ML18030A031

Final Deficiency Rept Re Ovality of Small Diameter Pipe at Bends Exceeding ASME Boiler & Pressure Vessel Code Tolerances,Initially Reported on 800411.Bends Will Be Dispositioned in Accordance W/Criteria by 810331

ML18030A031
Person / Time
Site:	Susquehanna
Issue date:	02/10/1981
From:	Curtis N PENNSYLVANIA POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, ER-100450, ER-100508, PLA-630, NUDOCS 8102180444
Download: ML18030A031 (7)

Text

0 0 REGULATORY 1NFORlLiATION DISTRIBUTION SYSTEM (RIOS)ACCESSION NdR:8102180444 DUC~DATE: 81/02/10 NOTARIZED:

NO FACIL:50-87 Susquehanna Steam Electric Station<Unit IR pennsylva sguehanna Steam El.ectric Station<Unit 2R Pennsylva A,~AU THUR AF F ILI ATION CU T I S g>I~Ti~Pennsylvania Power tr I ight Co.RECIP.~A~~E REC IPIc'NT AFFILIATION GR IER r 8, h.Reason IR Philaaelphia<

Office of the Director SUBJECT;Final deficiency rept re ovality of small diameter pipe at bends exceeoina AS4lE Boiler tt Pressure Vessel Code tolerancesiin>tiatly reported on 800411.Benos will oe dispositioned in accordance w/cr iteria by 810331R OISTRISUTIOR COOE: SOISS OORIES RECEIVES:LTR 3 ERCL f SIZE: TI TLE: Construction Oe f i c i ency Report (10CFR50~55E)NOTES:Send IH,E 3 copies FSAR 4 all amends'enal 16E 3 copies f-SAR 4 all amends'OCKET

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LTTR 39 FNCL 39 l TWO NORTH NINTH STREET, ALLENTOWN, PA.18101 PHONEr (215)770 5151 NORMAN W.CURTIS Vice President-Engineering 3 Construction-Nuclear 770.5381 February 10, 1981 Mr.Boyce H.Grier-Director, Region I U.S.Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 SUSQUEHANNA STEAM ELECTRIC STATION FINAL REPORT OF A DEFICIENCY RELATING TO OVALITY OF BENT PIPE ERs 100450/100508 FILE 840-4/900-10 PLA-630

Reference:

PLA-498 (6/20/80)'

Dear Mr.Grier:

This letter serves to provide the Commission with a final report of a deficiency relating to excessive ovality of small diameter pipe caused by bends which were produced in the field prior to the installation.

The ovality of the pipe at the bends exceeds the tolerances specified in the ASME Boiler and Pressure Vessel Code,Section III, NB4223.2.The condition was originally reported in PLA-498, and the information contained herein is submitted as a final report pursuant to the provisions of 10 CFR 50.55(e).The attachment to this letter contains a description of the problem;its cause, safety implications and significance; and the corrective action taken and planned to preclude recurrence.

We trust the Commission will find the information forwarded by this letter to be satisfactory.

Very truly yours, N.W.Curtis Vice President-Engineering

&Construction-Nuclear FLW:sab Qorrt 5 I/i Attachment al ezlaO PENNSYLVANIA POWER 5 LIGHT COAIPANY

~V~I Mr.Boyce H.Grier February 10, 1981 cc: Mr.Victor Stello (15)Director-Office of Inspection a Enforcement U.S.Nuclear Regulatory Commission Washington, D.C.20555 45 Office of Management Information

&Program Control U.S.Nuclear Regulatory Commission Washington, D.C.20555 Mr.Robert M.Gallo U.S.Nuclear Regulatory Commission P.O.Box 52 Shickshinny, PA 18655 1 1.Description of Problem NCR-5523 dated April 11,.1980, identified a nonconforming condition in.which small diameter pipe bent in'the field exceeds the tolerance stated in ASME,Section III,"NB-4223.2.

Ovality Tolerance.

Unless otherwise justified by the Stress Report, the ovality of piping after bending shall not exceed 8 percent as determined by 100 K (D-.D.)/D where.D 0 D min D max The minimum pipe outside diameter before bending or forming, in.(mm)=The minimum outside diameter'after bending or forming, in.'mm).=The maximum outside diameter after bending or forming, in.(mm)1 I Nuclear Class II and III piping are subject to the same provisions.

