ML20140F714
| ML20140F714 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/28/1986 |
| From: | Zimmerman S CAROLINA POWER & LIGHT CO. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| References | |
| NLS-86-094, NLS-86-94, NUDOCS 8604010138 | |
| Download: ML20140F714 (3) | |
Text
6-J Cp&L Carolina Poser & t.lght Company SERIAL: ES-866 MAR 2 81986 Director of Nuclear Reactor Regulation Attention:
Mr. Dan Muller, Director BWR Project Directorate #2 Division of BWR Licensing United States Nuclear Regulatory Commission Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 & $0-324/ LICENSE NOS. DPR-71 & DPR-62 SUPPLEM6NT REQUEST FOR LICENSE AMENDMENT CHLORINE DETECTION SYSTEM
Dear Mr. Muller:
On March 5,1986, Carolina Power & Light Company requested a license amendment concerning the chlorine detection system at Brunswick. The proposed amendment revises Technical Specification Section 3/4.3.5.5 to reflect modifications made to the chlorine detection system which provides automatic isolation of the control room upon detection of high chlorine concentration either at the tank car ciding or at the control room air intake. In addition, the action statements regarding inoperable chlorine detectors have been revised to more adequately reflect Brunswick's chlorine detection system design.
Upon review by the Brunswick Project Manager, it was determined that a more detailed significant hazards analysis for this request is necessary. Enclosure 1 contains the revised analysis which supersedes the significant hazards analysis provided in the March 5,1936 submittal.
Please refer any further questions regarding this matter to Mr. Stephen D. Floyd at (919) 836-6901.
Yours very truly, mm-S. R.
ierman Manager Nuclear Licensing Section MAT /ccc (3564 MAT)
Enclosure "cc: Mr. W. H. Ruland (NRC-BNP)
Dr. J. Nelson Grace (NRC-RII)
Mr. E. Sylvester (NRC)
Mr. Dayne H. Brown f
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- Enclosure with all cc's.
B604010138 860329 PDR ADOCM 05000 4
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ENCLOSURE 1 i
TO SERIAL: NLS-86-094 SIGNIFICANT liAZARDS ANALYSIS The Commission has provided standards for determining whether a significant hazards I
consideration exists in 10 CFR 50.92(c). 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:
The proposed amendment does not involve a significant increase in the probability 4
or consequences of an accident previously evaluated nor does it create the possibility of a new or different kind of accident than previously evaluated because j
the modifications made to the chlorine detection system do not result in changes to g
the assumptions or results of any accidant analyses previously performed. In fact, the safety evaluation in the Brunswick FSAR assumes failure of both chlorine detectors located near the tank car siding. The configuration of the chlorine detection system is consistent with descriptions provided in the Brunswick Control Room Habitability Study. The NRC issued a Safety Evaluation Report finding this design acceptable on October 18,1983.
The revision to Action Statement 3.3.5.5.a, allowing operation for up to seven days with one chlorine detector of either or both subsystems inoperable, does not involve L
i a significant increase in the probability or consequences of an accident previously evaluated nor does it create the pessibility of a new er different kind of accident than previously evaluated because chlorine detection system redundancy will ensure 3
4 control room isolation in the event of a chlorine leak. The chlorine detection system is designed so that failure of a single detector in either subsystem does not render that subsystem inoperable. The chlorine detection system redundancy is L
ensured by the proposed revision to Specification 3/4.3.5.5 through the requirement for four operable chlorine detectors, two per subsystem. This is more restrictive i
than the current specification which requires only two operable chlorine detectors and, thereby, offsets the seven day out-of-service allowance for a single chlorme detector of either or both subsystems. Action Statement 3.3.5.5.b has been added to ensure that the control room is isolated within one hour should both detectors of a subsystem become inoperable. This is more conservative than the current Brunswick technical specification which allows operation for up to eight hours with an inoperable chlorine detection system prior to initiating shutdown of the plant.
Requiring isolation of the control room rather than plant shutdown provides protection for the operators without placing the plant in an unnecessary operating L
t transient.
i The proposed amendment does not involve a significant reduction in a margin of safety because the modifications made to the plant provide for better chlorine detection capabilities. The clarification of the system design in the revised TS will help to avoid possible operator confusion. Operation with the control room isolated rather than shutting down the plant when the chlorine detection system is inoperable provides adequate operator protection in the unlikely event of a chlorine l
(3564MA Uccc)
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leak without placing the plant in an unnecessary operating transient. Allowing for operation for seven days with one detector in either or both chlorine detection system subsystems inoperable does not decrease the margin of safety because the system redundancy ensures control room isolation if required.
Based on the above reasoning, Carolina Power & Light Company has determined that the proposed amendment does not involve a significant hazards consideration.
(3564 MAT /ccc)