ML21137A191

Byron/Braidwood Stations - Amendment 29 to Fire Protection Report, Chapter 2.0-2.3, Area Design Hazards Analysis-Redacted

ML21137A191
Person / Time
Site:	Byron, Braidwood
Issue date:	05/17/2021
From:	Haskell R Plant Licensing Branch III
To:	Rhoades D Exelon Generation Co
Haskell R
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References
EPID-L-2020-LRO-0086
Download: ML21137A191 (373)

Text

B/B - FPR AMENDMENT 29 DECEMBER 2020 Chapter 2.0 FPR Section / NRC Question Cross-Reference Guide*

FPR Section Question Number 2.4 10.55 10.56 10.57 Secu 10.58 10.59 40.167 40.184 40.185 40.186 40.187 40.188

• The complete test of the questions and responses given in the FSAR volumes entitled, Responses to NRC Questions.

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B/B - FPR AMENDEMENT 29 DECEMBER 2020 2.0 FIRE HAZARDS ANALYSIS 2.1 Introduction This section of the report contains the results of the Fire Hazards Analysis required by Sections A.2 and D.1(b) of Appendix A to Branch Technical Position APCSB 9.5-1. These results have been utilized in reevaluating the existing Fire Protection Program and in providing a basis for the comparison of this program with the guidelines of Appendix A. These results provide the information requested in Enclosure 2 to Mr. R. S. Boyd's letter to Mr. R. L. Bolger of September 30, 1976.

To satisfy the NRC requirement for a qualified fire protection engineer, the assistance and technical direction of Schirmer Engineering Corporation was utilized in the initial preparation of this fire hazards analysis.

2.1.1 Assumptions This fire hazards analysis was based on the following assumptions:

a. Fire areas are designated, based on the existing conditions, as those portions of a building which are separated from other areas by physical boundaries whose construction approaches that of a rated fire barrier. This is necessary since the plant did not incorporate the "fire-area" concept in its original design. Based on the relatively low fire loading which exists throughout the plant, the fire resistance of existing barriers was found sufficient. For areas of high fire loadings, upgrading of some barriers was performed in areas where postulated fires might have affected safety-related systems.

b. Fire areas are further subdivided into fire zones for purposes of this analysis.

Within the major plant structures, fire zone boundaries generally consist of walls, floors and ceilings of substantial construction. These boundaries could be qualified as 3-hour rated fire barriers if the openings and penetrations were properly protected with rated seals, dampers, doors, etc. Separation of fire areas into zones is also accomplished in some cases by elevation. This has been done for convenience in the analysis, in that it is questionable that a credible fire will spread between elevations, even though there are floor openings for stairwells and equipment removal hatches. This assumption is based on the relatively low fire loading that generally exists throughout those areas. For equipment located outdoors, and for outbuildings, fire zone boundaries are somewhat arbitrarily assigned based primarily on distance and separation from other equipment and buildings.

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c. The calculation of fire loads in each fire zone is accomplished by considering the effect of the potential total heat release on the total floor area. Although this does not account for combustible concentrations, it provides a more realistic picture of the effects of a potential fire than considering a maximum concentration in a limited area. The floor areas specified for each zone may be lower than the actual floor areas calculated from station architectural and structural design drawings. The floor areas listed in the FHA are used in the station combustible load by the listed floor area. Therefore, using a smaller floor area in the FHA will establish additional margin and create a more conservative heat load. Due to the spaciousness of a typical power plant, the total unimpeded area will function as a heat sink, to some extent, due to the temperature differentials that will be established by a postulated fire. This method still provides a relative indication of areas of combustible concentrations and a basis for evaluation of fire barrier adequacy and protective system design.

d. The arbitrary 3-hour rating of barriers has not been used as suggested in BTP CMEB 9.5-1 but rather the fire hazards analysis was conducted. Most fire barriers in the plant had been designated and ratings determine prior to the issuance of NRC fire protection guidance documents. The analysis approach taken was to examine the fire loading in each zone and based on the fire loading determine if the fire barriers are adequate. The factors considered when evaluating the adequacy of existing walls and floors, whether or not they carry a fire rating, include the following: 1) the materials of construction and design details of the wall or floor; 2) the combustible materials present in the area or zone, and the calculated fire loading; and 3) the potential impact of a fire in the area or zone on both safety-related and safe shutdown systems and components. A fire loading of less than 30,000 Btu/ft2, when the combustible material within the area or zone consists primarily of Class A combustibles, was assumed to be incapable of damaging exposed structural steel. The actual fire ratings of plant walls and floors are described in Section 2.3.

e. Transient fire loads are unidentified combustibles, generally given as being equivalent in Btu content to the fire load that would be contributed by the combustion of one or more 55-gallon drums of lubricating oil.

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f. The design-basis fire for each individual zone is the most severe fire evaluated in both the Fire Hazard Analysis (FHA) and the Safe Shutdown Analysis (SSA).

The design-basis fire is a non-mechanistic fire which is assumed to consume all combustibles within the fire zone. All unprotected equipment and cables which are subject to fire damage are assumed to be damaged. The design-basis fire concept dictates the design of protective measures. In most areas, the design-basis fire is not considered a credible event. Fire initiation is assumed, as is the failure of existing automatic protection systems as suggested in Brach Technical Position CMEB 9.5-1. Thus, the analysis is highly conservative.

g. Electrical cable tray fire propagation is limited by the provision of existing horizontal and vertical fire breaks. These breaks are described in Appendix 5.2.

h. In the analysis of fires affecting fluid systems, the fluid system pressure integrity is assumed to remain intact. Fire damage assumptions for mechanical system components are as follows: Tanks, heat exchangers, passive check valves, and piping are assumed to be unaffected by fire, and their ability to perform their design function, both during and following the fire, is assumed to remain unimpaired. Manual valves are assumed to remain operable following extinguishment of the fire and return of the valve body and handle to the normal ambient temperature. Motor operated valves are assumed to be electrically disabled by fires; however, the valve itself, and its handwheel and associated gear train are assumed to be undamaged. Motor operated valves are assumed to remain operable via local manual action following extinguishment of the fire and return of the valve body, handwheel and related components to the normal ambient temperature. Solenoid operated valves and air operated, solenoid-controlled valves are assumed to be electrically disabled by fires; these valves are assumed to fail to their loss of power/loss of air positions. If these valves are provided with manual operation capability, then they are assumed to remain operable via local manual action following extinguishment of the fire and return of the valve body and manual operator to normal ambient temperature. Pumps are assumed to be electrically disabled by fires; however, the pump body and fluid system pressure integrity are assumed to remain intact.

i. Within the limits of the separation criteria described in Appendix 5.2 and the protection afforded by the existing fire breaks, it is assumed that physical separation is maintained between redundant Class 1E circuits so that any fire is highly unlikely to affect its counterpart circuit.

j. Credit is taken for the tripping of breakers and other electrical protective devices to mitigate the consequences of electrical faults due to fires.

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k. When it is shown that a fire involving a safety-related system will not propagate to its redundant counterpart, the availability of the second system is assumed.

l. A fire is not considered to occur simultaneously with other accidents, events, or phenomena such as a design-basis accident. The capability exists to safely shut down the reactor in the event of any design-basis fire which may occur, as demonstrated in Section 2.4, "Safe Shutdown Analysis."

m. To demonstrate safe shutdown capability, it is sufficient to show that at least two physically separate and electrically isolated duplicate system components are available to perform each required function such that if a fire prevents any component or system in the fire zone from functioning, the second will perform that function. Safe shutdown capability following a fire in any fire zone of the plant is demonstrated in Section 2.4 Safe Shutdown Analysis.

2.1.2 Fire Hazards Analysis Methodology A systematic approach was established for the preparation of the Fire Hazards Analysis. Fire zones and areas were established based upon existing barriers.

The fire zones were then reviewed to identify fire hazards. Safety-related equipment and components which could be used for safe shutdown of the reactor were also identified. The combustible materials, the type of fire hazard, the quantity, the combustible loading which the material imposed on the area, and the fire detection and suppression capabilities for the area were then reviewed. The severity of the design-basis fire without any fire suppression activity was estimated based on the equivalent wood fire loading. Then the present fire barrier rating was compared with the fire severity for the subject zone to determine if the barrier was sufficient. Next the effects of the design-basis fire on the capability to safely shut down the reactor and the possible radioactive releases to the environment were evaluated. Finally, the distance required between two areas or pieces of equipment so that a fire could not propagate from one area to the other was checked.

Actual arrangement of the equipment and combustible materials in the area, location of doors, provisions of the ventilation system and the penetrations in the walls were considered. Existence of floor or equipment drains, curbs, and confining structures were considered to determine the effects of oil spills and fire-fighting water.

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B/B - FPR AMENDEMENT 29 DECEMBER 2020 2.1.3 Design Features and Criteria Features and criteria which are incorporated in the current station design which would assist in limiting the spread and adverse effect of a postulated fire are discussed below.

2.1.3.1 Station Layout The station general arrangement drawings, Figures 2.3-1 through 2.3-42, are plan and section views which indicate plant layout. It should be noted that the station layouts of Byron and Braidwood are 180 degrees out of phase with each other. The Fire Hazards Analysis was written based upon the Byron orientation.

Thus, the descriptions of walls for the Braidwood Station are opposite those of the Byron Station. For example, the Fire Barrier Description might discuss features of the west wall. For Braidwood, the description would be the same, but it would be for the east wall, etc. The station layout aids in the containment of fires by the utilization of area separation and segregation of combustibles. These figures do not necessarily give the exact locations of manual fire-fighting equipment.

2.1.3.2 Fire Protection System Description 2.1.3.2.1 Design Basis Plant fire protection is provided by a loop fire header system, fire hose reels, and portable fire extinguishers. At Byron, most of the hoses and associated hose reels have been removed per EC 626870 as the fire brigade utilizes high-rise hose packs transported to the scene. Selected areas are provided with fixed extinguishing systems which are designed in accordance with Nuclear Mutual Limited (NML) Property Loss Prevention Standards and the National Fire Protection Association (NFPA) Standards.

Fire hose stations, portable extinguishers and fixed automatic extinguishing systems are shown on the applicable figures in Section 2.3.

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B/B - FPR AMENDEMENT 29 DECEMBER 2020 2.1.3.2.2 Coverage A looped 12-inch yard main (14-inch at Braidwood) encircles the entire plant with fire hydrants spaced at approximately 250 feet intervals. This yard main can be isolated into at least four segments. The Turbine Building has a 12-inch loop header following the exterior walls of the Turbine Building. The Turbine Building is supplied by a 12-inch header which is fed from the yard main on both the Unit 1 and Unit 2 sides and from the Auxiliary Building loop header. The Auxiliary Building is fed from the yard main and from the cross connection to the Turbine Building mentioned above. The Reactor Containments and the Fuel Handling Building are fed from the Auxiliary Building 12-inch header. The Circulating Water Pump House or Lake Screen House is fed directly from the fire pump discharge header. Hose reels are located throughout the plant. Each hose reel contains 50 feet or more of 1-1/2-inch hose with appropriate nozzles and is supplied from a riser coming from one of the main headers. At Byron, most of the hoses and associated hose reels have been removed per EC 626870 as the fire brigade utilizes high-rise hose packs transported to the scene.

