ML20247H651
| ML20247H651 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 07/21/1989 |
| From: | Frizzle C Maine Yankee |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CDF-89-125, IEB-88-011, IEB-88-11, MN-89-97, NUDOCS 8907310088 | |
| Download: ML20247H651 (4) | |
Text
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,c:1 MaineYankee 1
RELIABLE ELECTRICITY FOR MAINE SINCE 1972 C1arle DL Ftszie Eden Dme President Augusta, Maine 04336 (207) 6224868 July 21, 1989 MN-89-97 CDF-89-125
. UNITED STATES NUCLEAR REGULATORY COMMISSION Attention: Document Control Desk Washington. D. C.
20555
References:
(a)
License No. DPR-36 (Docket No. 50-309)
(b) NRC Bulletin No. 88-11:
Pressurizer Surge Line Thermal Stratification, dated December 20, 1988
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(c) Maine Yankee Letter to USNRC dated March 6, 1989, (MN-89-29), Response to Bulletin No. 88-11 (d) Combustion Engineering Report CEN 387-P, " Pressurizer Surge Line Flow Stratification"
Subject:
Pressurizer Surge Line Thermal Stratification Gentlemen:
This letter is in response to Reference (b) which requested licensees to establish and implement a program to confirm pressurizer surgt line integrity in view of the occurrence of thermal stratification.
Maine Yankee has completed a visual inspection of the pressurizer surge line in accordance with Action la of Bulletin No. 88-11. The results of the inspection were provided in Reference (c). He found no evidence of permanent deformation or distress to either the surge line or its spring hangers.
Action Ib of Bulletin No. 88-11 requested that an analysis be performed to demonstrate that the pressurizer surge line meets the applicable design codes and other regulatory requirements for the licensed life of the plant, considering the phenomenon of thermal stratification and thermal striping.
For Maine Yankee, this analysis was requested to be performed within four months of the bulletin.
In Reference (c), Maine Yankee submitted an alternative schedule with justification for the schedule; this was to comply with Reporting Requirement 2 of the bulletin.
L The analysis requested by Action 1b of the bulletin has now been completed. Maine Yankee's surge line is included in the analytical work l
conducted by the Combustion Engineering Owners Group and documented in Reference (d).
The Maine Yankee surge line, when including the effects of r
i thermal stratification and striping, satisfies appropriate ASME code criteria.
The surge line has been demonstrated to have a forty (40) year design fatigue life. A summary of the analysis process is provided in the 1
attachment to this letter.
I 8907310088 890721 o
PDR ADOCK 05000309 03421-RCC-00161 O
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MaineYankee United States Nuclear Regulatory Commission MN-89-97 Attention: Document Control Desk Page two Action Ic of Bulletin No. 88-11 stipulated actions should the analysis discussed above not show compliance with requirements and licensing commitments stated in the bulletin. Since the analysis showed the Maine Yankee surge line to be structurally adequate, no actions are necessary in response to this Action Item.
Action ld of Bulletin No. 88-11 requested licensees to update their stress and fatigue analyses no later than two years after receipt of the bulletin.
The original structural analysis report of the pressurizer surge line (dated October,1970) will be updated to indicate that the Combustion Engineering Report CEN 387-P (Reference d) is now part of the analysis of record; this is currently scheduled for completion by November 30, 1989.
Action 2 of Bulletin No. 88-11 applies to applicants for operating licenses and is not appplicable to Maine Yankee.
Action 3 of Bulletin No. 88-11 requested licensees to generate records to document the development and implementation of the program requested by Action 1 and.to maintain these records in accordance with 10 CFR 50, Appendix B and plant procedures. The surge line and support inspection was conducted in accordance with approved procedures.
The Visual Examination Report of the surge line is being retained in accordance with Maine Yankee's Inservice Inspection Program. The surge line analysis (Combustion Engineering Report CEN 387-P) was conducted in accordance with Combustion Engineering's Quality i
Assurance Program.
The aforementioned update of the original analysis report and the long term retention of the new analysis report (CEN 387-P) will be performed in accordance with Haine Yankee's Quality Assurance Records Management System; this is currently scheduled for completion by November 30, 1989.
l In summary, inspection and analysis reveal that the Maine Yankee pressurizer surge line is in good condition and has been demonstrated to have a forty (40) year design fatigue life. Actions remaining are to update our current pressurizer surge line structural analysis report and maintain this as a quality assurance record; we currently plan to complete these actions by November 30, 1989. Otherwise, applicable actions requested by Bulletin No.
88-11 have been completed and results are available for inspection. We cor. aider this letter to be a final report in response to NRC Bulletin No.
88-11.
03421-RCC-00161
LMaineYankee
- United. States Nuclear Regulatory Commission MN-89-97
- Attention: Document Control Desk' Page three.
.Should you have any questions on this matter, plesse contact us.
Very truly yours, MAINE YANKEE-d
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Js.,
Charles D. Frizzle President' CDF:BPB.
Attachment c: Mr. Richard H. Nessman Mr. Hilliam T. Russell Mr. Eric 7. Leeds Mr. Patrick M. Sears Mr. Cornelius F. Holden STATE OF MAINE Then personally appeared before me, Charles D. Frizzle, who being duly sworn did state that he is Vice President of Maine Yankee Atomic Power Company, that he is duly authorized to execute and file the foregoing response in the name and on behalf of Maine Yankee Atomic Power Company, and that the statements-therein are true to the best of his knowledge and belief.
SV4 14 Notary Public
' $s?YrlNWY emamwm 03421-RCC-00161
l l
ATTACHMENT Summary of the Analytical Approach to Verify the Structural Adequacy of the Pressurizer Surge Line While Including the Effects of Thermal Stratification and Striping The Maine Yankee pressurizer surge line structural adequacy analysis was conducted as part of the Combustion Engineering Owners Group Task 587. The results are recorded in Combustion Engineering Report CEN 387-P. The analysis was performed in the following steps:
1)
The pressurizer surge lines' outside wall temperatures were recorded l
at three operating plants.
2)
Surge line fluid conditions that could create the measured outside wall temperatures were identified.
3)
New design loading conditions and cycles were identified reflecting the temperature variations recorded in Step 1.
4)
Code stress analyses of the pressurizer surge line were conducted for the newly identified design conditions.
a.
Effects of thermal striping were included.
(Striping has a negligible effect).
l b.
Effects of thermal stratification *fere included in the analysis, c.
The surge line complies with the 1986 ASME Section III analysis criteria.
(This includes verifiution of a forty (40) year design fatigue life).
l i
03421-RCC-00161 i