ML23156A431
| ML23156A431 | |
| Person / Time | |
|---|---|
| Issue date: | 08/25/1986 |
| From: | Ross D Office of Nuclear Regulatory Research |
| To: | |
| References | |
| PR-100, 51FR30224 | |
| Download: ML23156A431 (1) | |
Text
DOCUMENT DATE:
TITLE:
CASE
REFERENCE:
KEYWORD:
ADAMS Template: SECY-067 08/25/1986 PR-100 - 51 FR30224 - SEISMIC AND GEOLOGIC SITING CRITERIA FOR NUCLEAR POWER PLANTS:
REASSESSMENT OF CURRENT CRITERIA PR-100 51FR30224 RULEMAKING COMMENTS Document Sensitivity: Non-sensitive - SUNSI Review Complete
PAGE 1 OF 2 STATUS OF RULEMAKING RECORD 1 OF PROPOSED RULE:
PR-100 RULE NAME:
SEISMIC AND GEOLOGIC SITING CRITERIA FOR NUCLEAR P OWER PLANTS: REASSESSMENT OF CURRENT CRITERIA PROPOSED RULE FED REG CITE:
51FR30224 PROPOSED RULE PUBLICATION DATE:
08/25/86 ORIGINAL DATE FOR COMMENTS: 09/22/86 NUMBER OF COMMENTS:
EXTENSION DATE:
I I
FINAL RULE FED. REG. CITE:
FINAL RULE PUBLICATION DATE:
1 1
I I
OTES ON: THIS WAS A NOTICE FOR A MEETING AND A REQUEST FOR COMMENTS ON APPE TATUS
- NDIX A PART 100. ACTING DIRECTOR OF NUCLEAR REGULATORY RESEARCH SI OF RULE GNED THE ITEM ON 8/19/86.
FILE LOCATED ON Pl.
PRESS PAGE DOWN OR ENTER TO SEE RULE HISTORY OR STAFF CONTACT PRESS ESC TO SEE ADDITIONAL RULES OR (S) TO STOP DISPLAY PAGE 2 OF 2 HISTORY OF THE RULE PART AFFECTED: PR-100 RULE TITLE:
SEISMIC AND GEOLOGIC SITING CRITERIA FOR NUCLEAR P OWER PLANTS: REASSESSMENT OF CURRENT CRITERI A DATE PROPOSED RULE PROPOSED RULE SECY PAPER:*
PROPOSED RULE SRM DATE:
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SIGNED BY SECRETARY:
08 / 19/ 86 FINAL RULE SECY PAPER:
FINAL RULE SRM DATE:
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DATE FINAL RULE SIGNED BY SECRETARY:
STAFF CONTACTS ON THE RULE I
I CONTACTl: LEON BERATAN CONTACT2:
MAIL STOP: 1130-SS PHONE: 44 3-7671 MAIL STOP:
PHONE:
PRESS PAGEUP TO SEE STATUS OF RULEMAKING PRESS ESC TO SEE ADDITIONAL RULES OR (S) TO STOP DISPLAY
DOCKET NO. PR-100 (51FR30224)
DATE DOCKETED 08/21/86 09/29/86 In the Matter of SEISMIC AND GEOLOGIC SITING CRITERIA FOR NUCLEAR P OWER PLANTS: REASSESSMENT OF CURRENT CRITERIA DATE OF TITLE OR DOCUMENT DESCRI PTION OF DOCUMENT 08/19/86 FEDERAL REGISTER NOTICE - PROPOSED RULE 09/22/86 COMMENT OF WESTI NGHOUSE ELECTRIC CORPORATION
( E. P. RAHE, JR.) (
- 1)
Westinghouse Electric Corporation Power Systems The Office of the Secretary U.S. Nuclear Regulatory Co1T1T1ission Washington, D.C.
20555
Subject:
Co1T1T1ents on the Conmission's Reassessment of its Current Seismic and Geologic Siting Criteria for Nuclear Power Plants, Federal Register Notice 51FR30224-30225 dated August 25, 1986; Re: 10 CFR Part 100, Appendi x A Gentlemen:
Westinghouse submits the following in response to the Conrnission's request for co1T1T1ents in the subject FR notice.
In view of the experience gained in the application of the procedures and methods set forth in Appendix A to 10 CFR Part 100, "Reactor Siting Criteria", the following should be considered in the reassessment of Appendix A to determine the need for its revision.
- 1.
ELIMINATION OF OBE REQUIREMENTS The Operating Basis Earthquake (OBE) should not be included in the Nuclear Power Plant criteria nor should it be used to introduce safety margin in a Nuclear Power Plant design.
The OBE was originally intended to be used by the Utility to provide the means of assuring that a plant could be expected to remain operational after being subjected to an earthquake that might reasonably be expected to occur during the life of the plant. It provides a utility with the means of minimiziTig potential repair and lost power costs.
