ML19309G454

Slide Presentation Entitled, Identification of Issues Pertaining to Seismic & Geologic Siting Regulation,Policy & Practice for Nuclear Power Plants

ML19309G454
Person / Time
Issue date:	04/10/1980
From:	NRC COMMISSION (OCM)
To:
Shared Package
ML19309G451	List: ML19309G450 ML19309G452 ML19309G453 ML19309G454
References
SECY-79-300, NUDOCS 8005060334
Download: ML19309G454 (15)

Text

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O COMMISSION BRIEFING ON INFORMATION REPORT SECY-79-300

" IDENTIFICATION OF ISSUES PERTAINING TO SEISMIC AND GEOLOGIC SITING REGULATION, POLICY, AND PRACTICE FOR NUCLEAR POWER PLANTS."

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l CHRONOLOGY OF APPENDIX A MAJOR SITING PROBLEMS IN CALIFORNIA IN THE MID 1960'S.

FOUNDATION FOR REGULATION LAID IN LATE 1960'S, MAJOR INPUT TO INITIAL DRAFT OF PROPOSED REGULATION BY USGS.

NUMEROUS REVISIONS WITH PUBLIC AND PROFESSIONAL INPUT.

DEVELOPING METHODOLOGY AND THINKING USED IN SITE REVIEWS STARTING IN EARLY 1969.

PROPOSED RULE PUBLISHED FOR COMMENT IN 1971.

PROPOSED REGULATION FAIRLY WELL CODIFIED AND REGULARLY EMPLOYED IN REVIEWS STARTING IN 1972.

REGULATION PUBLISHED IN LATE 1973.

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SINCE LATE 1960'S THERE HAVE BEEN SIGNIFICANT ADVANCES IN THE STATE OF THE ART IN THE EARTH SCIENCES.

THE DATA BASE IN THE AREAS OF BOTH GEOLOGY AND SEISMOLOGY HAS EXPANDED.

GEOSCIENCE ISSUES HAVE ARISEN IN REVIEW OF NUCLEAR POWER PLANT SITES WHICH WERE NOT FORESEEN.

INCIDENTAL HANDLING OF ENGINEERING ISSUES IN AN EARTH SCIENCE RULE HAS CREATED DIFFICULTIES.

COMMISSION OBJECTIVES IN THE EARTH SCIENCE AREA ESTIMATE THE SEVERITY OF GROUND SHAKING AT A SITE DUE TO POTENTIAL EARTHQUAKES FOR USE IN NUCLEAR POWER PLANT DESIGN.

ASSESS THE POTENTIAL FOR GROUND RUPTURE THAT COULD AFFECT PLANT STRUCTURES DUE TO FAULT MOVEMENT.

EVALUATE THE EFFECTS ON THE SIT,E PHENOMENA ASSOCIATED WITH EARTHQUAKES SUCH AS THE SEISMICALLY GENERATED SEA WAVES.

ASSESS THE POTENTIAL FOR OTHER GEOLOGIC HAZARDS AT A SITE SUCH AS LANDSLIDES, SUBSIDENCE, AND S0ll INSTABILITY.

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DATA FOR MOST OBJECTIVES ASSESSED THROUGH FOUR CONCEPTUAL EIFMENTS TECTONIC PROVINCE.

TECTONIC STRUCTURE.

CAPABLE FAULT.

REASONABLE CORRELATION OF SEISMICITY WITH 6E0 LOGIC STRUCTURE.

5 THESE ELEMENTS ARE USED:

TO ASSESS IF EARTHQUAKES ARE TO BE EXPECTED TO OCCUR RANDOMLY OR CAN BE RESTRICTED TO A.GIVEN. GEOLOGIC STRUCTURE.

TO ESTIMATE THE SIZE, FREQUENCY, AND ENERGY RELEASED FROM A GIVEN EARTHQUAKE EVENT AND ITS RELATIONSHIP TO THE SITE IN THE FORM OF DESIGN ACCELERATION.

TO ASSESS THE POTENTIAL FOR GROUND RUPTURE OR GROUND FAILURE, AND OTHER GEOLOGIC HAZARDS.

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n' TECTONIC PROVINCE "A TECTONIC PROVINCE IS A REGION OF THE NORTH AMERICAN CONTINENT CHARACTERIZED BY A RELATIVE CONSISTENCY OF THE GEOLOGIC STRUCTURAL FEATURES CONTAINED THEREIN."

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'7 ISSUES BEARING ON THE APPLICATION OF TECTONIC PROVINCE CONCEPT THE BASIC IMPLIED PREMISE THAT AREAS OF CONSISTENT STRUCTURAL GEOLOGY NECESSARILY REPRESENT AREAS OF UNIFORM SEISMIC POTENTIAL.

-NEED FOR ADEQUATE CONSIDERATION OF NE0 TECTONIC PROCESSES AND STRUCTURES IN THE EASTERN U.S.

QUESTIONABLE SIGNIFICANCE IN ASSESSING SEISMIC POTENTIAL OF THE PALE 0 TECTONIC STRUCTURAL SUBDIVISIONS DEPICTED ON MOST REGIONAL MAPS OF THE EASTERN U.S.

THAT THE PRESENT DEFINITION IS RESTRICTIVE IN THAT IT DOES NOT SPECIFICALLY INCLUDE OTHER RELEVANT FACTORS, E.G., SEISMICITY AND INFLUENCES OF GEOLOGIC TIME.

THAT THE NRC AT PRESENT DOES NOT HAVE A GENERIC MAP MEETING THE DEFINITION AND INTENT OF THE CONCEPT.

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TECTONIC STRUCTURE "A TECTONIC STRUCTURE IS A LARGE SCALE DISLOCATION OR DISTORTION WITHIN THE EARTH'S CRUST.

