ML20205M271
| ML20205M271 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 10/26/1988 |
| From: | Warembourg D PUBLIC SERVICE CO. OF COLORADO |
| To: | Calvo J Office of Nuclear Reactor Regulation |
| References | |
| P-88387, NUDOCS 8811030003 | |
| Download: ML20205M271 (3) | |
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Company of Colorado 16805 WCR 19 1/2, Plattevillo, Colorado 80651 October 26, 1988 Fort St. Vrain Unit No. 1 P-88387 U. 5. Nuclear Regulatory Conmission ATTN:
Document Control Desk Washington, D.C.
20555 Attention: Mr. Jose A. Calvo Director, Project Directorate IV Docket No. 50-267
SUBJECT:
Helium Circulator C-2101 Steam Scroll and Strut Weld Repairs and 35*.
Power Restriction for FSV
REFERENCE:
- 1) PSC Letter, Williams to Calvo, dated September 21, 1987 (P-87327)
- 2) PSC Letter, Warembourg to Calvo, dated October 21, 1988 (P-88366)
Dear Mr. Calvo:
In Reference 1,
PSC comnitted to not operating FSV at power levels above 35 percent unless all four helium circulators are operating until PSC has completed its evaluation of the damage in Circulator C-2101 and resulting corrective actions have been irplemented.
PSC has comoleted the evaluation of the damage in Circulator C-2101 and implementation of corrective actions on all circulators at Fort St.
Vrain.
The cetails of these completed corrective actions nave been provided in a separate submittal (Reference 2).
An NRC vendor inspection of General Atomics ( G8.)
in San Diego conducted September 12-16, 195S.
resulted in concerns about weld repairs of cracks in the steam scroll and struts of Circulator C-2101 performed by GA.
These concerns are documented as a violation in NRC Inspection Report 50-267/85-23 (Reference NRC Letter G-SB401).
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8811030003 881026 gDR ADOCK 05000267 I
P-88387 Page 2 October 26, 1988 Specific response by PSC to this violation will be provided in a separate submittal.
The operability of Circulator C-2101 came into question upon discovery cf the problems associated with the steam scroll and strut weld repairs.
The purpose of this letter is to report to the NRC on I
the results of PSC's audit of the steam scroll and strut weld repairs and PSC's determination concerning the operability of Circulator C-2101.
On October 10, 1988, PSC performed a special audit of CA to review concerns surrounding the weld repairs of the cracks in the steam scroll and struts of Circulator C-2101.
Involved in this audit from PSC were the QA Materials Engineering Supervisor, familiar with welding practices and procedures, and a OA Engineer familiar with general auditing practices.
Discusrions were held with the GA personnel involved with the weld repairs and the associated documentation for the weld repairs was reviewed.
Tne controls used for the weld repairs wers derived from GA's Procedure Qualification Records (PQRs) documenting the welding and testing of the weld coupons. No Weld Procedure specifications (WP55) were prepared at the time of the weld repairs.
The controls and essential and nonessential variables for tne welding process were taken from the PQRs and shop travellers. A QA inspector monitored preheat temperatures, interpass temperatures and electrical characteristics during the actual welding.
These controls and variables have since been found to be acceptable for the weld repair i
of C-2101.
The testing of the weld coupons as documented on the PQRs at the time l
of the weld repairs did not fully meet ASME Section IX as required by a note on the drawing for the steam scroll and strut assembly However, the steva scroll and strut assembly is not actually an ASME Code assemoly and the note on the orawing for compliance with ASME j
5ection !\\ was added as a matter of good practice and not as a Code requirement for this equipment.
Since the weld repairs were completed, GA has made every effort to meet the ASME Section IX requirement of the orawing note. WP5s have been generated for both the scroll and strut weld repairs which roflect the actual essential and nonessential variable
- utilized in the weld repairs and which are in compliance with ASME Section IX. A second weld coupon for the strut repair was prepared utilicing the same controls and essential variables as used during the actual 4
welding.
This coupon was tested in accordance with ASME Section IX requirements and found to be acceptable, The original weld coupon for tne scroll weld repair was tested in accordance with ASME Section IX except that a bend test was not performed.
Prior to the actual j
i welding, however GA performed a technical evaluation of the weld i.
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P-88387 Page 3 October 26, 1988 repair area of the scroll and determined that the actual mechanical properties of the weld repair would be acceptable.
1 After review of the final documentation of the weld repairs and I
discussions with the GA personnel directly involved with the welding, f
PSC's OA Materials Engineering Supervisor determined that the technical aspects of the welding controls and essential variables t
were applied properly during the actual welding and has concluded that the weld repairs on C-2101 would meet the recently qualified l
WPSs.
l PSC has advised GA that, in the future, properly qualified weld procedures must be developed for specialty repair welds.
- Also, for future weld repairs, GA will be required to have PSC review and approve the weld procedures prior to commencement of welding even 1
though PSC determined from the audit that the C-2101 weld repair violations were an isolated incident and not a programmatic problem.
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As a result of the review of the weld repairs performed on the steam i
scroll and struts of Circulstor C-2101, PSC consicert C-2101 to be fully operable with templet,e capability to perform its intended safety functioas.
If you have any questions concerning the weld repairs performed on Ci rculator C-2101, please contact Mr. M. H. Holmes at (303) 480-6960.
a Very truly yours, 4
l W ft44 N 1
D. W. Warembourg U
- Manager, Nuclear Engineering Division OW/TSE:ej e cc: Regional Administrator, Region IV ATTN:
Mr. T. F. Westerman j
Chief, Projects Section B I
Mr. Rooert Farrtil Senior Resident inspector Fort St. Vrain