Zones where oil or other combustible materials are stored or handled are provided with a fixed fire protection system as follows:

a. Wet pipe sprinkler system:

1. Entire Turbine Building basement.

2. Entire Turbine Building grade floor.

3. Portions of Turbine Building mezzanine floor.

4. Clean/dirty oil tanks room.

5. Auxiliary boiler rooms.

6. Station Auxiliary Diesel Generator room.

7. Station Auxiliary Diesel Generator Oil Storage room.

8. Diesel Fire Pump room.

9. Portions of Radwaste/Service Building.

10. Auxiliary Building Main Stairwells and hatchways.

11. Containment pipe penetration areas.

12. Auxiliary building waste oil tank.

13. Waste Treatment building waste oil tank.

14. Receiving Building Warehouse.

15. Component cooling pumps on elevation 364 feet 0 inch.

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b. Deluge system:

1. Main power transformers.

2. Unit auxiliary transformers.

3. System auxiliary transformers.

4. Hydrogen seal oil units.

5. Charcoal filters (manual).

6. Turbine oil reservoir areas.

7. Turbine bearings.

c. Foam systems

1. Indoor diesel-generator oil storage tank rooms.

d. Halon 1301

1. QA vault (Service Building).

2. Upper Cable Spreading Area.

e. Carbon dioxide system

1. Portions of Byron River Screen House.

2. Diesel-generator and day tank rooms.

3. Upper and lower cable spreading areas.

4. Cable tunnels.

5. Diesel auxiliary feedwater pump and day tank rooms.

2.1.3.2.3 Operation The wet pipe sprinkler systems are actuated by individual fusible sprinkler heads which are set to fuse at a fixed temperature. Water flow detection devices are provided to give an alarm. The automatic deluge systems for the hydrogen seal oil units, turbine oil reservoir areas, and turbine bearings are actuated by fire detecting devices on a predetermined rise in temperature. The deluge systems for the main power transformers, unit auxiliary transformers, and system auxiliary transformers are manually actuated after a fire. Heat detection devices actuate on a predetermined rise in temperature and send an alarm to the fire alarm control panel and to the control room, and operators respond. These transformer deluge systems are automatically 2.1-7

B/B - FPR AMENDEMENT 29 DECEMBER 2020 actuated if either differential current or sudden pressure relay setpoints are reached. The entire area is deluged with water by the opening of the electrically operated deluge valve. Alarms and interlocks are provided to indicate operation of the system and to monitor the system for malfunctions. Local manual controls are also provided for each system.

The carbon dioxide systems are supplied from a 10-ton carbon dioxide storage tank. The automatic carbon dioxide fire suppression systems are actuated by fire detecting devices. Local pushbutton stations will also actuate the control valves.

The carbon dioxide system at the main station is supplied from a 10-ton capacity storage tank. The Byron River Screen House is supplied with a 2-ton storage unit. The 10-ton units are also used for generator purging. A description of this system is provided in Appendix 5.4.

The upper cable spreading area Halon systems are supplied from bottles located in the Turbine Building. The Halon supply is sized for the largest hazard. The QA vault system is supplied from bottles located in the service building. Halon 1301 is used in these systems.

The fire protection system takes its water from the forebay of the Byron Circulating Water Pump House or Braidwood Lake Screen House. Pressure is maintained in the system by two motor-driven jockey pumps of 100 gpm capacity each. If the jockey pumps are unable to maintain system pressure, the motor-driven main fire pump is actuated. If the motor-driven fire pump is unable to meet the demand, or is not functional, the diesel-driven fire pump will automatically start. Both main fire pumps are rated for 2,500 gpm at 388 TDH.

The diesel-driven fire pump is battery started and does not rely on external electrical power for operation.

In the event both main fire pumps should be out of service, water could still be supplied via the Essential Service Water system tie-in located in the Auxiliary Building. The tie-in is Seismic Category I.

2.1.3.2.4 Fire Protection System Description The description of the Byron/Braidwood Stations Units 1 and 2 Fire Protection System is contained in Appendix 5.4.

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B/B - FPR AMENDEMENT 29 DECEMBER 2020 2.1.4 Generic Notes The following items are generally applicable to most fire zones, as listed in Section 2.3. They are listed under the heading in which they were utilized for convenience and brevity. The figures listed at the beginning of each zone's description illustrate that zone. Table 2.2-2 lists figures and equipment.

Electrical figures showing the routing of ESF cable trays in the auxiliary and containment buildings are included in the report.

2.1.4.1 Fire Barrier Descriptions

a. Structural design elements are as outlined in Section 2.3 of this report. The material descriptions as follows apply to these structural elements:

1. The concrete used in the construction of walls, floor slabs and roof slabs, and as a fire-resistant covering of embedded steel beams and columns, is of a mix which includes a proportion or carbonate-type aggregate. This aggregate is a factor in determining the fire resistance of these structural elements.

2. Hollow concrete masonry units used in the construction of walls and as a fire-resistant covering of columns or beams conform to the applicable requirements of ASTM C 90 for Type I Grade "N" moisture-controlled units.

Units are formed from a mix containing lightweight, expanded slag aggregate.

This aggregate is a factor in determining the fire resistance of walls or the masonry covering of steel members.

3. Solid concrete masonry units used in the construction of walls and as a fire-resistant covering of columns or beams are 100% solid and conform to the applicable requirements of ASTM C-145, Grade N, Type I moisture-controlled units. Units are formed from a mix containing normal weight aggregate and have a density of 140 PCF. This aggregate is a factor in determining the fire resistance of walls or a masonry covering of steel members.

4. Except for several Service Building walls, masonry units are laid in a standard running-bond pattern with 3/8-inch thick horizontal and vertical joints of type "M" mortar. (This mortar conforms to ASTM C-270.) Heavy-duty steel truss-type continuous reinforcing ties are provided in the horizontal joints at 16 inches on centers vertically.

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5. Portions of masonry walls indicated as "removable areas" consist of solid concrete masonry units laid without mortar in a running bond pattern to completely fill the designated area of the permanent walls. These portions are braced on both faces of the wall by a system of steel columns, beams and steel grating panels, which also provides a resistance to seismic forces.

6. Firestops have been provided to seal the tops of firewalls as described in Section 2.3. The Thermafiber Safing Insulation used as the firestop material is a mineral fiber semirigid felt and, as installed, provides a fire resistance of three hours. This resistance is determined from results of fire tests of similar assemblies as conducted by the United States Gypsum Company.

7. All door openings in fire walls have been provided with self-closing fire doors as described in Section 2.3. The fire rating of the doors used is in all cases equivalent to the rating of the firewalls in which they are used. Many of these doors, including their frames and hardware, have been tested by Underwriters' Laboratories, Inc. of Chicago, Illinois. These doors are provided with a UL label, and are referred to in the text as Label "A" (or "B") doors.

Other doors have not been tested by Underwriters' Laboratories, Inc. and thus do not have UL labels. These doors are referred to in the text as "fire doors of label construction."

These doors of label construction are constructed of the same materials and to the same standards as the UL labeled doors. The hardware used with these doors is of the same high quality as that used with UL labeled doors.

The installation of the door assembly in the firewall is identical to that of the UL labeled doors. Their fire resistance is thus equivalent to that of the doors with the UL label.

UL labels can only be applied to door assemblies (i.e., door plus frame and hardware) which have been previously tested by the Underwriters' Laboratories, Inc. At Byron/Braidwood, plant specific situations and requirements sometimes result in the installation of fire doors in a configuration which has not been tested by UL. Examples of such occurrences include:

a. Doors Larger Than UL Listed Sizes with Single Point Latches/Locks.

Doors were manufactured at a height of 8 feet 6 inch at a time when UL had not approved doors greater than 8 feet 0 inch in height with single point latches. UL procedures have now been approved for doors up to 10 feet 0 inch in height.

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b. Doors with Modified Two-Point Latches and Electric Strikes.

The basic two-point latch and three-point lock system used on the project for double doors was a UL approved device. Electric strikes were added to these devices for security purposes. It was therefore necessary to modify the two-point latch by off-setting its vertical rods to accommodate the strike which was installed in the inactive leaf. Although physically modified, the actual function of the two-point latch remained unchanged.

The three-point lock remained intact without any physical or functional modification.

c. Fixed Doors Which Function as Fire Panels.

The function of these doors is equipment removal and not personnel ingress or egress. Due to nearby system locations these doors cannot be opened on hinges but must be completely detached and removed.

Servicing is infrequent and the doors are generally in a closed position secured to a four-sided frame by 1-1/2 pairs of ULs listed butts on both jamb sides of the frame. Therefore, other fire hardware such as latches, and closers are not necessary for fixed fire panels.

d. Door Frames with Applied Inverted Stops.

Some of the door frames installed in concrete openings are detailed with an applied door stop to conceal expansion anchor fasteners on the frame.

This stop is inserted into a 14-gauge steel-formed rabbet in the frame and fastened with sheet metal screws at UL standard spacing. All frames are also filled with grout.

e. Magnetic Position Switches Welded to Frames.

Magnetic electric position switches are welded to the security fire door assemblies. These switches are welded to the top of the door and frame near the door closers.

f. Sheet Metal Electrical Raceways Welded to Doors.

Raceways are installed on double doors which have electric strikes. The raceway is welded to the face of the inactive leaf. This application is preferred to routing wiring through the inside of the door which would have required cutting of the door stiffeners.

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g. Holes in Frames for Electrical Conduit Penetrations.

A cutout is made of the top corner of security/fire door frames which allows power transfer from one side of the door to the other. These cutouts are closed by welding a metal closure plate of equivalent gauge thickness across the opening. A hole is drilled in this plate to facilitate the electrical conduit connection.

h. Security Lock Guards.

As a security feature, Folger Adams 310-2-3 astragal lock guards are applied to security/fire door assemblies to prevent tampering with the lock bolt keeper. These lock guards are attached to the doors using 2-1/4 machine screws fasteners through the secure side of the door.

i. Door Pulls Added to Facilitate Closing.

Door pulls have been added to some fire doors to facilitate closing the door against differential air pressure that may exist across the fire barrier.

The door pull handles are installed with through-door threaded sleeves, located where they will not affect the capability of the door to close and latch or resist deflection due to the heat of a fire. Because this hardware may not be UL listed, doors so modified are considered "fire doors of label construction."

j. Cardboard Shims for Door Alignment.

In accordance with fire door supplier recommendations, some labeled fire doors may have been aligned with the use of cardboard shims in the door hinge. The use of the shims ensures proper alignment of the door. The presence of the cardboard shim does not affect the capability of the door to close and latch or impact the fire endurance rating of the labeled door.

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k. Doors Designated to Resist Blast Intrusion Blast Resistant Doors are installed in the vestibules of some critical access locations such as the Containment Building Emergency Airlocks.

The doors have a steel framework and are filled with concrete. The doors have a single operating handle that latches multiple locking bolts into the door frame.

Some locations where fire doors of label construction have been used are described in Section 2.3. However, fire doors of label construction that are configured as described above may not be specifically identified in Section 2.3 in all cases.

The location of these doors is no longer specified in Section 2.3 since they are considered equivalent to UL label doors.

The Underwriters' Laboratories, Inc., do not "approve" the products of any manufacturer. The UL label on a product only indicates that the product was tested by UL and met certain performance standards. All the fire doors installed at Byron/Braidwood are constructed of high-quality fire-resistant materials and are manufactured and installed to high standards which assure that they possess a fire rating equivalent to that specified for the barrier in which they are installed.

8. Elevator shaft doors are 1-1/2-hour fire rated doors that have been approved by Underwriters' Laboratories or by the Factory Mutual System of Norwood, Massachusetts.

9. Precast concrete channel roof slabs are of Portland cement and lightweight aggregate and conform to the requirements of the American Concrete Institute Document 525-63. Slabs are of a "channel" design, 24 inches wide, having 3-1/2 inch-thick reinforced concrete legs, and a 1-1/4 inch-thick concrete web reinforced with steel welded wire fabric, and are anchored to supporting steel members with metal clips. Joints between slabs are sealed on the upper side with high-melting-point asphaltic cement.

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10. The roof covering for all roofs of the plant is a four-ply built-up pitch, felt, and gravel roofing system over preformed board insulation, except as noted below. This roof covering complies in all respects with the applicable requirements of the Underwriters' Laboratories Inc. (UL) listing for a "Class A" rating. As stated in the UL Building Materials Directory, (1975) this rating applies to roof coverings which are effective against severe fire exposures and under such exposures "are not readily flammable and do not carry or communicate fire; afford a fairly high degree of fire protection to the roof deck; do not slip from position; possess no flying brand hazard; and do not require frequent repairs in order to maintain their fire resistive properties."

11. At Braidwood Station, the Turbine Building roof covering is an asphalt built-up roofing system and the Service/Radwaste Building roof covering is a single-ply membrane, fully adhered roofing system. These roofing systems comply in all respects with the applicable requirements of the UL listing for a Class A rating as indicated in the 1995 UL Roofing Materials and System Directory.

