ML18030A301

Final Deficiency Rept Re Discrepancies Between Hanger Loadings on Pipe Support Detail Drawings Vs Stress Isometrics.Verification Program Has Resolved Problem for Unit 1.Procedure Changes Effected for Unit 2

ML18030A301
Person / Time
Site:	Susquehanna
Issue date:	06/04/1981
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, PLA-829, NUDOCS 8106090597
Download: ML18030A301 (5)

Text

REGULATORS INFORMATION OISTRIBUTION TEM (RIOS)

ACCESSION NBR:8106090597 OOC ~ DATE: 81/06/04 NOTARIZED: NO DOCKET ¹ FACIL:50 387 Susquehanna Steam Electric Stations Unit 1> Pennsylva 0944 7 50 388 suaouenanna steam Eleetnto station, Unit 20 Pennaylva ~50003008 AUTHaNAME AUTHOR AFFILIATION C UR T IS E N ~

'Ill ~ Pennsylvania Power 8, Light Co.

RECIP, VAHE REC IP IEilT AF F ILIATION GRIEREB ~ H ~ Reaion 1E Philadelphian Office of the Director (81/03/01)

SUBJECT; Final deficiency rept re discrepancies between hanger loadinqs on pipe support detail drawing stress isometrics.

Veri<ication program has resolved problem for Unit 1, Procedure changes effected for UEIit 28 OISTRISUTIOR COOS: 8010S COPIES RECEIVES:LTR TITLE: Cons t ruc t i on Oe f i c i ency Repor t (10CFR50.55E) l ENCL 4 8

SIZE:

NOTES: Send IS E 3 copi es FSAR 8 a 1 1 amends 81 cy: B'AR L"G PM(L RIB) ~ 05000387 Send I8E 3 copi es FSAR lt, al 1 a~ends,1 cy B'HR LRG PM(L.RIB) 05000388 RECIPIENT COPIES RECIPIENT COPIES IO COOE/NAltlE LTTR ENCL IO C05E/NAME LTTR ENCL ACTION: A/0 LI CENSNG Oil 1 1 LIC BR ¹2 BC 05 LIC BR <2 LA Oo 1 STARKERS 07 1 INTERNAL( ASLBP/J ~ HARD 1 0/OIR HUM FAC15 1 1 EDO 8, STAFF 19 1 EQUIP QUAL BR11 1 1 HYI)/GEO BR 22 1 1 IKE 09 1 1 IE/EES 1 1 LIC QUAL BR 12 1 1 MPA 20 1 VRC POR 02 1 1 OELO 21 1 P 1',REV 13 1 1 GA BR 1 il 1 RLc, 01 1 1 STANDROS OEV 21 1 1 EXTERNAl; ACRS 16 16 16 LPOR 03 NSIC 08 1 1 TOTAL NULiBER OF COPIES REQUIRED! LTTR ENCL

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NL4 TWO NORTH NINTH STREET, ALLENTOWN, PA. 18101 PHONEr t215) 770 ~ 5151 NORMAN W. CURTIS vice preslcenI.Engineering rs ccnslruction-Nuclear 770 5381 June 4, 1981

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Hr. Boyce H. Grier 6 ~Up~ QQ 'l% I 3 sscr nATOLL Director, Region I ~1 Visr N"cXAR

~

CC

~IcaiCN U. S. Nuclear Regulatory Commission 631 Park Avenue King of Pruss'a, PA 19406 SUSQUE~iA STEAN ELECTRIC STATION PENAL REPORT OP A DEFICIENCY RELATING TO LOAD DISCREPANCIES ON PIPE SUPPORT DETAILS ERs 100450/100508 PILE 840-4/900-10 PLA-829 Re erences: PLA-391 (9/5/79)

PLA-462 (3/24/80)

PLA-514 (7/22/80)

Dear Hr. Grier:

This letter serves to provide the Commission with a final report of a deficiency relating to discrepancies between hanger loadings s'nown on pipe support detail drawings as compared to those shown on st ess isometrics. This def'ciency was originally reported in PLA-391 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 deficiency, its cause, safety implications, and the corrective action taken and planned.

