L-23-129, Response to Request for Additional Information for 10 CFR 50.55a Request 2-TYP-4-RV-06 for Alternative Repair Methods for Reactor Pressure Vessel Head Penetrations

Response to Request for Additional Information for 10 CFR 50.55a Request 2-TYP-4-RV-06 for Alternative Repair Methods for Reactor Pressure Vessel Head Penetrations

ML23125A290
Person / Time
Site:	Beaver Valley
Issue date:	05/05/2023
From:	Blair B Energy Harbor Nuclear Corp
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-23-129, EPID L-2023-LLR-0021
Download: ML23125A290 (1)

Text

1ra energy Energy Harbor Nuclear Corp.

Beaver Valley Power Station

~ harbor P. 0. Box4 Shippingport, PA 15077 Barry Blair 724-682-5234 Site Vice President, Beaver Valley Nuclear May 5, 2023 10 CFR 50.55a L-23-129 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 Response to Request for Additional Information for 10 CFR 50.55a Request 2-TYP-4-RV-06 for Alternative Repair Methods for Reactor Pressure Vessel Head Penetrations (EPID L-2023-LLR-0021 )

By letter dated April 28, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23118A381) and pursuant to 10 CFR 50.55a(z)(2),

Energy Harbor Nuclear Corp. requested an alternative to the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code

{ASME Code), Code Case N-638-10, Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique. The proposed alternative, 2-TYP-4-RV-06, was submitted for U.S. Nuclear Regulatory Commission (NRC) review and approval to support repair of two unacceptable flaw indications in the reactor vessel head (RVH) vent penetration tube material and associated weld at Beaver Valley Power Station, Unit No. 2 (BVPS2). The repair will be in accordance with IWA-4311 and ASME Code Case N-638-10, with two exceptions to N-638-10. The exceptions are to eliminate the 48-hour hold time for final examination and to allow use of progressive liquid penetrant tests in lieu of volumetric examination. The proposed alternative is requested until the RVH is replaced.

The Nuclear Regulatory Commission (NRC) staff determined that additional information is needed to complete the review of the requested amendment. By electronic mail dated May 5, 2023, the NRC staff issued a request for additional information (RAI) to support the review. The Energy Harbor Nuclear Corp. RAI response is attached.

There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Mr. Phil H. Lashley, Manager - Fleet Licensing, at 330-696-7208.

Barry Blair

Beaver Valley Power Station, Unit No. 2 L-23-133 Page2

Attachment:

Response to Request for Additional Information cc: NRC Region I Administrator NRC Resident Inspector NRC Project Manager Director BRP/DEP Site BRP/DEP Representative

Attachment L-23-133 Response to Request for Additional Information Page 1 of 1 The NRC staff's request for additional information is presented below in bold text, followed by the response from Energy Harbor Nuclear Corp.

RAl-1 In Section 5.0, "Proposed Alternative and Basis for Use" of the submittal the licensee states that, " .. .a seal weld will be made between the excavation and the remaining tube to prevent LP [liquid dye penetrant] material from entering the gap between the tube and head materials." The NRC staff request details on the seal weld installation, including welding process, any filler materials used, and its effects on the subsequent temper bead process.

Response

The seal weld between the reactor vessel level indication system vent line and the excavation surface was performed using Gas-Tungsten Arc Welding - Machine Welding Process. The parameters used for the seal weld are the temper bead parameters utilized for the temper bead layer installation. The filler used was Special Metals Alloy 52M, ERNiCrFe-7A, a primary water stress corrosion cracking resistant material. The welding procedure specification used was 3G3-52M MC-GTAW-Vent Line-N638 Rev 0.

The support procedure qualification record 770 qualified in accordance with the requirements of Code Case N638-1 provides the qualification for temper bead welding.