L-15-250, Deviation from MRP-227A, Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines.

Deviation from MRP-227A, Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines.

ML15223B189
Person / Time
Site:	Davis Besse
Issue date:	08/12/2015
From:	Boles B FirstEnergy Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-15-250, MRP-227A
Download: ML15223B189 (3)

Text

TM 5501 North State Route 2 Oak Harbor, Ohio 43449 FirstEnergy Nuclear Operating Company Brian D. Boles 419-321-7676 Vice President, Fax: 419-321-7582 Nuclear August 12, 2015 L-15-250 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Davis-Besse Nuclear Power Station, Unit No. 1 Docket No. 50-346, License No. NPF-3 Deviation from MRP-227A. "Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines" In accordance with Nuclear Energy Institute (NEI) 03-08, "Guideline for the Management of Materials Issues," FirstEnergy Nuclear Operating Company (FENOC) is informing the Nuclear Regulatory Commission (NRC) of a deviation from MRP-227A.

The following is a ~ummary of the technical justification for the deviation from MRP-227A inspection requirements for primary and expansion reactor internals components listed in Table 4-1, "B&W Plants Primary Components," and Table 4-4, "B&W Plants Expansion Components." This information is being provided by FE NOC for the Davis-Besse Nuclear Power Station (DBNPS), Unit. No. 1 and is for information only. FENOC is not requesting any action from the NRC staff.

Specifically, the deviation addresses an MPR-227A "needed" requirement because MRP-227A Tables 4-1 and 4-4 cannot be implemented as written. MRP-227A, Table 4-1, for primary component, Lower Grid Assembly, Alloy X-750 dowel-to-guide block welds is no longer applicable to DBNPS because the block was modified after hot functional testing and the X-750 material and associated nickel based weld were removed and replaced with stainless steel materials. The expansion link for the Alloy X-750 dowel-to-guide block welds is the Alloy X-750 dowel locking welds to the upper and lower grid fuel assembly support pads. Table 4-4 states that the upper grid assembly, X-750 dowel-to-upper-grid fuel assembly support pad welds applies to all plants with the exception of DBNPS. However, after review of the fabrication records, Alloy X-750 dowel-to-upper grid fuel assembly support pads were transferred to the DBNPS contract and installed in the plant.

Davis-Besse Nuclear Power Station, Unit No. 1 L-15-250 Page 2 of 3 The deviation replaces the MRP-227A, Table 4-1, Primary Component, Lower Grid Assembly, Alloy X-750 dowel-to-guide block welds with the current MRP-227A, Table 4-4, Expansion Component, Lower Grid Assembly, lower grid fuel assembly Alloy X-750 dowel-to-lower grid fuel assembly support pad welds. The Alloy X-750 dowel-to-upper grid fuel assembly support pads will become the linked expansion component for the Lower Grid Assembly, lower grid fuel assembly support.

The deviation will add two new table rows applicable to DBNPS as follows.

T a bl e 4- 1 B&W Pl ~n t s Pnmary

. componen ts Item Applicability Effect Expansion Examination Examination (Mechanism) Link Method/Frequency Coverage (Note 2) (Note 2)

Lower Grid Davis- Cracking Alloy X-750 Initial visual (VT-3) Accessible Assembly Besse (SCC), dowel-to- examination no later surfaces of Alloy X-750 including the upper than two 100% of the dowel-to- detection of grid fuel refueling outages dowel lockin~

lower grid separated or assembly from the welds.

fuel missing support pad beginning of the assembly locking welds license support welds, or renewal period.

pad welds missing Subsequent dowels. examinations on the 10-year ISi interval.

t Expans1on c omponen ts T a bl e 4 -4 B&W Pl ans Item Applicability Effect Primary Examination Examination (Mechanism) Link Method/Frequency Coverage (Note 1) (Note 1)

Upper Grid Davis- Cracking Alloy X-750 Visual (VT-3) Accessible Assembly Besse (SCC), dowel-to- examination. surfaces of Alloy X-750 including the lower Subsequent 100% of the dowel-to- detection of grid fuel examinations on dowel lockin~

upper grid separated or assembly the 10-year IS I welds fuel missing support pad interval unless assembly locking welds an applicanUlicensee support welds, or provides pad welds missing an evaluation for dowels NRC staff approval that justifies a longer interval between inspections.

Davis-Besse Nuclear Power Station, Unit No. 1 L-15-250 Page 3 of 3 By letter dated July 20, 2015 the Electric Power Research Institute Materials Reliability Program has been notified of the aforementioned needed revision to MRP-227 to address the DBNPS as-built configuration.

The duration of this deviation is from April 22, 2015 until MRP-227 is revised to include the as-built configuration for DBNPS.

Because the alternate actions meet the objective and level of conservatism of MRP-227A, there is no postulated impact to safety.

There are no regulatory commitments contained in this letter. If there are any questions or if additional information is required, please contact Mr. Thomas A. Lentz, Manager-Fleet Licensing at (330) 315-6810.

Sincerely,

~~~

Brian D. Boles cc: NRC Region Ill Administrator NRR Project Manager NRC DLR Project Manager NRC Resident Inspector NRR Division of Component Integrity Utility Radiological Safety Board