ML20107C471
| ML20107C471 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 01/17/1985 |
| From: | Foster D, Foster D GEORGIA POWER CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-85, REF-PT21-85-115-000 GN-511, PT21-85-115, PT21-85-115-000, NUDOCS 8502210326 | |
| Download: ML20107C471 (5) | |
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Georg a Power Company Route 2. Box 299A Waynesboro, Georgia 30830 Telephone 404 554-9961. Ext 3360 404 724-8114, Ext. 3360 m
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Georgia Power
- o. o. roster Vice President and Project Genera! Manager January 17, 1985 me =te em'c 5v*m Vogtte Project United States Nuclear Regulatory Commission Office of Inspection and Enforcement File:
X7BG03-M73 Region II - Suite 2900 Log:
GN-511 101 Marietta Street, Northwest Atlanta, Georgia 30323
Reference:
Vogtle Electric Generating Plant-Units 1 and 2, 50-424, 50-425; NSCW Piping System Design Temperatures Attention: Mr. James P. O'Reilly On December 18, 1984, Mr. R. E. Folker of Georgia Power Company reported a potentially reportable condition to Mr.
W.
H.
Rankin of the USNRC, Region II, concerning the use of an incorrect design temperature for piping design analyses in the Nuclear Service Cooling Water piping system.
Georgia Power Company has concluded its evaluation of this condition and determined that a reportable condition per the criteria of Part 10CFR21 and 10CFR 50.55(e) does exist.
In accordance with regulatory guidelines in NUREG-0302 and other NRC documents, Georgia Power Company is reporting this condition per the reporting requirements of Part 10CFR 50.55(e).
Enclosed is a summary of our evaluation.
This response contains no proprietary information and may be placed in the NRC Public Document Room.
Very uly y j
B502210326 850117-PDR ADOCK 05000424 S
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D. O. Foster REF/D0F/tdm xc:
U. S. Nuclear Regulatory Commission Document Control Desk Washington, D. C.
20555 R. J. Kelly J. A. Bailey G. Bockhold R. E. Conway
- 0. Batum P. D. Rise G. F. Head H. H. Gregory C. S. McCall (OPC)
J.:T. Beckham W. T. Nickerson E. L. Blake, Jr.
R. A. Thomas D. R. Altman (Shaw, et. al.)
D..E. Dutton D. L. Kinnsch (BPC)
J. E. Joiner W. F. Sanders (NRC)
J. L. Vota (W)
(Troutman, et. al.)
R. H. Pinson L. T. Gucwa D. C. TeperJGANE B. M. Guthrie C. E. Belflower L. Fowler (.
AE COPY E. D. Groover M. Malcom (BPC)
T. Johnson (E R. W. McManus j-
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NUCLEAR SERVICE COOLING WATER PIPING SYSTEM DESIGN TEMPERATURE EVALUATION FOR A REPORTABLE CONDITION Initial Re) ort:
Mr.
R.
E.
Folker, Georgia Power Company Quality Assurance Engineer, reported a potential deficiency to Mr.
W.
H.
Rankin of the USNRC, Region II on December 18, 1984, concerning the design temperature used for some of the piping system analyses in the Nuclear Service Cooling Water Piping System (NSCW).
Background Information:
The analyses of some of the NSCW piping system was completed based on a design temperature of 1500F.
This temperature was used since the maximum mixed mean return water temperatuare to the NSCW cooling tower will always be less than 1500F.
However, as a result of the ultimate heat sirk analysis, it was found that a portion of the NSCW piping could operate at temperatures greater than 1500F for a limited time following a design basis accident with single train operation.
For these conditions, the affected piping could reach a peak temperature of 2700F, remain above 2000F for about one hour, and above 1500F for about twelve hours.
Engineering Evaluation:
The stress analyses for the affected lines were completed using a design temperature of 1500F.
Since the design temperature was changed to 2800F, the piping stress analyses were revised.
Design modifications were made to the pipe support systems as required to keep the piping system stresses below the allowable values.
Exposing a piping / support system which was designed for 1500F to 2800F temperatures produces pipe thermal stresses above. the amount considered in the original analysis.
It is not obvious, without more analysis, if the affected pipe support system would have allowed for the additional thermal stresses.
If this discrepancy were to have remained uncorrected, the thermal stresses resulting from the temperature increase could have caused the failure of the supports given in Attachment 1.
These lines are essential to the safe opera-tion of the plant.
Evaluation for Quality Assurance Program Breakdown:
It has been concluded that a significant breakdown in the. Quality.
Assurance Program of Bechtel Power Corporation did not occur.
This error affected only 31 lines of approximately 12,800 lines and was detected during a design review.
==
Conclusion:==
It has been concluded that the use of the incorrect design temperature for this piping system constitues a reportable. condition pursuant-to the critera of 10CFR21 and 10CFR50.55(e).
Georgia Power Company is reporting this event per the regulatory criteria of 10CFR50.55(e) to avoid duplicate reporting in accordance with NRC directions in NUREG-0302 Rev. 1.
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l Corrective Action:
All Nuclear Service Cooling Water (NSCW) piping / support system compo-nents - affected by.this -temperature change have been reanalyzed and, if required, appropriate design enanges were made.
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ATTACHMENT 1 NSCW CONTAINMENT PIPING LINES REQUIRING PIPE SUPPORT SYSTEM DESIGN MODIFICATION
- LINE NO.
ISO (1-1202-L4-XXX) 001 1K4-1202-002-01/04/05 002 1K3-1202-002-02 099 1K3-1202-099-01/02 138 1K4-1202-138-02 139 1K4-1202-139-02 140 1K4-1202-140-01 141 1K4-1202-141-01 151 1K3-1202-099-01 181 1K3-1202-181-02 188 1K4-1202-188-01/03 189 1K4-1202-188-02 192 1K4-1202-192-01/02/04 i
1K4-1202-290-02 196 1K4-1202-196-01/04/05 197 1K4-1202-196-05 202 1K4-1202-192-04
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204 1K4-1202-001-05 205 1K4-1202-205-01 1K4-1202-212-02 207 1K4-1202-220-02/04 f
.. -.. ~...... -
ATTACHMENT 1 (Cont'd)
LINE NO.
ISO (1-).202-L4-XXX) 209 1K4-1202-209-01/02 1
211 1K4-1202-211-01 212 1K4-1202-212-01/02
- !16 1K4-1202-216-02/03/04 218 1K4-1202-216-04 220 1K4-1202-220-01/02/04 i-l 223 1K3-1202-222-01 1K4-1202-223-01/03 225 1K3-1202-226-01 1K4-1202-225-01/03 229 1K4-1202-229-01/04/05 231 1K4-1202-231-02/04/05 291 1K4-1202-188-03 i
292 1K4-1202-209-02 351 1K4-1202-188-03
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- Design temperature changed from 150* to 280*F.
Lines were originally analyzed based on 150*F.
Reanalysis based on 280*F required redesign l
of some pipe supports.
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