12. At Byron Station, the turbine building, TSC, and EM shop building roof coverings are a block-ballasted, single-ply, roofing system over insulated boards. The roofing system complies in all respects with the applicable requirements of the UL listing for a Class A rating as indicated in the 1995 UL Roofing Material and System Directory.

a. HVAC penetrations in horizontal fire barriers consist of either two UL 1-1/2 hour fire dampers mounted in series or one 3-hour fire damper. These fire dampers are of the solid steel curtain type with interlocking blades and are of galvanized steel construction. The dampers shall close when the electrical thermal links receive an actuation signal or when the temperature exceeds the rating of the link.

b. In the fire hazards analysis portions of this report, Section 2.3, the assumption is made that all fire dampers are 1-1/2 hour labeled unless otherwise noted.

c. Locations of all rated fire barriers are shown symbolically on the drawings in Section 2.3. These drawings are not intended to show the detailed boundaries of rated fire barriers. They are as accurate as possible for drawings of this small scale. The text in Section 2.3 describes the fire barriers in more detail. Fire barrier location drawings,

d. which are not included in the report, have been prepared and define explicitly the location and boundaries of all rated fire barriers in the plant 2.1-14

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13. Within the major plant structures, fire areas and fire zones are designated using the assumptions of FPR Section 2.1.1 and the methodology described in FPR Section 2.1.2. Walls/ceilings/floors defining these fire zones may be non-fire rated, based upon the Fire Hazard Analysis performed for the Fire Zone. Non-fire rated walls/ceilings/floors are typically comprised of fire rated construction (poured concrete and/or concrete block) but are considered non-fire rated due to unsealed openings in the barrier, such as equipment hatches, stairwells, and other penetrations. Selected limited areas of the non-fire rated barrier may be sealed with fire rated seals to separate and protect specific equipment from a postulated fire on the other side of the barrier and/or to prevent the propagation of fire through the barrier from a specific hazard to the adjacent fire zone. These fire rated seals in non-fire rated walls/ceilings/floor will be repaired as necessary (following maintenance on penetrating systems or seal damage) to maintain the Fire Hazard Analysis evaluations of the barrier.

14. Firewall extension panels with a minimum 2-hour fire integrity rating have been added to the firewalls that separate the 1E and 1W main power transformers from each other, from the adjacent unit auxiliary transformers 141-1/2, and from system auxiliary transformer 142-1. The panels consist of modular sections of tube steel frames with fire resistant sheeting material (FBI Board) attached to its face. The fire-resistant sheeting material is a composite board manufactured with a fiber-reinforced cementitious core and outer facings of perforated galvanized steel that are mechanically bonded to each surface of core material.

Firewall extension panels with a minimum 2-hour fire integrity rating have been added to the firewalls that separate the 2E and 2W main power transformers from each other, from the adjacent unit auxiliary transformers 241-1/2, and from system auxiliary transformer 242-1. The panels consist of modular sections of tube steel frames with fire resistant sheeting material (FBI Board) attached to its face. The fire-resistant sheeting material is a composite board manufactured with a fiber-reinforced cementitious core and outer facings of perforated galvanized steel that are mechanically bonded to each surface of core material.

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15. Referencing EC #404746, the configuration of unprotected auxiliary/secondary steel attached to protected structural steel is an acceptable configuration as the associated structural steel will maintain its required 3-hour fire barrier rating.

Section 2.3 describes the fire barriers in more detail. Fire barrier location drawings, which are not included in the report, have been prepared and define explicitly the location and boundaries of all rated fire barriers in the plant.

2.1.4.2 Safety-Related Equipment For the purpose of this report, safety-related equipment is defined to be any and all equipment that is Safety Category I. All safety-related equipment is not necessary to shut down the reactor. All equipment and instrumentation identified as being required to safely shut down the plant are listed in Section 2.4, "Safe Shutdown Analysis." Details of this classification system are indicated in Appendix 5.3.

2.1.4.3 Protection Criteria and Measures

a. Physical separation of redundant divisions of cables is accomplished by use of cable raceway system as described in Appendix 5.2.

b. Table 2.2-3 lists the fire protection system(s) available in each fire zone.

c. Amendment 9 includes revision to the "Protection Criteria and Measures" section of all fire zones to delete reference to equipment provided with Appendix R emergency lighting (i.e., 8-hour battery packs). Appendix R emergency lighting is shown on lighting drawings for each plant. These drawings are the appropriate design document to reference.

2.1-16

B/B - FPR AMENDEMENT 29 DECEMBER 2020 2.1.4.4 Combustible Materials

a. Cables do not use PVC insulation or jacketing. The cables can be self-extinguishing and non-flame propagating. For electrical equipment within the NSSS scope of supply, Westinghouse specified noncombustible or fire retardant material and conducts vendor-supplied specification reviews of this equipment which includes assurance that materials will not be used which may ignite or explode from an electrical spark, flame, or from heating, or will independently support combustion. These reviews also include assurance of conservative current carrying capacities of all instrument cabinet wiring, which precludes electrical fires resulting from excessive overcurrent (I2 R) losses. For example, wiring used for instrument cabinet construction has Teflon or Tefzel insulation and is adequately sized based on current-carrying capacities set forth by the National Electric Code. Braided sheathed material is noncombustible.

b. Combustibles associated with the insulation inside each motor are negligible and are not considered.

c. Combustibles associated with cable insulation of conductors that are in rigid conduit are negligible and are not considered. The only combustibles considered in any of the control panels, switchgear, and motor control centers is the cable insulation. Any other combustibles that may be present in these panels is considered negligible and, therefore, not counted

d. The combustion characteristics of both the cable insulation and jacketing materials are the same.

e. Permanently installed low voltage power cords, which are not assigned cable numbers in the SLICE cable management database, (or equivalent database) are not described in the FPR Fire Hazards Analysis and are not considered as a contributor to fire loadings. These cords are not heavily concentrated throughout the plant and the fire loading attributed to these cords is insignificant.

f. Each cell of the non-safety-related batteries at both stations are enclosed with a plastic jar and cover. The plastic jar and cover for each cell weighs approximately 10-1/4 pounds. The Btu value of the plastic is considered to be 14,600 Btu/lb. Therefore, it is assumed that each cell of the battery will have a rating of 149,650 Btu.

2.1-17

B/B - FPR AMENDEMENT 29 DECEMBER 2020

g. Each cell of the 125-Vdc safety-related batteries at Braidwood is encased in a polycarbonate jar weighing 12 pounds and a flame-retardant PVC cover weighing 1.5 pounds. The Btu values for the jar and the cover are 13,310 Btu/lb. and 8,800 Btu/lb., respectively. Therefore, each cell has a rating of 172,920 Btu.

Each cell of the safety-related 125-Vdc station batteries at Byron consists of a polycarbonate cell jar with a flame-retardant PVC cover with a total heat content of 172,920 Btu/cell.

h. The specific heat loads of various combustibles are as follows:

Material Heat Content Lubricating Oil 155,000 Btu / gal.

Transformer Oil 135,700 Btu / gal.

Diesel Fuel Oil 156,000 Btu / gal.

Cable Insulation 10,990 Btu / lb.

Wood 9,100 Btu / gal.

Battery Casing (Acrylic Plastic) 14,600 Btu / lb.

Battery Casing (Polycarbonate) 13,310 Btu / lb.

Battery Casing (Transparent Fire-Retardant PVC) 8,800 Btu / lb.

Battery Rail Covers (Fire Retardant Polyethylene) 20,020 Btu / lb.

Battery Cell Spacers (PVC Blend) 17,860 Btu / lb.

Flex Connections 11,000 Btu / lb.

HEPA Filters 191,000 Btu / filter Prefilters 62,700 Btu / filter Charcoal Filters 15,000 Btu / lb.

Duct External Insulation 2,500 Btu/lb.

Internal Duct Lining (Gasketing) 19,600 Btu / lb.

Mixing Box Blanket (Silencing Material) 11,600 Btu / lb.

Acetone 87,500 Btu / lb.

Methanol 64,500 Btu / gal.

Chloroethene 65,300 Btu / gal.

Cloth (Cotton) 8,800 Btu / lb.

Rubber 19,700 Btu / lb.

Hydrogen 325 Btu / ft3 Acetylene 1,500 Btu / ft3 Polyurethane 13,600 Btu / lb.

Ethylene Glycol 76,100 Btu / gal.

Hydrazine 186,500 Btu / gal.

Propanol 96,700 Btu / gal.

Grease 161,600 Btu / gal.

19,000 Btu / lb.

2.1-18

B/B - FPR AMENDEMENT 29 DECEMBER 2020 Material Heat Content Polypropylene 20,000 Btu / lb.

Propane 21,700 Btu / lb.

Methane 23,900 Btu / lb.

Paper 8,500 Btu / lb.

1. 2 Fuel Oil 146,000 Btu / gal.

Cellulose Filter 7,600 Btu / lb.

Benzene 131,900 Btu / gal.

Paint / Paint Thinner 139,382 Btu / gal.

Polyethylene 20,000 Btu / lb.

Polyvinyl Chloride (PVC) 7,730 Btu / lb.

Nylon 15,900 Btu / lb.

Acrylonitrile Butadiene Styrene (ABS) 15,200 Btu / lb.

Fiberglass-Reinforces Plastic (FRP) 14,000 Btu / lb.

Neoprene 11,500 Btu / lb.

Thermo-Lag Fire Barrier 7,000 Btu / lb.

Lead Shielding Covering (vinyl-polyester) 4,883 Btu/ft2

i. Those combustibles with a flame spread less than 25, though described and listed in the combustible sections, are ignored when calculating the fire loading.

This is a partial listing of those combustibles used:

Smoke Flame Material Fuel Spread Developed Contribution Thermafiber Mineral Insulation 15 0 0 Grograin II acrylic carpeting 15 10 25 Ceiling acoustical tiles 15 15 15 Initial Bigelow Grograin II carpet installation has a Class A rating in accordance with ASTM E 84 Tunnel Test as shown above. All future carpet installations and replacement shall have a Class I rating in accordance with the following criteria:

1. Flammability: ASTM E 648/Standard Test Method for Critical Radiant Flux of Floor Covering Systems using a Radiant Heat Energy Source.

Critical Radiant Flux - 0.45 w/cm2 or greater

2. Ignition: DOC-FF1-70/Tablet Test for Determining the Ease-of-Ignition of Carpet.

2.1-19

B/B - FPR AMENDEMENT 29 DECEMBER 2020

3. Smoke Density: ASTM E 662/Standard Test Method for Specific Optical Density of Smoke Generated by Smoke Materials. Smoke Developed - 450 or less Dm (corr.)

j. The insulation on piping was not considered in the heat load calculation because of its low "Btu" content, and the dispersed nature of this loading throughout the station.

k. The lubricant contained in motor-operated valves was not considered because of the limited number of those valves which contained a significant amount of lubricant and their spatial separation within the plant.

l. Combustible foam isolation materials are utilized in several circumstances within the plants to isolate expansion joints. The following typical situations where polyurethane foam is used have been identified and are described below:

1. Inside the containment at Elevation 377 feet 0 inch there is a 2-inch isolation joint between the fill slab and the containment steel liner plate. The exposed surface of this joint at Elevation 377 feet 0 inch is protected by a 3-hour fire rated joint system.

2. There is a 2-inch joint between walls and slabs of the auxiliary building abutting with the exterior of the concrete containment. This joint is provided to allow movement of the structures during an earthquake. Where these joints are filled with polyurethane foam, they are typically protected with a 3-hour fire rated joint system.

3. There are abutting walls and slabs on the outside of the containment for the buttress enclosures and the emergency air lock where the isolation joint is filled with polyurethane foam and sealant. For some of these cases, the polyurethane foam is not protected by a fire-resistant joint material. However, these areas are external to the containment and auxiliary building and are not included in the fire zones in the fire protection report. There is no safe shutdown equipment in these areas. Thus, the presence of small amounts of combustible joint materials in these locations is not of concern.

2.1-20

B/B - FPR AMENDEMENT 29 DECEMBER 2020

4. There are concrete partition walls in the auxiliary building which have a 1-inch isolation gap between the top of the wall and the underside of the ceiling slab, which may be filled with unprotected polyurethane foam and sealant. Where present, this material tends to be located in such a way as to present minimal exposure to roof contents.

