ML20207H662
| ML20207H662 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/08/1999 |
| From: | Dan Collins NRC (Affiliation Not Assigned) |
| To: | Cross J DUQUESNE LIGHT CO. |
| References | |
| TAC-M83590, TAC-M83591, NUDOCS 9907140214 | |
| Download: ML20207H662 (5) | |
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Mr. J. E. Cross July 8, 1999 Pr:sid:nt-Grn: ration Group Duquesne Light Company Post Office Box 4 Shippingport, PA 15077
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAl) REGARDING REVIEW OF BEAVER VALLEY POWER STATION, UNIT NOS.1 AND 2 (DVPS-1 AND BVPS-2), INDIVIDUAL PLANT EXAMINATION OF EXTERNAL EVENTS (IPE'EE)
(TAC NOS. M83590 AND M83591)
Dear Mr. Cross:
By letter dated November 12,1998, the Duquesne Light Company (DLC) submitted a response to the Nuclear Regulatory Commission's (NRC) RAI regarding DLC's IPEEE event evaluations for BVPS-2. The NRC staff has reviewed this response and found that it does not adequately address the issues raised in the seismic RAls.
On June 28,1999, a conference call was conducted between members of the NRC staff; Brookhaven National Laboratory, acting as an NRC contractor; DLC; and Stevens &
Associates, acting as a DLC contractor, to discuss the additional information needed by the NRC staff in order to complete the IPEEE review for BVPS-1 and BVPS-2. The purpose of the call was to ensure a clear and consistent understanding by all parties of the information needed by the NRC staff. The required information is detailed in the attached RAl. Although these questions are specific to the BVPS-2 response, they are also applicable to BVPS-1. Therefore, please address the following questions in the context of both BVPS-1 and BVPS-2.
The NRC requests that you provide your response to the enclosed RAI within 60 days of receipt ;
of this lettar. This was discussed with Mr. J. Maracek of your staff, and was established as a 1 mutually agreeable timetable for your response. If circumstances result in the need to revise the target date, please call me at the earliest opportunity.
Should you have any questions regarding this request, please contact me at (301) 4151427.
Sincerely, ORIGINAL SIGNED BY:
9907140214 99070s adel S. Cohs, Ned Manager, Sedon 1 PDR ADOCK 05000334 Project Directorate l P PDR Division of Licensing Project Management /
Office of Nuclear Reactor Regulation /j/
Docket Nos. 50-334 and 50-412 gg p
Enclosure:
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l cc w/ encl: See next page J
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l July 8, 1999 l Mr. J. E. Cross President-Generation Group Duquesne Light Company l
l Post Office Box 4 l l Shippingport, PA 15077
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING REVIEW OF BEAVER VALLEY POWER STATION, UNIT NOS.1 AND 2 (BVPS-1 AND BVPS-2), INDIVIDUAL PLANT EXAMINATION OF EXTERNAL EVENTS (IPEEE) ;
(TAC NOS. M83590 AND M83591) l
Dear Mr. Cross:
By letter dated November 12,1998, the Duquesne Light Company (DLC) submitted a response to the Nuclear Regulatory Commission's (NRC) RAI regarding DLC's IPEEE event evaluations for BVPS-2. The NRC staff has reviewed this response and found that it does not adequately address the issues raised in the seismic RAls.
On June 28,1999, a conference call was conducted between members of the NRC staff; Brookhaven National Laboratory, acting as an NRC contractor; DLC; and Stevens &
Associates, acting as a DLC contractor, to discuss the additional information needed by the NRC staff in order to complete the IPEEE review for BVPS-1 and BVPS-2. The purpose of the call was to ensure a clear and consistent understanding by all parties of the information needed by the NRC staff. The required information is detailed in the attached RAl. Although these questions are specific to the BVPS-2 response, they are also applicable to BVPS-1. Therefore, please address the following questions in the context of both BVPS-1 and BVPS-2.
The NRC requests that you provide your response to the enclosed RAI within 60 days of receipt oi this letter. This was discussed with Mr. J. Maracek of your staff, and was established as a mutua' y agreeable timetable for your response. If circumstances result in the need to revise the target date, please call me at the earliest opportunity.
Should you have any questions regarding this request, please contact me at (301) 415-1427.
Sincerely, l
/ u/ C Old aniel S. Collins, Project Manager, Section 1 Project Directorate i Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-334 and 50-412
Enclosure:
RAI cc w/ encl: See next page e
r Beaver Valley Power Station, Units 1 and 2 Jay E. Silberg, Esquire Duquesne Light Company Shaw, Pittman, Potts & Trowbridge Beaver Valley Power Station 2300 N Street, NW. PO Box 4 Washington, DC 20037 Shippingport, PA 15077 ATTN: Kevin L. Ostrowski, Division Vice Duquesne Light Company President, Nuclear Operations Group I Safety and Licensing Department and Plant Manager (BV-SOSB-7)
Mark S. Ackerman, Manager (2 Copies)
Beaver Valley Power Station Bureau of Radiation Protection PO Box 4, BV-A Pennsylvania Department of Shippingport, PA 15077 Environmental Protection ATTN: Michael P. Murphy Commissioner Roy M. Smith Post Office Box 2063 ;
West Virginia Department of Labor Harrisburg, PA 17120 '
Building 3, Room 319
- Capitol Complex Mayor of the Borough of Charleston, WV 25305 Shippingport Post Office Box 3 Director, Utilities Department Shippingport, PA 15077 Public Utilities Commission 180 East Broad Street Regional Administrator, Region l Columbus, OH 43266-0573 U.S. Nuclear Regulatory Commission 475 Allendle Road Director, Pennsylvania Emergency King of Prussia, PA 19406 Management Agency Post Office Box 3321 Resident inspector Harrisburg, PA 17105-3321 U.S. Nuclear Regulatory Commission Post Office Box 298 Ohio EPA DERR Shippingport, PA 15077 i ATTN
- Zack A. Clayton
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Post Office Box 1049 Duquesne Light Company !
