ML20246M675
| ML20246M675 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/20/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20246M661 | List: |
| References | |
| NUDOCS 8903270223 | |
| Download: ML20246M675 (3) | |
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j WASHINGTON, D. C. 20066
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SAFETY EVALUATION BY THE OFFICE 0F NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.126 TO FACILITY OPERATING LICENSE NO. DPR-71 AND AMENDMENT NO.156 TO FACILITY OPERATING LICENSE NO. DPR-62 CAROLINA POWER & LIGHT COMPANY, et al.
BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 DOCKET NOS. 50-325 AND 50-324
1.0 INTRODUCTION
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By letter dated August 23, 1988, Carolina Power & Light Company (the licensee) submitted a request for changes to the Brunswick Steam Electric Plant, Units 1 and 2 Technical. Specifications to reflect a proposed modification to the fire detection instruments in the fire Cetection zones DGS, DG6, DG7, and DG8 in the diesel generator (DG) building.
The amendments change Table 3.3.5.7-1 in the Units 1 and 2 Tech 01 cal Specifications to reflect the proposed modification of the preset.t fire detection system for the diesel generator cells.
The detection sy. stem will be modified by replacing the present smoke detectors with a combina-tion of heat and flame detectors.
2.0 EVALUATION In the request for changes, the licensee provided the staff with the following appraisal of the existing fire detection, particularly in the DG building.
The function of the plant's fire detection system is to monitor continuously for the presence of a fire and to alarm in the event of a fire. The system consists of detectors, control panels, annunciator panels, and associated electrical circuits. The fire detection system is arranged into detector zones which consist of an electrical circuit with its associated detectors.
Detector zones are used where a common area or hazard is covered by fire detectors. A separate fire detector zone (DG5, DG6, DG7, and DG8) has been designated for each diesel generator cell.
Based on the fire hazards analysis contained in Section 9.5 of the Updated FSAR, there are two basic fire hazards 8903270223 890320 DR ADOCK 05000324 PDC l
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~2 associated with the diesel generator cells.
These are:
4 (1) fires associated with ordinary combustible materials
-due to transient combustibles in the area, and (2) fires associated with combustion of fuel oil. Exposure from ordinary combustible fires is not expected to be severe enough to damage safety related equipment.
Fuel oil fires are also not projected to be severe unless they occur between the diesel generator fuel pump and the fuel injectors.
Because of-the high pressure and atomized spray of fuel oil at this location, the fire would be intense and' severe damage to the diesel generator could occur..This type of fire would produce intense heat and visible flame.
Currently, the diesel generator cells are equipped with smoke detectors. Smoke detectors are sensitive instruments capable of detecting the early products of combustion before they become visible smoke. Due to their sensitivity to aerosols, i
other than i. hose produced by a fire, the subject smoke detectors have been yielding an excessive number of unnecessary alams.
To reduce the number of unnecessary alarms, the licensee proposes to modify the present fire detection system for the diesel generator cells by replac-ing the present smoke detectors with a combination of Feat and flame detectors.
The heat detectors are of the fixed temperature / rate of temperature rise time type and are extremely reliable. The flame detectors are of the infrared type.
Both detector types are expected to initiate few unnecessary alarms in this application. Although smoke detectors respond faster than the heat detectors to most fires, this shortcoming is more than compensated for by the flame detectors that respond faster than smoke detectors to flaming fires, which is
.the type of fire expected. The proposed combination of heat and flame detectors is expected to provide a more depenoable service than that from smoke detectors, without sacrificing performance.
The staff has reviewed the propw Jnodification and associated Technical the licensee's appraisal of the poten-Specification changes and agrea 2'
tial problems with the existing y;.e of the detection system instruments.
The staff found the proposed changes, to be consistent with the guidance of SRP BTP 9.5-1 and NFPA 72D, Standard for the Installation, Maintenance and Use of Pro)rietary Protective signaling Systems, published by the National Fire 'rotection Association.
l The modifications proposed by the licensee for the fire detection systems in the emergency diesel-generator butidings and the corresponding changes to their operating license Technical Specifications are, therefore, acceptable to the staff.
3.0 ENVIRONMENTAL CONSIDERATION
S These amendments change a requirement with respect to installation or use of a facility component located within the restricted areas as defined in 10 CFR Part 20. The staff has determined that these amendments involve no significant increase in the amounts, and no significant change in the q
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3 types, of any effluents that may be released off site; and that there
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is no significant increase in individual or cumulative occupational i
radiation exposure. The Comission has previously issued a proposed finding that these amendments involve no significant hazards consider-ation, and there has been no public comment on such finding. Accord-inc'ay, these amendments meet the eligibility criteria for categorical e.clusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b),
no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CONCLUSION
The Commission made a proposed determination that this amendment involves no significant hazards consideration which was published in the Federal Register on February 1, 1989 at 54 FR 5161, and consulted with the State of North Carolina.
No public coments or requests for hearing were received, and the State of North Carolina did not have any comments.
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendments will not be inimical to the comon defense and security or to the health and safety of the public.
Principal Contributor:
N. B. Le Dated: March 20, 1989 i
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