In summary, combustible foam isolation materials are not included in the calculated combustible inventories for one or more of the following reasons:

a) it is used in exterior structures, or b) it is protected with a fire-rated joint system, or c) it is present in small quantities, located in relatively unexposed positions, and is dispersed throughout the rooms or zones, rather than concentrated, and thus presents no significant hazard to the room contents.

m. A blend of Number 1 and Number 2 diesel fuel oil may be stored or used in the diesel generator engines and diesel-driven pumps at Byron and Braidwood.

According to NFPA 30, Flammable and Combustible Liquids, and FPR Appendix 5.5, Glossary of terms, any liquid that has a flash point at or above 100 Degrees Fahrenheit (37.8 Degrees Celsius) and below 140 Degrees Fahrenheit (60 Degrees Celsius) is classified as an NFPA Class II Combustible Liquid. According to NFPA 325M, Fire Hazard Properties of Flammable Liquids, Gases, and Volatile Solids, flash point for Number 1 diesel fuel oil is 100 Degrees Fahrenheit and the flash point for Number 2 diesel fuel oil is 125 Degrees Fahrenheit. Thus, a blend of Number 1 and Number 2, regardless of its blended percentage/proportion, is classified as Class II Combustible Liquid. In addition, heat content (Btu/gal) of Number 2 diesel fuel oil is higher than Number 1 diesel fuel oil. Thus, it is conservative to use straight Number 2 diesel fuel oil instead of blended fuel for combustible loading since Number 2 diesel fuel oil provides bounding values for Class II Combustible Liquid.

2.1.4.5 Fire Loading

a. Fire loading has been classified as low, moderate or high. Guidance from the NFPA Handbook was used in developing the low, moderate, and high categories.

The three classifications are defined as:

i. Low - Fire loading does not exceed an average of 100,000 Btu/ft2.

ii. Moderate - Fire loading exceeds an average of 100,000 Btu/ft2 but does not exceed 200,000 Btu/ft2.

iii. High - Fire loading exceeds an average of 200,000 Btu/ft2 2.1-21

B/B - FPR AMENDEMENT 29 DECEMBER 2020 2.1.4.6 Extinguishing and Detecting Capabilities

a. Hose station locations have been finalized and are shown as close as possible to their actual locations on the figures in Section 2.3. Hose lengths and nozzle types are listed in Figure M-52, Sheets 11 and 12 located at the end of Appendix 5.4 in Volume II of this report.

b. Portable fire extinguisher locations are indicated symbolically in the figures in Section 2.3. These drawings are not intended to show the actual number and location of extinguishers, but rather to indicate those areas in which fire extinguishers are available. Information on actual numbers, type, and locations of portable extinguishers is maintained at the site. The type of portable extinguishers used depends on the hazards which they may be used upon.

c. Fire detector locations are indicated symbolically in the figures in Section 2.3.

These drawings are not intended to show the actual number and location of fire detectors, but rather to indicate those areas which are protected by automatic detection systems. Actual numbers and locations of fire detectors are shown on installation drawings which are not included in this report.

2.1.4.7 Design-Basis Fire A design-basis fire of total floor loading less than 1000 Btu/ft2 is considered minimal severity.

2.1-22

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.2 AREA DESIGNATION The station is divided into fire areas as listed in Table 2.2-1. The area designation was based on Subsection IV.D, "Guideline for Specific Plant Areas" of Appendix A of BTP APCSB 9.5-1. The station is divided into the zones listed in Tables 2.2-2 and 2.2-3 and shown in Figures 2.2-1 through 2.2-30. The numbering system of Tables 2.2-2 and 2.2-3 is used throughout this report.

The digits before the decimal point of the zone designation corresponds to the numbers listed in Table 2.2-1 and are termed fire areas. In most cases, individual areas are further subdivided. In general, fire areas and zones are separated from each other by walls or barriers of noncombustible construction, or by distance. Numbering of fire zones within a fire area is generally sequential from the zone at the lowest elevation to the zone at the highest elevation; the numeral after the decimal point is this level/zone designation. When an elevation has numerous fire zones, these are usually identified by a letter after the second digit. For example, the Unit 1 Containment Spray Pump Room is located on level 11.2 and is identified as Fire Zone 11.2E-1. The numeral after the dash in the zone number indicates with which unit the zone is associated. For example, Fire Zone 1.1-1 is the zone at the lowest elevation in the Unit 1 Primary Containment.

Some fire zones are associated with, or contain equipment from, both units. For example, Zone 2.1-0 is the Control Room, which serves both units.

Examples:

Fire Zones: 2.1 Control Room 11.3B Residual Heat Removal Heat Exchanger 2A Room Levels: 11.3 - Auxiliary Building zones, level 364 feet 0 inch Fire Areas: 2 - Control Room areas 11 - Auxiliary Building 2.2.1 Tabular Listing of Fire Zones Table 2.2-2 lists each fire zone by name and number. The fire protection figure numbers for each zone are listed under the appropriate column in the table. The safety-related equipment in each zone is listed. The radioactive material in each zone is also listed.

2.2.2 Tabular Listing of Fire Hazards Data by Fire Zone Table 2.2-3 lists each fire zone by name and number. For each zone the resultant fire loading classification, the type of fire detection provided and the fire suppression systems/equipment available for each zone are listed.

2.2-1

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-1 PLANT FIRE AREAS 1.0 Primary Containment 2.0 Control Room Areas 3.0 Cable Spreading Rooms 4.0 Plant Computer Rooms 5.0 Switchgear Areas 6.0 Remote Safety-Related Panels (Not Used) 7.0 Station Battery Room Areas 8.0 Turbine Building 9.0 Diesel-Generator Areas 10.0 Diesel Fuel Oil Storage Areas 11.0 Auxiliary Building 12.0 Fuel Handling Building 13.0 QA Record Storage Area 14.0 Radwaste Areas 15.0 Decontamination Areas (Not Used) 16.0 Safety-Related Water Tanks 17.0 Cooling Towers (Byron Station) 18.0 Miscellaneous Areas 2.2-2

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 1.1-1 2.3-10, 1 of 4 Reactor coolant pressure This zone is a high Unit 1 Containment 2.3-12, 1 of 4 boundary, essential radiation area Missile Shield Area 2.3-13, 1 of 4 cabling during reactor 2.4-14, 1 of 4 operation 2.3-15 2.3-26, 1 of 2 1.1-2 2.3-10, 3 of 4 Reactor coolant pressure This zone is a high Unit 2 Containment 2.3-12, 3 of 4 boundary, essential radiation area Missile Shield Area 2.3-13, 2 of 2 cabling during reactor 2.3-14, 3 of 4 operation 2.3-15 2.3-21, 2 of 2 2.3-26, 2 of 2 1.2-1 2.3-12, 1 of 4 Fan coolers, essential This zone is a high Unit 1 Annular Area 2.3-13, 1 of 2 cabling radiation area 2.3-14, 1 of 4 during reactor 2.3-26, 1 of 2 operation 1.2-2 2.3-12, 3 of 4 Fan coolers, essential This zone is a high Unit 2 Annular Area 2.3-13, 2 of 2 cabling radiation area 2.3-14, 3 of 4 during reactor 2.3-21, 2 of 2 operation 2.3-26, 2 of 2 1.3-1 2.3-8, 1 of 4 Containment spray This zone is a high Unit 1 Containment 2.3-10, 1 of 4 system, Accumulator radiation area Upper Area 2.3-12, 1 of 4 tanks, reactor coolant during reactor 2.3-26, 1 of 2 pressure boundary, fan operation cooler ductwork 1.3-2 2.3-8, 3 of 4 Containment spray This zone is a high Unit 2 Containment 2.3-10, 3 of 4 system, Accumulator radiation area Upper Area 2.3-12, 3 of 4 tanks, reactor coolant during reactor 2.3-21, 2 of 2 pressure boundary, fan operation 2.3-26, 2 of 2 cooler ductwork 2.1-0 2.3-8, 1 of 4 Control panels; HVAC None Control Room 2.3-8, 3 of 4 supply air diffusers, return 2.3-22, 2 of 2 air registers 2.3-25, 1 of 2 2.3-25, 2 of 2 2.1-1 2.3-8, 1 of 4 None None Record Storage Room 2.2-3

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 2.1-2 2.3-8, 3 of 4 None None Record Storage and Toilet Room 3.1-1 2.3-12, 1 of 4 Essential cable pans None Unit 1 Cable Tunnel 2.3-25, 1 of 2 3.1-2 2.3-12, 3 of 4 Essential cable pans None Unit 2 Cable Tunnel 2.3-25, 2 of 2 3.2-0 2.3-9 Essential cable pans None Auxiliary Building El. 2.3-22, 2 of 2 auxiliary building 439' ventilation system 3.2 A-1 2.3-9 Essential cable pans None Unit 1 Non segregated 2.3-25, 1 of 2 Switchgear ventilation Bus Duct Area system ductwork 3.2 A-2 2.3-9 Essential cable pans None Unit 2 Non segregated 2.3-21, 1 of 2 Switchgear ventilation Bus Duct Area 2.3-25, 2 of 2 system ductwork 3.2 B-1 2.3-9 Essential cable pans None Lower Cable 2.3-25, 1 of 2 Spreading Room, Zone B-1 3.2 B-2 2.3-9 Essential cable pans None Lower Cable 2.3-25, 2 of 2 Spreading Room, Zone B-2 3.2 C-1 2.3-9 Essential cable pans None Lower Cable 2.3-22, 2 of 2 Spreading Room, 2.3-25, 1 of 2 Zone C-1 3.2 C-2 2.3-9 Essential cable pans None Lower Cable 2.3-25, 2 of 2 Spreading Room, Zone C-2 3.2 D-1 2.3-9 Essential cable pans None Lower Cable 2.3-22, 1 of 2 Spreading Room, Zone D-1 2.2-4

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 3.2 D-2 2.3-9 Essential cable pans None Lower Cable 2.3-22, 2 of 2 Spreading Room, Zone D-2 3.2 E-1 2.3-9 Essential cable pans None Division 11 Cable Riser, Lower Spreading Room 3.2 E-2 2.3-9 Essential cable pans None Division 21 Cable Riser, Lower Spreading Room 3.3 A-1 2.3-7 Essential cable pans; None Upper Cable HVAC ductwork, gaskets, Spreading Room, misc. accessories; Zone A-1 makeup air filter and fan; motor-operated damper; flexible connections 3.3 A-2 2.3-7 Essential cable pans; None Upper Cable HVAC ductwork, gaskets, Spreading Room, misc. accessories; Zone A-2 makeup air filter and fan; motor-operated damper; flexible connections 3.3 B-1 2.3-7 Essential cable pans; None Upper Cable HVAC ductwork, gaskets, Spreading Room, misc. accessories; Zone B-1 silencer; motor-operated dampers 3.3 B-2 2.3-7 Essential cable pans; None Upper Cable 2.3-21, 1 of 2 HVAC ductwork, gaskets, Spreading Room, misc. accessories; Zone B-2 silencer; motor-operated dampers 3.3 C-1 2.3-7 Essential cable pans; None Upper Cable 2.3-22, 2 of 2 HVAC ductwork, gaskets, Spreading Room, 2.3-25, 1 of 2 misc. accessories; motor-Zone C-1 operated dampers 2.2-5

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 3.3 C-2 2.3-7 Essential cable pans; None Upper Cable 2.3-25, 2 of 2 HVAC ductwork, gaskets, Spreading Room, misc. accessories; motor-Zone C-2 operated dampers 3.3 D-1 2.3-7 Essential cable pans; None Upper Cable HVAC ductwork, gaskets, Spreading Room, misc. accessories Zone D-1 3.3 D-2 2.3-7 Essential cable pans; None Upper Cable HVAC ductwork, gaskets, Spreading Room, misc. accessories Zone D-2 3.4 A-1 2.3-8, 1 of 4 Essential cable pans None Unit 1 Cable Riser Area El. 451' 3.4 A-2 2.3-8, 3 of 4 Essential cable pans None Unit 2 Cable Riser Area El. 451' 4.1-1 2.3-8, 1 of 4 None None Unit 1 Computer Room 2.3-22, 2 of 2 4.1-2 2.3-8, 3 of 4 None None Unit 2 Computer Room 5.1-1 2.3-10, 1 of 4 ESF switchgear room None Division 12 ESF 2.3-25, 1 of 2 ventilation system, Switchgear Room switchgear: 1AP06E, 4160-V ESF switchgear 142 1AP12E, 480-V ESF unit substation 132X 1AP13E, 480-V ESF unit substation 132Y 2.2-6

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 5.1-2 2.3-10, 3 of 4 ESF switchgear room None Division 22 ESF 2.3-25, 2 of 2 ventilation system, Switchgear Room switchgear: 2AP06E, 4160-V ESF switchgear 242 2AP12E, 480-V ESF unit substation 232X 2AP13E, 480-V ESF unit substation 232Y 5.2-1 2.3-10, 1 of 4 ESF switchgear room None Division 11 ESF 2.3-25, 1 of 2 ventilation system, Switchgear Room switchgear: 1AP05E, 4160-V ESF switchgear 141 1AP10E, 480-V ESF unit substation 131X 1AP11E, 480-V ESF unit substation 131Y 5.2-2 2.3-10, 3 of 4 ESF switchgear room None Division 21 ESF 2.3-25, 2 of 2 ventilation system, Switchgear Room switchgear: 2AP05E, 4160-V ESF switchgear 241 2AP10E, 480-V ESF unit substation 231X 2AP11E, 480-V ESF unit substation 231Y 5.3-1 2.3-8, 1 of 4 Vent system local control None Unit 1 Non-ESF 2.3-25, 1 of 2 panel; portions of misc.

