ML19289D446
| ML19289D446 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/01/1979 |
| From: | Utley E CAROLINA POWER & LIGHT CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| GD-79-573, NUDOCS 7903060330 | |
| Download: ML19289D446 (9) | |
Text
Cp&L Carolina Power & Light Company March 1, 1979 FILE: NG 3514(B)
SERIAL: GD-79-573 Office of Nuclear Reactor Regulation ATTENTION:
Mr. Albert Schwencer, Chief Operating Reactors Branch No. 1 United States uclear Regulatory Commission Washington, D. C.
20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 & 2 DOCKET NOS. 50-325 AND 50-324 LICENSE NOS. DPR-71 AND DPR-62 FIRE PROTECTION PROGRAM INFORMATION
Dear Mr. Schwencer:
Your letter of February 21, 1979 requested additional design details concerning certain fire protection modifications as discussed in Section 3.1 of the NRC's Safety Evaluation Report (SER).
In response to your February 21 letter, we are enclosing fifteen copies of the requested information. Part of the information for items 3.1.9, 3.1.24, 3.1.28 is contained in full size drawings, too large to facilitate reproduction for inclusion with this submittal. These drawings are being hand carried to the NRC staff by separate cover.
If reduced size copies of these drawings are needed for filing in the Brunswick dockets, please contact our staff to make the necessary arrangements.
As discussed with the NRC project manager, we believe a meeting between NRC and CP&L on March 9 would be beneficial to insure that we have provided all the information required to complete the staff's review of our fire pro-tection system.
If you require any further information prior to the meeting, please contact our staff.
Yours very truly,
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Senior Vice President Power Supply DLB/gts 7903060'53o 9
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3.1.2 Fire Retardant Coating & Fire Proofing 71ame retardant coatings will be applied te PVC coated conduit in the cable ac assways and to uncoated cable spreading room cables. Three-hour fire prooft will be provided for the steel beams in the diesel fuel oil supply tank bunkers.
CP&L Additicnal Information The function of the flame retardant coating applied to conduits and cable trays is to localize and limit fire damage to safety related cables in the cable accessways and cable spreading areas. The coating will prevent the impair-ment of function of both primary and redundant cables within the area in the event of a design basis fire by imparting non-propagating and self-extinguishing characteristics to the coated material. A flame retardant coating will be applied to the PVC jacketed flexible conduits in the cable accessways and to all cable trays in the cable spreading area. The flame retardant coatings utilized will be asbestos free "Flamemastic 77" as manufactured by Flamemaster Corporation of Sun Valley, California and/or "Quelpyri Mastic 703B" as manufactured by Quelcor, Inc. of Media, Pennsylvania. The coating will be applied by spraying or brushing to a thickness of 1/8 inch as measured when the coating is wet, which dries to a 1/16 inch thickness. The manufacturer's instructions for application will be followed and an inspector will make frequent chect:w of the coating thickness before the coating dries.
Derating of cable ampacity due to the heat insulating qualities of the flame retardant coating is not a significant consideration in this application because most of the cables in these areas are control cables, where heat dissipation is not a factor. Also, derating factors for flame retardant coating were applied in the sizing of power cables in the initial installation, since some portions of the cable runs (such as location where redundant channels are in physical proximity) were Flamemastic coated.
The three-hour fire proofing for the steel beams in the diesel fuel oil tank supply bunkers will be accomplished by a 9/16 inch thick coating of pyrocrete 102 on a galvanized metal lath attached to the exposed surface of the roof beams.
3.1.5 Remote Shutdown Capabilities Keylock remote isolation switches will be installed at the local diesel generator control panel for local control of diesel generators, diesel generator breakers, and breakers feeding 480 volt "E" bus unit substation. These =odifica-tions will co=plete the changes required to provide a safe shutdown capability independent of the cable spreading room and control room.
CP&L Additional Information The modifications required to adequately provide for remote shutdown capability in the event of a cable spreading room or control room fire are described in detail in our report, " Analysis of Safe Shutdown Capabilities,"
October 28, 1977.
3.1.9 Curbs and Barriers Curbs will be provided to limit the spread of oil, and barriers added to prevent flame impingecent on adjacent equipment for pump s at the intake s t ructure.
CP&L Additional Information The portions of drawing 9527-F-1303 pertaining to the service water building are attached for your information showing the enclosures around each of the service water pu=ps which are designed to prevent flame spreading or " impinge-ment" on adjacent safety-related equip =ent arising from a pu=p fire. Plan views and details are provided to show the intended installations. Between each of the pump bays, curbs consisting of 6-inch high angle resting on a 2 inch mini =um grout base (Section 5-5) are provided to prevent oil / water mixtures from spreading between pumps before it is channeled off into the existing drainage system.