.This formula is derived from the 1971 edition of Section III with.Addenda thru Winter, 1972..This is the Code in effect for.this pro j e'ct.Construction determined the values for D , D., D through actual measurement of the pipe.D.anl D were 5etermined by taking 3 sets of readings inside tEe oend.Ponstruction used.the values from the point that produced the greatest variation.

D was determined by a reading taken adjacent to the bend.The deficiency identified four stainless steel pipe bends where the ovality exceeds 8g.2.'Cause.of Deficiency The subject non-conforming condition has been primarily on pipe bends that were made in place, apparently using the Greenlee Model jj884 One Shot.hydraulic ram type bender;Sample bends made on this bender did not meet the 8$ovality requirement.

Bends made in the onsite pipe prefab facility on the Pedrick mechanical bender have been observed to be better than those made on the Greenlee machine.However, even these bends have very little margin with respect to ovality.Bends made in place with the Ensley mechanical bender d'o not appear to have ovality discrepancies.

Another contributing factor is the lack of specific instructions to construction forces (via specifications for fabrication and installation of piping)for qualification and control of pipe bending performed at the jobsite.1of 3 Siace there is no record of which bends were made on which machiae, all installed bends are being checked for ovality.Only after a complete iaspection will the full magnitude of the problem be Mown.This inspectioa is being performed and documented as part of the'isposition of NCR-5523,.

NCR-5674 aad additional NCR's.3.Analysis of Safety Impli'cation Project Engiaeeriag has developed acceptaace criteria based on stress analysis for pipe bends with.ovality up'to 15$.Maximumovality permitted is 8$for pipiag which is subject to temperature traasients and 15$for piping which is not subject.to temperature transients.

Additionally the bends must be free of rapid chaages in curvature aad circumferential kinks or concavity as defined in the criteria.Wall thickaess, after bending, must meet desiga.minimum;The effect on flow (pressure drop)due to reduced cross~sectional area of bends with up to 15$ovality was addressed and.found to be insignificaat.

Approximately 700 bends, including all bends in small piping within the primary reactor pressure vessel bouadary have been iaspected aad dispositioaed ia accordance with the criteria;Although the balance of bends (approximately 5,000), in safety related systems have not been inspected it is felt that the work to date i's a represeatative sample and is adequate to evaluate the safety impli-cations.Of the approximately 700 bends checked as of Dec.1980, one exceeded 15X ovality and two exceeded the 8$ovality limit for piping subject.to temperature transients.

These three bends have been replaced.Approximately 240 bends measured fell between the 8-15$limit allowed for systems not subject to temperature transients.

Three installed bends in safety related piping had to be replaced to'meet the project engineering acceptance criteria.Aay bends which d'o not meet the acceptaace criteria are ass~ed to fail in service.Such failures could'ave affected adversely the safety of operatioas of'the plant.Therefore, this coaditioa is-considered reportable under 10 CZR 50.55(e)'.

5.Corrective Action The acceptance criteria was issued on May 30, 1980.Coastructioa anticipates completiag approximately 1250 bends per month and that final corrective action will be completed, for Unit 1 aad Common, by March, 1981.~~~Specificatioa M-204 for fabrication and, installation of pi>fag has been amended to require field procedures to control and monitor future bending to ensure that 8$.ovality is not exceeded and that beads exceeding this limit or any other criteria shall be rejected.2qf 3 6.Corrective Action'to Preclude Recurrence-E~bdb'd'pd'd*'PP Engineering-acceptance criteria.All measurements are being verified by on site quality control personnel.

For future bends, a program has been instituted to'ave all bends checked for ovality by the responsible system engineers prior to installation of the bend.Also, all applicable superintendents have been directed to insure that proper bending equipment, and techniques are used for all.pipe.behds.In addition, Quality Control has been requested to inspect and document all Q-bends for ovality.Use of the Greenlee"one shot" bender has been discontinued for bending pipe.Also, a Pedrick representative visited the jobsite and.provided instruction as to the proper use and maintenance of the Pedrick bending machine, and re'commended some replacement parts where the shoes were worn.Those.parts have been replaced.2U/AAW 3of 3