ML20010C161
| ML20010C161 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 06/18/1981 |
| From: | Swart F PUBLIC SERVICE CO. OF COLORADO |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| IEB-79-14, P-81172, NUDOCS 8108190203 | |
| Download: ML20010C161 (2) | |
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i puwie service company ce cenerado 4
12015 East 46th Avenue, Suite 44d; Denver, CO 80239 LM
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.3 June 18, 1981 Fort St. Vrain Unit No.1 P-81172 f 1!'"D f Mr. Karl V. Seyfrit, Dinctor Nuclear Regulatory Commission
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&' y Region IV V
Office of Inspection and Enforcement e
'ch,//g I [ pgj 611 Ryan P1aza Drive Suite 1000 j
Arlington, TX 76012
Subject:
Seismic Piping System Redocumentation Program Status 1
j References : PSC Letter P-80442, dtd 12/30/80 PSC Letter P-81019, dt6 01/20/81
Dear Mr. Seyfrit:
This supplemental reply is to continue PSC's January 20, 1981 commit-ment to report the status of the Fort St. Vrain Seismic Piping System Redocumentation Program on a semiannual br.is.
PSC's redocumentation program consists of the drafting, quality assurance verification and analytical analysis of the as-built drawings of the Class I piping systems and seismic pipe restraints. As stated in PSC reference cor-respondence P-81019, dated January 20, 1981, the Seismic Piping Sys-tem redocumentation Program includes the 21/2" and Larger Class I piping systems as well as the 2" and UnUer Class I piping systems.
The drafting activities for all of the 21/2" and Larger Class I isometric drswings and pipe support drawings has been completed.
Quality Assurance verification has been completed on 743 of the 833 isometrics and 2355 of the 2978 pipe support drawings.
PSC has recently completed the definition of structural criteria associated with AISC portion of the support structures. Completion of this criteria has provided for subsequent processing of documents prior to analysis redocumentation.
The quality Assurance activity of the se-1smic redocumentation project has generated 75 craft actions (CA's) of which 57 have been completed by construction. These CA's are being processed in a manner similar to that utilized for the CA's that were generated in the Audit phase of the seismic project for I&E Bulletin g6Il s
/0 0108190203 810618 PDR ADOCK 05000267 O
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79-14.
The two most predominant types of Quality Assurance craf t ac-tions are those associated with undersized welds and modification of "U"-bolts both of which are being identified during the verification of the AISC portion of the support structures.
Analysis has been completed on 41 of the 190, 21/2" and Larger pip-ing analysis packages and on 25 pipe supports.
The completion of one or more piping analysis packages is required to detennine the loads for a given pipe support, therefore the pipe support analysis will necessarily lag behind the piping analysis.
To date, the analysis process has identified one case requiring corrective action. This case was corrected by preparing and implementing a craft action within the 30 day time period specified in our procedures as described in P-80442, dated December 30, 1980. Post-corrective action reanalysis of the affected piping, utilizing the computerizel analytical methods standard in PSC's redocumentation program, resulted in calculated stresses less than the conservative allowable stresses being applied by this program.
Draf ting and Quality Assurance verification of the 2" and !Mder Class I piping isometrics and pipe support drawings has been completed along with a majority of the pipe ar.d pipe support analyses.
The remaining 2" and Under Analyses have been scheduled in parallel with the 21/2" and Larger Analysis, primarily because of interface between the small and large bore piping.
The remaining 2" and Under Craf t Actions are being canpleted in parallel with the 21/2" and Larger Seismic Redocumentation Program.
The scheduled completion date for PSC's redocumentation program is mid-1983, with the Quality Assurance verification being completed by July of 1981. Based oil the results of the program to date, PSC an-ticipates identifying few system impaiments.
Very truly yours,
\\
l rederic E. Swart Nuclear Project Manager FES:pa
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