ML20141K437

Trip Rept of 850923-26 Audit of S&W as-built Verification Walkdown.Contingent Upon Acceptable Resolution Re Piping Run Geometry & Clearances,S&W Walkdown Well Documented & Easily Verifiable

ML20141K437
Person / Time
Site:	Comanche Peak
Issue date:	10/11/1985
From:	Shao L NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM)
To:	Noonan V NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM)
References
IEB-79-14, NUDOCS 8601220522
Download: ML20141K437 (4)

Text

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.  % UNITED STATES y k NUCLEAR REGULATORY COMMisslON

j jz WASHINGTON. D. C. 20555 S OCT 111985

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Ros: 50-445/50-446 MEMORANDUM FOR: Vincent S. Noonan, Director, Comanche Peak Project FROM: Larry C. Shao, Manager, Engineering Group, Comanche Peak l Project j

SUBJECT:

TRIP REPORT

SUMMARY

- AUDIT OF CPSES AS-BUILT VERIFICATION BY SWEC On September 23-26, 1985, the staff and its consultants from Teledyne Engineering Services (TES) perfomed an audit of the Stone & Webster Engineering Corporation (SWEC) as-built verification walkdown at the Comanche ,

Peak site. The SWEC walkdown was performed based on a random sample of large .

bore pipe supports and valves. The purpose of the staff audit was to verify the adequacy of SWEC walkdown. The staff audit included: 1) a review of the as-built walkdown procedures and results report, 2) a review and walkdown of a sample of the SWEC as-built walkdown pacuges. 3) a walkdown of two large bore piping stress isometric drawings, and 4) a review of the as-built reverification of snubber, strut, and valve crientations by TUGCO.

As-Built Walkdown Procedure and Results Report The staff reviewed a draft copy of Project Procedure CPPP-5, " Field Walk Procedure - Unit 1" (Revision 1), and a preliminary copy of the result report -

entitled, "Large Bore Field Walkdown Report." The purpose of the SWEC as-built walkdown was to verify that the as-built documentation is adequate to initiate the pipe stress analysis. The SWEC as-built walkdown was not intended to verify the adequacy of the as-built program. The Construction Assessment Program will assess the adequacy of the existing as-built documentation against the construction tolerances.

The SWEC walkdown verified the adequacy of four attribi;tes obtained from a random selection of 680 large bore supports and valvet. The four attributes

- were:

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1) Valve location (sample size of 80),

2) Pipe support location (sample size of 200),

3) Pipe support function (sample size of 200), and

4) Valve and support orientation (sample size of 200).

Of the four attributes evaluated, several discrepancies were noted in the valve and support orientation attribute which exceeded the sampling acceptance criterion. As a result. TUGC0 had initiated corrective actions to reverify 100%

of snubber, strut, and valve orientations for the large bore piping systems to be reanalyzed by SWEC. The staff review of this corrective action is further discussed later in this memorandum.

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Staff Walkdown of As-Built Verification Packages The staff and consultants selected a sample of approximately 10 percent of the l SWEC as-built walkdown packages for each of the four attributes. The staff

review consisting of three 2-man teams independently verified each as-built package for the respective attribute checked by SWEC. Additionally, the staff checked the support or valve in each walkdown package for other attributes which can potentially affect the validity of the piping stress analysis. The .

ctaff walkdown of the SWEC as-built packages provided the staff with a clear  !

understanding of hcw Project Proecedure CPPP-5 was implemented. The results  ;

and conclusions of the staff walkdown will be documented in a sunmary report

, currently in preparation.  ;

Staff Walkdown of Piping Stress Isometrics The staff consultants selected two piping stress probit.ms (which consisted of ,

j several piping isometric drawings) for an independent engineering walkdown. The  :

^

staff walkdown was intended to provide an engineering assessment of the  ;

attributes associated with the IE Bulletin 79-14 as applicable to the two  ;

i piping stress problems. The walkdown focused on those attributes which could

impact the stress analysis results and should be considered in tha piping '

4 analytical model. As a result of the walkdown, the staff noted several l instances where the piping run geometry and clearances were not clearly  :

j identified in the piping isometric drawings. The staff requires additional

information for resolution and this item will be discussed further with the applicant.

I Reverification of Snubber, Strut, and Valve Orientation i The applicant is currently in the process of perfoming a 100% reverification  !

of snubber, strut, and valve orientations for large bore piping systems to be t reanalyzed by SWEC. The staff review in this area consisted of two parts.  ;

j First, the staff reviewed the 200 support and valve drawings which were

included in the SWEC sample population for this attribute in order to establish i the homogeneity of the population. Second, the staff accompanied a TUGC0/ Brown

& Root as-built team who was perfoming the reverification walkdown.

! Conclusions i Contingent upon an acceptable resolution of the att va identified item regarding l

. . piping run geometry and clearances, the staff concludes the following. Based l on the staff review of the SWEC as-built walkdown results, the staff finds the l SWEC walkdown to be well-documented and easily verifiable. The dimensions t

obtained in the staff.'s walkdown verified the accuracy of the SWEC dimensions as marked in the SWEC as-built walkdown packages. ' As a result, the staff j concurs with the conclusions reached by SWEC regarding the acceptability of the four as-built attr,1butes evaluated. The staff found no significant deviations with respect to valve location, support type, and support location. For

support and valve orientation, the staff walkdown confimed SWEC's finding that

! several support and valve orientations exceeded their tolerance. The staff review of the reverification effort initiated by TUGC0 as a corrective action l

l

V. Noonan D U I 1 1 '" #

finds the actions taken by TUGC0 adequately addresses the concern identified by the SWEC walkdown. With res run geometry, clearances, etc.)pect , the SWEC to other as-built walkdown attributes (e.g.,

must be supplemented by a pipe TUGC0 or CPRT as-built walkdown to assure the adequacy of the previous as-built program, associated with IE Bulletin 79-14 L. C. Shao, Manager Engineering Group Comanche Peak Project cc: D. Eisenhut, NRR C. Trammell, DL R. Bosnak, DE O. Norkin, IE S. Hou, TRT R. Masterson, TRT V. Ferrarini TRT D. Landers TES R. Hookway, TES (5 i

D. Terao, TRT f

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OCT 111985 NRC Staff and Consultants D. Terao NRC/TRT R. D. Hookway. TES M. F. Moran TES J. J. Rivard TES W. J. Carey TES P. J. Hurley TES Personnel Interviewed J. Finneran TUGC0 J. Burgess CPPE J. Oliver SWEC C. Watters SWEC e

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