Columbus, OH 43266-0149 Beaver Valley Power Station l PO Box 4 I Dr. Judith Johnsrud Shippingport, PA 15077 National Energy Committee ATTN: S. C. Jain, Senior Vice President Sierra Club Nuclear Services (BV-A) 433 Orlando Avenue State College, PA 16803 Mr. J. A. Hultz, Manager Projects & Support Services Duquesne Light Company First Energy Beaver Valley Power Station 76 South Main Street J.' J. Maracek Akron, OH 44308 P. O. Box 4, BV-A Shippingport, PA 15077 l
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l REQUEST FOR ADDITIONAL INFORMATION (rah I i
REGARDING INDIVIDUAL PLANT EXAM! NATION OF EXTERNAL EVENTS !
l BEAVER VALLEY POWER STATION. UNIT NOS 1 AND 2 DOCKET NOS. 50-334 AND 50-412 l
l Seismic Events I
- 1. According to the response to the previous seismic RAl-1(a) regarding the anchorage of I the uniform hazard spectrum (UHS) curve (page 20 of the BVPS-2 response), the peak ground acceleration (PGA) of 0.099 anchored at 50Hz is appropriate for tne Beaver ,
Valley site. Therefore, the UHS spectral shape should change to that of a more typical response spectrum which differs from the unrealistic shape that is defined for the l current UHS curve. Such a change in the spectral shape directly impacts fragility l calculations that use the UHS as input, because the component fragilities depend on the (
ground spectrum shape, not the specific PGA value to which the spectrum is anchored.
{
This is readily illustrated by taking the sample fragility calculations BVPS-2 provided in '
the attachments to the RAI response (e.g., on sheet 4 or 10 of Attachment B), and i replacing 0.159 by 0.09g in the equation. This reduces the median capacity Am by 40 %.
Therefore, the previous response that the use of an unrealistic UHS shape in fragility calculations, defined by anchoring the curve at 0.151g at 25Hz, is more conservative, is l incorrect.
Please provide the correct UHS curve and show how it compares to the design basis spectrum. Please also update all fragility analyses that are affected by the UHS shape change, and discuss the impact of the changes in fragilities on the seismic accident l cequences, the ranking of dominant contributors, and the total seismic core damage I frequency.
- 2. Linear scaling was used to determine the UHS floor response spectra (FRS) from the design basis FRS. According to the BVPS-2 response to RAi-1(b)(page 26 of the response), scaling was performed using a Stevens & Associates program TFRS, the description of which was included in the DLC response as Attachment A. The foimula for computing the amplification factors consists of two parameters: (1) amplification due to the structure and the soil-structure interaction effect, and (2) amplification due to the difference in zero period ground acceleration (ZPGA) between the UHS and design basis earthquake (DBE) spectra. However, the formula does not address how the change in damping and the differences in the spectral shapes between the UHS and the DBE affect the amplification factors.
Enclosure
l' Please provide clarification on these points. Please also use the calculation in Attachment B to the BVPS-2 RAI response as an example, to illustrate in detail the process by which the UHS FRS was constructed from the DBE FRS, and provide the detailed calculation including the spectral plots.
- 3. In Attachment 3 to the BVPS-2 response to the RAls, the fragility calculation for the BVPS 1 reactor coolant pumps (RCP) was provided. A review of this calculation indicates that the strength factor and ductility factor were reasonably computed and were interpreted in our review as being the factors computed using the DBE input.
However, there are a number of apparent inconsistencies regarding the computation of the median capacity. Specifically, sheet 2 of 10, under item #2, describes the DBE peak l
spectrum value as 6.0g and the ZPGA value as 1.5g for the RCPs. This information should have been used for the median capacity calculation. However, it was not mentioned and it was not applied in the median capacity calculation. Secondly, on sheet 3 of 10, the UHS FRS value at SHz and Elevation 767 feet of the containment internal structure was identified to be 0.42g, which may represent the seismic demand -
from the UHS ground input. Therefore,0.42g should be used for converting the strength factor from the DBE to the UHS, and should enter into the formula for the median capacity A, on sheet 4 of 10 in the denominator (in place of 0.4g). Also, the corresponding numerator should be the corresponding DBE FRS value at SHz (If one goes by sheet 2 of 10, this value becomes 6.0g). Lastly, it is not clear how the first term (0.429/0.4g) in the formula for the median capacity A, was computed.
In light of the above, please clarify how the fragility calculation for the RCPs was carried out and provide allinformation relevant to the calculation, such as the DBE FRS and UHS FRS used for the seismic demand. Please also correct the median capacity of the RCPs using the correct UHS shape (UHS curve anchored to 0.09g at 50Hz).
There are no additional questions for fires or high winds, floods and other external events.