ML20148B548
| ML20148B548 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/15/1988 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML16152A683 | List: |
| References | |
| NUDOCS 8803220017 | |
| Download: ML20148B548 (5) | |
Text
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7' DUKE POWER GOMPANY P.O. BOX 33189 01MRLOTTE, N.O. 28949 HAL B. TUCKER TELEPHONE (704) 07:F4831 vica Paesment NWLBAR PRODUCTHMB
. March 15, 1988
'U.S. Nuclear Regulatory Commission
-Document Control Desk Washington, D.C.
20555
Subject:
Oconee. Nuclear Station Docket Nos. 50-269, -270, -287 E4cond Ten Year Interval l
Request for Relief No. 88-02 Gentlemen:
l Pursuant to 10CFR 50, 550.55a, please find attached request for relief number 88-02 from the requirements of Section XI of the ASME Boiler and Pressure Vessel Code (with Addenda ' through Winter 1980).
This request is being submitted due to the impracticality of pressure testing specific welds as required by the Code fol-lowing repair.
The attached requests concern the inservice inspection at.0conee Unit 2 being performed during the second ten year interval.
It is requested that this request for relief be reviewed and approved by NRC prior to Unit 2 Cycle 10 startup currently scheduled for April 10, 1988.
This request is considered to supplement the request made by my letter dated Sep-tember 13, 1984. As such, no additional fees are required.
Very truly yours,
/
/4 Hal B. Tucker
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Attachment
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8803220017 880315 PDR ADOCK 05000269 4
7-n Document Control Desk
' March 15, 1988 Page 2 xc: w/o diagrams.
Dr. J. Nelson Grace Regional Administrator-U.S. Nuclear Regulatory Commission - Region II 101 Marietta St. NW Suite 2900 - Atlanta, GA 30323 Ms. Helen Pastis Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. Heysard Shaaly, Chief Bureau of Radiological Health S.C. Departasnt of Health and Environmental Control 2600 Bull Street Columbus, S.C.
29201 Mr. P.H. Skinner NRC Resident Inspector Oconee Nuclear Station
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Duke Power Company Oconee Nuclear Station Second Ten Year Interval Request for Relief No. 88-02 I.
Component for which relief is requested:
(a) Name and Numbert Main Steam (MS). System velds for installing valves 2MS-83 and 2MS-85 (see attached flow diagram).
(b)
Function:
2MS-83 and 2MS-85 prevent backflow between main steam headers 2A and 2B respectively.
(c)
ISI Class / Duke Class:
ISI Class C/ Duke Clan F (d)
IWV-2200 Valve Category: C II.
Reference Code requirement that has been determined to be impractical:
ASME Boiler and Pressure Vessel Code Section XI, 1980 Edition (with Addenda through Winter 1980) paragraph IWA-4400(a), which states that atter repairs by welding on the pressure retaining boundary, a system hydrostatic test shall be performed in accordance with IWA-5000.
Paragraph IWC-5210 (a) states that the pressure retaining components within each system boundq shall be subjected to the following system pressure tests and visually examined by the method specified in Table IWC-2500-1, Examination Category C-H (2) a system hydrostatic test (IWA-5211(d)] for each system or portion of systems and for repaired or replaced components, o s; altered portions of systems.
III. Basis for requesting relief:
Hydrostatic testing would require filling the main steam lines with water.
The piping and welds associated with installation of the 2MS~83 and 2MS-85 cannot be isolated from the main steam headers based on past experience using 2MS-82 and 2MS-84 as boundary valves and past experience with trying to make the main steam system water tight.
In addition the emergency feedwater pump turbine could potentially be damaged by the required hydrotest.
IV. Alternate examination:
Welds will be 100% radiographed and a VT-2 inspection will be performed at operating temperature and pressure.
In addition, the welds will be l
hydrostatically tested during the second ten year interval inservice inspection hydro of the main steam lines.
i
V.
Evaluation of acceptability of proposed alternate testing with respect to the level of quality and safety as well as public health and safety:
The specified method of hydrostatic testing verifies that there are no leaks at 1.25 times the design pressure.
The alternate examination of a 100% radiograph of welds assures that no significant flaws are evident in the welds.
The VT-2 inspection indicates that no leaks are detectable when the system is at operating temperature and pressure.
The alternate tests provide an equivalent method to indicate a leak at the higher stress level which is normally verified by the specified method of hydrostatic testing.
As such, the proposed alternat e examinations provide an acceptable level of quality and safety and will not endanger the health and safety of the public.
VI.
Implementation Schedule:
The 100% radiograph will be performed during the current Unit 2 End of Cycle 9 refueling outage.
The VT-2 inspection will be performed during startup from the current Unit 2 End of Cycle 9 refueling outage.
Hydro-static testing will be performed during the second ten year interval inservice inspection hydro of the main steam lines.
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OVERSIZE DOCUMENT PAGE PULLED SEE APERTURE CARDS b
NUMBER OF OVERSIZE PAGES FILMED ON APERTURE CARDS APERTURE CARD /HARD COPY AVAILABLE FROM RECORD SERV FTS 492-8989 1
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