54) for renewal of operating license No. NPF-30 for the Callaway Plant, Unit 1 (Callaway). The staff of the U.S. Nuclear Regulatory Commission (NRC or the staff) is reviewing this application in accordance with the guidance in NUREG-1800, "Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants." During its review, the staff has identified areas where additional information is needed to complete the review.

The staff's request for additional information is included in the enclosure. Further requests for additional information may be issued in the future.

Items in the enclosure were discussed with David E. Shafer, of your staff, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me by telephone at 301-415-2946 or by e-mail at Samuel. CuadradoDeJesus@nrc.gov.

Docket No. 50-483

Enclosure:

Request for Additional Information cc: Listserv Sincerely,. U/(!7 amuel Cuadrado de Jesus, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation

ML14029A192 Sincerely, IRA/

Samuel Cuadrado de Jesus, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation OFFICE LA:DLR/RPB2 PM:DLR/RPB1 BC:DLR/RPB1 PM:DLR/RPB1 NAME YEdmonds SCuadrado YDiaz-Sanabria SCuadrado DATE 2/7/2014 2/12/2014 2/12/2014 2/12/2014

Letter to F. Diya from S. Cuadrado de Jesus dated February 12, 2014

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE CALLAWAY PLANT, UNIT 1, LICENSE RENEWAL APPLICATION, SET 30 (TAC NO. ME7708)

DISTRIBUTION:

HARD COPY:

DLR R/F E-MAIL:

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Background:

CALLAWAY PLANT, UNIT 1 LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION, SET 30 By letter dated October 24, 2012, Union Electric Company (Ameren Missouri) provided License Renewal Application (LRA) Amendment No. 13 which revised LRA Table 3.1.2-1, "Reactor Vessel, Internals, and Reactor Coolant System -Summary of Aging Management Evaluation -

Reactor Vessel and Internals," to provide an amended aging management review (AMR) for the reactor vessel internals clevis insert bolts. In this amended AMR, the applicant confirmed that the clevis insert bolts are fabricated from nickel alloy materials and that potential cracking and loss of material due to wear will be managed by the applicant's American Society of Mechanical Engineers (ASME)Section XI lnservice Inspection (lSI), Subsections IWB, IWC, and IWD Program.

Issue:

Appendix A to Electric Power Research Institute (EPRI) Technical Report No. 1022863, "Materials Reliability Program: Pressured Water Reactor (PWR) Internals Inspection and Evaluation Guidelines (MRP-227-A)," indicates that failures of nickel alloy (Alloy X-750) clevis insert bolts were reported by the licensee for one domestic Westinghouse-designed pressurized water reactor in 2010. The ASME Section XI visual VT-3 inspections of the clevis insert assemblies on a 1 0-year frequency may not be adequate to ensure the integrity of clevis insert assemblies during design basis events if multiple bolt failures occur prior to detection and a design basis event occurs.

Request:

(a)

Describe the configuration of clevis insert assemblies at Callaway Plant, Unit 1 (Callaway) including number of bolts in the assemblies. Specify the material of fabrication, including any applicable heat treatment, that were used for the design of the clevis insert bolts at Callaway.

(b)

Discuss and justify whether the operating experience associated with cracking of the clevis insert bolts is applicable to clevis insert assembly designs at Callaway.

(c)

Describe the inspections that have been performed of the clevis insert bolts, including the type of inspection (e.g., VT-3). Clarify the visual inspection coverage that was achieved during these inspections. Clarify the ASME examination category that applies to inspections of the clevis insert bolts (and identify the applicable inspection method and frequency) and whether the past examinations have resulted in the detection of any ENCLOSURE

indications of cracking or failures of the clevis insert bolts that are included in the clevis insert assembly designs. If so, provide the details of the inspection results and clarify the corrective actions that were taken at the facility to justify the structural integrity of the clevis insert assemblies and the intended safety function of the plant's core support structure and its components during plant operations.

(d)

Based on your responses to Parts (a) through (c) of this request, clarify whether the 1 0-year lSI basis for the clevis insert bolts is sufficient to manage cracking and wear of the bolts during the period of extended operation. Justify your response to this request.

ENCLOSURE