Switchgear Room electrical equipment room vent system 5.3-2 2.3-8, 3 of 4 Vent system local control None Unit 2 Non-ESF 2.3-24, 2 of 2 panel; portions of misc.

Switchgear Room 2.3-25, 2 of 2 electrical equipment room vent system 2.2-7

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 5.4-1 2.3-8, 1 of 4 Rod control MG sets 1A, None Division 12 Misc. 2.3-25, 1 of 2 1B and associated Electrical Equipment switchgear; electrical and Battery Room panels 1DC02E, 1DC06E, 1DC08E, 1IP06E, 1IP08E, 1IP05E Battery 112, 1IP04E, 1IP02E, HVAC equipment 5.4-2 2.3-8, 3 of 4 Rod control MG sets 2A, None Division 22 Misc. 2.3-25, 2 of 2 2B and associated Electrical Equipment switchgear; electrical and Battery Room panels 2DC02E, 2DC06E, 2DC08E, 2IP06E, 2IP08E, 2IP05E Battery 212, 2IP04E, 2IP02E, HVAC equipment 5.5-1 2.3-8, 1 of 4 Electrical panels:1PA31J, None Unit 1 Auxiliary 1PA32J, 1PA34J,1PA10J, Electrical Equipment 1PA12J, 1PA14J,1PA16J, Room 1PA28J, 1IP01J,1IP02J, 1IP03J, 1IP04J,1PA01J, 1PA02J, 1PA03J,1PA04J, 1PA33J, 1PA09J,1PA11J, 1PA13J, 1PA15J,1PA27J and HVAC equipment 5.5-2 2.3-8, 3 of 4 Electrical panels:2PA31J, None Unit 2 Auxiliary 2PA32J, 2PA34J,2PA10J, Electrical Equipment 2PA12J, 2PA14J,2PA16J, Room 2PA28J, 2IP01J,2IP02J, 2IP03J, 2IP04J,2PA01J, 2PA02J, 2PA03J,2PA04J, 2PA26J, 2PA33J,2PA09J, 2PA11J, 2PA13J,2PA15J, 2PA27J and HVAC equipment 5.6-1 2.3-8, 1 of 4 Electrical panels:1DC03E, None Division 11 Misc. 2.3-25, 1 of 2 1DC05E, 1IP05E,1IP07E, Electrical Equipment 1DC01E, 1IP01E,1IP03E and Battery Room Battery 111 and HVAC equipment 2.2-8

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 5.6-2 2.3-8, 3 of 4 Electrical panels: None Division 21 Misc. 2.3-25, 2 of 2 2DC03E, 2DC05E, Electrical Equipment 2IP05E, 2IP07E, 2DC01E, and Battery Room 2IP01E, 2IP03E, Battery 211 and HVAC equipment 7.1-1 2.3-12, 2 of 4 None None Unit 1 BOP Battery Room 7.1-2 2.3-12, 4 of 4 None None Unit 2 BOP Battery 2.3-22, 1 of 2 Room 8.1-0 2.3-14, 2 of 4 None None Clean and Dirty Oil 2.3-22, 1 of 2 Tank Room 2.3-24, 1 of 2 8.2-1 2.3-14, 2 of 4 None None Unit 1 Turbine Building 2.3-22, 1 of 2 Basement 2.3-23, 1 of 2 2.3-24, 1 of 2 8.2-2 2.3-14, 4 of 4 None None Unit 2 Turbine Building 2.3-21, 1 of 2 Basement 2.3-23, 2 of 2 2.3-24, 2 of 2 8.3-1 2.3-12, 2 of 4 None None Unit 1 Turbine Building 2.3-22, 1 of 2 Grade Floor 2.3-23, 1 of 2 2.3-24, 1 of 2 8.3-2 2.3-12, 4 of 4 None None Unit 2 Turbine Building 2.3-21, 1 of 2 Grade floor 2.3-23, 1 of 2 2.3-24, 2 of 2 8.4-1 2.3-12, 2 of 4 None None Unit 1 Auxiliary Boiler 2.3-23, 1 of 2 Room 8.4-2 2.3-12, 4 of 4 None None Unit 2 Auxiliary Boiler 2.3-21, 1 of 2 Room 2.3-23, 2 of 2 2.2-9

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 8.5-1 2.3-10, 2 of 4 None None Unit 1 Turbine Building 2.3-22, 1 of 2 Mezzanine Floor 2.3-23, 1 of 2 2.3-24, 1 of 2 8.5-2 2.3-10, 4 of 4 None None Unit 2 Turbine Building 2.3-21, 1 of 2 Mezzanine Floor 2.3-23, 2 of 2 2.3-24, 2 of 2 8.6-0 2.3-8, 2 of 4 None None Turbine Building 2.3-8, 4 of 4 Operating Floor 2.3-21, 1 of 2 2.3-22, 1 of 2 2.3-23, 1 of 2 2.3-23, 2 of 2 2.3-24, 1 of 2 2.3-24, 2 of 2 8.7 A-0 2.3-12 None None Station Auxiliary Diesel Generator Room 8.7 B-0 2.3-12 None None Station Auxiliary Diesel Oil Tank Room 9.1-1 2.3-12, 1 of 4 Diesel-generator (DG), None Diesel Generator 1B 2.3-25 Portions of DG auxiliary Room equipment, DG control panel, DG neutral grounding cabinet, DG ventilation panel, DG room ventilation system 9.1-2 2.3-12, 3 of 4 Diesel-generator (DG), None Diesel Generator 2B 2.3-25 Portions of DG auxiliary Room equipment, DG control panel, DG neutral grounding cabinet, DG ventilation panel, DG room ventilation system 2.2-10

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 9.2-1 2.3-12, 1 of 4 Diesel-generator (DG), None Diesel Generator 1A 2.3-25 Portions of DG auxiliary Room equipment, DG control panel, DG neutral grounding cabinet, DG ventilation panel, DG room ventilation system 9.2-2 2.3-12, 3 of 4 Diesel-generator (DG), None Diesel Generator 2A 2.3-25 Portions of DG auxiliary Room equipment, DG control panel, DG neutral grounding cabinet, DG ventilation panel, DG room ventilation system 9.3-1 2.3-12, 1 of 4 Diesel-generator day tank None Diesel Generator 1A Day Tank Room 9.3-2 2.3-12, 3 of 4 Diesel-generator day tank None Diesel Generator 2A Day Tank Room 9.4-1 2.3-12, 1 of 4 Diesel-generator day tank None Diesel Generator 1B Day Tank Room 9.4-2 2.3-12, 3 of 4 Diesel-generator day tank None Diesel Generator 2B Day Tank Room 10.1-1 2.3-13, 1 of 2 25,000 gal. diesel fuel oil None Diesel Fuel Oil 2.3-25, 1 of 2 storage tanks (2) 7 gpm Storage Tank 1B fuel oil transfer pumps (2) ventilation fans (2);

ductwork and accessories 10.1-2 2.3-13, 2 of 2 50,000 gal. diesel fuel oil None Diesel Fuel Oil 2.3-25, 2 of 2 storage tanks, 7 gpm fuel Storage Tank 2B oil transfer pumps (2) ventilation fans (2);

ductwork and accessories 2.2-11

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 10.2-1 2.3-13, 1 of 2 25,000 gal. diesel fuel oil None Diesel Fuel Oil 2.3-25, 1 of 2 storage tanks (2) 7 gpm Storage Tank 1A fuel oil transfer pumps (2) ventilation fans (2);

ductwork and accessories 10.2-2 2.3-13, 2 of 2 50,000 gal. diesel fuel oil None Diesel Fuel Oil 2.3-25, 2 of 2 storage tanks, 7 gpm fuel Storage Tank 2A oil transfer pumps (2) ventilation fans (2);

ductwork and accessories 11.1 A-0 2.3-16 Auxiliary building None Unit 1 Auxiliary 2.3-25, 1 of 2 ventilation system, ESW Building Basement El 2.3-26, 2 of 2 pump 1A and strainer; 330' ESW pump 2A and strainer; coolers 11.1 B-0 2.3-16 Auxiliary building None Unit 2 Auxiliary 2.3-26, 1 of 2 ventilation system, ESW Building Basement EL. 2.3-26, 2 of 2 pump 1B and strainer; 330' ESW pump 2B and strainer; coolers 11.2-0 Auxiliary 2.3-15 Auxiliary building Recycle Building General Area 2.3-22, 2 of 2 ventilation system; recycle evaporation feed El. 346' 2.3-25, 1 of 2 evaporation feed pumps pumps; gas decay 2.3-25, 2 of 2 0A, 0B, gas decay tanks tanks, recycle 2.3-26, 1 of 2 0A, 0B, 0C, 0D, 0E, 0F; waste evaporators, 2.3-26, 2 of 2 recycle waste evaporators auxiliary building 0A, 0B; moderating heat equipment drain exchangers; letdown tanks reheat heat exchangers and letdown chiller heat exchangers, panels 1PL82JA, 1PL82JB, 2PL82JA, 2PL82JB 11.2A-1 2.3-15 Auxiliary building RHR pump Residual Hear ventilation system, Removal Pump 1A residual heat removal Room pump 1A and cooler 2.2-12

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 11.2A-2 2.3-15 Auxiliary building RHR pump Residual Heat ventilation system, Removal Pump 2A residual heat removal Room pump 2A and cooler 11.2B-1 2.3-15 Containment spray pump None Containment Spray 1A and cooler Pump 1A Room 11.2B-2 2.3-15 Containment spray pump None Containment Spray 2A and cooler Pump 2A Room 11.2C-1 2.3-15 Containment spray pump None Containment Spray 1B and cooler Pump 1B Room 11.2C-2 2.3-15 Containment spray pump None Containment Spray 2B and cooler Pump 2B Room 11.2D-1 2.3-15 Residual heat removal RHR pump Residual Heat pump 1B and cooler; Removal Pump 1B auxiliary building vent Room system 11.2D-2 2.3-15 Residual heat removal RHR pump Residual Heat pump 2B and cooler; Removal Pump 2B auxiliary building vent Room system 11.3-0 2.3-14, 1 of 4 Component cooling heat Recycle holdup Auxiliary Building 2.3-14, 3 of 4 exchangers, component tanks General Area El. 364' 2.3-15 cooling pumps, spray 2.3-22, 2 of 2 additive tank, recycle 2.3-25, 1 of 2 holdup tanks panel 2.3-25, 2 of 2 1AP23E, auxiliary building 2.3-26, 1 of 2 ventilation system, 2.3-26, 2 of 2 blowdown condensers, auxiliary building floor drain tank and pump, regeneration waste drain tank and pumps, remote shutdown panel 1PL05JA 2.2-13

