ML18152B337

SER Accepting Third 10-year Interval Inservice Insp Plan Request for Relief SR-026 for Surry Power Station Unit 2

ML18152B337
Person / Time
Site:	Surry
Issue date:	09/24/1999
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML18152B336	List: ML18152B335 ML18152B337
References
NUDOCS 9909270101
Download: ML18152B337 (5)

Text

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e UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555--0001 OF THE THIRD 10-YEAR INTERVAL INSERVICE INSPECTION PLAN REQUEST FOR RELIEF SR-026 FOR VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT 2 DOCKET NUMBER: 50-281

1.0 INTRODUCTION

lnservice inspection (ISi) 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 (B&PV) Code and applicable addenda as required by 1 O CFR 50.SSa(g),

. except where specific written relief has been granted by the Commission pursuant to 1 O CFR 50.55a(6)(g)(i).

Pursuant to 10 GFR 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 pre-service 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 and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. For Surry Power Station, Unit 2, the applicable edition of Section XI of the ASME Code for the third 10-year ISi interval is the 1989 Edition.

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.

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e 2.0 EVALUATION By letter dated February 16, 1999, Virginia Electric and Power Company (licensee), submitted Request for Relief No. SR-026 seeking relief from the requirements of the ASME Code,Section XI, for the Surry Power Station, Unit 2. The Idaho National Engineering and Environmental Laboratory (INEEL) staff's evaluation of the subject request for relief is in Enclosure 2. Based on our review of INEEL's report, the staff adopts the contractor's conclusions presented in the Technical Letter Report.

The information provided by the licensee in support of the request for relief from Code requirements has been evaluated arid the basis for disposition is documented below.

Request for Relief SR-026:

ASME Code,Section XI, Examination Categort. B-F, Item 85.70 requires 100% volumetric arid surface examinations, as defined by Figure IWB-2500-8, for steam generator nozzle-to-safe end welds in 4-inch nominal pipe size or larger.

Pursuant to 1 O CFR 50.55a(g)(5)(iii), the licensee requested relief from the volumetric coverage requirements of the Code for steam generator nozzle-to-safe end weld No.1-06DM on loop "B" of the Reactor Coolant System (Line No. 31 "-RC-30502501 R).

The staff determined that nozzle geometry and surface conditions make complete volumetric examination impractical for the subject weld. To meet the Code requirements, the nozzle safe end and associated piping :would require design modifications to allow access for examination.

Imposition of this requirement would place a considerable burden on the licensee.

The licensee obtained approximately 57% of the Code-required volumetric examination and 100% of the Code-required surface examination for the steam generator safe end weld. The combination of the completed surface examination, partial volumetric examination, and the examination of other similar welds provides reasonable assurance of structural integrity of the dissimilar metal safe end weld. The staff finds that the alternative requirements are 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. Therefore, relief is granted pursuant to 1 b CFR 50.55a(g)(6)(i).

3.0 CONCLUSION

The staff concludes that for the subject welds in Request for Relief SR-026, the Code requirements are impractical at Surry Power Station, Unit 2, and the examinations performed provide reasonable assurance of structural integrity of the subject weld. Therefore, relief is granted pursuant to 1 O CFR 50,55a(g)(6)(i).

• Principal Contributor: T. Mclellan Date: September 24, 1999

- -***- -*-7. ***--

TECHNICAL LETTER REPORT THIRD 10-YEAR INTERVAL INSERVICE INSPECTION REQUEST FOR RELIEF SR-026

• • • VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT 2 DOCKET NUMBER 50-281

1.0 INTRODUCTION

By letter dated February 16, 1999, the licensee, Virginia Electric and Power Company, submitted Request for Relief SR-026, seeking relief from the examination requirements of Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. The Idaho National Engineering and Environmental Laboratory (INEEL) staff has evaluated the information provided by the licensee in support of this request for relief in the following section.

