ML20154P749

SE Accepting Second ten-year Interval Inservice Insp Request for Relief RR-1-TYP-2-B5.40-1,Rev 0,for Plant, Unit 1

ML20154P749
Person / Time
Site:	Beaver Valley
Issue date:	10/19/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20154P729	List: ML20154P725 ML20154P749
References
NUDOCS 9810230068
Download: ML20154P749 (5)

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UNITED STATES

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• NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20056 4 001

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION i

REGARDING THE SECOND 10-YEAR INTERVAL INSERVICE INSPECTION REQUEST FOR RELIEF NO. RR-1-TYP-2-B5.40-1. REV. O EDB.

BEAVER vat i FY POWER STATION. UNIT NO.1 DUQUESNE LIGHT COMPANY OHIO EDISON COMPANY PENNSYLVANIA POWER COMPANY DOCKET NO. 50-334

1.0 INTRODUCTION

The Technical Specifications (TSs) for Beaver Valley Power Station, Unit No.1 (BVPS-1), state that the inservice inspection 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 10 CFR 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(1).

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 pre-service 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 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 the 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The applicable edition of Section XI of the ASME Code for the Beaver Valley Power Station, Unit No.1 (BVPS-1) second 10-year inservice inspection (ISI) interval is the 1983 edition through Summer 1983 Addenda.

By letter dated March 25,1998, the licensee proposed attematives contained in the Request for Relief No. RR-1-TYP-2-B5.40-1, Rev. O, for Beaver Valley Power Station, Unit No.1.

2.0 EVALUATION

. l The staff, with technical assistance from its contractor, the Idaho National Engineering and Environmental Laboratory (INEEL), has evaluated the information provided by the licensee in I suppori of the licensee's proposed attematives contained in Request for Relief No. RR-1-TYP -

B5.40-1, Rev. O, for BVPS-1. Based on the results of the review, the staff adopts the contractor's conclusions and recommendations presented in the Technical Letter Report (TLR) attached.

Request for Relief RR 1-TYP-2-B5.40-1, Rev. 0: The ASME Code,Section XI, Table IWB-2500-1, Examination Category B-F, requires a 100% volumetric and surface examination of Pressurizer Nozzle-To-Safe End Butt Welds as defined by figure IWB-2500-8.

9810230068 981019 PDR G ADOCK 05000334 ENCLOSURE pm

2-In accordance with 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code-required 100% volumetric examination of Pressurizer Nozzle-To-Safe End Welds RC-98-1E-02, RC-99 E-03, and RC-104-1-E-01 for impracticality. These welds received 64.55%,84.42%, and 72.84%

l of the Code-required examination, respectively.

l l The licensee's proposed attemative to the examination requirement is to perform the complete i surface examination and to perform a modified ultrasonic examination, due to the search unit lift-off caused by the nozzle-to-safe end outside diameter configuration, to the maximum extent practical using a 45

• refracted longitudinal angle and a supplemental 60

• refracted longitudinal angle for the volumetric examination. These angles represent the most current technology available for this examination and result in the maximum coverage allowed by the joint design and materials involved. The percentage of the examination limitation has been noted on the licensee examination reports and in the outage summary report.

Pressurizer nozzle-to-safe end welds require 100% volumetric and surface examination during each inspection interval. However, the configuration of the subject nozzle to-safe end welds causes transducer liftoff, which limits ultrasonic examination coverage to between 64.55% and 84.42%. The Code-required 100% examination is, therefore, impractical to achieve. The licensee has supplemented the 45

• refracted longitudinal angle scan with a 60 refracted longitudinal angle scan, which increased the examination coverage by at least 15%.

l Implementing a refracted longitudinal angle greater than 60 is not considered effective due to i the thickness / depth of the welds. In addition, the licensee has completed the Code-required surface examination. To achieve the Code-required volumetric examination coverage, the  ;

pressurizer nozzles would have to be redesigned and modified. Imposition of this requirement '

would cause a significant burden on the licensee.

The licensee has performed the volumetric examination to the maximum extent practical. These examinations, in addition to the surface examination of the nozzle-to-safe end welds, provide ,

reasonable assurance that the structural integrity will be maintained and the presence of l degradation will be detected using the stated attemative. Based on the impracticality of meeting the Code coverage requirements for the subject welds, and the reasonable assurance provided by modified volumetric examination performed in conjunction with the 100% surface examination completed, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).

3.0 CONCLUSION

The staff evaluated the licensee's submittal and concluded that complete examination coverage to the extent required by the Code is impractical for certain inservice examinations at BVPS-1.

The licensee has submitted information to substantiate its position of impracticality of the Code-required volumetric examination coverage for Pressurizer Nozzle-To-Safe End Welds RC-98-1-E-02, RC-99-1 E-03, and RC-104-1 E-01. The proposed attemative provides reasonable assurance of structuralintegrity. Therefore, the staff concludes that Request for Relief RR TYP-2-85.40-1 is granted and the attemative imposed for the current interval pursuant to 10 CFR 50.55a(g)(6)(i). 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.