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 11.3-1 2.3-14, 1 of 4 Spray additive tank; safety None Unit 1 Containment 2.3-26, 1 of 2 injection, containment Pipe Penetration Area spray, and ESW systems piping panel 1AP21E 11.3-2 2.3-14, 3 of 4 Spray additive tank; safety None Unit 2 Containment 2.3-26, 2 of 2 injection, containment Pipe Penetration Area spray, and ESW systems piping panel 2AP21E 11.3A-1 2.3-14, 1 of 4 Safety injection pump 1A Safety injection Safety Injection Pump 2.3-22, 2 of 2 and cooler auxiliary pump 1A Room 2.3-26, 1 of 2 building ventilation system 11.3A-2 2.3-14, 3 of 4 Safety injection pump 2A Safety injection Safety Injection Pump 2.3-26, 2 of 2 and cooler auxiliary pump 2A Room building ventilation system 11.3B-1 2.3-13, 1 of 2 Auxiliary building RHR heat Residual Heat 2.3-14, 3 of 4 ventilation system, exchanger Removal HX 1A Room 2.3-22, 2 of 2 residual heat removal heat exchanger 1A 11.3B-2 2.3-13, 2 of 2 Auxiliary building RHR heat Residual Heat 2.3-14, 3 of 4 ventilation system, exchanger Removal HX 2A Room residual heat removal heat exchanger 2A 11.3C-1 2.3-14, 1 of 4 Positive displacement Positive Unit 1 Positive 2.3-22, 2 of 2 charging pump displacement Displacement charging pump Charging Pump Room 11.3C-2 2.3-14, 3 of 4 Positive displacement Positive Unit 2 Positive charging pump displacement Displacement charging pump Charging Pump Room 11.3D-1 2.3-14, 1 of 4 Centrifugal charging pump Centrifugal Centrifugal Charging 2.3-22, 2 of 2 and cooler Auxiliary charging pump Pump 1A Room Building Ventilation System (also D-2) 11.3D-2 2.3-14, 3 of 4 Centrifugal charging pump Centrifugal Centrifugal Charging charging pump Pump 2A Room 2.2-14

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 11.3E-1 2.3-13, 1 of 2 Residual heat removal RHR heat Residual Heat 2.3-14, 1 of 4 heat exchanger 1B and exchanger Removal HX 1B Room cooler 11.3E-2 2.3-13, 2 of 2 Residual heat removal RHR heat Residual Heat 2.3-14, 3 of 4 heat exchanger 2B and exchanger Removal HX 2B Room cooler 11.3F-1 2.3-14, 1 of 4 Safety injection pump 1B Safety injection Safety Injection Pump and cooler pump 1B Room 11.3F-2 2.3-14, 3 of 4 Safety injection pump 2B Safety injection Safety Injection Pump and cooler pump 2B Room 11.3G-1 2.3-14, 1 of 4 Centrifugal charging pump Centrifugal Centrifugal Charging 2.3-22, 2 of 2 1B and cooler charging pump Pump 1B Room 11.3G-2 2.3-14, 3 of 4 Centrifugal charging pump Centrifugal Centrifugal Charging 2B and cooler charging pump Pump 2B Room 11.4-0 2.3-13, 1 of 2 Reactor coolant filters, Reactor coolant Auxiliary Building 2.3-13, 2 of 2 seal water filter, seal water filters, Recycle General Area El. 383' 2.3-22, 2 of 2 injection filter, auxiliary evaporator feed 2.3-25, 1 of 2 feedwater motor- driven filter, all safety-2.3-25, 2 of 2 pumps, mixed bed related filters, and 2.3-26, 1 of 2 demineralizers, after- mixed bed 2.3-26, 2 of 2 filters, drain filter, demineralizers blowdown filter, skimmer filter and panels 11.4A-0 2.3-13, 1 of 2 Auxiliary building None Control Room 2.3-25, 1 of 2 ventilation system Refrigeration Equipment Room 11.4B-0 2.3-13, 2 of 2 None None Radwaste / RSP Ventilation Control Room 2.2-15

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 11.4A-1 2.3-13, 1 of 2 Auxiliary building None Unit 1 Auxiliary 2.3-22, 2 of 2 ventilation system, Feedwater Pump 1B 2.3-25, 1 of 2 auxiliary feedwater diesel Room driven pump, diesel oil day tank 11.4A-2 2.3-13, 2 of 2 Auxiliary building None Unit 2 Auxiliary 2.3-25, 2 of 2 ventilation system, Feedwater Pump 2B auxiliary feedwater diesel Room driven pump, diesel oil day tank 11.4B-1 2.3-13, 1 of 2 Seal water heat Seal water heat Unit 1 Seal Water HX 2.3-22, 2 of 2 exchanger exchanger Room 2.3-26, 1 of 2 11.4B-2 2.3-13, 1 of 2 Seal water heat Seal water heat Unit 2 Seal Water HX 2.3-26, 2 of 2 exchanger exchanger Room 11.4C-0 2.3-13, 2 of 2 Remote shutdown panels: None Radwaste/Remote 2.3-25, 2 of 2 div 11, div 12, div 21, Shutdown Control div 22 Room 11.4C-1 2.3-13, 1 of 2 Letdown heat exchanger Letdown heat Letdown HX 1A Room 2.3-22, 2 of 2 exchanger 11.4C-2 2.3-13, 2 of 2 Letdown heat exchanger Letdown heat Letdown HX 2A Room exchanger 11.4D-1 2.3-13, 1 of 2 Letdown heat exchanger Letdown heat Letdown HX 1B Room 2.3-22, 2 of 2 exchanger 11.4D-2 2.3-13, 2 of 2 Letdown heat exchanger Letdown heat Letdown HX 2B Room exchanger 2.2-16

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 11.5-0 Auxiliary 2.3-12, 1 of 4 Auxiliary building Boron thermal Building General Area 2.3-12, 3 of 4 ventilation system; boron regenerative heat EL. 401' 2.3-22, 2 of 2 thermal regenerative exchanger, 2.3-25, 1 of 2 demineralizers; cation bed demineralizers 2.3-25, 2 of 2 and mixed bed 2.3-26, 1 of 2 demineralizers; recycle 2.3-26, 2 of 2 evaporator feed demineralizers; condensate demineralizer, boric acid tank and transfer pumps; boric acid filters.

The H2 recombiners and panels are abandoned in place 11.5-1 2.3-12, 1 of 4 None None Unit 1 Containment 2.3-26, 1 of 2 Refrigeration Equipment Room 11.5-2 2.3-12, 3 of 4 None None Unit 2 Containment 2.3-21, 2 of 2 Refrigeration 2.3-26, 1 of 2 Equipment Room 11.5A-0 2.3-12, 1 of 4 Division 11 and 12 cabling None Radiological Equipment Calibration Room 11.5A-1 2.3-11 Auxiliary building None Division 11 ventilation system; division Containment Electrical 11 ESF cabling and Penetration Area, El. panels UPS cabinet and 414' battery rack 11.5A-2 2.3-11 Auxiliary building None Division 21 ventilation system; division Containment Electrical 21 ESF cabling and Penetration Area, EL. panels; UPS Cabinet and 414' Battery Rack 11.5B-1 2.3-11 ESF Division 12 cables None Division 12 Cable and cable trays Riser Area 2.2-17

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 11.5B-2 2.3-11 ESF Division 22 cables None Division 22 Cable and cable trays Riser Area 11.6-0 2.3-10, 1 of 4 Auxiliary building None Auxiliary Building 2.3-10, 3 of 4 ventilation system; General Area, El. 426' 2.3-22, 2 of 2 component cooling surge 2.3-25, 1 of 2 tanks; cable and panels:

2.3-25, 2 of 2 divisions 11, 12, 21 and 2.3-26, 1 of 2 22 UPS cabinet and 2.3-26, 2 of 2 battery rack 11.6-1 2.3-10, 1 of 4 Division 12 cabling, MCC None Division 12 2.3-26, 1 of 2 132X2, MCC 132X4 Containment Electrical Penetration Area, El.

426' 11.6-2 2.3-10, 3 of 4 Division 22 cabling, MCC None Division 22 2.3-21, 2 of 2 232X2, MCC 232X4 Containment Electrical 2.3-22, 2 of 2 Penetration Area, El.

426' 11.6A-0 2.3-10, 1 of 4 Division 11 cabling (BY), None Laboratory HVAC 2.3-25, 1 of 2 Division 11 and 12 cabling Equipment Room (BR) 11.6A-1 2.3-10, 1 of 4 Volume control tank Volume control Unit 1 Volume Control 2.3-26, 1 of 2 tank Tank Room 11.6A-2 2.3-10, 3 of 4 Volume control tank Volume control Unit 2 Volume Control 2.3-26, 2 of 2 tank Tank Room 11.6B-0 2.3-10, 1 of 4 ESF Division 11 and 21 None Auxiliary Building 2.3-10, 3 of 4 cables and cable trays Offices, El. 426' 2.3-22, 2 of 2 2.3-25, 1 of 2 11.6C-0 2.3-10, 1 of 4 ESF Division 11 cables None Auxiliary Building and cable trays Laundry Room, El.

426' 2.2-18

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 11.6D-0 2.3-10, 1 of 4 ESF Division 11 cables None Auxiliary Building Hot and cable trays

Showers, Decontamination (Byron Only). Mask Cleaning and Issuance Room (Braidwood Only), Change Areas (B/B), El. 426' 11.6E-0 2.3-10, 3 of 4 ESF Division 21 cables None Auxiliary Building and cable trays Decontamination Pad and Storage (Byron Only), Tool Storage Room (Braidwood Only), El. 426' 11.7-0 2.3-8, 1 of 4 Auxiliary building HEPA filters Auxiliary Building 2.3-8, 3 of 4 ventilation system HVAC Exhaust 2.3-4 w/HEPA filters Complex 2.3-5 2.3-6 2.3-21,1 of 2 2.3-21, 2 of 2 2.3-22, 2 of 2 2.3-26, 1 of 2 2.3-26, 2 of 2 11.7-1 2.3-8, 1 of 4 Containment isolation HEPA filters Unit 1 Purge Room 2.3-5 valves 2.3-26, 1 of 2 2.3-6 11.7-2 2.3-8, 3 of 4 Containment isolation HEPA filters Unit 2 Purge Room 2.3-5 valves 2.3-26, 2 of 2 2.3-6 2.2-19

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 12.1-0 2.3-19 Essential cable pans fuel Spent fuel Fuel Handling Building 2.3-20 handling crane; HVAC 2.3-22, 2 of 2 auxiliary building ductwork, accessories, cubicle coolers; spent fuel pit pumps; spent fuel pit skimmer pump; spent fuel heat exchanger and pumps; Byron reactor cavity seal (storage only);

Braidwood spare RCP motor (storage only) 13.0 2.3-17 None None QA vault 14.1-0 2.3-13, 2 of 2 None Drum processing Radwaste Drumming unit; decanting Station and Tunnel tank, pump, and piston pump; concentration piston pump 14.2-0 2.3-12, 3 of 4 Auxiliary building Radwaste Radwaste Evaporator 2.3-25, 2 of 2 ventilation system evaporator monitor Tank/Spent Resin tanks; spent resin Pump Room pump; concentrate transfer pumps 14.3-0 2.3-12, 3 of 4 None Radwaste Surface Condenser evaporator surface Room condensers; radwaste evaporator distillate after-cooler; radwaste evaporator distillate pumps; radwaste evaporator condensate pumps, distillate pumps 2.2-20

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 14.4-0 2.3-10, 3 of 4 Spent resin tank, auxiliary Spent resin tank; Spent Resin 2.3-25, 2 of 2 building ventilation system concentrates Tank/Waste Gas holding tank; waste Compressor Room gas compressors 14.5-0 2.3-10, 3 of 4 None Radwaste Radwaste Evaporator evaporator heating Room elements; radwaste evaporator vapor bodies; radwaste evaporator concentrates receiver tanks; radwaste evaporator concentrates after-coolers; radwaste evaporator recycle pumps; radwaste evaporator concentrates pumps 14.6-0 2.3-18 None Stored drums, Radwaste Building volume reduction Ground Floor system equipment Dry waste processor, waste lower storage tank fluid bed dryer, scrubber preconcentration 16.1-1 2.3-1 (Byron) Tank None Unit 1 Refueling Water 2.3-2 Storage Tank (Braidwood) 2.3-19, 2.3-20, 2.3-22 16.1-2 2.3-1 (Byron) Tank None Unit 2 Refueling Water 2.3-2 Storage Tank (Braidwood) 2.3-19, 2.3-20 2.2-21

