ML19309H231
| ML19309H231 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 05/07/1980 |
| From: | Tribble J YANKEE ATOMIC ELECTRIC CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| TASK-02-04.A, TASK-02-04.B, TASK-02-04.C, TASK-03-06, TASK-3-6, TASK-RR WYR-80-49, NUDOCS 8005090386 | |
| Download: ML19309H231 (3) | |
Text
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P Telephone 617 366-9011 TwX 710-390-0739 YANh'EE ATOMIC ELECTRIC COMPANY 3-1 WYR 80-49
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May 7, 1980 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation United States Nuclear Regulatory Co; mission Washington, DC 20555
Subject:
Seismic Evaluation Yankee Atomic Electric Company, Rowe, MA
Dear Sir:
This is to set forth our position regarding the seismic evaluation of the Yankee Atomic Electric Company plant in Rowe, Massachusetts, under Systematic Evaluation Program topics III-6 (Seismic Design Considerations) and II-4A, B, C (Geology and Seismology).
In response to these topics, Yankee initiated in 1978 studies to define appropriate seismic design criteria for the Rowe plant. The results of these studies were submitted to NRC in the form of two technical reports.
These reports were prepared by Weston Geophysical Corporation and Dr. Erik Vanmarcke of M.I.T.
Our first report, " Geology and Seismology - Yankee Rowe Nuclear Power Plant" by Weston Geophysical, was transmitted to you on February 23, 1979.
This report is a well-documented assessment of the maximum earthquake potential for the Rowe site.
It concludes that an intensity VI(mm) event is an appropriately conservative estimate for the Safe Shutdown Earthquake.
Such an intensity would result in a ground acceleration of.06g to.07g.
Our second report, " Site Dependent Response Spectra - Yankee Rowe" by Weston Geophysical and Dr. Erik Vanmarcke, was transmitted to you on February 29, 1980. This report describes the methods and results of a program to develop site dependent response spectra.
It was prepared partially in response to an NRC letter to us of January 15, 1979 stating the necessity for Yankee to assess the seismic design criteria for the Rowe site and suggesting the " evaluation of various site specific response spectra methodologies".
Dr. Alan Cornell of M.I.T. was also involved in this study in an advisory and l
review capacity and he concurs with the conclusions set forth in the report.
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4 Mr. Harold R. Denton Msy 7, 1980 Office of Nuclear Racetor Regulation Page 2
- j Despite the fact that the aforementioned studies indicate that a ground acceleration of 0.06g to 0.07g is sufficient for the Rowe site, it is our intention to proceed with seismic evaluation of the Yankee plant to demonstrate safe shutdown capability at a ground acceleration of 0.lg, using response spectra appropriate to the Rowe site as set forth in the aforementioned reports. This is consistent with the requirements of Appendix A of 10 CFR 100. Our schedule for completion of this work is attached.
We are also proceeding immediately with the installation of seismic supports for the steam generators, and with strengthening the anchor bolts and foundations at the base of the containment structure.
These two modifications will greatly improve the ability of the plant to withstand a seismic event.
We believe that this approach is completely appropriate for a small plant in a remote, seismically stable location like Rowe.
Moreover, as previously stated, it is consistent with the requirements of 10 CFR 100.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY
/
/
J. E. Tribble
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President Attachment cc:
Mr. Darrell G. Eisenhut, Director Division of Licensing i
Mr. Richard 11. Vollmer, Director Division of Engineering Mr. Dennis M. Crutchfield, Chief Division of Licensing 4
Operating Reactors Branch #5
i 0-i i '
i ATTACHMENT I
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Proposed Yr-kee Rowe Seismic Milestones-Week or Date 4
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A.
Action plan / criteria document complete July 1, 1980 i
B.
Analysis and evaluation of reactor building and RCPS complete 30
}
i C.
Analysis of other Cat. I buildings complete (floor spectra, response profiles) 34 D.
Analysis and evaluation of safe shutdown l
systems complete (piping, anchorage of i
mechanical / electrical equipment) 60 l
l E.
Structural Evaluations of (C) above complete 60 F.
Analysis and evaluation of ECCS/ES systems complete (piping, anchorage or mechanical /
l electrical equipment) 78 G.
Evaluation of mechanical / electrical equipment complete (incl. operability) 94 4
H.
Licensee submits final reports 102 i
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