[Federal Register Volume 59, Number 200 (Tuesday, October 18, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-25709]
[[Page Unknown]]
[Federal Register: October 18, 1994]
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NUCLEAR REGULATORY COMMISSION
Agenda for Public Workshop in the Seismic Revisit of the
Individual Plant Examination of External Events (IPEEE) for Severe
Accident Vulnerabilities
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice of Workshop Agenda on Seismic Revisit of Individual
Plant Examination of External Events (IPEEE).
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SUMMARY: On September 22, 1994, the NRC announced in FRN (Vol. 59, No.
183) that it plans to conduct a workshop on October 21, 1994 to discuss
the results of the seismic IPEEE revisit. The staff intends to use this
workshop to identify approaches and issues, and solicit comments from
the public that will be used to develop a proposed position. Draft
contractor reports on a proposed seismic revisit are available at the
NRC Public Document Room (PDR), Gelman Building, 2120 L Street NW,
Washington, DC. These reports and other related information will be
discussed in the workshop.
DATES: October 21, 1994; 9:00-5:00.
ADDRESSES: The NRC Auditorium, 11555 Rockville Pike, Rockville, MD.
20852-2738.
Agenda
9:00-9:15 Opening Remarks/General Introduction
9:15-9:45 ERI Reports
9:45-10:15 NRC Staff Discussion on Potential Approaches and Issues
10:15-10:30 Break
10:30-12:00 Panel Discussion on ERI Reports and Potential Approaches
12:00-13:00 Lunch Break
13:00-14:00 Public Comment
14:30-14:45 Break
14:45-16:00 Queston & Answer
FOR FURTHER INFORMATION CONTACT:
John T. Chen, Office of Nuclear Regulatory Research, U.S. Nuclear
Regulatory Commission, Washington, DC 20555. Telephone (301) 415-6549.
SUPPLEMENTARY INFORMATION: On June 28, 1991 the NRC issued Generic
Letter 88-20. Supplement 4, Individual Plant Examination of External
Events (IPEEE) for Severe Accident Vulnerabilities, and NUREG-1407
containing procedural and submittal guidance for IPEEE. The Generic
Letter requested all licensees to perform an IPEEE to identify plant-
specific vulnerabilities to severe accidents due to external events and
report the results to the NRC. Key elements of the development of the
IPEEE guidance included assigning earthquake review level and review
scope for the seismic events. In this development, for central and
eastern U.S. plants, the process of assigning plants to appropriate
review categories has relied largely on the use of available seismic
hazard estimates: those published in 1989 by Lawrence Livermore
National Laboratory (LLNL) and the Electric Power Research Institute
(EPRI). However, grouping of the plants relied heavily on a grouping
technique with a number of attributes using seismic hazard on a
relative basis. In 1993, based on a re-elicitation of LLNL ground-
motion and seismicity experts, revised seismic hazard estimates were
published in NUREG-1488. The revised mean hazard estimates are lower
than the 1989 LLNL estimates. The results prompted the NRC to revisit
the seismic IPEEE program and consider the potential impact of the
revised LLNL results.
The contractor's study has been completed and the draft reports are
available and will be discussed in the workshop. These reports have
investigated various schemes of rebinning the plant and redefining the
scope of examination within a bin. The proposed schemes have involved
consideration of absolute value of estimated core damage frequency with
a generic fragility as suggested by NEI as well as reexamination of
insights obtained from past PRAs. On the basis of evaluation of these
reports, the staff is considering several approaches to revisit the
scope of the seismic IPEEE. Fundamental to the staff consideration is
maintaining the IPEEE objectives, that is, to obtain insights regarding
severe accident vulnerabilities and behavior. The staff intends to
discuss these approaches as well as key issues including:
(1) The need for revisit;
(2) The suitability of an approach to identify severe accident
vulnerabilities and meet IPEEE objectives;
(3) The appropriateness of absolute numerical core damage value as
a criterion in light of large inherent uncertainties in the seismic
hazard and risk estimates;
(4) An appropriate numerical value and its basis;
(5) Limiting the evaluation to selected components and the basis
for selection of components; and
(6) The role and extent of use and documentation of engineering
judgment by the seismic review team in conducting an examination.
(Note that the FRN dated Sept. 22, 1994 incorrectly indicated that
the NRC staff position would be discussed at this workshop. The
workshop will discuss the draft contractor reports and these
discussions will serve as a basis for development of a staff position.)
These reports have been reviewed by an independent group of
experts, whose views will be presented at this workshop. In addition,
an opportunity will be available for members of the public, utility
representatives or other interested parties to comment on the
contractor reports and staff presentation on the possible approaches
for rebinning. Those persons who wish to make a brief presentation at
the workshop, should indicate their desire to the contact listed above,
so that they can be added to the agenda. Written comments will also be
accepted up to 4 weeks following the workshop.
Dated in Rockville, MD this 12th day of October, 1994.
For the Nuclear Regulatory Commission.
Joseph Murphy,
Acting Director, Division of Safety Issue Resolution, Office of Nuclear
Regulatory Research.
[FR Doc. 94-25709 Filed 10-17-94; 8:45 am]
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