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 17.1-0 2.3-1 (Byron) None None Open flume 17.1-1 2.3-1 (Byron) None None Natural Draft Cooling Tower - Unit 1 17.1-2 2.3-1 (Byron) None None Natural Draft Cooling Tower - Unit 2 17.2-1 2.3-1 (Byron) ESW cooling tower fans None Essential Service Water (ESW) Cooling Tower - Division 12/22 (Byron) 17.2-2 2.3-1 (Byron) ESW cooling tower fans None Essential Service Water (ESW) Cooling Tower - Division 11/21 (Byron) 18.1-1 2.3-8, 1 of 4 DG exhaust None Diesel-Generator 1B 2.3-10, 1 of 4 and Switchgear Room 2.3-12, 1 of 4 Air Shaft 18.1-2 2.3-8, 3 of 4 DG exhaust None Diesel-Generator 2B 2.3-10, 3 of 4 and Switchgear Room 2.3-12, 3 of 4 Air Shaft 2.3-21, 2 of 2 18.2-1 2.3-8, 1 of 4 DG exhaust None Diesel-Generator 1A 2.3-10, 1 of 4 and Switchgear Room 2.3-12, 1 of 4 Air Shaft 18.2-2 2.3-8, 3 of 4 DG exhaust None Diesel-Generator 2A 2.3-10, 3 of 4 and Switchgear Room 2.3-12, 3 of 4 Air Shaft 18.3-1 2.3-13, 1 of 2 Piping, Main steam and None Unit 1 Main Steam and 2.3-14, 1 of 4 feedwater isolation valves Auxiliary Feedwater Pipe Tunnel 2.2-22

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 18.3-2 2.3-13, 2 of 2 Piping, Main steam and None Unit 2 Main Steam and 2.3-14, 3 of 4 feedwater isolation valves Auxiliary Feedwater Pipe Tunnel 18.4-1 2.3-8, 1 of 4 Control room HVAC None Control Room HVAC 2.3-25, 1 of 2 system, Train A panel Equipment Room, 0VC01JA Train A 18.4-2 2.3-8, 3 of 4 Control room HVAC None Control Room HVAC 2.3-25, 2 of 2 system, Train B panel Equipment Room, 0VC01JB Train B 18.5-1 2.3-8, 1 of 4 None None Locker Room Area (Byron) and Kitchen/Locker Room Area (Braidwood) 18.5-2 2.3-8, 3 of 4 None None Security Control Center and Electronics Shop 18.6-0 2.3-18 None None Service Building, Ground Floor 18.7-0 2.3-18 None None Service Building, Second Floor 18.8-0 2.3-17 None None Service Building, Third Floor 18.9-0 2.3-17 None None Service Building, Fourth Floor 18.10A-1 2.3-1 None None Main Power 2.3-2 Transformer 1E 2.2-23

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 18.10A-2 2.3-1 None None Main Power 2.3-2 Transformer 2E 18.10B-1 2.3-1 None None Main Power 2.3-2 Transformer 1W 18.10B-2 2.3-1 None None Main Power 2.3-2 Transformer 2W 18.10C-1 2.3-10, 1 of 4 None None Unit Auxiliary 2.3-12, 1 of 4 Transformer 141-1 18.10C-2 2.3-10, 3 of 4 None None Unit Auxiliary 2.3-12, 3 of 4 Transformer 241-1 18.10D-1 2.3-10, 1 of 4 None None Unit Auxiliary 2.3-12, 1 of 4 Transformer 141-2 18.10D-2 2.3-10, 3 of 4 None None Unit Auxiliary 2.3-12, 3 of 4 Transformer 241-2 18.10E-1 2.3-10, 1 of 4 None None System Auxiliary 2.3-12, 1 of 4 Transformers 142-1 and 142-2 18.10E-2 2.3-10, 3 of 4 None None System Auxiliary 2.3-12 Transformer 242-1 and 242-2 18.11-0 2.3-29 (Byron) Byron - ESW makeup None River Screen House 2.3-30 pumps (Braidwood) Braidwood - None 18.11-1 2.3-29 Oil tank None Byron River Screen House Diesel Oil Storage Tank Room 1 2.2-24

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 18.11-2 2.3-29 Oil tank None Byron River Screen House Diesel Oil Storage Tank Room 2 18.12-0 2.3-27 (Byron) Byron -None None Circulating Water 2.3-28 Braidwood - ESW pump Pump House (Byron) (Braidwood) suction header upstream Lake Screen House isolation valves (Braidwood) 18.13-0 2.3-27 (Byron) None None Diesel Driven Fire 2.3-28 Pump Cubicle (Braidwood) 18.14A-1 2.3-31, 2 of 2 Electrical panels 132Z1, None ESW Cooling Tower 132Z; Ventilation system Electrical Substation 0B, Div. 12 (Byron Only) 18.14A-2 2.3-31, 1 of 2 Electrical panels 232Z1, None ESW Cooling Tower 232Z; Ventilation system Electrical Substation 0B, Div. 22 (Byron Only) 18.14B-1 2.3-31, 2 of 2 Electrical panels 131Z1, None ESW Cooling Tower 131Z; Ventilation system Electrical Substation 0A, Div. 11 (Byron Only) 18.14B-2 2.3-31, 1 of 2 Electrical panels 231Z1, None ESW Cooling Tower 121Z; Ventilation system Electrical Substation 0A, Div. 21 (Byron Only) 18.15-0 2.3-2, 2.3-42 None None Makeup Demineralizer Building (Braidwood) 18.16-1 2.3-1 (Byron) None None Sulfuric Acid Rank #1 (Byron Only) 2.2-25

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 18.16-2 2.3-1 (Byron) None None Sulfuric Acid Tank #2 (Byron Only) 18.17-0 2.3-1 (Byron) None None Hydrogen / Nitrogen 2.3-2 Storage Area (Braidwood) 18.19-0 2.3-1 (Byron) None None Sodium Hypochlorite Tank 18.20-0 2.3-1 (Byron) None None 125,000 and 50,000- 2.3-2 gallon Fuel Oil Storage (Braidwood)

Tanks 18.21-0 (Deleted) N/A N/A N/A 18.22-0 2.3-1 None None Makeup Demineralizer Building (Byron Only) 18.23-0 2.3-1 (Byron) None None Condensate Storage 2.3-2 Tanks, Deep well, and (Braidwood)

Construction Fire Pump Area 18.24-0 2.3-12, 2 of 4 None None Turbine Building 2.3-12, 4 of 4 Sampling Room 18.25-1 2.3-1 (Byron) Tank None Primary Water Storage 2.3-2 Tank #1 (Braidwood) 18.25-2 2.3-1 (Byron) Tank None Primary Water Storage 2.3-2 Tank #2 (Braidwood) 18.26-0 2.3-41 None None TSC/Condensate Cleanup Building 2.2-26

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 18.27-0 2.3-1 (Byron) None None Level B Storage 2.3-2 Building (Byron) (Braidwood)

Bottle Storage Enclosure (Braidwood) 18.28-0 2.3-1 (Byron) None None Waste Treatment 2.3-2 Building (Braidwood) 18.29-0 2.3-1 (Byron) None None Aboveground Vehicle 2.3-2 Fuel Dispensing Areas (Braidwood) 18.30-0 2.3-1 (Byron) None None New and Used Oil 2.3-2 Storage Pads (Braidwood) 18.31-0 2.3-1 (Byron) None None Acid Pump House (Byron Only) 18.32-0 2.3-1 (Byron) None None Receiving Building and 2.3-2 Warehouse (Braidwood) 18.33-0 2.3-1 (Byron) None None Gatehouse 2.3-2 (Braidwood) 18.34-0 2.3-1 (Byron) None None Welding Gas Storage 2.3-2 Building (Braidwood) 18.35-0 2.3-10 None None Security Diesel MCC 18.36-0 2.3-1 (Byron) None None Relay House 2.3-2 (Braidwood) 18.37-0 2.3-1 (Byron) None None Maintenance Building 2.3-2 (Braidwood) 2.2-27

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-2 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / ZONE FIGURE SAFETY-RELATED RADIOACTIVE NUMBER AND NAME NUMBER EQUIPMENT EQUIPMENT 18.38-0 2.3-1 (Byron) None None Illinois Department of 2.3-2 Nuclear Safety (IDNS) (Braidwood)

Building 18.40-0 2.3-3, 2.3-8 None None Braidwood electrical 2.3-10, 2.3-12 and instrument (Braidwood) maintenance (EM/IM) shop building 18.41-0 2.3-2 None None Unit 1 Containment (Braidwood)

Access Facility (Braidwood Only) 18.42-0 2.3-2 None None Unit 2 Containment (Braidwood)

Access Facility (Braidwood Only) 18.43-0 2.3-2 None Radwaste Storage Braidwood Radwaste (Braidwood) Tank (RST) and Storage Tank Overflow Tank 2.2-28

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 1.1-1 Spatial Separation Heat detection over reactor 5,202 Low (Byron)

Unit 1 Containment coolant pumps (Unit 1 detection Low (Braidwood)

Missile Shield Area Zones 2, 3, 4 and 5) 1.1-2 Spatial Separation Heat detection over reactor 5,202 Low (Byron)

Unit 2 Containment coolant pumps (Unit 2 detection Low (Braidwood)

Missile Shield Area Zones 2, 3, 4 and 5) 1.2-1 Spatial Separation Ionization (or photoelectric) 7,112 Low (Byron)

Unit 1 Annular Area (Note 1) detection over cable penetration Low (Braidwood) area (Unit 1 detection Zone 7 1.2-2 Spatial Separation Ionization (or photoelectric) 7,112 Low (Byron)

Unit 2 Annular Area (Note 1) detection over cable penetration Low (Braidwood) area (Unit 2 detection Zone 7 1.3-1 Note 1 Temperature switches in 8,887 Low (Byron)

Unit 1 Containment charcoal absorber banks 1A & Low (Braidwood)

Upper Area 1B on El. 426' (Byron). Ionization (or photoelectric) detection over cable penetration area (Unit 1 detection Zone 6) 2.2-29

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 1.3-2 Manual charcoal deluge Temperature switches in 8,887 Low (Byron)

Unit 2 Containment systems (Unit 2 suppression charcoal absorber banks 2A & Low (Braidwood)

Upper Area Zones 11 & 12) (Abandoned in 2B on El. 426' (Byron). Ionization place). Deluge System isolated (or photoelectric) detection over (Byron Unit 2) cable penetration area (Unit 2 (Note 1) detection (Zone 6) 2.1-0 Note 1 Ionization (or photoelectric) 4,163 Low (Byron)

Control Room detection (Unit 1 detection Zone Low (Braidwood) 75) 2.1-1 Note 1 Ionization (or photoelectric) 198 Low (Byron)

Record Storage detection (Unit 1 detection Zone Low (Braidwood)

Room 70) 2.1-2 Note 1 Ionization (or photoelectric) 203 Low (Byron)

Record Storage detection (Unit 2 detection Zone Low (Braidwood) and Toilet Room 70) 3.1-1 Automatic total flooding carbon Ionization (or photoelectric) 1,139 Low (Byron)

Unit 1 Cable dioxide system (Unit 1 detection (Unit 1 detection Zone Low (Braidwood)

Tunnel suppression Zone 47) 64) Fenwal thermal (Unit 1 detection Zone 65) Note 3 3.1-2 Automatic total flooding carbon Ionization (or photoelectric) 1,139 Low (Byron)

Unit 2 Cable dioxide system (Unit 2 detection (Unit 2 detection Zone Low (Braidwood)

Tunnel suppression Zone 47) 64) Fenwal thermal (Unit 2 detection Zone 65) Note 3 2.2-30

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 3.2-0 Note 1 Ionization (or photoelectric) 1,128 Low (Byron)

Auxiliary Building detection (Unit 2 detection Zone Low (Braidwood)

El. 439' 61) 3.2 A-1 Automatic total flooding carbon Ionization (or photoelectric) 4,891 Low (Byron)

Unit 1 Non dioxide system (Unit 1 detection (Unit 1 detection Zone Low (Braidwood) segregated Bus suppression Zone 43) 49) Fenwal thermal (Unit 1 Duct Area detection Zone 50) Note 3 3.2 A-2 Automatic total flooding carbon Ionization (or photoelectric) 4,794 Low (Byron)

