ML19289C852
| ML19289C852 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 01/15/1979 |
| From: | Stello V Office of Nuclear Reactor Regulation |
| To: | Groce R YANKEE ATOMIC ELECTRIC CO. |
| References | |
| TASK-03-06, TASK-03-07.B, TASK-3-6, TASK-3-7.B, TASK-RR NUDOCS 7901250307 | |
| Download: ML19289C852 (3) | |
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- kxg vY J t.....f January 15, 1979 Docket No. 50-29 Yankee Atomic Electric Company ATTN: Mr. Robert H. Groce Licensing Engineer 20 Turnpike Road Westboro, Massachusetts 01581 Gentlement:
RE: YANKEE R0WE ATOMIC POWER STATION As part of the Systematic Evaluation Program (SEP) the NRC staff has completed a search of your docket for pertinent infomation related to the seismic design bases of your facility. We find that your docket lacks sufficient infomation concerning the seismic design input and structural capability for safety-related structures, systems and equip-ment to withstand earthquake effects to enable us to complete our eval uation.
As you know, the major NRC regulations dealing with seismic design are 10 CFR Part 50, Appendix A (General Design Criterion 2) and 10 CFR Part 100, Appendix A.
We recognize that botn of these regulations were issued subsequent to the design of your facility. However, one of the objectives of the SEP is to compare the original design basis with current criteria. Currently, the infomation on the docket is not sufficiently complete to adequately address the potential hazard of earthquakes, nor to detemine whether backfitting of additional seismic resistance would provide substantial additional protection required for safety.
We recognize that your facility possesses inherent structural capabili-ties to withstand earthquake effects. However, there is insufficient infomation docketed to adequately quantify such capability. We believe that a significant effort on your part may be required to assess the seismic safety margins of your facility. This matter has been generally discussed with your representatives, as part of the SEP, to assure that the issue will be properly resolved within the time frame of the SEP.
7901250307
Yankee Atomic Electric Company January 15. 1979 While the docket does not contain sufficient infomation on geologic and seismic input to allow a comparison to current criteria, seismic input information for your facility could be developed based on current criteria and a bounding conservative assessment; however, evaluation of various site specific response spectra methodologies may demonstrate a more realistic approach in determining seismic input. Staff effort in these methodologies is expected to lead to acceptable procedures for detemining site specific spectra.
We understand that you have initiated work to characterize the geology and seismicity at Yankee Rowe. While we believe that this effort will provide benefit to your facility evaluation and to the SEP, we encourage you to closely follow the progress of our work and provide input as necessary. The staff expects to work with you to develop a documented seismic design basis for your facility.
In addition to seismic input, this would include the definition of acceptable structural design criteria and analytical or other procedures for demonstrating that these criteria are satisfied. Your letter to the NRC, dated October 3,1978, states that you are preparing a seismic assessment of major structures including piping analyses inside containment. The program described represents a significant engineering effor' aad indicates initiation of an overall seismic assessment. To pro-d 1. maximum assurance that both the scope and schedule are acceptable, we suggest that detailed working meetings for your facility in the next 90 days would be beneficial.
Please let us know within 30 days of your plans for completion of this program. Additionally, please provide within 90 days a description out-lining your program for docu;nenting a seismic design basis and a program schedule.
S ncerely, 1
$ Victor tei lo, Jr., Directot Division of Operating Reactors Office of Nuclear Reactor Regulation cc:
See next page
Yankee. Atomic Electric Company January 15, 1979 cc :
Mr. Lawrence E. Minnick, President Yankee Ator,iic Electric Company 20 Turnpike Road Westboro, Massachusetts 01581 Gresfield Community College 1 College Drive Greenfield, Massachusetts 01301 E