ML16131A405
| ML16131A405 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/14/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML16131A403 | List: |
| References | |
| NUDOCS 9210220176 | |
| Download: ML16131A405 (4) | |
Text
0 PSREG(t UNITED STATES NUCLEAR REGULATORY COMMISSION Z
WASHINGTON, D.C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE SECOND TEN-YEAR INTERVAL INSERVICE INSPECTION RELIEF REQUEST NO. 92-10 FOR DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS 1. 2. AND 3 DOCKET NO. 50-269, 50-270, and 50-287
1.0 INTRODUCTION
Technical Specification 4.2.1 for the Oconee Nuclear Station, Units 1, 2, and 3, states that inservice inspection and testing of American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable Addenda as required by 10 CFR 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Under 10 CFR 50.55a(a)(3), alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulties without a compensating increase in the level of quality and safety.
Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the second ten-year interval comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) on the date twelve months prior to the start of the 120-month inspection interval, subject to the limitations and modifications listed therein.
The applicable edition of Section XI of the ASME Code for Oconee Nuclear Station, Unit 3, Second Ten-Year Inservice Inspection (ISI) Interval, is the 1980 Edition through Winter 1980 Addenda. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein.
9210220176 921014 PDR ADOCK 05000269 P
-2 Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement.
After evaluation of the determination, the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law and will not endanger life or property or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed.
In a letter dated July 15, 1992, Duke Power Company (licensee) submitted Request for Relief No. 92-10 requesting relief from performing the Code required surface examinations on pipe branch connection welds for the Main Steam Relief Valve piping. The licensee also proposed alternative testing.
2.0 EVALUATION The information provided by the licensee in support of the request for relief has been evaluated and documented below.
Request for Relief No. 92 Surface Examinations of Branch Welds Off The Main Steam Relief Valve System Piping.
Code Requirement: ASME Boiler and Pressure Vessel Code Section XI, 1980 Edition (with Addenda through Winter 1980) Table IWC-2500-1, "Examination Categories," Category C-F, Item No. C5.31 and Figure IWC-2500-9.
Licensee's Code Relief Request:
Relief is requested from performing the Code required surface examinations on pipe branch connection welds for the Main Steam Relief Valve piping, where the welds are protected by guard pipes.
Licensee's Basis for Requesting Relief: The licensee stated that the welds are inaccessible for surface examination due to the location of the guard pipes.
Licensee's Proposed Alternative Examination:
The licensee proposed surface examination (Magnetic-Particle Inspection) of the guard pipe and reinforcing collar welds, and a system pressure test in accordance with the normal schedule.
Staff Evaluation: The Code requires each inspection interval that surface examinations are to be performed on pipe branch connection welds for the Main Steam Relief Valve piping. The staff has determined that the Code requirements are impractical to perform because the guard piping would have to be redesigned in order to perform the Code-required examinations. The licensee has performed the Code-required pressure tests on the piping during previous refueling outages (Unit 1-7th RFO, Unit 2 - 5th RFO, and Unit 3 7th RFO) and there were no indications of leakage at the weld joint. The licensee's proposed alternative examinations and pressure testing will reasonably assure the structural integrity of the main steam piping.
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Conclusion:==
Paragraph 10 CFR 50.55a(g)(4) requires that components (including supports) that are classified as ASME Code Class 1, 2, and 3 meet the requirements, except the design and access provisions and preservice requirements, set forth in applicable editions of ASME Section XI to the extent practical within the limitation of design, geometry, and materials of construction of the components. Pursuant to 10 CFR 50.55a(g)(6)(i), the staff has determined that certain requirements of the Code are impractical for Oconee Nuclear Station, Units 1, 2, and 3 and relief may be granted for the issues described in Request for Relief No. 92-10. Such a relief is authorized by law and will not endanger life, property, or the common defense and security, and is otherwise in the public interest. However, if the occasion should arise that the guard piping is disassembled, the licensee should perform the Code-required examinations.
Date:
October 16, 1992
DATED:
October 14, 1992 DISTRIBUTION:
Docket File
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NRC/Local PDRs PDII-3 READING Oconee READING SVarga GLainas DMatthews SKirslis LWiens LBerry OGC, 15B18 EJordan, MNBB3701 ACRS, P-315 (10)
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