ML20217K846

Safety Evaluation Approving Proposed Use of Code Case N-535 at Brunswick Unit 1 During Second 10-yr Interval,Pursuant to 10CFR50.55a(a)(3)(i).Authorizes Use of Code Case N-535 Until Code Case Included in Future Rev of Rg 1.147

ML20217K846
Person / Time
Site:	Brunswick
Issue date:	04/24/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20217K796	List: ML20217K793 ML20217K846
References
RTR-REGGD-01.147, RTR-REGGD-1.147 NUDOCS 9805040160
Download: ML20217K846 (3)

Text

pur4 9 g k UNITED STATES s* Ijt NUCLEAR RESULATORY COMMISSION WASHINGTON, D.C. Me66 0001 l l

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ON USE OF ASME CODE CASE N-535 '

RELIEF REQUEST SERIAL NO. BSEP 97-0459 BRUNSWICK STEAM Ft FCTRIC PLANT UNIT NOS.1 AND 2 CAROLINA POWER & LIGHT COMPANY QQCKET NOS: 50-325 AND 50-324

1.0 INTRODUCTION

l The Technical Specifications (TS) for the Brunswick Steam Electric Plant (BSEP), Unit Nos 1 and 2, 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 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). 10 CFR 50.55a(a)(3) states that attematives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed attematives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship 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) 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 first 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of the ASME Code,Section XI, incorporated by reference in 10 CFR 50.55a(b) on the date 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The applicable ASME Code,Section XI, for Brunswick Units 1 and 2, during the second 10-year inservice inspection (ISI) interval is the 1980 Edition through the Winter 1981 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 and subject to Commission approval.

Pursuant to 10 CFR 50.55a(a)(3), by [[letter::BSEP-97-0459, Requests Approval to Use Alternative Requirements for ISI Delineated in ASME Section XI Code Case N-535.Alternative Is Needed to Extend Third Period of Second ten-yr ISI Interval to Coincide W/End of Bsep,Unit 1,refueling Outage 11|letter dated November 17,1997]], Carolina Power & Light Company (CP&L or the licensee) requested approval for implementing the attemative rules of ASME Section XI Code Cas N-SSS, "Altemative Requirements for Inservice inspection Enclosure 9805040160 990424 PDR ADOCK 05000324 P PDR

l l . .

Intervals,Section XI, Division 1," to be applied to the ISI program for Brunswick Units 1 and 2. l For Brunswick Unit 1, Code Case N-535 will be applied to the third period of the second 10-year i l inspection interval. The staff's review and evaluation of the licensee's request and supporting i information is noted below.

l 2.0 DISCUSSION l Code Case N-535. Altamative Reauirements for Inservice Insnardian intervals 1 l

Component identification ASME Code Class 1, 2, and 3 components and their supports for Brunswick Units 1 and 2. l Code Requirement The ASME Code,Section XI,1980 Edition with Winter 1981 Addenda, Paragraph l IWB-2412(b) states; "The inspection period specified in (a) above may be decreased or l extended by as much as 1 year to enable an inspection to coincide with a plam outage, within j the limitations of IWA-2400(c)."

The Paragraph IWA-2400(c) states; "Each inspection interval may be decreased or extended

' (but not cumulatively) by as much as 1 year. For power units that are out of service l continuously for 6 months or more, the inspection interval during which the outage occurred 1 may be extended for a period equivalent to the outage."

l- Licensee's Basis for Relief l

l The second 10-year inservice inspection interval for Brunswick Units 1 and 2, ends May 10,1998. The Unit 1 refueling outage is scheduled to begin on April 25,1998. The short time period between the start of the refueling outage and end of the inspection interval is not sufficient to complete the remaining second 10-year interval Code examinations. Therefore, the third inspection period of the inspection interval needs to be extended to coincide with the end of Brunswick Unit 1 Refueling Outage 11.

The ASME Code,Section XI allows extending the inspection interval by as much as 1 year to enable an inspection to coincide with a plant outage. However, extending the end date of the second 10-year interval extends the start date of the third 10-year interval. The altamat've r

requirements of ASME Code Case N-535 have been reviewed by CP&L, and it was determined that the use of this Code Case would provide an acceptable level of quality and safety.

Proposed Altemative CP&L proposes to extend the third inspection period of the second 10-year inspection interval for Brunswick Units 1 and 2 (without affecting the start date of the successive interval) as allowed by ASME Code Case N-535. The attemative provisions of Code Case N-535 allow CP&L to extend the third period of the second 10-year inspection inteNai to coincide with the end of BSEP Unit No,1 Refueling Outage 11. Therefore, approval to use Code Case N-535 is I

i

being requested for the remainder of the second 10-year inspection interval. Approval for Unit q

No. 2 is requested solely to permit use of a common interval closure date in plant procedures and documentation for the second 10-year inspection interval. There are no scheduled Unit 2 inspection activities that require use of Code Case N-535.

3.0 EVALUATION 1

The staff has reviewed the attemative requirements for inservice inspection intervals as provided in Code Case N-535, and has determined that the implementation of the Code Case neither require any change to the start and the end date, nor the inservice inspection program for the successive interval. This, therefore, will maintain the inspection intervals more closely to the original pattem of intervals than that of the ASME Code,Section XI. However, Code Case N-535 has provisions for reducing or extending an inspection interval by as much as 1 year as does the ASME Code Further, the Code Case specifies that an examination performed to satisfy requirements of either the extended interval or the successive interval shall not be credited to both intervals. Hence, the extent of examination coverage for each component i remains unchanged for a given inspection interval. Moreover, the implementation of the Code Case would require that the inspection interval during which an examination is performed, must be identified on examination records. Thus, the use of the Code Case requires explicit documentation of changes to scope of examination during an inservice inspection interval. The staff has, therefore, determined that the use of Code Case N-535 on Unit 1 would provide an acceptable level of quality and safety equivalent to the applicable ASME Code,Section XI. We do not authorize the use of Code Case N-535 at Unit 2, as there are no scheduled Unit 2 inspection activities that require the use of Code Case N-535.

4.0 CONCLUSION

Based on the above discussions, the staff concludes that the licensee's proposed use of Code Case N-535 Unit 1 would provide an acceptable level of quality and safety equivalent to the provisions of the ASME Code,Section XI,1980 Edition including the Winter 1981 Addendum.

Therefore, the licerisee's proposed attemative to use Code Case N-535 at Brunswick Unit 1 during the second 10-year interval, is authorized pursuant to 10 CFR 50.55a(c)(3)(i). The licensee is authorized to use Code Case N-535 until such time as the Code Case is included in a future revision of Regulatory Guide 1.147. At that time the licensee should follow all provisions and any limitations that may be described in the Regulatory Guide 1.147 conceming the use of Code Case N-535.

Principal Contributor: P. Patnaik, ECGB Date: April 24, 1998 e