ML20008D832
| ML20008D832 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 08/25/1980 |
| From: | Swart F PUBLIC SERVICE CO. OF COLORADO |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| IEB-79-14, P-80282, NUDOCS 8010230097 | |
| Download: ML20008D832 (4) | |
Text
TO DAC:ADM:
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D August 25, 1980 STATE Fort St. Vrain Unit No. 1 P-80282 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012
Subject:
Safety Related Piping System Audit
References:
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 02/15/8C PSC Letter P-80091 dtd 04/23/80 PSC Letter P-80194 dtd 06/30/80
Dear Mr. Seyfrit:
This supplemental reply to I&E Bulletin 79-14 is to continue PSC's October 15, 1979 commitment to report in summary form discrepancies and corrective actions associated witn the Fort St. Vrain seismic review program and to report the status of the program progress.
To date, 617 seismic Class I isometric packages out of a total Class I population of 758 have been audited.
The total Class I population has increased from the total reported in our June 30th letter by 29 isometrics as a result of the inclusion of two inch and under isometrics which interact with 2 1/2 inch and above piping and 2 1/2 inch and above Class II isometrics which were either redefined as Class I in order to bound an analysis problem or are attached to a Class I hanger structure.
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To date, 990 field audit craft actions have been initiated as a result of piping and pipe support audits of which 820 have'been completed by construction.
The numerical differences between= initiated craft actions and craft actions completed by construction reflects the review, approval I
l and construction process required by the seismic program procedures.
l The most common types of_ corrective actions required during the program to date have been:
l Remove undocumented attachments from the hanger structure l'
- Modification of "U"-bolts
- Restoration of hanger structures to intended configuration Table 1 contains a detailed tabulation of discrepancies identified with l
the audit phase of our program since our letter of June 30, 1980.
The types of corrective actions listed in Table 1 are the same as reported in our June 30, 1980 program status reports with no significant distribution variations.
The majority of these corrective actions continue to oe with-l in the AISC portion of the hanger structure.
The anticipated completion date for the audit phase of PSC's seismic piping review program as well as for completion of the associated field audit craft actions is still December 1980.
It is PSC's conclusion-that at that time Fort St. Vrain Unit #1 will be in compliance with the intent of I&E Bulletin 79-14.
That is the plant as-built piping configu-rations will have been reviewed and assessed for compliance with the documentation which was the basis for the original seismic analysis.
l Analysis results continue to indicate that the piping installation as originally designed are conservative relative to the requirements of the Final Safety Analysis Report. As stated in our April 23, 1980 letter, the seismic analysis redocumentation program is being implimented to make the 2 1/2 to 8 inch piping system analysis methods and documents similar to those used to seismically qualify the 10 inch and larger piping systems.
l There are currently 34 piping analysis packages containing 116 Class I piping isometrics involved in PSC's seismic analysis redocumentation program.
The seismic analysis redocumentation program is currently scheduled for completion in September 1981.
F
.P-80282-Page 3 of 3 To date, no system impairments have been identified, however, should one be identified, PSC will follow the necessary Technical Specification action statements.
If there are any questions, please-contact this office.
i Very truly yours, < !
A f
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Frederic E. Swart Nuclear Project Manager UN/RLC/scp 1
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August 25, 1980 Attachm:nt'I TABLE I CORRECTIVE ACTION
SUMMARY
JUNE.13 to AUGUST 22, 1980 l
Discrepancy Type Percent
- l' 1.
Repair ' structural welds 10%
2.
Remove undocumented attachment from hanger structures 27%
l' 3.
Shim plates - minor item incorporated into Item 5 4.
Modify U-bolts 11%
l l
5.
U-bolt adjustment 6%
6.
Restore hanger structures to intended configuration 25%
l l
7.
Install lugs and clips -
2%
8.
Add nuts and washers and tighten loose hardware 11%
9.
Install new hanger 2%
10.
Install c1cmps 5%
j 11.
Change anchor bolts 1%
l Frequency of occurrence of a discrepancy type as a percentage
' of. total discrepancies identified, i
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