[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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