ML20196G133
| ML20196G133 | |
| Person / Time | |
|---|---|
| Issue date: | 11/09/1993 |
| From: | Shao L NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Rasin W NUCLEAR ENERGY INSTITUTE (FORMERLY NUCLEAR MGMT & |
| Shared Package | |
| ML20196G123 | List: |
| References | |
| FRN-57FR47802, FRN-59FR52255, RULE-PR-100, RULE-PR-50, RULE-PR-52 AD93-1-087, AD93-1-87, NUDOCS 9705140219 | |
| Download: ML20196G133 (5) | |
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION p93
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g WASHf NGTON, D. C. 70554 PP(L Ik.,*****}
NOV 9 1993 Mr. William H. Rasin Vice President & Director Technical Division Nuclear Management and Resources Council Suite 300 1776 Eye Street, N.W.
Washington, DC 20006-3706
Dear Mr. Ras:
n:
The purpose of the public meeting on November 30, 1993, is to obtain understanding of the basis and rationale for the NUMARC suggested changes to the proposed regulations Appendix B to 10 CFR P?rt 100 and Appendix S to 10 CFR Part 50) and associated guides. 'inile we intend to review the entire NUMARC comment package at the meeting, the enclosure identifies major areas where better understanding is required.
The meeting and questions have been coordinated between Dr. Chokshi of my staff and Dr. Farukhi of your staff.
Please contact Dr. Murphy or Dr. Chokshi of my staff should you have any questions. They can be reached at 301-492-3860.
i Lawrence C. Shao, Di.ector Division of Engineering Office of Nuclear Regulatory Research cc:
E. Beckjord T. Speis T. Murley l
9705140219 970422 PDR PR 50 57FR47,8,02,.PDR
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ENCLOSURE QUESTIONS FOR NOVEMBER 30, 1993 PUBLIC MEETING AND TOPICS-FOR DISCUSSIONS The Nuclear Management and Resources Council, on behalf of. the nuclear power indu',try, reviewed the proposed rule, 10 CFR Parts 50, 52, and 100, Reactor
' Siting Criteria; Including Seismic and Earthquake Engineering Criteria for Nuclear Power Plants and Proposed Denial of Petition for Rulemaking from Free i
Environment, Inc., et al. (57 FR 47802), and offered comments in March 24, j
1993 and May 28, 1993 letters from William H. Rasin. The comments provided in j
their letter, line in/line out enclosures of the regulations and supporting guidance documents, and responses to NRC questions were not accompanied by any-l supporting rationale for the suggested enanges.
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The purpose of this meeting.is to meet with NUMARC and other industry repre-
'sentatives to obtain the rationale for their suggested changes. The following examples of topics'for discussion are grouped by seismic and geologic siting, and earthquake engineering:
1 SEISMIC AND GEOLOGIC SITI'!S i
1
' NRC Ouestions. Section XI-B of the Federal Reaister Notice 1
1.
- For the purpose of determining the controlling earthquakes' mean magnitude and distance, why deaggregated the mean hazard results instead of the median (Enclosure 5, A3)? The result is slightly larger
[
magnitudes at much greater distances..
2.
Explain why the Safe Shutdown Earthquake Ground Motion response spectrum should be determined based on scaling an accepted response spectrum shape (to the probabilistic seismic hazard analysis results for the average of 5 Hz and 10 Hz and the average of 1 and 2.5 Hz spectral i
f accelerations) consistent with the reference probability level rather than the site-specific response spectrum approach used by the NRC.
(Enclosure 5, A5).
Annendix B to Part 100. Criteria for the Seismic and Geoloaic Sitina... Rule 4
What is.the rationale for the following:
Section I, Purpose.
j 1.
The elimination of the statement that the criteria-are based on current information and will be revised if necessary.
4 2.
The elimination of the footnote referring to regulatory guides and standard review plan sections.
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Section II, Scope.
l 1.
The elimination of the requirement for additional investigations or more l
conservative determinations for locations in areas with complex geology, recent tectonic deformation, or in areas of high seismicity.
