ML20086Q541
| ML20086Q541 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/20/1991 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-88-20, TXX-91460, NUDOCS 9112300248 | |
| Download: ML20086Q541 (4) | |
Text
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- TXX 91460 File # 10035 2.
GL88-20 TUELECTRIC December 20, 1991 William J. Cahill, Jr.
Greup Vice trenlent U. S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, D.C. 20555
Subject:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50 445 AND 50-446 NRC GENERIC LETTER 88-20:
INDIVIDUAL PLANT EXAMINATION OF EXTERNAL EVENTS FOR SEVERE ACCIDENT VULNERABILITIES Ref:
1)
NRC Generic Letter 88-20, Supplement 4:
' Individual Plant Examination of External Events for Severe Accident Vulnerabilities,' dated June 28, 1991.
2)
NUREG 1407:
- Procedural and Submittal Guidance for the Individual Plant Examination of External Events for Severe Accident Vulnerabilities," dated June 1991, Gentlemen:
The following CPSES information is provided in response to NRC Generic letter (GL) 88-20, Supplement 4.
NRC GL 88-20, Supplement 4 requests Licensees to submit a response which describes their proposed programs for completing the.
Individual Plant Examination of External Events (IPEEE).
(1)
GL 88-20 Reauest:
Identify the methods and approach selected for performing the IPEEE.
CPSES Response:
Consistent with the NRC recommendations, TU Electric intends to evaluate the following external events for CPSES Units 1 and 2:
Seismic Events Internal Fires High Winds and Tornadoes External Floods l
Transportation and Nearby Facility Accidents gk e n n
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TXX 91460 Page 2 of 3 o
At the present time TO Electric has not identified any plant u'nique external events with the potential to initiate severe accidents.
However, as part of the IPEEE program, TV Electric will confirm that no such events are excluded.
For seismic events, the Seismic Margin Method (SMM) with enhancements developed by EPRI will be utilized.
The guidelines and procedures described in NUREG-1407 and EPRI report NP-6041 will be used to perform the seismic IPEEE.
Since the CPSES site is east of the Rocky Mountains, it is qualified as a reduced scope plant as defined in NUREG 1407.
Therefore, a reduced-scope SMH with emphasis on the plant walkdown is determined to be adequate and will be utilized for CPSES.
Internal fires will be_ evaluated using a Level-! fire probabilistic risk assessment (PRA) method.
The steps and general guidelines described in NUREG/CR-2300 ard NVREG-1407 will-be followed.
The EPRI fire events database will be utilized as well as the FIVE fire _ propagation and damage assessment models for screening purposes.
A containment performance study will-be done -to ~ identify any sequences leading to -
containment failure that are different from those identified in the internal events of individual plant examination (IPE).
High winds, external floods, transportation accidents and nearby facility 6ccidents will be assessed using a screening type approach.
This screening type approach is consistent with the steps and guidelines provided in NUREG 1407.
!f any of these external events are judged to be significant contributorsfto the core damage frequency, then a more detailed analysis, such as a bounding analysis or a PRA, will be performed for those events.
In accordance with the requirements of GL 88-20. Tu-Electric intends to address the following issues:through the-IPEEE:
l 1he external event portion of USI A-45, ' Shutdown Decay Heat Removal Requirements' GI-131, " Potential Seismic Interaction Involving the Hovaale In-
' Core Flux Mapping System used in Westinghouse Plants' The Eastern U.S. Seismicity (The Chirleston Earthquake) Issue.
(2)
GL 88-20 Reauesti Describe the method to be used if it has not been previously submitted for staff review (the description may be by reference).
l CPSES Respontg1 CPSES will-perform the IPEEE using methods that are consistent with the methods and guidelines described in. references (1) and-(2).
TXX 91460 Page 3 of 3 (3)
GL 88-20 Recuest:
Identify the milestones and schedule for performing the IPEEE, and submitting the results to the NRC.
CPSES ResDonse:
The projected schedule for submittal of final results of the IPEEE to the NRC is June 28, 1995.
This will allow TV Electric to utilize its in-house resources to the maximum extent possible as recommended in the generic letter.
Currently, the IPE team members are fully dedicated to the internal events IPE which is to be submitted to the NRC by September 1, 1992.
Until then, the IPE team will be unable to work on the IPEEE except for preparation and planning of the IPEEE Program.
It is estimated that the IPEEE Project will take approximately 3 years to complete.
Therefore TV Electric is proposing a submittal date which is one year beyond the schedule requested by the generic letter, The proposed schedule will allow TV Electric to fully participate in the development and implerentation of the IPEEE, and will allow TV Electric personnel to use the b ]wledge gained to enhance the safety and economics of CPSES Units J
,d 2.
Sincerely, s
/
- ? -
William J. habill Jr.
JLR/isr Attachment c-Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (2)
Mr. M. B. Fields. NRR Mr T. A. Bergman NRR l
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Attachment to TXX-91460 Page 1 of 1 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION in the Matter of
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Texas Utilities Electric Company
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Docket Nos. 50-445
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and 50-446 (Comanche Peak Steam Electric
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Station, Unit 1 & 2)
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AFFIDAVIT William J. Cahill, Jr. being duly sworn, hereby deposes and says that he is Group Vice President. Nuclear of TV Electric, the lead Applicant herein: that he is duly authorized to sign and file with the Nuclear Regulatory Commission this response to Generic Letter 88-20, Supplement 4 for the captioned facility: that he is familiar with the content thereof: and that the matters set forth therein are true and correct to the best of his knowledge, information and belief.
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t WilllamJ.Cahil[/Jr.
V Group Vice PresiGent, Nuclear STATE OF TEXAS
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COUNTY OF DALIAS )
Subscribed and sworn to before me, on this 20th day of Decembd 1991.
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