ML20040B863
| ML20040B863 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 01/12/1982 |
| From: | Robert E. Uhrig FLORIDA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, L-82-11, NUDOCS 8201260491 | |
| Download: ML20040B863 (3) | |
Text
9 P O. BOX 529100 Ml AMI, FL 33152 5
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FLORIDA POWER & LIGHT COMPANY e
January 12, 1982 L-82-11 Mr. James P. O'Reilly f e..ll:
Regional Administrator, Region II xY 4
s U. S. Nuclear Regulatory Commission
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101 Marietta Street, Suite 3100
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Atlanta, Georgia 30303
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Dear Mr. O'Reilly:
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Re:
RII:JP0 I4 i
50-389 i
Linear Indications in Reactor Coolant Pump Volute
._ f On June 10, 1981, Florida Power & Light Company (FPL) informed you, in accordance with 10CFR50.55(e), of a potentially reportable item concern-l ing linear indications found in the reactor coolant pump 2A1 volute.
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i On July 14, 1981 and August 28, 1981, we reported that our preliminary assessment was that in all likelihood there was no safety concern because of safety factors included in tne case thickness and design analysis and because the casing had successfully passed the hydrostatic test.
We have successfully completed repairs using ASME Code (Section III) procedures. We still believe that the defect in the pump casing would not have adversely affected the safe operation of St. Lucie Unit 2; l
,l however, we are reporting this issue according to 10CFR50.55(e) since our evaluation did not include a rigorous analysis of the potential for crack growth under all normal and accident conditions. A final report is attached for your review.
Very truly yours,
$. R j$t k's+h:u f
Robertk.rvUhrig Vice President Advanced Systems & Technology I
REU/DME/ah cc:
Director of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Harold F. Reis, Esquire
((p0fAI, copy 8201260491 820112 PDR ADOCK 05000389 Q
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FINAL REPORT l
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Linear Indications in Reactor Coolant Pump Volute l
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Name of Station:
St. Lucie Unit 2 Owner:
llorida Power & Light Company l
NSSS Supplier: Combustion Engineering, Inc.
l Architect / Engineer: Ebasco Services, Inc.
NRC Notification: June 10, 1981 l
Interim Reports Filed: July 14, 1981 l
August 28, 1981 l
l Final Report Filed: January 12, 1982 l
l l
I.
Summary On June 10, 1981 a linear indication in the volute of reactor coolant pump 2A1 1
was identified as a potentially reportable item, in accordance with 10CFR50.55(e).
Repairs to the pumps have been successfully completed according to ASME Code, 4
Section III procedures. Florida Power & Light Company (FPL) believes that the defect in the pump casing would not have adversely affected safe operation of St. Lucie Unit 2.
However, this issue is being reported in accordance with i
10CFR50.55(e) since FPL's evaluation did not include a rigorous analysis of the potential for crack growth under all normal and accident conditions.
II.
Description During an evaluation of reactor coolant loop welds, four linear indications were identified by radiography adjacent to weld #RC-0112-004 in the casing (volute) of J
pump 2A1. Triangulation radiography was performed for one of the linear indications and it was determined that the defect was approximately 5/8" below the surface of the weld.
l III. Corrective Action Non-conformance report (NCR) #1738M was issued to initiate repairs according to ASME Code,Section II, Subsection NB procedures. Reinspection was not satis-i factory and NCR 1849M was issued. Again, reinspection was unsatisfactory and a j
new NCR (1972M) was issued.
Excavations approximately 3S" deep were required to remove defects. The cavities were weld repaired, cleaned after each pass, and radiographically tested at midpoints or every 3/4" interval.
Final penetrant testing and radiographic testing were performed after finish grinding. Use of this procedure was successful, with one exception. NCR 2028M was issued to initiate repair for the remaining defect. Due to the large excavation required 4
to remove the remaining defect a new NCR (2033M) was issued. The repair was completed and penetrant and radiographic testing verified success.
IV.
Safety Implication As indicated in the interim reports dated July 14, 1981 and August 28, 1981, the i
linear indications were not thought to be a safety concern due to the safety l
factors in the pump casing design and due to the successful hydrostatic test.
j rhe pump casing was designed for a pressure of 2500 psia and a tempgrature of 650 F, whereas normal operation is expected to be 2250 psia and 540 F.
Addition-ally, the pump supplier (Byron-Jackson) performed a successful hydrostatic test at 3125 psia, which is greater than the design pressure and the peak pressure i
(2807 psia) for accident conditions.
Based on the above, FPL still believes that the defect would not have advtrsely affected safe operation of St. Lucie Unit 2.
However, the review of stress calculations did not include an analysis i
of the potential for crack growth under all normal and accident conditions.
Therefore, this issue is being reported as a 10CFR50.55(e) item.
V.
Conclusion The action in Section III corrected the deficiency described in Section II. This report closes out this issue with respect to the reporting requirements of 10CFR 50.55(e).
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