2.0 EVALUATION The Code of record for the Surry Power Station, Unit 2, third 10-year inservice

• inspection (ISi) interval, which began May 10, 1994, is the 1989 Edition of ASME Code,Section XI.

Request for Relief SR-026, Examination Category B-F, Item 85.70, Steam Generator Nozzle-to-Safe End Weld Code Requirement: Examination Category 8-F, Item BS.70 requires 100% volumetric and surface examinations, as defined by Figure IWB-2500-8, for steam generator nozzle-to-safe end welds 4-inch nominal pipe size or larger.

Licensee's Code Relief Request: Pursuant to 1 O CFR 50.55a(g)(5)(iii), relief is requested from the volumetric coverage requirements of the Code for steam generator nozzle-to-safe end weld No.1-06DM on loop "B" of the Reactor Coolant System (Line No. 31 "-RC-30502501 R).

Licensee's Basis for Requesting Relief (as stated):

The component listed above have been examined to the extent practical as required by the Code. However, full volumetric coverage could not be achieved due to joint configuration. Coverage of the-volumetric and surface examinations is detailed in Table SR-026-1 ". Figure SR-026-1" is provided as graphic detail of the limitations experienced. Substitution with another weld is not feasible because all welds in the Category and Item must be examined."

The licensee provided the following completed ultrasonic and surface coverage.

percentages:

Contained in licensee's submittal but not this report.

ENCLOSURE2

e Axial scan (opposite flow) - 47%

Axial scan (with flow) - 0% Circumferential scan (clockwise to flow) - 90.8%

Circumferential scan (counter-clockwise to flow) - 90.8%

Surface examination - 100% -

e The basis for reduced volumetric coverages, as stated by the licensee:

Weld is limited by the nozzle geometry, surface condition and limited surface preparation on the pipe side of the weld. The surface on the pipe side of the weld, which is a cast elbow, is machined for a distance of approximately three inches from the edge of the weld. Ultrasonic examination is limited to this machined area of the pipe and weld since the nozzle side is in the rough as-cast condition. The use of alternate angles would not have improved volumetric coverage. Because of the use of the longitudinal wave form only % node examinations were possible."

Licensee's Proposed Alternative (as stated):

"It is proposed that the examination already completed at the reduced coverage be counted as meeting the Code requirements. In addition:

1.

"A visual (VT-2) examination will be performed during the normally scheduled system leakage test each refueling outage.

2.

Technical Specifications require that the reactor coolant system leak rate be limited to one gallon per minute unidentified leakage. This value is calculated at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

3.

"The containment atmosphere particulate radioactivity is checked every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

"The proposed alternative examinations stated above will ensure that the overall level of plant quality and safety will not be compromised."

Evaluation: The Code requires mo% volumetric and surface examination of the subject steam generator nozzle-to-safe end weld. However, nozzle geometry and surface conditions make complete volumetric examination impractical for this weld. To meet the Code coverage requirements;*the nozzle safe end and associated piping would require design modifications to allow access for examination. Imposition of this requirement would place a considerable burden on the licensee.

Approximately 57% (cumulative) of the Code-required volumetric examination and 100%

of the Code-required surface examination was obtained for the steam generator safe end weld. In addition, there are other safe-end welds in the reactor coolant $ystem that are receiving volumetric examination. The combination of the completed surface examination, partial volumetric examination, and the examination of other similar welds should detect any existing patterns of degradation. As a result, reasonable assurance of the structural integrity of the dissimilar metal safe end weld has been provided.

Therefore, it is recommended that relief be granted pursuant to 1 O CFR 50.55a(g)(6)(i).

e e

3.0 CONCLUSION

The INEEL staff has reviewed the licensee's submittal and concludes that for Request for Relief SR-026 the Code requirements are impractical at Surry Power Station, Unit 2 and that reasonable assurance of the structural integrity is provided by the examinations performed.

Therefore, it is recommended that relief be granted pursuant to 1 O CFR 50.55a(g)(6)(i).