As a result of this definition, OBE should not be the controlling factor for design.
However, due to damping and system nonlinearities, cases have occurred where the OBE actually controls this design. This implies that SSE is no longer the controlling factor for safety shutdown of a pl ant, which is a contradiction from the original design intent.
The safety margi n that should be achieved should be accomplished using only t he SSE.
In this way, a utility can reduce over-conservatism, engineering analysis, and related hardware costs.
U.S. Nl',..
DOCK I
(
p::. m r-
,.opi Add' I
- 2. NS-NRC-86-3169 September 22. 1986 Elimination of the OBE will require minor changes in criteria for the seismic evaluation since there are conditions that are currently only considered for the smaller earthquake.
As an example. fatigue evaluation for OBE loads will not be necessary.
However. to ensure that the plant will be able to operate continuously following an earthquake. it may be necessary to establish a threshold (e.g.*
operating shutdown earthquake) at a fraction of the SSE level.
At and above this (OSE) level. the plant would be shutdown for inspection and evaluation.
RECURRENCE INTERVAL FOR THE SAFE SHUTDOWN EARTHQUAKE The requirement for the SSE should be specified in terms of a recurrence interval that is consistent with the overall risk goals for a nuclear power plant.
On existing plants. it is estimated that the magnitudes used for the SSE correspond to a recurrence interval of 10.000 years. Recent probabilistic investigations of structures have resulted in the recommendation of a load factor greater than unity partly to account for earthquakes larger than the SSE.
This is not consistent with the current definition of the SSE which is the largest earthquake for which the plant must be designed to assure safe shutdown.
If you have any questions on this information. please contact me or Mr. J. J.
Mcinerney of my staff at (412) 374-5933.
Clark/1338n:52/wh Very truly yours *
. Rahe. Jr., Manager Nuclear Safety Department
[7590-0]J OOC:KETEl:
USNRC "86 Alli 21 All :20 U.S. Nuclear Regulatory Commission OFFICE Of S£,JK iAKY
[10 CFR Part 100]
HCKETJ~i:c~ RVICf.
SEISMIC AND GEOLOGIC SITING CRITERIA FOR NUCLEAR POWER PLANTS:
REASSESSMENT OF CURRENT CRITERIA AGENCY:
Nuclear Regulatory Commission ACTION:
Notice of meeting and request for comments.
SUMMARY
The Nuclear Regulatory Commission is initiating a reassessment of its current seismic and geologic siting criteria for nuclear power plants.
The NRC is taking this action in view of the experience gained in applying the current procedures and because of state-of-the-art advances that have been made in earth sciences since the promulgation of the regulations setting forth these criteria.
DATES:
Submit written comments by S£P 221986
,
- Public meeting to be held on October 7, 8, and 9, 1986.
ADDRESSES:
Submit written comments to: The Office of the Secretary, U.S.
Nuclear Regulatory Commission, Washington, D.C.
20555.
Public meeting to be held at the Ramada Inn, Route 28 and 1-270, Rockville, Maryland. Copies of conments received will be available for inspection in the NRC Public Document Room, 1717 H. Street, N.W., Washington, D.C.
FOR FURTHER INFORMATION CONTACT:
Mr. Leon Beratan, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory ColTlllission, Washington, D.C.
20555, telephone (301) 443-767i.
[7590-01]
SUPPLEMENTARY INFORMATION:
The Atomic Energy Commission published Appendix A, "Seismic and Geologic Siting Criteria for Nuclear Power Plants," to 10 CFR Part 100, "Reactor Site Criteria," as a rule in 1973 (C38 FR 2575; November 27, 1973).
In view of the experience gained in the application of t he procedures and methods set forth therein, and the advancement of the state-of-the-art of earth sciences, the NRC staff has initiated a reassessment of Appendix A to detennine the need for its revision.
To aid the staff in this reassessment, all interested persons are invited to submit infonnation, comments, and suggestions.
The staff is interested in learning both about the problems that may have been encountered in applying 9
Appendix A and about those portions that may have been particularly helpful in its application.
Commenters are invited to describe these in detail, to support their conclusions and, if they can, to recommend corrective actions.
In addition to soliciting written comments on Appendix A, the staff plans to hold a public meeting on this subject to provide all interested parties an opportunity to express their views and present information to the staff. The meeting is scheduled for October 7, 8, and 9, 1986, at the Ramada Inn (Route 28 and I-270), Rockville, Maryland, starting at 8:30. Parties are requested to notify the staff of t heir intention to speak at the meeting and/or attend the meeting. Specific details for the time and place of the meeting will be provided to all parties requesting the infonnation.
Dated at Rockville, Md. this 19th day of August 1986.
For the Nuclear Regulatory Commission.
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Ross, Jr., Acting Director Office of Nuclear Regulatory Research