ML16130A161

TMI Fhar Volume 1 (011) Chapter 6B

ML16130A161
Person / Time
Site:	Three Mile Island
Issue date:	04/11/2016
From:	Exelon Generation Co
To:	Office of Nuclear Reactor Regulation
Shared Package
ML16127A520	List: ML16127A469 ML16127A471 ML16127A474 ML16127A476 ML16127A477 ML16127A479 ML16127A480 ML16127A481 ML16127A483 ML16127A484 ML16127A485 ML16127A486 ML16127A491 ML16127A492 ML16127A493 ML16127A494 ML16127A495 ML16127A496 ML16127A498 ML16127A499 ML16127A500 ML16127A501 ML16127A502 ML16127A503 ML16127A504 ML16127A506 ML16127A507 ML16127A508 ML16127A510 ML16127A511 ML16127A512 ML16127A513 ML16127A514 ML16127A516 ML16127A517 ML16127A518 ML16127A519 ML16127A521 ML16130A150 ML16130A151 ML16130A152 ML16130A153 ML16130A154 ML16130A155 ML16130A156 ML16130A157 ML16130A158 ML16130A159 ML16130A161 ML16130A162 ... further results
References
TMI-16-035
Download: ML16130A161 (7)

Text

6-3FHAR6B.TMIRev27.docAuxiliary BuildingThis building covers elevations 261*-0, 271*-0, 281*-0, and 305*-0. All equipment is located in open areas or cubicles with open doorways. Allareas have floor drains with backwater valves to prevent cross flooding of adjacent compartments and equipment pads higher than doorthresholds to prevent the accumulation of standing water and prevent flooding of any floor mounted safety related equipment.Fire protection for all areas consists of hose reels at accessible locations with adequate hose length to reach the equipment to be protected foreach area. One location, AB-FZ-4 (penetration area-elev. 281*-0) is protected by an automatic pre-action sprinkler system and AB-FZ-7(cooling pump area-elev. 305*-0) is protected by an automatic pre-action sprinkler system, which forms a water curtain for the openpassageway to adjacent zone AB-FZ-6. Water from the floor drain system flows by gravity to the Auxiliary Building Sump located at elevation261*-0 where it is pumped to holding tanks. The expected water to be discharged from simultaneous operation of two (2) fire hoses is 250 gpm.The maximum expected flow from either of the two automatic pre-action sprinkler systems is about 400gpm. With an average of 30 floor drainsavailableon each Auxiliary Building elevation and assuming the drain system is running full, 1600 gpm can be removed to the sump.Charcoal filter plenums in the Aux and Fuel Handling Ventilation and Reactor Purge Systems (elev. 305*-0) contain deluge systems, the largestof which could discharge a total of 408 gpm. This water remains contained within each filter housing and is allowed to drainat a combined flowrate of 130 gpm through 55 separate 1 diameter check valves to open area floor drains adjacent to each filter housing. The main filter roomcontains 3 separate floor drains with a combined capacity of 160 gpm flowing full.The following lists major safety related components in the Auxiliary Building with a discussion of water damage prevention features:TABLE 6-1WATER DAMAGE STUDYAUXILIARY BUILDINGEQUIPMENTFIRE AREA/ZONETYPE OF FIRE SUPPRESSIONDISCUSSION1A & 1B Eng. Safeguards Valves andHeating Control CenterAB-FZ-6, AB-FZ-6aManual HoseDrip shields have been installed on the MCCs toprotect against water spray. More substantialprotection has been provided by a fire barrierconstructed between the two MCCs, thus preventingfire suppression activities at one MCC from affectingthe redundant train MCC.

6-3FHAR6B.TMIRev27.docAuxiliary BuildingThis building covers elevations 261*-0, 271*-0, 281*-0, and 305*-0. All equipment is located in open areas or cubicles with open doorways. Allareas have floor drains with backwater valves to prevent cross flooding of adjacent compartments and equipment pads higher than doorthresholds to prevent the accumulation of standing water and prevent flooding of any floor mounted safety related equipment.Fire protection for all areas consists of hose reels at accessible locations with adequate hose length to reach the equipment to be protected foreach area. One location, AB-FZ-4 (penetration area-elev. 281*-0) is protected by an automatic pre-action sprinkler system and AB-FZ-7(cooling pump area-elev. 305*-0) is protected by an automatic pre-action sprinkler system, which forms a water curtain for the openpassageway to adjacent zone AB-FZ-6. Water from the floor drain system flows by gravity to the Auxiliary Building Sump located at elevation261*-0 where it is pumped to holding tanks. The expected water to be discharged from simultaneous operation of two (2) fire hoses is 250 gpm.The maximum expected flow from either of the two automatic pre-action sprinkler systems is about 400gpm. With an average of 30 floor drainsavailableon each Auxiliary Building elevation and assuming the drain system is running full, 1600 gpm can be removed to the sump.Charcoal filter plenums in the Aux and Fuel Handling Ventilation and Reactor Purge Systems (elev. 305*-0) contain deluge systems, the largestof which could discharge a total of 408 gpm. This water remains contained within each filter housing and is allowed to drainat a combined flowrate of 130 gpm through 55 separate 1 diameter check valves to open area floor drains adjacent to each filter housing. The main filter roomcontains 3 separate floor drains with a combined capacity of 160 gpm flowing full.The following lists major safety related components in the Auxiliary Building with a discussion of water damage prevention features:TABLE 6-1WATER DAMAGE STUDYAUXILIARY BUILDINGEQUIPMENTFIRE AREA/ZONETYPE OF FIRE SUPPRESSIONDISCUSSION1A & 1B Eng. Safeguards Valves andHeating Control CenterAB-FZ-6, AB-FZ-6aManual HoseDrip shields have been installed on the MCCs toprotect against water spray. More substantialprotection has been provided by a fire barrierconstructed between the two MCCs, thus preventingfire suppression activities at one MCC from affectingthe redundant train MCC.