ML20140H475

Trip Rept of 851120-22 Site Audit of S&W Implementation of Project Procedure CPPP-8 for Piping & Pipe Supports.No Items of Noncompliance or Deviations Noted

ML20140H475
Person / Time
Site:	Comanche Peak
Issue date:	04/01/1986
From:	Terao D NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM)
To:	Shao L NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM)
References
NUDOCS 8604040125
Download: ML20140H475 (2)

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\ , . . . . ** APR 1gg Docket Nos. 50-445/50-446 MEMORANDUM FOR: Larry C. Shao, Group Leader, Comanche Peak Project FROM: David Terao, Mechanical Engineer, Comanche Peak Project

SUBJECT:

TRIP REPORT

SUMMARY

FOR SWEC ENGINEERING WALKDOWN AUDIT On November 20-22, 1985, the NRC staff and its consultants from Teledyne Engineering Services (TES) audited the implementation of the Project Procedure CPPP-8 performed by Stone & Webster Engineering Corporation (SWEC) for the piping and pipe supports at the Comanche Peak plant. The Project Procedure CPPP-8, " Piping and Support System Engineering Walkduwn Procedure," Revision 0, issued on October 28, 1985 was developed by SWEC to review physical relation-ships and critical configurations associated with the installed piping systems which could potentially impact the validity of the piping stress analyses and pipe support calculations.

In addition, the staff continued its review of selected items from the QA/QC reinspection of the piping and pipe supports being performed by ERC as part of the overall Construction Adequacy Program. The details of our audit findings follow. Attendees at the exit meeting held on November 22, 1985 were:

Dennis Alexander, ERC Tom Westennan, NRC/RIV Roger Stuart, TES/NRC John Tableriou, ERC Bob Hookway, TES/NRC David Terao, NRC John Finneran, TUGC0 Audit of Engineering Walkdown Procedure CPPP-8 The SWEC walkdown teams were in the process of icolementing Project Procedure CPPP-8 during the period from November 12-22, 198b. The staff reviewed the sumary sheets for those piping systems which had beer. completed and selected two piping stress problems for the staff to walkdown. The two stress problems selected were 1-055A (Component Cooling Water System) and 1-015Y (Safety In-jection System). In addition, the staff accompanied a SWEC walkdown tean to observe the walkdown in progress, in general, the staff found the SWEC personnel to be well qualified in identi-fying the types of physical interactions between piping and pipe supports which could affect the assumptions used in the piping stress analyses and pipe support calculations. The SWEC teams identified several generic items which will re-quire further evaluation. These items included the following:

(1) The use of washers of smaller diameter than the busings in the paddle of a strut or snubber. The smaller diameter washer would allow the paddle to slip off the bearing.

(2) Excessively varying gap sizes were found in lugs for axial restraints whose calculations assumed equal load distribution. The different gaps could result in an uneven load distribution.

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. L. Shao. APR 1M (3) Moment restraints were found to have excessive gaps and might be incapable of resisting bending moments and torsion.

The staff verified the SWEC observations in the field and concurs with the SWEC concerns. The SWEC concerns are preliminary at this time and require further review and evaluation in order to detemine the overall significance of the items. The staff will continue its overview of the SWEC walkdown effort and, upon completion of the SWEC walkdown results report, the staff will review the final SWEC conclusions and provide our findings at that time.

0A/QC Reinspection of Piping and Pipe Supports The staff continued its review of the QA/QC reinspection of piping and pipe supports being perfomed by ERC as part of the Construction Adequacy Program.

(See memorandum f rom D. Terao to L. Shao dated December 6,1985.)

The staff discussed the treatment of grouted floor and wall penetrations with the applicant. The different types of sealant materials and their analytical assumptions were discussed. A penetration seal schedule lists the penetration numbers, type of sealant, location, drawing number and stress problem number for an analyst to obtain the information necessary for proper modelling in the piping analysis. However, the staff did not find that the adequacy of grouted penetrations was addressed in the QA/QC Construction Adequacy Program. The staff will evaluate the need for reinspection of grouted penetrations and provide our conclusions in our final report.

The staff further discussed the acceptability of dispositioned NCM which have been previously resolved by reviewing Gibbs & Hill stress analyses. The staff was provided a copy of a TUGC0 procedure which describes SWEC's responsibility for reviewing NCRs. The staff will review the acceptability of this procedure and provide our findings in our final report.

The staff completed its review of the population samples for (1) large bore supports (rigid); (2) large bore supports (non-rigid); and (3) small bore supports which have been reinspected by ERC. The staf f compiled a list of the different types of supports and their general configurations and will assest the infomation gathered this week to detemine the adequacy and representa-tiveness of the samples.

The staff identified ro items of noncompliance or deviations as a result of this audit.

t CAde David Terao Mechanical Engineer Comanche Peak Project cc: V. Noonan, NRR J. Calvo, DE S. Hou, DE D. Landers, TES C. Tramell, R. Hookway, TES G. Mizuno, ELD T. Westerman, RIV A. Vietti-Cook, DL 5. Hou, DE P. Chen, ETEC