ML16341B467
| ML16341B467 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 12/11/1980 |
| From: | Miraglia F Office of Nuclear Reactor Regulation |
| To: | Robinson T AFFILIATION NOT ASSIGNED |
| References | |
| NUDOCS 8101090372 | |
| Download: ML16341B467 (4) | |
Text
Hr. Tom Robinson
~0 2 po ug I I )98II I trust that this information is responsive to your request.
Sincerely,
Enclosure:
As Stated DISTRI BUTION:
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ENCLOSURE Concern:
Response
The proximity of the Hosgri Fault to the Diablo Canyon site and the ability of the plant to withstand a severe earthquake.
The Hosgri fault, which is located 3 1/2 miles from the Diablo
- plants, was discovered in 1971 and has been the subject of intensive investigation by the Pacific Gas 5 Electric Company (PGEE), the U.S. Geological Survey (USGS) and the Nuclear Regulatory Commission.
As a principal geologic advisor for the Coranission, the USGS in 1975 suggested that a magnitude of 7.5 be assigned as a potential seismic value for the Hosgri Fault.
It is important to note that the USGS did not say that the Hosgri would experience a 7.5M earthquake but from a conserva-tive standpoint that magnitude could not be ruled out.
Compre-hensive public hearings on this matter were held by the Atomic Safety and Licensing Board (ASLB) over about a two-month period (from December 1978 to early 1979).
Some of this nation's and the world's leading authorities testified and were subject to cross-examination.
The experts from the NRC staff and PGSE went on to say that the plant has been designed to withstand the greater seismic event of 7.5.
On September 26, 1979, the ASLB assigned to conduct the licensing hearings issued its partial initial decision which found that a 7.5 magnitude earthquake is a reasonable basis for the design reanalysis of the Diablo Canyon facility.
On June 23, 1980 the Atomic Safety and Licensing Appeal Board issued a decision reopening the hearing record to obtain testimony related to a major earthquake which occurred in California's Imperial Valley in October 1979 (shortly after the ASLB's favorable partial initial decision in September 1979).
Hearings on this matter were completed on October 25, 1980.
A decision will be issued following the submission of briefs by the parties.
9EC 16 1989