Section III, Definitions.
1 1.
The elimination of the definitions for capable tectonic source, combined
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license, deterministic source earthquake, early site permit, fault, i
magnitude, seismic source, seismogenic source, and surface faulting.
Section IV, Required Investigations.
1.
Changes to the requirements associated with vibratory ground motion and nontectonic deformation.
Section V, Seismic and Geologic Desig'i Basis.
1.
The alimination of Paragraphs V(a), Determination of Deterministic Source Earthquakes, and V(b), Determination of the Ground Motion at the Site.
1 2.
The elimination of " hypothetical rock outcrop, as appropriate," and the minimum value of the Safe Shutdown Earthquake Ground Motion at the l
foundation level from paragraph V(c).
3.
Changes to paragraphs V(f)(1) to (4)
Reaulatory Guide DG-1015. Identification and Characterization... Motion and SRP ection 2.5.2. Vibratory Ground Motion What is the rationale for the following:
The proposed changes to DG-1015 and SRP 2.5.2 will be the major focus of attention. The following are some of the general areas of greater interest.
1.
Basis for referring to the geological, geophysical and seismological investigations as confirmatory.
2.
Bases for limiting the regional investigations to 200 km from ine site and the reconnaissance investigatior.s to 25 km from the site?
3.
Basis for elimimnating concept of the controlling earthquake.
l 4.
Basis for procedure of Appendix C.
5.
Changes to definitions and investigation requirements (Appendices A and i
D).
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EARTH 00AKE ENGINEERING 1
Apoendix S to Part 50. Earthouake Enoineerino Criteria.... Power Plants i
Section III, Definitions.
1.
Eliminating the " functionality requirement" in the OBE definition, j
Section IV, Application to Engineering Design.
1.
Changes to the SSE requirements; for example, eliminating the phrases i
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" hypothetical rock outcrop" and "within applicable stress and
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deformation limits," and the general allowance that the SSE design will allow strain limits in excess of yield strain.
2.
Changes to the OBE requirements; for example, the increasing of the OBE value for plants designed at a higher ievel than the SSE determined for the site - new paragraph (a)(2)(C).
(If the site SSE is less than the standard design SSE, allow an OBE 1
greater than 1/3 the SSE without performing the seismic analysis? -
Cover letter, page 5).
3.
Changes to the plant shutdown, seismic instrumentation, surface deformation requirements.
Reaulatory Guide DG-1016. Seismic Instrumentation for Nuclear Power Plants What is the rationale for the following:
Section C1, Seismic Instrumentation Type and Location 1.
The number and location of the seismic instruments.
2.
Elimination of instrumentation if the design SSE exceeds the site SSE by 33% or more.
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3.
The option to locate sensors in the free field or on the foundation for rock founded sites.
1 Section C4, Instrumentation Characteristics 1.
Eliminating the interconnection of the instrumentation for common starting and common timing 2.
Limiting the external remote alarm (to indicate actuation) to sensors located in inaccessible areas.
3.
The recording capability, 25 minutes of continuous operation or the final 10 minutes of sensed motion.
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4.
Battery capacity to fulfill the requirements without line power between battery maintenance check intervals.
Reaulatory Guide DG-1017. Pre-Earthauake Plannina... Post Earthauake Actions Section C1, Base-Line Data 1.
Information contained in the plant file pertaining to time history, and CAV and response spectrum data, clarify the contents of what is kept in l
this file.
Section C4, Determining OBE Exceedance i
1.
Limiting of the response spectrum check to 10 frequencies between 1 and l
10 Hertz.
Section C5, Criteria for Plant Shutdown l
l.
Under what conditions could only the response spectrum check or the CAV be assessed?
Appendix A, Interim OBE Exceedance Guidelines 1.
The use of EPRI Damage Intensity instead of Modified Mercalli Intensity l
l 2.
The addition to the magnitude 6.0 criterion that the earthquake was felt l
within the plant.
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