ML20133E168

Safety Evaluation Re Third 10-yr Interval ISI Plan,Rev 1 to Relief Request R11 for Plant.Proposed Alternative to ASME Requirements Authorized

ML20133E168
Person / Time
Site:	Oyster Creek
Issue date:	01/07/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20133E162	List: ML20133E158 ML20133E168
References
GL-88-01, GL-88-1, NUDOCS 9701100227
Download: ML20133E168 (5)

Text

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e ur ug p *4 UNITED STATES j

s* NUCLEAR REGULATORY COMMISSION

• WASHINGTON, D.C. *aans nang Q.....l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION THE THIRD TEN YEAR INTERVAL INSERVICE INSPECTION PLAN j REVISION 1 TO RELIEF RE0 VEST N0.R11 GPU NUCLEAR CORPORATION OYSTER CREEK NUCLEAR GENERATING STATION DOCKET NUMBER: 50-219

l. INTRODUCTION The Technical Specifications for Oyster Creek Nuclear Generating Station, a state that the inservice inspection and testing of the Am3rican Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 components shall be l performed in accordance with Section XI of the ASME Boiler and Pressure Vessel  !

Code (ASME Code) and applicable addenda as required by Title 10 of the Code of I Federal Reaulations (10 CFR) 50.55a(g), except where specific written relief l has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(1). l

Section 10 CFR 50.55a(a)(3) states that alternatives to the requirements of I

paragraph (g) may be used, when authorized by the NRC, if (1) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) i 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 comporents ,

(including supports) shall meet the requirements, except the design and access I 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, i 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) on 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 Oyster Creek Nuclear Generating Station, during the third 10-year inservice inspection (ISI) interval, is the 1986 edition. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the AStiE 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(g)(5), if the licensee determines that conformance with an examination reouirement 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 9701100227 970107 PDR ADOCK 05000219 G PDR l

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 December 12, 1996, GPU Nuclear Corporation, the licensee for Oyster Creek Nuclear Generating Station, requested a revision to relief request R11 approved by the NRC on October 25, 1994, from the redundancies of examinations conducted in accordance with the ASME Boiler and Pressure Vessel Code,Section XI, and Generic Letter (GL) 88-01 for certain welds common to the scope of both programs.

The NRC staff has reviewed and evaluated the licensee's request and the supporting information on the proposed revision to relief request R11 for Oyster Creek Nuclear Generating Station, pursuant to the provisions of 10 CFR 50.55a(a)(3)(i).

1 2.0 DISCUSSION 1986 ASME Code Section XI Reauirements: (as stated) l Category B-F/B5.10 examinations are required of each dissimilar metal I weld in systems that see reactor coolant.

l Category B-J/B9.10 examinations are required for piping of nominal pipe l size four inches and larger and are subject to a surface and volumetric examination. The total number of circumferential butt welds selected l for examination shall equal 25% of the circumferential butt welds in the i class 1 piping systems in accordance with Table IWB-2500-1, Examination Category B-J.

Category C-F-1/C5.10 examinations are required for 7.5% of the total number of welds, but not less than 28 welds, of all austenitic stainless steel high alloy welds not exempted by IWC-1200. The examinations shall be distributed in accordance with Table IWC-2500-1.

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Licensee's Code Relief Reauesi;. (as stated) l l

The following requests are based on the dual inspection requirements for ASME Section XI and Generic Letter 88-01. The three ASME Section XI i examination categories described above are inclusive with the I examination criteria for IGSCC detection in accordance with the Generic Letter. The subject welds are piping of austenitic stainless steel, 4 inches or larger in nominal diameter, and contain reactor coolant at a temperature greater than or equal to 200 *F during power operation.

GPUN requests the following relief:

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i 1. Apply credit to ASME Section XI ultrasonic examination requirements i when an IGSCC ultrasonic examination that meets Generic Letter 88-01

! requirements is performed on a weld. (This has already been approved as Relief Request Rll.)

j 2. A> ply credit to ASME Section XI ultrasonic examination requirements wien ultrasonic examination techniques and personnel qualified to i Performance Demonstration Initiative (PDI) criteria for the detection of IGSCC are utilized. 1 Licensee's Basis for Relief: (as stated) j Relief Request No. 1 i There are more )than 300 welds identified as having both ISI and IGSCC l inspection requirements. For ISI, these welds are examined to ,

i categories B-F/85.10, B-J/89.10 and C-F-1/C5.10 requirements. For IGSCC l 1 these welds are examined to Generic Letter 88-01 requirements. Efforts j have been made to consolidate the two inspection schedules for ASME XI 2

and IGSCC scope's, but the differences between the two scheduling

! criteria often result in a duplication of inspections. The limitations j imposed by IGSCC requirements were due to the extreme inspection 4

frequency criteria for the IGSCC examinations. The schedule can range l

! from a 25% inspection sample within the Ten Year Inspection Interval to  ;

as many as five inspections for the same weld within the Ten Year I i Inspection Interval. The scope criteria for ASME Section XI are, B-F '

i (100%), B-J (25%), and C-F-1 (7.5%). The limitations caused by ASME  ;

i Section XI were due to the maximum examination credit per period and '

l sequence of examinations from interval to interval per IWB-2400 and IWC-i 2400. In complying with both the ISI schedule and IGSCC schedule, GPUN has experienced scheduling hardships that have resulted in unwarranted i

radiation exposures, and bath unnecessary labor and material costs.

