ML20211H537
| ML20211H537 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 02/20/1987 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20211H541 | List: |
| References | |
| RTR-NUREG-0313 SL-1951, TAC-64777, NUDOCS 8702260204 | |
| Download: ML20211H537 (3) | |
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. Georpja Power Company
'J 333 Piedmont Avenue
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Atlanta. Georgia 30308 j
Telephor e 404 526-6526 Maang Address:
Post Office Box 4545 Atlanta. Georgia 30302 Georgia Power L. T. Gucwa N' #** 5'"
Manager Nuclear Safety and Licensing SL-1951 1102C February 20, 1987 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.
20555 NRC DOCKET 50-321
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OPERATING LICENSE DPR-57 EDWIN I. HATCH NUCLEAR PLANT UNIT 1 PIPE CRACK IN3PECTION/ MITIGATION PROGRAM 1987 MAINTENANCE / REFUELING OUTAGE Gentlemen:
Pursuant to your April 24, 1986, letter, Georgia Power Company (GPC) hereby submits for your review the proposed program for the mitigation of Intergranular Stress Corrosion Cracking (IGSCC) in, and the inspection of, the main recirculation and other reactor pressure boundary stainless steel piping and components.
The program will be implemented during the Plant Hatch Unit 1 1987 maintenance / refueling outage.
(Reference.)
Based, upon this submittal, GPC also requests that the NRC approve an additional operating cycle with the existing Hatch Unit 1 weld overlays (Reference Enclosure 2).
The proposed inspection program includes GPC's criteria used for weld selection, ultrasonic examination, flaw evaluation, IGSCC mitigation, and weld overlay repairs. Also, in Enclosure 1, our proposed inspection procedure and personnel qualification criteria, as well as leak detection and leakage limits for the next fuel
- cycle, are discussed.
These criteria are consistent with the intent of draft, Revision 2 of NUREG-0313, " Technical Report on Material Selection and Processing Guidelines for BWR Coolant Pressure Boundary Piping," as commented upon by the EPRI/BWR Owners Group for IGSCC Research (BWROG-II) and GPC.
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'U. S. Nuclear Regulatory Commission ATTN: Document Control Desk February 20, 1987 Page Two 1
As an adjunct to the proposed inspection program, GPC submits as a report prepared by Structural Integrity Associates which provides technical justification for continued service with weld overlays at Hatch Unit 1 during the upcoming and subsequent cycles.
The report also includes a discussion relative to the upgrading of existing weld overlays, their improved surface finish, and the application of induction heating stress improvement (IHSI) to cracked and uncracked weldments performed during the last Hatch Unit 1 maintenance / refueling outage.
, is a draft Electric Power Research Institute (EPRI) report which discusses many of the generic technical arguments supporting weld overlays as long term repairs.
Georgia Power Company has obtained EPRI approval to include this report as a supplement to the Hatch Unit I report contained in Enclosure 2.
Given the continued favorable results of weld overlay testir.g performed to date and the developments in the nondestructive examination (NDE) of weld overlays, GPC is confident that weld overlays will ultimately prove to be technically justifiable for long-term treatment of stainless steel piping and components having IGSCC.
Georgia Power Company is continuing to mitigate the potential for IGSCC in the subject piping welds through either IHSI or weld overlay.
The type of treatment is dependent upon such variables as piping and flaw size.
As delineated in Enclosure 2, a substantial effort in the area of IGSCC mitigation took place during the previous Hatch Unit 1 outage.
As committed to in our July 1,1985, letter, a hydrogen water chemistry mini-test is currently in progress at Hatch Unit 1.
A pemanent program of additional IGSCC mitigation by hydrogen addition will be evaluated for j
implementation based upon the results of the mini-test and the ongoing l
industry experience with hydrogen water chemistry and IHSI.
The Hatch Unit 1 maintenance / refueling outage is scheduled to comence on April 22, 1987.
Because of the extensive pre-outage manpower planning associated with this effort, any questions concerning the i
enclosed proposed inspection program and technical justification for continued service with weld overlays should be brought to our immediate attention.
To support our planning effort, we request that the NRC approve the inspection plans described herein by April 10, 1987.
Georgia Power Company requests that the infomation submitted herein be rev', ed w
l in an expeditious manner so that our outage plans can be solidi:1ed.
Should you have any questions in this regard, please contact this office at any time.
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1102C
9 Georgia Power A U. S. Nuclear Regulatory Commission ATTN: Document Control Desk February 20, 1987 Page Three Pursuant to the requirements of 10 CFR 170, enclosed herein as payment of the application fee for review of the subject information is our check in the amount of one hundred and fifty dollars.
Sincerely, c:#"7C.
L. T. Gucwa GKM/lc
Enclosures:
1.
Encl osure 1
" Hatch Unit 1 IGSCC-Susceptible, Primary Pressure Boundary Stainless Steel Piping and Components Inspection / Mitigation Program - 1987 Maintenance / Refueling Outage."
- 2. - Structural Integrity Associates Report No. SIR-87-004, Revision 0, " Justification for Continued Operation with Existing Weld Overlays at Plant Hatch Unit 1."
- 3. - Structural Integrity Associates Report No. SIR-86-021 (DRAFT), " Technical Justification for Extended Weld Overlay Design Life", prepared for EPRI, December 1986.
c:
Georgia Power Company U. S. Nuclear Regulatory Commission Mr. d. P. O'Reilly Dr. J. N. Grace, Regional Administrator Mr. J. T. Beckham, Jr.
Mr. P. Holmes-Ray, Senior Resident fir. H. C. Nix, Jr.
Inspector - Hatch GO-NORMS Mr. G. Rivenbark, Licensing Project Manager 1102C 700775
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