ML20086R652
| ML20086R652 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 12/23/1991 |
| From: | Gates W OMAHA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-88-20, LIC-91-330R, NUDOCS 9201020156 | |
| Download: ML20086R652 (2) | |
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Omaha Public Power District December 23, 1991 444 South 16th street WlI LIC-91 330R Omaha, Netska 68102 2247 402/63G 2000 U. S. Nuclear Regulatory Commission ATTN:
Document Control Desk Mail Station PI-137 Washington, DC 20555
References:
1.
Docket No. 50 285 Letter from OPPD 2.
Desk) dated Octob(erK. J. Morris) to NRC (Document 31, 1989 (LIC 89-930) 3.
SECY 90 039 " Individual Plant Examinations Licensing Schedules" dated February 7, 1990 4.
Letter from the NRC 27, 1990(A. Bournia) to OPPD (W. G. Gates) dated March 5.
NUREG 1407 " Procedural and Submittal Guidance for the Individual Plant Examination of External Events for Severe Accident Vulnerabilities" June 1991.(IPEEE) 6.
Generic Letter (GL) 88-20 Supplement 4 dated June 28, 1991 Centlemen:
SUBJECT:
INDIVIDUAL PLANT EXAMINATION Of EXTERNAL EVENTS (IPEEE) FOR SEVERE ACCIDENT VULNERABILITIES - 10CfR 50.54 (f)
In response to GL 88-20 Supplemer.t 4 (Reference 6, Omaha Public Pover District (OPPD) will perform a Severe Accident Vulnerabil)itics Assessment for External Events for fort Calhoun Station TCS as described below.
Interrelationships between the individual IPEEE conc (erns), especially seismic, require a coincident schedule. Due to the delay in issuance of the Sunlementa Safety Evaluation Report (SSER) on the Seismic Qualification Utili<.1es Grou)
(SQUG) Generic Implementation Procedure is unable to provide a schedule for comple(GlP) for resolution of USl A 46, OPP) l tion of the IPEEE effort at this time.
I In a telephone call on December 18, 1991, Mr. Tom Therkildsen of OPPD notified Mr. Steve Bloom of the NRC that OPPD needed to review the SSER before it would be possible to submit a firm schedule.
Internal fir u : An internal fires IPEEE will bc accomplish 3d by performing a fire probabilistic risk assessment (PRA) under a joint effort with EPRI and several other utilities.
The internal fire PRA will be performed using the analysis steps of Section 4.1 of Reference 5 and the general guidance of NUREG/CR 2300.
The EPRI fire events database will be used to incorporate the most current generic fire events information. The internal fire PRA will also adopt the fire Vulnerability Evaluation Methodology (flVE propagation and damage assessment models for screening purposes and the FIVE)walkdown procedures for addressing fire Risk Scoping Study (fRSS) issues, l
Hiah Winds. External floods and Transportation and Nearby f acility Acci@nh:
Examination of these events will follow the process prescribed in Section 5.2 of Reference 5.
Analysis of high winds will include determination of site hazards from NUREG/CR-4461 and bounding PRA of potential vulnerabilities at FCS.
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U. S. Nuclear Regulatory Conrnission LIC 91-330R Page 2 Seismic Events: Fort Calhoun Station is a USI A 46 plant and a member of SQUG.
As stated in Nkt SECY-91 102, the procedures for the seismic walkdown portion of this program are "one of the most important ingredients in the seismic IPEEE,
[and) are similar to those that will be used in the implementation of Unresolved Safety issue (USI)A-46 A-46..."
Reference 6 encourages coordination of the seismic IPEEE with USI
'so that the objectives of both activities may be accomplished with a single walkdown effort."
OPPD agrees with the NRC staff and intends to conduct the sei mic IPEEE and USI A 46 walkdowns at the same time. OPPD is planning to perform the seismic IPEEE as a 0.3g focused scope plant using the NRC seismic margins methodolo in accordance with Reference 5.
However OPPD reserves the right to modif the program for conducting the seismic IPEE[ depending on the content of the SS R and resolution of open issues, in response to GL 88 20 Supplement 1, OPPD provided a schedule for completion of a full scope Level 111 PRA with an external events analysis (Reference 2), which was approved by the NRC in Reference 3.
In Reference 4, the NRC indicated that the issuance of external events requirements was not expected to affect the schedule. However, with the issuance of the requirements in References 5 and 6 OPPD has determined that the scope of work far exceeds that of the original commitment made in Reference 2.
OPPD personnet are actively articipating in the IPE/IPEEE project and have contributed approximately 40 f0% of the manhours expended to date.OPPD wishes to continue this level of involvement and submit the report as an integrated IPE/IPEEE program.
Therefore OPPD proposes to submit a revised schedule for completionoftheIPE/IPEEEeffortwithin120daysofreceiptoftheSSER.
in that submittal, OPPD will discuss proposed changes to the IPE/IPEEE project.
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If you should have any questions, please do not hesitate to contact me.
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Sincerely,
&'. 5 5%
W. G. Gates Division Manager Nuclear Operations WGG/sel c:
LeBoeuf, lamb, Leiby & MacRae R. D. Martin, NRC Regional Administrator, Region IV D. L. W'.gginton, NRC Senior Project Manager R. P. fullikin, NRC Senior Resident inspector i
S. D. Bloom, NRC Project Engineer M. Borchert, Director - Division of Radiological Health, Nebraska Department of Health
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