Relief Request No. 2

} By letter dated March 1, 1996, Russell to Donovan, the USNRC approved l

Intergranular Stress Corrosion Cracking (IGSCC) examiner qualifications

! obtained by passing the PDI qualification program. Further, in that

same letter the USNRC states in part:

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...it is intended that the PDI program eventually replace the IGSCC

. Coordination Plan and that the IGSCC Coordination Plan will i subsequently be dissolved..."

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In the recent refueling outage, 16R, the IGSCC examinations were i performed by ultrasonic procedures and contractor personnel that were

! qualified under the PDI Program.Section XI credit was intended to be taken for some of the IGSCC examinations based on Relief Request Rll, I which was granted by NRC letter dated October 25, 1994. It was

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l subsequently determined that a revision to Relief Request R11 would be  !

necessary in order to take Section XI credit for the examinations that l

j were completed this refueling outage. The NIS-1 and NIS-2 forms are due 1 j for submittal to the USNRC by January 23, 1997.

Licensee's Pronosed Alternative Examination:

j Substitution of GL 88-01 examination for the Code-required volumetric j examination during the 16R outage.

l 3.0 EVALUATION

) The licensee's original relief request R11 was authorized pursuant to 1 10 CFR 50.55a(a)(3)(1) on October 25, 1994, which granted relief from performing the ASME Code Section XI volumetric examination of welds in B-F, B-J, and C-F-1 categories that were common to the ongoing IGSCC examination program under GL 88-01. Based on the premises of Code acceptance of j alternative examination as stated in paragraph IWA-2240, " Alternative

Examinations," the staff evaluated and compared the ultrasonic examination

techniques used for IGSCC examination and the examination conducted in i accordance with Appendix III " Ultrasonic Examination of Piping Systems" to

satisfy the requirements of the ASME Code Section XI. The staff concluded j that the techniques required to detect and size IGSCC were more rigorous than

those required by the' Code. Therefore, the ultrasonic examination techniques  ;

used to satisfy the requirements of GL 88-01 will also satisfy the Code

requirements in accordance with IWA-2240. Hence, the ultrasonic examination

required by GL 88-01 can be considered an acceptable alternative to the "

J ultrasonic examination required by the Code. In the same inservice inspection 1

interval, but during the sixteenth refueling outage, the licensee has

requested relief from performing ASME Code Section XI examinations of welds in

! the examination categories listed in relief request R11, that were examined i for IGSCC under the GL 88-01 program. Based on the foregoing discussion, the staff recommends that the licensee be giten credit to ASME Code Section XI ultrasonic examination requirements when an IGSCC ultrasonic examination that

! meets Generic Letter 88-01 requirements is performed on a weld.

l During the 16R outage, the IGSCC examinations were performed using ultrasonic procedures and personnel that were qualified under the Performance Demonstration Initiative (PDI) program. Prior to this, the IGSCC qualification of nondestructive examination (NDE) personnel was conducted under the IGSCC Coordination Plan, sponsored by EPRI and the BWR Owners' Group (BWROG) and agreed by the NRC. In a letter dated January 23, 1996, the BWROG i

submitted a proposal to the NRC to implement the PDI program in qualification of examiners for IGSCC. The staff reviewed and evaluated the PDI program and noted its finding in a letter dated March 1, 1996, to the BWROG that use of

the PDI program for qualification of BWR IGSCC examination personnel is preferred over the use of the IGSCC Coordination Plan. Therefore, the

. ultrasonic examination techniques and personnel qualified to the PDI program I

is an acceptable alternative to the IGSCC examination program under GL 88-01.

i Based on paragraph IWA-2240, " Alternative Examinations" of the ASME Code Section XI, which states that: " Alternative examination methods, a combination i

of methods, or newly developed techniques may be substituted for the methods i

specified in this Division, provided that the Inspector is satisfied that the

! results are demonstrated to be equivalent or superior to those of the I

specified method," the staff recommends that the licensee be given credit to ASME Code Section XI ultrasonic examination requirements when examination techniques and personnel qualified to PDI criteria for the detection of IGSCC are utilized.

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4.0 CONCLUSION

The staff has reviewed and evaluated the revision to the licensee's previously approved relief request Rll. It is con:19ded that the ultrasonic examination requirements including the technique and personnel qualification using the Performance Demonstration Initiative criteria for the detection and sizing of intergranular stress corrosion cracks performed under the Generic Letter 88-01 program, is an alternative to the ASME Code Section XI examination scheduled to have been performed on the same welds during the 16R outage at Oyster Creek. .

The IGSCC examination of welds provides an acceptable level of quality and safety by providing equivalent protection as provided by the Code. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i).

Principal Contributor: P. Patnaik Date: January 7, 1997 l

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