ML20236B670

Responds to ,Expressing Concerns Re Proximity of Geologic Faults to Plant.Aec & USGS Conducting Review & Evaluation of Geologic & Seismic Info Presented by Util in Fsar.Safety Evaluation Issuance Scheduled for Jul 1974

ML20236B670
Person / Time
Site:	Diablo Canyon, 05000000
Issue date:	01/29/1974
From:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
To:	Marth V AFFILIATION NOT ASSIGNED
Shared Package
ML20236A877	List: ML20236A874 ML20236A896 ML20236A920 ML20236A950 ML20236A959 ML20236A975 ML20236B012 ML20236B016 ML20236B024 ML20236B067 ML20236B072 ML20236B116 ML20236B278 ML20236B286 ML20236B312 ML20236B315 ML20236B345 ML20236B356 ML20236B362 ML20236B403 ML20236B420 ML20236B436 ML20236B440 ML20236B476 ML20236B480 ML20236B506 ML20236B514 ML20236B522 ML20236B539 ML20236B547 ML20236B550 ML20236B560 ML20236B571 ML20236B594 ML20236B612 ML20236B630 ML20236B635 ML20236B650 ML20236B655 ML20236B670 ML20236B686 ML20236B695 ML20236B701 ML20236B705 ML20236B708 ML20236B726 ML20236B737 ML20236B748 ML20236B755 ML20236B793 ... further results
References
FOIA-87-214 NUDOCS 8707290190
Download: ML20236B670 (2)

Text

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l Docket Nos. 50-275 M2SE 50-323 and 50-206  !

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i Mr. Verlyn G. Marth 3197 Cape Verde i Costa Mesa, California 92626 Dear Mr. Marth I am pleased to respond to your letter to Chairman Ray dated January 11, 1974, in which you expressed concern regarding the proximity of geologic faults to the Diablo Canyon Nuclear Plant.

Pacific Gas and Electric Company first made application for a construction permit for Unit 1 in 1967; after a public hearing, this permit was granted on April 3, 1968. Similarly, after another public hearing, Unit 2 was granted a construction permit on December 9, 1970. During both of these hearings, the issue of adequate seismic design was a contention, and in both cases the Atomic Safety and Licensing Board ruled that PG&E was appropriately designing the plant to withstand the effects of potential seismic events in the area. In addition, following the passage of the National Environmental Protection Act in 1969, an environmental hearing was convened to consider the environmental impact of the Diablo Canyon Units. This hearing is still not completed. Since the issuance of the above nentioned construction permits, construction of Units 1 and 2 has proceeded such that they are approximately B0 and 40% complete, respectively.

In July of 1973, Pacific Gas and Electric Company tendered an application, ,

to the Atomic Energy Commission for licenses to operate the Diablo Canyon Nuclear Plant, Units 1 and 2. Included in this application is an eight volume Final Safety Analysis Report; Section 2.5 of this report, titled Geology and Seismology, contains a detailed discussion of all geologic faults which the applicant believes to be sources of potential earthquake activity. Based on analyses of these faults, PG&E postulates a maximum earthquake that it believes con'.( :,ccur during the life of the plant, along with the maximum ground acceleration that this earthquake could produce at the site. This maximum expected acceleration was doubled to produce an additional factor of safety, and the plant was designed to withstand accelerations of up to this doubled value.

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Mr. Verlyn G. March '

i The AEC assulatory staff, with the assistance of the U. 3. Geological I

survey, is presently conducting a thorough review and evaluation of the j geologic and seismic information presented by PGM for- the Diablo Canyon )

l site. In our review we will determine the suitability of the seismic l design criteria proposed by the applicant. The results of our overall i review will be presented in a gefety Evaluation Reportl we will send you l a copy as soon as it becomes available. Our eurrent sehedule calls for

issuance of this report in July of 1974.

l l With regard to new information on geabsic faults in the vtainity of the Diablo Canyon site U303 conducted extensive offshore geologic mapping near the site during the Fall of 1973, and in November reported the discovery of possible additional offshore faults in this region. Subse-

! quently, PCs also performed additional mapping work in this of fehore j area during December of 1973. Representatives of the Reguistory staff met recently with USG8 and PCM to discuss the data obtained from these explorations. Minutes of this meeting are enclosed. Based on our review

, of the information obtained at this meeting, our conclusion at this time l is that these new)y-discovered faults could not produos ground accelerations

at the site that are greater than those for which the plant is designed.

i I hope that this information will be helpful to you.

sincerely, Mina154DSN 1 aprS M A. Giambusso, Deputy Director for Reactor Projects Directorate of Licensing I Enclosures DISTRIBUTION:

1. Summary of Meeting Held t.s Diseues Dockets (3) GErtter (DR-6568) i Recent Offshore Explorations of L Reading JCook USGS and PGM dated 1/11/74 RP Reading MGroff

2. Homo of Gammeill to Hendrie LWR 1-3 Reading EHughes dated 11/21/73 AEC PDR (3) EAGreen Local PDR (2) JYore JF0' Leary R0 (3) dniW LWR 1/2 Branch AGiatnbuaao Chiefa l RCDeYoung RABirkel Licensing Assistant to do followup H

VHWilson*

FOR PREVIOUS CONCURRENCES SEE ATTACHED YELLOW T rNmdier o,,,,,, L....: L. .WR.. 1 .3.. L: LWR 1-3 L : AD/ LWR-1 OGC L:TR L.: ..D ...

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