ML19347C874
| ML19347C874 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 02/25/1981 |
| From: | Caruso R Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8103100197 | |
| Download: ML19347C874 (6) | |
Text
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'o UNITED STATES "g
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- ,E WASHINGTON, D. C. 20555 February 25, 1981
%,..... p Docket No. 50-29 FACILITY:
Yankee Rowe LICENSEE:
Yankee Atomic Electric Company (YAECo)
SUBJECT:
SUMMARY
OF DECEMBEP, 17, 1980 MEETING CONCERNING THE SEISMIC CAPABILITY OF YANKEE-ROWE INTRODUCTION This meeting was held as a result of an NRC letter dated August 4,1980, which requested that the licensee provide justification for the continued operation of Yankee-Rowe until the completion of the seismic evaluation program being conducted as part of the Systematic Evaluation Program (SEP).
SUMMARY
After opening remarks the meeting was turned over to YAECo representatives who expanded upon the results stated in their two letters dated October 15, 1980, and December 5,1980. Dr. A. Cornell presented a discussion of the methodology used by YAECo to develop an Interim Design Basis Spectrum and responded to questions raised by NRC consultants and steff members. The licensee then discussed the seismic analyses which have t,een performed to date and presented detailed results of calculations which determined the limiting stresses on systems, components, and structures. The following significant points were made:
- The reactor containment structure has available margins that are higher than those previously estimated. The installation of additional collar supports at the base of the containment support columns provides additional margin and is expected to be complete for all outer columns by April 1981.
- Concrete reinforcing bars which extend from the columns into the con-tainment structure are not mechanically " locked" into the upper structure and the length of the embedment is smaller than would be provided in such construction today. However, an evaluation performed by the licensee indicates that the actual embedments are adequate to withstand the postulated loads (interim seismic input).
Analysis of fluid systems indicated that allowable stresses in piping 9 -systems would be exceeded at a few nodes, but the margins available throughout the systems are generally large. Examples of excessive load points were given (interim seismic input).
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su NRC representatives asked questions about and discussed the assumptions in the models used for these calculations. The licensee then discussed the results of a probabilistic analysis performed to determine the potential risk to the public as a result of continued operation of Yankee-Rowe. He stated that it was his feeling that in the interim, until the completion of the seismic evaluation effort in January 1983, Yankee-Rowe should be allowed to operate, based upon the low probability
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of an earthquake in the area, the available margins in the structure and systems, and the low risk to the public.
CONCLUSION Following an adjournment and caucus, the NRC participants met with the senior licensee representatives and informed them that it had been concluded that continued operation of Yankee-Rowe was acceptable, subject to the submission of certain information by the licensee. The licensee agreed to submit the following information by January 31, 1981:
1.
Documentation containing detailed stress information concerning the-reactor containment structure. This documentation would
' include and would expand upon the information presented orally, and would indicate the calculated and allowable loads at the limiting points in the structure.
2.
More detail concerning the piping analyses performed, including -
a listing of all nodes which exceed allowable stresses, and the value of.the stresses. A listing of the conservatism in these analyses would also be provided. Because the number of points which could experience loads slightly in excess.of code allowable limits is small, and because of the large margins available throughout the rest of these systems, it is not necessary to take immediate action to upgrade the existing piping supports.
3.
An explanation why the' licensee selected a seismic spectrum using mean values, rather than the more conservative mean "plus" one standard deviation.
4.
A copy of an electrical' inspection report which detailed an evaluation of the seismic resistance of safety related electrical equi pment.
5.
A committment to re-analyze piping systems after additional pipe supports have been installed to ensure that the new supports do not cause new stress problems.
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3-The NRC representatives agreed to reevaluate the licensee's site specific spectra and estimated that a final spectrum wouid b'e decided upon by June 1981.
(
Ralph C uso, Project Manager Operating Reactors Branch #5 Division of Licensing
Enclosure:
List of Attendees 1
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Mr. James A. Kay February 25, 1981 cc Mr. James E. Tribble, President Yankee Atomic Electric Conpany 25 Research Drive Westborough, Massachusetts 01581 Greenfield Community College 1 College Drive Greenfield, Massachusetts 01301 Chairman Board of Selectmen Town of Rowe Rowe, Massachusetts 01367 Energy Facilities Siting Council 14th F]g.)r One Ashburton Place Boston, Massachusetts 02108 Director, Criteria and Standards Division Office of Radiation Prograns (ANR-460)
U. S. Environmental Protection Agency Washington, D. C.
20460
. U. S. Environmental Protection Agency -
Region I Office ATTN: EIS C0ORDINATOR JFK Federal Building Boston, Massachusetts 02203 Resident Inspector Yankee Rowe Nuclear Power Station c/o U.S. NRC Post Office Box 28 Monroe Bridge, Hassachusetts 01350 5
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w LIST OF ATTENDEES R. Caruso-NRC-T. Foley NRC A. Ei-Bassiani NRC P. - Vall enas EES
- B. Kacyra.
- J. Hoffman -
YANKEE i
Eric Van. Stijgeren EES
' D.. Crutchfield -
NRC J.,Haseltinc YANKEE Allin Cornell MIT CONSULTANT R. Holt
- YANKEE
.T. O'Hara YANKEE i-
. R. MacPherson ~
YANKEE J. Tribble YANKEE J. Kay-YANKEE K. Jurentsuff YANKEE
. W. Jones YANKEE
- D. Edwards.
YANKEE
~A. Kadak YANKEE-
' Fei-Ying Chen NRC
- G. Lainas NRC W. Russell NRC N.-Newmark~
NRC W. Hall NRC T.-M. Cheng-NRC t
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