ITS EXTENT IS MEASURED IN MILES."

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ISSUES BEARING ON THE APPLICA~ ION OF THE TECTONIC STRUCTURE CONCEPT LACK OF DETAILED INFORMATION IN THE REGULATION AS TO WHAT CONSTITUTES A TECTONIC STRUCTURE.

SCOPE OF INFORMATION REQUIRED FOR IDENTIFICATION NOT SPECIFIED.

LACK OF GUIDANCE ON WHAT CONSTITUTES A REASONABLE (OR ADEQUATE FOR THE LICENSING PROCESS) CORRELATION OF EARTHQUAKE ACTIVITY WITH STRUCTURE.

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CAPABLE FAULT "A CAPABLE FAULT IS A FAULT WHICH HAS EXHIBITED ONE OR MORE OF THE FOLLOWING CHARACTERISTICS:

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MOVEMENT AT OR NEAR THE GROUND SURFACE AT LEAST ONCE WITHIN THE PAST 35,000 YEARS OR MOVEMENT OF A RECURRING NATURE WITHIN THE PAST 500,000 YEARS.

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MACRO-SEISMICITY INSTRUMENTALLY DETERMINED WITH RECORDS OF SUFFICIENT PRECISION TO DEMONSTRATE A DIRECT RELATIONSHIP WITH THE FAULT.

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A STRUCTURAL RELATIONSHIP TO A CAPABLE FAULT ACCORDING TO CHARACTERISTICS 1 OR 2 0F THIS PARAGRAPH SUCH THAT MOVEMENT ON ONE COULD BE REASONABLY EXPECTED TO BE ACCOMPANIED BY MOVEMENT ON THE OTHER."

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ll ISSUES BEARING ON THE APPLICATION OF THE CAPABLE FAULT CONCEPT IHAT MOVEMENT ONCE IN 35,000 YEARS OR MULTIPLE MOVEMENTS IN 500,000 YEARS DOES NOT NECESSARILY CORRESPOND TO A RATE OF DEFORMATIONAL' ACTIVITY REPRESENTED BY MACRO-SE!SMICITY WHAT CONSTITUTES RECURRENT MOVEMENT ON A FAULT (E.G., HORIZONTAL AND VERTICAL

' MOVEMENTS ALONG A FAULT AT DIFFERENT PLACES OR ELSE SIZE OF DISPLACEMENTJ SIGNI-FICANCE OF MOVEMENTS ALONG DIFFERENT SEGMENTS OF A FAULT SYSTEM).

EFFECTIVE USE OF RELATIVE AGE-DATING TECHNIQUES.

WHAT CONSTITUTES MACRO-SEISMIC!TY.

WHAT CONSTITUTES A STRUCTURAL RELATIONSHIP OF FAULTS TO ONE ANOTHER.

a TREATMENT OF FAULTS RELATED TO OLD STRUCTURES (I.E., IN THE EASTERN U.S.).

DESIGNING AND CONSTRUCTION FOR FAULTINGJ IS INTENT A PROHIBITION.

EXTENT OF INVESTIGATION NECESSARY TO DETERMINE IF A FAULT IS CAPABLE.

APPLICATION OF NEW TECHNIQUES.

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RELATIONSHIP OF SEISMICITY AND GE0 LOGIC STRUCTURE TECTONIC STRUCTURE:

" CORRELATION OF EPICENTERS OR LOCATIONS OF HIGHEST INTENSITY OF HISTORICALLY REPORTED EARTHQUAKES, WHERE POSSIBLE, WITH TECTONIC STRUCTURE..."

CAPABLE FAULT:

" MACRO-SEISMICITY DETERMINED WITH RECORDS OF SUFFICIENT PRECISION TO DEMONSTRATE

.A DIRECT RELATIONSHIP WITH THE FAULT."

"A STRUCTUR L~ RELATIONSilIP TO A CAPABLE FAULT ACCORDING TO CHARACTERISTICS 1 OR 2 0F THIS PARAGRAPH S,UCH THAT MOVEMENT ON ONE COULD BE REASONABLY EXPECTED TO BE ACCOMPANIED BY MOVEMENT ON THE OTHER."

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JSSUES BEARING ON THE RELATIONSHIP OF SEISMICITY TO TECTONIC STRUCTURE AND/0R CAPABLE FAULTS WHAT IS A REASONABLE CORRELATION AND A DIRECT RELATIONSHIP BETWEEN SEISMICITY (HISTORICAL AND INSTRUMENTAL EVENTS AND MACRO-SEISMICITY) AND GEOLOGIC STRUCTURE.

MEANING OF CORRELATION.

MEANING OF DIRECT RELATIONSHIP.

MEANING OF MACRO-SEISMICITY.

USE OF RECENT TECTONISM (SEISMIC ZONES AND CLUSTERS) IN DEFINING GEOLOGIC STRUCTURE.

USE OF MICR0 EARTHQUAKE SURVEYS AND IN SITU STRESS MEASUREMENTS, ETC. TO DETERMINE iLATIONSHIP.

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ENGINEERING ISSUES

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SPECIFICATION OF VIBRATORY GROUND MOTION.

SITE SPECIFIC VS. GENERALIZED RESPONSE SPECTRA.

VARIATION OF GROUND MOTION WITH DEPTH.

SPECIFICATION OF TIME HISTORY.

DURATION OF SHAKING.

l OBE USE IN ENGINEERING.

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CONSIDERATION OF AFTERSHOCKS.

CONSIDERATION OF POTENTIAL DAMAGE FROM EARTHQUAKES LESS THAN THE SSE.

USE OF PROBABILITY FOR CONSIDERING COMBINATIONS OF LOADS.

l NEED FOR SEISMIC SCRAM.

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