The location of the two nuclear and three conventional service water pumps for each unit are noted on the drawing. As may be seen, the curbing between the two nuclear service water pumps extends past the drain locations, ensuring that an oil / water mixture resulting from the effects of co= bating a fire on one pu=p will not affect the ocher purp before being drained from the area. Details of the drainage system have been reviewed previously with regard to oil / water separation and drainage capabilities under the postulated fire conditions.
3.1.17 Communication Equipment Additional sound-powered communication sets will be obtained for use at various contrcl panels. Additionally, portable radio communication equip-ment will be provided for fire brigade use.
CP&L Additional Information Ten sound-powered phone sets have been purchased for exclusive use by the fire brigade. Additionally, walkie-talkies, of a similar design to those being used by the security forces, are being purchased for exclusive fire brigade use.
3.1.24 Battery Room Cables One safety division of battery cables vill be re-routed outside of the cable spreading room.
CP&L Additional Information Cables from Division II Batteries 1B and 2B are required fo-Remote Shutdown and are presently routed through the cable spreading rooms of both Units 1 and 2.
Secti7n VI of our October 28, 1977, report on Analysis of Safe Shutdown capability decails the cables that require rerouting as a result of our analysis.
Drawing Nos. 9527-F-3006 and 9527-F-30006 show the single-line diagra=s for the 125/250 volt DC system for Units 2 and 1, respectively.
The cabler that require re-routing are shown by the plant modification nu=ber APM77-370. The revised cable routings are shown on the following drawings:
Unit 1 Unit 2 9527-F-38025 9527-F-3825 9527-F-34047 9527-F-3448 9527-F-34048 9527-F-3447 9527-F-35026 9527-F-3526 9527-F-35027 The routings are designated as follows:
Unit 1 Unit 2 AAHl/BB AAKl/BB AAll/BB AALl/BB AAP AAMl/BB AAM2/BB As may be seen, these cables are routed out of the unit battery rooms into the turbine building breezeway and then into the unit reactor buildings until they are returned to their former pathway through the reactor building.
With this routing, a cable spreading room fire cannot cause a loss of redundant safety-related batteries.
3.1.28 Water Damage Protection Spray deflectors, shields, and curbs are being provided to protect safety-related equipment against water dsmage.
CP&L Additional Information Following detailed design of the sprinkler systems already installed or to be installed in the various plant areas, it has been determined that spray deflectors on the sprinkler heads are not required to protect safety-related equipment, but rather spray shields will be installed in areas where water damage could be postulated to occur. The design of these spray deflectors and the areas in which they will be installed are shown on attached Brunswick Plant drawings 9527-F-1305, 9527-F-1306, 9527-F-1319, 9527-F-25001, and 9527-F-2501, with the applicable plant modifications being PM77-347, -348, -349, -353, and 365.
Shields 2, 5, 6, 7, 8, 9, and 10 on the first two drawings have been deleted since the drawings were issued resulting from further analysis showing that the shields we ; not required. The equipment protected consists of instrument racks 1.s the reactor building, motor control centers in the SW building, and transformers in the DG building. No additional curbing is required in any of the areas since the equipment is either mounted on pads or suf ficiently above floor level to avoid flooding damage, and drainage of plant areas has been previously shown to be adequate for removal of water resulting from sprinkler activation.
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3.1.33 Diesel Generator Bus Load Modifications will be made to the diesel generator bus loads such that only two diesel generators are required to handle safe shutdown loads in a fire situation.
CP&L Additional Information The analysis of this event and the modifications required to ensure the capability of achieving safe shutdown utilizing only the two diesel gen-erators assigned to the same division is contained in Section V of our report,
" Analysis of Safe Shutdown Capability," October 28, 1977. The modifications contained therein will be made to ensure that safe shutdown can be achieved and maintained under the postulated fire condition.
3.1.34 Recirculation Pump Protection Heat detectors and an oil collection sy.sem will be installed at the reactor recirculation pumps inside the drywell.
CP&L Additional Information The design of this modification has not been completed.
In our letter of January 17, 1979, we requested a delay in the installation of this modification since the Brunswick units are continuing to operate with an inerted atmosphere.
If approval is obtained to operate with a deinerted containment atmosphere, we will submit the design details of this modification for your review prior to installing it and commencing deinerted operation.