ML18152B801
| ML18152B801 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/04/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18152B798 | List: |
| References | |
| NUDOCS 9805080154 | |
| Download: ML18152B801 (3) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION THE THIRD 10-YEAR INTERVAL INSERVICE INSPECTION PLAN REQUEST FOR RELIEF NO. SR-19 VIRGINIA ELECTRIC AND POWER COMPANY
- SURRY POWER STATION, UNIT 1
- DOCKET NUMBER: 50-280
- 1. INTRODUCTION The Technical $pecifications for Surry Power Station, Unit 1, state that the inservice inspection and testing of the 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 1*0 CFR 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 1 O CFR 50.55a(g)(6)(i). The 1 O CFR 50.55a(a)(3) states that aiternatives 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 hards.hip
- or unusual difficulty 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) sh~fl meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for lnservice 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 first 10-year interval and subsequent intervals comply with the requirements in the latest edition ~nd addenda* of Section XI of the ASME Code incorporated by reference in 1 O CFR 50.55a(b) ori the date 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The applicable edition of the ASME Code,Section XI, for Surry Power Station, Units 1 and 2, during the third 10-year inservice inspection (ISi) interval, is the 1989 Edition. 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 and subject to Commission approval.
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PDR ENCLOSURE
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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, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not endanger life, 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.
By. letter *dated September 22, 1'997,* Virginia Electric* and Power Company; the licensee* for Surry Power Station, Unit 1, requested relief from performing 100% surface examination of two integral attachment welds on residual heat removal (RHR) heat exchangers due to interference
- from concrete support.
The NRC staff has reviewed and evaluated the licensee's request for relief and the supporting information, pursuant to the provisions of 1 O CFR 50;55a(a)(g)(6)(i).
2.0 DISCUSSION Identification of Component:
Weld No.
Weld H002-1 Weld H001-1 Component No.
1-RH-E-1A 1-RH-E-18 Drawing No.
Class 11448-WMKS-RH-E-1A 2
11448-WMKS-RH-E-18 2
The above welds are integrally welded attachments on the RHR heat exchangers 1-RH-E-1A
. arid 1-RH-E-1 B.
ASME Code Section XI Reguirement:
The 1989 Edition of ASME Section XI Table IWC-2500-1, Examination Category C"".C, Item Number C3.10 requires a surface examination of the weld and adjacent base metal as defined by Figure IWC-2500-5. The Code does not allow any limitations to the required surface examinations. Code Case N-460, Alternative Examination Coverage for Class 1 and Class 2 Welds, allows a reduction in coverage, if it is less than 10 percent.
Licensee's Code Relief Reguest:
The licensee requests relief from fully performing the the Code-required surface examination on the above identified integrally welded attachments on the RHR heat exchangers 1-RH-E-1A and 1-RH-E-18.
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3 Licensee's Basis for Reguesting Relief:
The components listed above have been examined to the extent practical as required by the Code. Approximately 74% of the.required examination was completed. Therefore, the reduction in coverage is approximately 26%. Full surface coverage could not be achieved due to interferences from the concrete support. The integrally welded attachments on the RHR heat exchangers 1-RH-E-1A and 1-RH-E-18 rest on the concrete support, which precludes accessibility to the whole bottom of the integrally welded attachment.
Licensee Proposed Alternate Examination:
It is proposed that the examination already completed at the reduced coverage be considered as satisfying the Code requirements. It is proposed that alternative examination will ensure that the overall level of plant quality and safety will not be compromised.
3.0 EVALUATION In accordance with the ASME Code Case N-460, it is permissible to examine over 90 percent of the weld to comply with the requirements of the ASME Code,Section XI. The configuration of the integrally welded attachments does not allow 100% surface examination of the welds to obtain code required examination coverage due to interference from the concrete support. The staff has determined that it is impractical to comply with the Code requirement due to the weld configurations. If the requirements of the applicable Code were to be imposed on the licensee, the heat exchangers have to be r~designed a*nd. replaced which imposes undue burden on the licensee. The surface examination coverage, however, obtained for each welcf would have detected presence of any significant degradation, with reasonable confidence. The surface examination of each weld did not reveal any unacceptable flaw which, therefore, ensures structural integrity of the weld and consequently, the operational readiness of the heat exchanger.
4.0 CONCLUSION
The staff has evaluated the information provided by Virginia Electric and Power Company in their relief re:quest and concludes that based on the impracticability of complying with the Code requirements and the burden on the licensee if the Code requirements were imposed, the Relief Request No. SR-019 is authorized, pursuant to 1 O CFR 50.55a(g)(6)(i) for the third 10-year interval of Surry Unit 1. The relief granted is authorized by law and will not endanger life or property or the common defense and security and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.