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

Very truly yours, gor 9 5

Curtis N. W.

Vice President-Engineering a Construction-Nuclear )/i PLWssab Attachment PENNSYLVANIA POWER 8 LIGHT COMPANY

Mr. Boyce H. Grier cc: Mr. Victor Stello (15)

Director-Office. of Inspection 6 Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. G. McDonald, Director (1)

Office of Management Information 9 Program Contxol U. S. Nucleax Regulatory Commission Washington, D AC. 20555 Mr. Gary Rhoads U. S. Nuclear Regulatory Commission P. O. Box 52 Shickshinny, PA 18655

0 Attachment to PLA-829 Descriotion o the Deficienc During a system walkdown in 1979, Bechtel Engineering discovered ciscrepancies between hanger loads shown on stress isometr'c sketches and the coxresponding loads shown on pipe support details. A random review of selected pipe support details and stress isometrics indi-cated that the problem was not generic or wicespread, but seemed to be restricted to isometr'cs issued prior to mid-1976. A verification program was instituted. As a result., some hardware changes were required in several safety-related systems in order to meet FSAR commitments. A QA aud' of the pipe suppo t desicn process revealed that some pipe support details lacked adequate supporting calculations.

In some cases, calculations in support of detailed design were not available.

2. Cause The causes for the deficiencies were:

Inacecuate internal design control and interface between Bechtel Plant Design Subgroups. Changes mace to the stress analysis by the Stress Groups were not coordinated with the Pipe Supoort Group.

Thus tnese changes were not incorporated into the pioe support design.

ii) Inadequate implementation of Bechtel Engineering Procedures Manual r (EPM) recuirements. Calculations were not properly orepared or were not generated as required.

Anal s's of Sa et Implications The verification program revealed that some pipe supports were designed for loads below those specified on the st ess isometrics. Correcting these discrepancies necessitated changes in the actual hardware for some of the pipe supports. Had this situation gone uncorrected, some supports might have fa'ed, adversely affecting the safe operation of the plant. Therefore, this deficiency is considered to be reportable in accordance with 10 CFR 50.55(e). s Corrective Action For Unit 1, a verification pxogram was established and all Stress isometrics and pipe support details were reviewed:

i) The loads specified on stress isometrics we e reviewed and the pipe support details we:c- revised to reflect correct information.

ii) A co'mparison was made between the revised loads and the loads used in hanger design. The revised loads we e then compared with actual hardware strength.

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iii) If the revised loads were lower than design or, if higher but still w'thin the capacity of existing hardware, no action was needed.

If, however, comparisons showed revised loads beyond hardware strength, hardware changes were required. This program or Unit 1 is now complete. The revised pipe support details have been issued for construction.

For Unit 2, an exploratory review showed that the problem was much smaller in scope and could be integrated into the ongoing project design effort. A complete verification for Unit 2 will be completed prior to fuel load as part of the hydrodynamic loads analys's and as-built review programs.

In correcting the problem of inadequate calculations for pipe supports, all Nuclear Class 1, 2, and 3 Seismic Category I piping systems are be'ng analyzed to verify the adequacy of the des'gn for the actual as-built condition. Supporting calculations will be performed and documented or all hangers which lack them.

Appendix B of the Bechtel Engineer'ng Procedures manual .(EPM) has been revised to require design coordination among each group in the Plant Design.. The stress isometrics are signed by each group prior to issuance to preclude recurrence of the d'screpant load problem. Also training sessions have been held w'h pipe support group supervisors, designe s and engineers to ensure that they are aware of tne recuirements to documen" calculat'ons as required by the EPH. These training sessions are ongoing.

5, Conclusion The vercation program nas resolved this discrepant load problem .

for Unit 1. The procedure changes effected will ensure the situation does not recur on Unit 2. The problem of hange" calculation deficiencies will be resolved with completion of the as-built design verification program Page 2 of 2