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g NUCLEAR REGULATORY COMMisslON WASHINGTON, D. C. 20555 E C ~9 f '. eD
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JUN 7 1982 O M U I ) ,1 Q MEMORANDUM FOR: H. R. Denton, Director /
Office of Nuclear Reactor Regulation FROM: Robert B. Minogue, Director PO Office of Nuclear Regulatory Research /V/d h
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SUBJECT:
SEISMIC HAZARDS AND SEISMIC SAFETY MARGIN RESEARCH PROGRAMS Your memorandum of December 10, 1981 identified some important geologic and seismologic work not then planned given the budget reductions planned at gM mf that time. My staff, in consultation with the NRR staff, has reviewed the pv NRC requirements for research in these areas and formulated a revised research program (enclosed). M
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At this time I plan to fund the current FY 1982 geotechnical research and the proposed FY 1983/84 program to the maximum extent possible within the y/U[
existing resource constraints. I plan to aggressively seek greater cost sharing by other agencies, governments and institutions. I believe that our seismic and geologic research can in this way be made responsive to your needs.
A related subject was covered in your memorandum of April 8,1982. It set forth (1) a redirection of the Seismic Safety Margins Research Program (SSMRP) to meet NRR needs and (2) guidelines for development of a Seismic Analysis Program Plan. It is obvious that considerable thought and time had gone into the development of the memorandum. I do not plan to address your enclosures in detail in this memorandum, but accept your suggestion that our staffs work clo'sely in the development of the Program Plan.
Regarding the SSMRP, a revised program plan is being developed and will be distributed for NRR review prio'rto the midyear review scheduled for June 4, 1982. At this time, the plan would have a peer review by the Senior Consultant Review Group (the reconstituted group of outside experts) that plans to meet a: on June 2 and 3.
n ca N' Regarding your needs and progranmatic goals that were sunmarized in the body S
m of your memorandum, I offer the following comments:
- 'd 1. Our entire research program is primarily directed at operating plants. ,
+n Thus, our plan will be directed at improving significantly deterministic' 8@d and probabilistic knowledge of seismic safety levels for application to n m W ACRSOFR8ECDPY o^
2 Jo k: Remove Tom AMSTice E@e-Emm
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H'. R. Denton ( f 2 the older operating plants and the current generation plants by FY '84 (the planned termination of the SSMRP) leaving application to new standdrdized plants for the post 1984 period.
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- 2. Your need for a short-term assessment of seismic hazards in the eastern United States is currently being addressed by a cooperative undertaking of the NRR and RES staffs. This cooperative effort'is a spin-off of the LLNL studies for SSMRP'and SEP. The~ effort is called " Seismic Hazard Characterization of the Eastern United' States." Your need for a long-term policy will be addressed in the development of the Seismic Analysis Program Plan. The seismology / geology portion of this plan is addressed in part by the enclosure referenced above. The results of this research will be used in the planned revision of Appendix A to 10 CFR Part 100.
- 3. We are already working closely with the probabilistic people in RES and-NRR to include seismic risk in IREP, NREP, and severe accident studies.
The seismic probabilistic work that'will flow, particularly from the SSMRP, will contrib0te to the implementation of the Commission's safety goal. N l
In summary, I believe your memorandum was well-thought-out, and I would like to respond ~in kind by' addressing its details in the development of the plans for SSMRP as well as the broader Seismic Analysis Program Plan. Working closely with your staff. I expect to have the broader plan completed for your ~
review in six months.
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1 Robert B. Minogue, Director Office of Nuclear' Regulatory Research cc: D. Guzy, RES J. Larkins, RES L. Beratan, RES B. Buchbinder, RES G. Burdick, RES S. Hanauer. NRR G. Knighton, NRR W. Dircks, ED0' F. Arsena01t O. Bassett '
ACRS (16)
R. Jackson, NRR
C, '. .. 4 o Seismotectonic Program: Geology and Seismology INTRODUCTION The NRC regulatory goal relative to seismicity is to reduce uncertainty in estimating the risk due to earthquakes at existing and future nuclear facilities, especially nuclear power plants. This reduction of uncertainty has an engineer-ing aspect -- how will the plant behave under seismic conditions? -- and a geo-scientific aspect -- what-is the design basis earthquake?
Establishing the appropriate design basis earthquake requires statistical data on the magnitude frequency and location of recent and historical earth-quakes, and sufficient knowledge of the seismogenic mechanisms in an area to permit the extrapolation of the statistical data. This program is designed to develop the data and information necessary for establishing appropriate desige basis earthquakes and to develop other information and data necessary for appropriate use of the design basis earthquakes in establishing vibratory ground motion. It is especially directed toward the Eastern United States.
There is a particular problem in establishing the design basis earthquakes in i
the Eastern United States. Although there'have been several earthquakes with large felt areas (such as Charleston 1886), tre
- ate of seismicity is moderate and the historical data base is relativel d Uc- (about 200 years) and of variable quality. Also, the seismogen1. .a6R sms in the Eastern United States t
are not known. Only in the Central United States, the New Madrid Seismic Zone, is there a working hypothesis for the cause of the sesimicity, and even in the New Madrid Seismic Zone there are still significant questions concerning the areal extent of the seismic zone.
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