ML20214T680
| ML20214T680 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/02/1986 |
| From: | Cutter A CAROLINA POWER & LIGHT CO. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20214T682 | List: |
| References | |
| NLS-86-416, NUDOCS 8612080664 | |
| Download: ML20214T680 (3) | |
Text
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s Cp&L Carolina Power & Light Company DEC 2 1986 SERIAL: NLS-86-416 86TSB20 Director of Nuclear Reactor Regulation Attention:
Mr. Dan Muller BWR Project Directorate #2 Division of BWR Licensing United States Nuclear Regulatory Commission Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO I DOCKET NO 50-325/ LICENSE NO DPR-71 REQUEST FOR LICENSE AMENDMENT STANDBY LIQUID CONTROL SYSTEM MODIFICATIONS
Dear Sir:
SUMMARY
In accordance with the Code of Federal Regulations, Title 10, Parts 50.90 and 2.101, Carolina Power & Light Company hereby requests a revision to the Technical Specifications (TS) for the Brunswick Steam Electric Plant, Unit No.1. The proposed change to Section 3/4.1.5 revises the standby liquid control system (SLCS) pump relief valve setpoint and the sodium pentaborate solution concentration curve to satisfy the ATWS rule requirements specified in 10 CFR 50.62.
DISCUSSION The purpose of this request is to revise the Brunswick-1 TS to reflect modifications being made to the plant during the upcoming Reload 5 outage. These modifications are being done to bring Brunswick-l into compliance with the requirements of paragraph (c)(4) of 10 CFR 50.62 which states, in part:
Each boiling water reactor must have a standby liquid control system with a minimum flow capacity and boon content equivalent in control capacity to 86 gallons per minute of 13-weight percent sodium pentaborate solution.
As stated in our October 15,1985 submittal, the Company evaluated several options by which the equivalent injection rate requirement could be met. Carolina Power & Light Company has determined that a two-pump operation with sodium pentaborate solution concentration maintained at greater than or equal to 13-weight percent is the preferred option. Since the ATWS function of the SLCS is a backup to other safety-related systems, new requirements due to ATWS modifications are not needed in the SLCS section of the Technical Specifications. This has been agreed to by the NRC in a letter from H. R. Denton to 3. M. Fulton dated August 19, 1985. Only the areas of the TS which cover specific SLCS physical characteristics need to be revised as a result of 10 CFR 50.62.
The existing SLCS includes two positive displacement pumps connected in parallel. ihe SLCS pump motor control logic is currently configured such that only one of the two pumps may be operated at any time. Modifications will be made during the upcoming I
l Reload 5 outage to permit two pump operation. To account for the higher system 8612030664 861202
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' Director of Nucl:ar Reactor R:gulation DEC 2 886 NLS-86-416 / Pag 2 2 pressures associated with two-pump operation, the SLCS pump relief valve setpoint specified in Surveillance Requirement 4.1.5.c.3 will be inc ased from 1400 50 psig to 1450 50 psig. The Company contacted the manufacture. and determined that the relief valves are capable of operating at the proposed setpoint without damage or malfunction. The portions of the SLCS affected by the increased setpoint were evaluated and determined to be capable of performing at the increased pressure without compromising the system integrity or function. In addition, tests were performed on Brunswick-? during the 1986 Reload 5 outage which verified that the SLCS is capable of operating under the increased pressures associated with two-pump operation.
Figure 3.1.5-1 has also been revised to set the lower limit for sodium pentaborate concentration at 13-weight percent. This is consistent with the requirements of 7aragraph (c)(4) of 10 CFR 50.62.
An administrative change has been made to Surveillance Requirement 4.1.5.c.2. The current requirement is to demonstrate that the minimum-flow requirement of 41.2 gpm at a pressure of greater than or equal to 1190 psig can be achieved. The revision specifies that this requirement is 41.2 gpm per pump, avoiding possible confusion under two pump operation. The 86 gallons per minute and 13-weight percent sodium pentaborate specified by paragraph (c)(4) of 10 CFR 50.62 are values used in NEDE-24222, " Assessment of BWR Mitigation of ATWS, Volumes I and II",
December 1979, for BWR/5 and BWR/6 plants with a 251-inch inside diameter vessel.
NEDE-24222 recognized that different values would be equivalent for smaller plants.
NEDE-24222 states that a 66-gpm control liquid injection rate in a 218-inch inside diameter vessel, as is used at Brunswick, is equivalent to the 86-gpm injection rate for a 251-inch vessel. Maintaining the minimum-flow requirement of 41.2 gpm per pump ensures that an injection rate in excess of 66 gpm will be achieved during two-pump operation.
SIGNIFICANT HAZARDS ANALYSIS The commission has provided standards in 10 CFR 50.92(c) for determining whether a significant hazards consideration exists. A proposed amendment to an operating license for a facility involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated;(2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. Carolina Power & Light Company has reviewed this request and determined that:
1.
The proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated because the ATWS function of the SLCS merely provides a backup to other safety-related systems. The effects of the increase in the SLCS Pump relief valve setpoint from 1400 psig to 1450 50 psig were evaluated, and it was determined that the system is capable of being operated at the increased pressure without compromising system integrity or function. The revision to Figure 3.1.5-1 ensures that the concentration of sodium pentaborate solution is maintained at or above 13-weight percent. This is in accordance with the requirements of 10 CFR 50.62. The change to Surveillance Requirement 4.1.5.c.2 is administrative in nature and, therefore, can not increase the probability of consequences of an accident previously evaluated.
2.
The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated because neither the safety function performed by the SLCS or the operability of the SLCS is affected by the
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proposed TS revisions or the accompanying plant modifications. The proposed TS changes will ensure that the SLCS is maintained such that it is capable of fulfilling the operability requirements of 10 CFR 50.62.
3.
The proposed amendment does not involve a significant reduction in a margin of safety. The proposed revisions are in accordance with the requirements of 10 CFR 50.62 and provide additional assurance that the SLCS is capable of safely shutting down the reactor should an ATWS event occur. The effects of the increase in the SLCS pump relief valve setpoint were evaluated, and it was determined that the system is capable of being operated at the increased pressure without compromising system integrity or function. The revision to Figure 3.1.5-1 ensures that the concentration of sodium pentaborate solution is maintained at or above 13-weight percent, which is more restrictive than the current specification. The revision to Surveillance Requirement 4.1.5.c.2 is administrativa in nature and,
- therefore, cannot cause a decrease in the margin of safety. As such, the proposed amendment leads to an increase in the margin of
- safety.
Based on the above, Carolina Power & Light Company has determined that the proposed amendment does not involve a significant hazards consideration.
ADMINIST'MTIVE INFORMATION The revised Brunswick-1 TS pages are provided in Enclosure 1. The Company has evaluated this request in accordance with the provisions of 10 CFR 170.12 and determined that a license amendment application fee is required. A check for $150 is enclosed in payment of this fee. Carolina Power & Light Company requests issuance of this amendment by March 2,1987, in order to support refueling of Brunswick-1.
Please refer questions regarding this submittal to Mr. Sherwood R. Zimmerman at (919) 836-6242.
Your very trul,
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. B. Cutter - Vice President MAT /bmc (5050 MAT)
Nuclear Engineering & Licensing cc:
Mr. W. H. Ruland (NRC-BSP)
Dr. 3. Nelson Grace (NRC-Ril)
Mr. E. Sylvester (NRC)
Mr. Dayne H. Brown A. B. Cutter, having been first duly sworn, did depose and say that the information contained herein is true and ' correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, contractors, and agents of Carolina Power & Light Company.
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