ML20147G116
| ML20147G116 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 03/01/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20147G122 | List: |
| References | |
| NUDOCS 8803080131 | |
| Download: ML20147G116 (4) | |
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o UNITED STATES 4
g NUCLEAR REGULATORY COMMISSION J
o WASHING TON, D. C. 205S5
_EFTLOSURE 1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATit$ TO STANDBY LIQUID CONTROL SYSTEM j
COMMONWEALTH EDIS0N COMPANY LASALLE COUNTY STATION UNITS 1 AND 2 DOCV.ET NOS 50-373 AND 50-374
1.0 INTRODUCTION
By letter dated April 6,1987 from C. P. Allen, comonwealth Edison Company (Ceco), to the U. S. Nuclear Regulatory Comission (NPC), Ceco submitted proposed system raodifications to the LaSalle County Station (LSCS) Units 1 and 2 required to meet the Anticipated Transients Without Scram (ATWS) rule, 10 CFR 50.62.
In addition, by letter dated October 23, 1987, from C. M. Allen (Ceco), to the NRC, Ceco responded to a request for additional infomation regarding ATWS system modifications which addresses the equivalency requirement in the Standby Liquid Control System (SLCS).
2.0 EVALUATION The present LSCS Standby Liquid Control System (SLCS) is a two-pump system for each unit. Each pump is designed to inject a minimum of 41.2 gpm. The j
present sodium pentaborate concentration is 13.4 weight percent. The proposed mode of operation to meet ATWS Rule requirements is for simultaneous two pump operation at a total flow rate of 82.4 gpm. This flow rate in conjunction with a minimum sodium pentaborate concentration of 13.6 weight percent is proposed to satisfy the "equivalent control" reouirements of paragraph (c)(4) of 10 CFR 50.62.
The system description provided by the licensee has been reviewed by the staff against the requirements of the ATVS Rule (10 CFR 50.62), and Generic Letter 85-03, "Clarification of Equivalent Control Capacity for Standby Liquid j
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Control Systems," dated January 28, 1985. The proposed mode of operation to achieve a flow rate of 82.4 gpm with a sodium pentaborate minimum concentration of 13.6 weight percent is equivalent to 86 gpm at 13 weight percent and therefore is in compliance with 10 CFR 50.62(c)(4). Accordingly, this proposed mode of operation is acceptable.
The licensee indicated that both SLCS pumps will be test-operated simultaneously to verify that a minimum allowable double pump flow rate of 82.4 gpm can be achieved. This test will be performed once as part of the post-modification testing program after which the original LSCS Technical Specification requirerents for periodic testing will be in effect. The licensee has also stated that the modifications will include pulsation dampers in the discharge piping to attenuate variations in the positive displacement punps' pressure and an increased relief valve setpoint to 1500 psi to avoid inadvertent lifting of the valve during system testing and operation. We find the proposed modifications acceptable. The described values of concentration, flow rate, and relief valve setpoint should be included in a Technical Specification revision applicable to the SLCS.
3.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that the Standby Liquid Control System for LaSalle County Station Units 1 and 2 meets the requirements of 10 CFR 50.62(c)(4) and is acceptable.
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EFTLOSURE 1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO STANDBY LIQUID CONTROL SYSTEM COMMONWEALTH EDISON COMPANY LASALLE COUNTY STATION UNITS 1 AND 2 DOCKET N05. 50-373 AND 50-374
1.0 INTRODUCTION
By letter dated April 6,1987 from C. M. Allen, comonwealth Edison Company (Ceco), to the U. S. Nuclear Regulatory Comission (NPC), Ceco submitted proposed system modifications to the LaSalle County Station (LSCS) Units 1 and 2 required to meet the Anticipated Transients Without Scram (ATWS) rule, 10 CFR 50.62.
In addition, by letter dated October 23, 1987, from C. M. Allen (CECO), to the NRC, Ceco responded to a request for additional infomation regarding ATWS system modifications which addresses the equivalency requirement in the Standby Liquid Control System (SLCS).
2.0 EVALUATION The present LSCS Standby Liquid Control System (SLCS) is a two-pump system for each unit. Each pump is designed to inject a minimum of 41.2 gpm. The present sodium pentaborate concentration is 13.4 weight percent. The proposed mode of operation to meet ATWS Rule requirements is for simultaneous two pump operation at a total flow rate of 82.4 gpm. This flow rate in conjunction with a minimum sodium pentaborate concentration of 13.6 weight percent is proposed to satisfy the "equivalent control" reouirements of paragraph (cI(4) of 10 CFR 50.62.
The system description provided by the licensee has been reviewed by the staff against the requirements of the ATWS Rule (10 CFR 50.621, and Generic letter 85-03, "Clarification of Equivalent Control Capacity for Standby Liquid
)
2 Control Systems," dated January 28, 1985.
The proposed mode of operation to achieve a flow rate of 82.4 gpm with a sodium pentaborate minimum concentration of 13.6 weight percent is equivalent to 86 gpm at 13 weight percent and therefore is in compliance with 10 CFR 50.62(c)(4). Accordingly, this proposed mode of operation is acceptable.
The licensee indicated that both SLCS pumps will be test-operated simultaneously to verify that a ninimum allowable double pump flow rate of 8?.4 gpm can be achieved. This test will be performed once as part of the post-modification testing program after which the original LSCS Technical Specification requirements for periodic testing will be in effect. The licensee has also stated that the modifications will include pulsation dampers in the discharge piping to attenuate variations in the positive displacement punps' pressure and an increased relief valve setpoint to 1500 psi to avoid inadvertent lifting of the valve during systen testing and operation. We find the proposed modifications acceptable. The described values of concentration, flow rate, and relief valve setpoint should be included in a Technical Specification revision applicable to the SLCS.
3.0 CONCLUSION
l The staff has concluded, based on the considerations discussed above, that the Standby liquid Controi System for LaSalle County Station Units 1 and 2 meets the requirements of 10 CFR 50.62(c)(4) and is acceptable.
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CO2008 LUT080C088 February 3,1988 Mr. Ronald D. W F INFORMATION Ccritracting Officer g QUEST Ccritract Negotiaticri Branch (2
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Divisicr1 of Contracts U.S. Nuclear Regulatory Mmairn M *//"((
Washingtcri, DC 20555
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Re: Fraark= cf Infomaticr1 Act, Request
Dear Mr. Thcapocrl:
Pursuant to the Fraarbn of Infor1 nation Act, 5 U.S.C. 8 552, and your agency's implementing regulaticris, please provide a ocpy of the winning technical proposal for the Energency Respcrise Data Systen (RTP RS-MD-87-129).
We are prepared to pay all reascriable costs of searth arri &Jplication. If it is estimated that such renscriable costs will exceed $500, please notify us prior to NRC's initiatics) of the seart:h or &plicaticri.
Sinoarely,
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V 1&ard E. Tegnamy Senior Vios President General Manager, Program Wtials EEL:au Systems Research and Apphcaticas Corporction 200015th Street Notth. Mington. Virginia 22201
- 703/558-4700 Cable: SRACORP
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