ML16131A397
| ML16131A397 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/28/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML16131A398 | List: |
| References | |
| NUDOCS 9209040067 | |
| Download: ML16131A397 (3) | |
Text
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0 oUNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE SECOND TEN-YEAR INTERVAL INSERVICE INSPECTION RELIEF REQUEST NO. 92-09 FOR DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNIT 1, 2 AND 3 DOCKET NOS. 50-269, 270, and 278
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 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, Units 1, 2, and 3 Second Ten-Year Interval Inservice Inspection (ISI), is the 1980 Edition through 1980 Winter 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.
9209040067 920828 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, 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 May 13, 1992, Duke Power Company (licensee) submitted Request for Relief No. 92-09 asking for relief from hydrostatic testing the Borated Water Storage Tank suction piping for the HPI pumps until such time that valves HP-101 and HP-102 can be disassembled. The staff has evaluated Request for Relief No. 92-09 in the section that follows.
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. 92-09 Hydrostatic test of Borated Water Storage Tank suction piping for HPI pumps.
Code Requirement: ASME Boiler and Pressure Vessel Code Section XI, 1980 Edition (with Addenda through Winter 1980) Articles IWC-5222(a) and IWC 2420(a), and Table IWC-2500-1, Category C-H, Item C7.21 All Pressure Containing Components.
Licensee's Code Relief Request: Relief is requested to delay hydrostatic testing of pressure containing components until valves HP-101 and HP-102 can be disassembled.
Licensee's Basis for Requesting Relief:
The licensee stated that the piping on the upstream side of HP-24 and 25 is rated at 100 psig at 200 degrees F.
The piping downstream of HP-24 and 25 is rated at 350 psig at 200 degrees F.
Valves HP-101 and 102 are check valves. The HP-101 and 102 check valves make it impractical to perform the hydrostatic test with HP-24 and 25 closed and pressurizing from the downstream piping to HP-24 and 25.
To pressurize the piping from the upstream direction with HP-24 and 25 open would cause overpressurization of the low pressure upstream piping. This request is to delay this test until the HP-101 and HP-102 valves can be disassembled.
Licensee's Proposed Alternative Examination: The licensee stated that no alternative examinations are needed as this request for relief is only to delay the periodic ISI hydrostatic test to a later time. The welds associated with this request have not been changed since the previous pressure test was performed. Implementation schedule of the hydrostatic testing will be at the next refueling outage for each.unit where disassembly of HP-101 and HP-102 is practical, but no later than the last refueling outage for each unit during the third period of the Second Inspection Interval, ending February 28, 1994.
-3 Staff Evaluation:
The staff has determined that the Code-required hydrostatic testing for the Borated Water Storage Tank suction piping for HPI pumps is impractical to perform. The system would have to be redesigned because some of the system's adjacent piping upstream of HP-24 and HP-25 is rated at 100 psig vs 350 psig for the piping downstream of HP-24 and HP-25. To pressurize the piping from the upstream direction with HP-24 and HP-25 open would cause overpressurization of the low pressure upstream piping. Thus, there are no reasonable methods to hydrostatically test this pipe until the HP-101 and HP-102 valves can be disassembled.
Furthermore, the hydrostatic testing will be performed at the next refueling outage for each unit where disassembly of HP-101 and HP-102 is practical, but no later than the last refueling outage for each unit during the third period of the Second Inspection Interval, ending February 28, 1994. This would ensure structural integrity of the piping and components.
3.0 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)(5)(iii), the licensee determined that conformance with a Code-requirement is impractical for his facility and submitted supporting technical justification.
Pursuant to 10 CFR 50.55a(g)(6)(i), the staff has determined that the requirement of the Code is impractical for Oconee Nuclear Station, Units 1, 2, and 3, and relief may be granted based on information described in Request for Relief No. 92-09. This relief is being granted giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Such relief and alternative examinations are authorized by law, will not endanger life, property, or the common defense and security, and is otherwise in the public interest.
Date:
August 28, 1992