Principal Contributors: D. Collins G. Hatchett Date: October 19, 1998

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e TECHNICAL LETTER REPORT ON THE SECOND 10-YEAR INTERVAL INSERVICE INSPECTION l REQUEST FOR RELIEF 1-TYP-2-85.40-1 (REV. On I fEB DUQUESNE LIGHT COMPANY l BEAVER VALLEY POWER STATION, UNIT 1 DOCKET NUMBER: 50-334

1. INTRODUCTION l

By letter dated March 25,1998, the licensee, Duquesne Light Company, submitted  !

Request for Relief 1-TYP-2-85.40-1 (Rev. 0) seeking relief from the requirements of the l ASME Code,Section XI, for the Beaver Valley Power Station, Unit 1. This relief request is for the second 10-year inservice inspection (ISI) interval. The Idaho National Engineering and Environmental Laboratory (INEEL) staff's evaluation of the subject request for relief is in the following section.

2. EVALUATION l

The information provided by Duquesne Ught Company in support of the request for relief from Code requirements has been evaluated and the bases for disposition is documented below. The Code of record for the Beaver Valley Power Station, Unit 1, second 10-year ISI interval, which ended September 20,1997, was the 1983 Edition through Summer 83 Addenda of Section XI of the ASME Boiler and Pressure Vessel Code.

Reauest for Relief No.1-TYP-2-85.40-1 (Rev. 0). Examination Cateaory B-F. Item B5.40.

Pressurizer Nozzle-To-Safe End Welds l

Code Reauirement--Examination Category B-F, item B5.40 requires a 100% volumetric and surface examination as defined by Figure IWB 2500-8.

Ucensee's Code Relief Reauest-in accordance with 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code-required 100% volumetric examination of Pressurizer Nozzle-to-Safe End Welds RC 98-1-E-02, RC-99-1-E-03, and RC-104-1-E-01.

These welds received 64.55%,84.42%, and 72.84% of the Code required examination, respectively.

ATTACHMENT l

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Ucensee's Basis for Reauestino Relief (as statedk '

"The ultrasonic examination of these welds was limited, to the extent noted above, due to the search unit lift-off caused by the noule to safe end outside diameter (OD) configuration. The change in diameter between the noule and the safe end results in an OD configuration that inhibits coverage from both the safe end and nonie. 64e attached sketches for each weld'. A 45" refracted longitudinal angle and a supplemental 60' refracted longitudinal angle wer) used for the UT examinations. Use of the 60' refracted longitudinal angle increased the coverage of examination by at least 15% for each weld.

A higher refracted longitudinal angle was considered for this examination but was deemed ineffective at this depth. The examination volume calculations are based on the required examination volurne illustrated in ASME Section XI, Figure IWB-25008. The limitations preventing coverage are inherent to the design of these noules. There are no current NDE methods that would appreciably increase the amount of the examination l coverage.

l "The surface examination can be performed on 100% of the required surface."

Licensee's Procosed Attemative Examination (as statedk "The altemative to the examination requirement is to perform the complete surface examination and to perform the ultrasonic examination to the maximum extent practical using the supplemental scan angle noted. These angles represent the most current technology available for this examination and result in the maximum coverage allowed by the joint design and materials involved. The percentage of the examination limitation has been noted on the examination reports and in the outage summary report."

Evaluation-Pressurizer nonle to safe end welds require 100% volumetric and surface examination during each inspection interval. However, the configuration of the subject nonle-to-safe end welds causes transducer lift-off, which limits ultrasonic examination coverage to between 64.55% and 84.42%. The Code-required 100% examination is, therefore, impractical to achieve. The licensee has supplemented the 45* refracted longitudinal angle scan with a 60' refracted longitudinal angle scan, which increased the examination coverage by at least 15%. Implementing a refracted longitudinal angle greater than 60' is not considered effective due to the thickness / depth of the welds. In addition, the licensee has completed the Code required surface examination. To achieve the Code-required volumetric examination coverage, the pressurizer noules would ha /e to be redesigned and modified. Imposition of this requirement would cause a significant burden on the licensee.

The licensee has performed the volumetric examination to the maximum extent practical.

l These examinations, in addition to the surface examination of the nonle-to-safe end L t. At a 1 L..u.' J. cat.. : &L a L .

• ATTACHMENT

welds, provide reasonable assurance that any existing pattoms of degradation would have been detected, if present. Therefore, based on the impracticality of the Code examination coverage' requirements and the examinations performed, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).

3. CONCLUSION The INEEL staff evaluated the licensee's submittal and concluded that certain inservice examinations cannot be performed to the extent required by the Code at the Beaver Valley Power Station, Unit 1. The licensee has provided information to support the determination that the Code-required volumetric examination coverage for Pressurizer Nozzle-to-Safe End Welds RC-98-1-E-02, RC-99-1-E-03, and RC-104-1-E-01 is impractical. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).

ATTACHMENT