ML19340C779
| ML19340C779 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 10/28/1980 |
| From: | Swart F PUBLIC SERVICE CO. OF COLORADO |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| IEB-79-14, P-80380, NUDOCS 8012170417 | |
| Download: ML19340C779 (3) | |
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.m 12015,,Eggtg Avenue, Suite 440; Deiver, C0 u.n it.ts Lg STATE 950 N0y 26 pf,; ; 3q October 28, 1980 Fort St. Vrain Unit No. 1 G pc P-80380 l 'D SERYlCES 6:".
fir. Karl V. Seyfrit, Difs2EEE Nuclear Regulatory Commission Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Sutie 1000 Arlington, Texas 76012
Subject:
Safety Related Piping System Audit
Reference:
PSC Letter P-79161, dtd 08/01/79 PSC Letter P-79198, dtd 09/04/79 PSC Letter P-79238, dtd 10/15/79 PSC Letter P-79292, dtd 12/04/79 PSC Letter P-80029, dtd 02/15/80 PSC Letter P-80091, dtd 04/23/80 PSC Letter P-80194, dtd 06/?'1/80 PSC Letter P-80282, dtd 08/25/60
Dear ftr. Seyfrit:
This supplemental reply to I&E Bulletin #79-14 is to continue PSC's Octobar 15, 1979 commitment to report in summary form discrepancies identified and correc-tive actions taken associated with the Fort St. Vrain seismic review program and to report the status of the program progress.
The audit phase of the seismic review program for all Class I piping :nd pipe supports is complete.
The associated field audit craft action program is al-so nearing completion with a total of 1080 field audit craft actions having been initiated as a result of the piping and pipe support audits of which 1043 have been completed by construction.
The numerical differences between initiated craft actions and craft actions completed by construction reflects the review, i
approval and construction process required by the seismic program procedures.
The most common types of corrective actions required during the program since the last report have been:
I Remove undocumented attachments from the hanger structure Modification of "U" -bolts Restoration of hanger structures to intended configuration.
f 8012170417 k
i Karl V. Seyfrit P-80380 Page Two October 28, 1980 Table 1 contains a detailed tabulation of discrepancies identified with the audit phase of our program since our letter of August 25, 1980.
The types of corrective actions listed in Table 1 are the same as reported in our August 25, 1980 program status reports with no significant distri-bution variations.
The majority of these corrective actions continue to be with the AISC portion of the hanger structure.
The field audit craft action phase of the PSC seismic review program for I&E Bulletin #79-14 will be complete by December 1980.
It is PSC's con-clusion that at that time Fort St. Vrain bit #1 will be in compliance with the intent of I&E Bulletin #79-14.
That is, the plant as-built con-figurations will have been reviewed and assessed for compliance with the documentation which was the basis for the original seismic analysis.
This assessnent utilized engineering judgement as allowed in I&E Bulletin #79-14 and delineated in the seismic program procedures for the determination of whether or not a craft action was required.
The engineering judgement used in the preparation of the field audit craft actions and the original design of the Class I piping systems has been confirmed via computerized seismic pipe stress analysis on 10% of the sensitive seismic Class I piping systems.
The drafting and quality assurance verification of the as-built drawings along with computerized analysis is continuing as part of PSC's seismic redocumentation program.
There are currently 77 piping analysis packages containing 249 Class I piping isometrics involved in the analysis phase fo the seismic redocumentation program.
The analysis results continue to indicate that the original design and the current installation of the piping systems are conservative relative to the requirements of the Final Safety Analysis Report.
The seismic redocumentation program has been scheduled for completion in June of 1983.
The sensitive systems are being redocumented on a priority basis, and are scheduled for completed in December of 1981.
A final supolemental reply to I&E Bulletin #79-14 will be supplied following the completion of the field audit craft actions.
Summary reports on the i
status of PSC's redocumentation program will be submitted to you on a semi-annual basis.
If there are any questions, please contact this office.
Very truly yours,
'7 h./ j.. n &
V<w:
l Frederic E. Swart Nuclear Project Manager i
FES:vt Attachment l
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I TABLE 1 CORRECTIVE ACTI0ff SUf1 MARY AUGUST 22 TO OCTOBER 27, 1980 1
h Discrecancy Tyce Percent 1.
Repair structural welds 17%
2.
Remove undocumented attachment from hanger structures 26%
3.
Shim plates-minor item incorporated into Item 5 j
4 tiodify U-bolts 18%
i 5.
U-bolt adjustment 16%
6.
Restore hanger structures to intended configura tion 16%
7.
Install lugs and clips 05%
8.
Add nuts and washers tighten loose hardware 02%
9.
Install new hanger 00%
10.
Install clamps 00%
11.
Change anchor bolts 00%
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- Frequency of occurrence of a discrepancy type as a percentage of total discrepancies identified.
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