Unit 2 Non dioxide system (Unit 2 detection (Unit 2 detection Zone Low (Braidwood) segregated Bus suppression Zone 43 49) Fenwal thermal (Unit 2 Duct Area detection Zone 50) Note 3 3.2 B-1 Automatic total flooding carbon Ionization (or photoelectric) 5,327 Low (Byron)

Lower Cable dioxide system (Unit 1 detection (Unit 1 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 44) 51) Fenwal thermal (Unit 1 Zone B-1 detection Zone 52) Note 3 3.2 B-2 Automatic total flooding carbon Ionization (or photoelectric) 5,251 Low (Byron)

Lower Cable dioxide system (Unit 2 detection (Unit 2 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 44) 51) Fenwal thermal (Unit 2 Zone B-2 detection Zone 52) Note 3 3.2 C-1 Automatic total flooding carbon Ionization (or photoelectric) 2,803 Low (Byron)

Lower Cable dioxide system (Unit 1 detection (Unit 1 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 45) 53) Fenwal thermal (Unit 1 Zone C-1 detection Zone 53) Note 3 2.2-31

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 3.2 C-2 Automatic total flooding carbon Ionization (or photoelectric) 2,815 Low (Byron)

Lower Cable dioxide system (Unit 2 detection (Unit 2 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 45) 53) Fenwal thermal (Unit 2 Zone C-2 detection Zone 54) Note 3 3.2 D-1 Automatic total flooding carbon Ionization (or photoelectric) 513 Low (Byron)

Lower Cable dioxide system (Unit 1 detection (Unit 1 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 46) 55) Fenwal thermal (Unit 1 Zone D-1 detection Zone 56) Note 3 3.2 D-2 Automatic total flooding carbon Ionization (or photoelectric) 416 Moderate (Byron)

Lower Cable dioxide system (Unit 2 detection (Unit 2 detection Zone Moderate (Braidwood)

Spreading Room, suppression Zone 46) 55) Fenwal thermal (Unit 2 Zone D-2 detection Zone 56) Note 3 3.2 E-1 Automatic total flooding carbon Ionization (or photoelectric) 132 Moderate (Byron)

Division 11 Cable dioxide system (Unit 1 detection (Unit 1 detection Zone Moderate (Braidwood)

Riser, Lower suppression Zone 46) 55) Fenwal thermal (Unit 1 Spreading Room detection Zone 56) Note 3 3.2 E-2 Automatic total flooding carbon Ionization (or photoelectric) 144 Moderate (Byron)

Division 21 Cable dioxide system (Unit 2 detection (Unit 2 detection Zone Moderate (Braidwood)

Riser, Lower suppression Zone 46) 55) Fenwal thermal (Unit 2 Spreading Room detection Zone 56) Note 3 2.2-32

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 3.3 A-1 Automatic total flooding Halon Ionization (or photoelectric) 963 Low (Byron)

Upper Cable 1301 system (Unit 1 detection (Unit 1 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 33); manual 41) Fenwal thermal (Unit 1 Zone A-1 total flooding carbon dioxide detection Zone 42) Temperature system Unit 1 suppression switch in charcoal adsorber.

Zone 48) 33 Manual charcoal Note 3 deluge system (Unit 1 suppression Zones 5 & 6) 3.3 A-2 Automatic total flooding Halon Ionization (or photoelectric) 1,051 Low (Byron)

Upper Cable 1301 system (Unit 2 detection (Unit 2 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 33); manual 41) Fenwal thermal (Unit 2 Zone A-2 total flooding carbon dioxide detection Zone 42). Temperature system Unit 2 suppression switch in charcoal adsorber.

Zone 48 Manual charcoal Note 3 deluge system (Unit 2 suppression Zones 5 & 6) 3.3 B-1 Automatic total flooding Halon Ionization (or photoelectric) 2,314 Moderate (Byron)

Upper Cable 1301 system (Unit 1 detection (Unit 1 detection Zone Moderate (Braidwood)

Spreading Room, suppression Zone 34); manual 43) Fenwal thermal (Unit 1 Zone B-1 total flooding carbon dioxide detection Zone 44). Note 3 system (Unit 1 suppression Zone 49) 2.2-33

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 3.3 B-2 Automatic total flooding Halon Ionization (or photoelectric) 2,296 Moderate (Byron)

Upper Cable 1301 system (Unit 2 detection (Unit 2 detection Zone Moderate (Braidwood)

Spreading Room, suppression Zone 34); manual 43) Fenwal thermal (Unit 2 Zone B-2 total flooding carbon dioxide detection Zone 44). Note 3 system (Unit 2 suppression Zone 49) 3.3 C-1 Automatic total flooding Halon Ionization (or photoelectric) 2,698 Moderate (Byron)

Upper Cable 1301 system (Unit 1 detection (Unit 1 detection Zone Moderate (Braidwood)

Spreading Room, suppression Zone 35); manual 45) Fenwal thermal (Unit 1 Zone C-1 total flooding carbon dioxide detection Zone 46). Note 3 system (Unit 1 suppression Zone 50) 3.3 C-2 Automatic total flooding Halon Ionization (or photoelectric) 2,707 Low (Byron)

Upper Cable 1301 system (Unit 2 detection (Unit 2 detection Zone Low (Braidwood)

Spreading Room, suppression Zone 35); manual 45) Fenwal thermal (Unit 2 Zone C-2 total flooding carbon dioxide detection Zone 46). Note 3 system (Unit 2 suppression Zone 50) 3.3 D-1 Automatic total flooding Halon Ionization (or photoelectric) 1,055 Moderate (Byron)

Upper Cable 1301 system (Unit 1 detection (Unit 1 detection Zone Moderate (Braidwood)

Spreading Room, suppression Zone 36); manual 47) Fenwal thermal (Unit 1 Zone D-1 total flooding carbon dioxide detection Zone 48). Note 3 system (Unit 1 suppression Zone 51) 2.2-34

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 3.3 D-2 Automatic total flooding Halon Ionization (or photoelectric) 1,117 Moderate (Byron)

Upper Cable 1301 system (Unit 2 detection (Unit 2 detection Zone Moderate (Braidwood)

Spreading Room, suppression Zone 36); manual 47) Fenwal thermal (Unit 2 Zone D-2 total flooding carbon dioxide detection Zone 48). Note 3 system (Unit 2 suppression Zone 51) 3.4 A-1 Note 1 Ionization (or photoelectric) 112.5 Moderate (Byron)

Unit 1 Cable Riser detection (Unit 1 detection Zone Moderate (Braidwood)

Area El. 451' 70) 3.4 A-2 Note 1 Ionization (or photoelectric) 142 Moderate (Byron)

Unit 2 Cable Riser detection (Unit 2 detection Zone Moderate (Braidwood)

Area El. 451' 70) 4.1-1 Note 1 Ionization (or photoelectric) 691 Low (Byron)

Unit 1 Computer detection (Unit 1 detection Zone Low (Braidwood)

Room 70) 4.1-2 Note 1 Ionization (or photoelectric) 691 Low (Byron)

Unit 2 Computer detection (Unit 2 detection Zone Low (Braidwood)

Room 70) 5.1-1 Note 1 Ionization (or photoelectric) 2,337 Low (Byron)

Division 12 ESF detection (Unit 1 detection Zone Low (Braidwood)

Switchgear Room 77) 2.2-35

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 5.1-2 Note 1 Ionization (or photoelectric) 2,337 Low (Byron)

Division 22 ESF detection (Unit 2 detection Zone Low (Braidwood)

Switchgear Room 77) 5.2-1 Note 1 Ionization (or photoelectric) 2,265 Low (Byron)

Division 11 ESF detection (Unit 1 detection Zone Low (Braidwood)

Switchgear Room 78) 5.2-2 Note 1 Ionization (or photoelectric) 2,265 Low (Byron)

Division 21 ESF detection (Unit 2 detection Zone Low (Braidwood)

Switchgear Room 78) 5.3-1 Note 1 Ionization (or photoelectric) 2,238 Low (Byron)

Unit 1 Non-ESF detection (Unit 1 detection Zone Low (Braidwood)

Switchgear Room 66) 5.3-2 Note 1 Ionization (or photoelectric) 2,259 Low (Byron)

Unit 2 Non-ESF detection (Unit 2 detection Zone Low (Braidwood)

Switchgear Room 66) 5.4-1 Note 1 Ionization (or photoelectric) 1,507 Low (Byron)

Division 12 Misc. detection (Unit 1 detection Zone Low (Braidwood)

Electrical 67)

Equipment and Battery Room 2.2-36

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 5.4-2 Note 1 Ionization (or photoelectric) 1,536 Low (Byron)

Division 22 Misc. detection (Unit 2 detection Zone Low (Braidwood)

Electrical 67)

Equipment and Battery Room 5.5-1 Note 1 Ionization (or photoelectric) 1,911 Low (Byron)

Unit 1 Auxiliary detection (Unit 1 detection Zone Low (Braidwood)

Electrical 69)

Equipment Room 5.5-2 Note 1 Ionization (or photoelectric) 2,030 Low (Byron)

Unit 2 Auxiliary detection (Unit 2 detection Zone Low (Braidwood)

Electrical 69)

Equipment Room 5.6-1 Note 1 Ionization (or photoelectric) 733 Low (Byron)

Division 11 Misc. detection (Unit 1 detection Zone Low (Braidwood)

Electrical 67)

Equipment and Battery Room 5.6-2 Note 1 Ionization (or photoelectric) 741 Low (Byron)

Division 21 Misc. detection (Unit 2 detection Zone Low (Braidwood)

Electrical 67)

Equipment and Battery Room 2.2-37

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 7.1-1 Note 1 Ionization (or photoelectric) 351 Low (Byron)

Unit 1 BOP Battery detection (Unit 1 detection Zone Low (Braidwood)

Room 36) 7.1-2 Note 1 Ionization (or photoelectric) 351 Low (Byron)

Unit 2 BOP Battery detection (Unit 2 detection Zone Low (Braidwood)

Room 36) 8.1-0 Automatic sprinkler system Byron: Ionization (or 1,238 High (Byron)

Clean and Dirty Oil (Unit 1 suppression Zone 21) photoelectric) detection (Unit 2 High (Braidwood)

Tank Room detection Zone 23)

Braidwood: None 8.2-1 Automatic sprinkler system None 23,918 Low (Byron)

Unit 1 Turbine (Unit 1 suppression Zone 24) Low (Braidwood)

Building Basement 8.2-2 Automatic sprinkler system None 25,156 Low (Byron)

Unit 2 Turbine (Unit 2 suppression Zone 24) Low (Braidwood)

Building Basement 8.3-1 Automatic sprinkler system Note 2 40,602 Low (Byron)

Unit 1 Turbine Note 2 (Unit 1 suppression Low (Braidwood)

Building Grade Zones 22 & 23)

Floor 2.2-38

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 8.3-2 Automatic sprinkler system Note 2 46,625.5 Low (Byron)

Unit 2 Turbine Note 2 (Unit 2 suppression (At Byron, Low (Braidwood)

Building Grade Zones 22 & 23) including floor IM/EM shop is 50,434.5) 8.4-1 Automatic sprinkler system None 2,243 Low (Byron)

Unit 1 Auxiliary (Unit 1 suppression Zone 31) Low (Braidwood)

Boiler Room 8.4-2 Automatic sprinkler system None 2,243 Low (Byron)

Unit 2 Auxiliary (Unit 2 suppression Zone 31) Low (Braidwood)

Boiler Room 8.5-1 Automatic sprinkler system Note 2 37,974.5 Low (Byron)

Unit 1 Turbine Note 2 (Unit 1 suppression Low (Braidwood)

Building Mezzanine Zones 19, 20)

Floor 8.5-2 Automatic sprinkler system Note 2 40,722 Low (Byron)

Unit 2 Turbine Note 2 (Unit 2 suppression (At Byron, Low (Braidwood)

Building Mezzanine Zones 19, 20) including Floor IM/EM shop is 44,531) 2.2-39

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 8.6-0 Manual charcoal deluge Temperature switch (in charcoal 101,287 Low (Byron)

Turbine Building system; (Suppression Zone 29, absorber) Low (Braidwood)

Operating Floor both units; Unit 1 suppression Zones 8 and 9 for charcoal Note 2 filters)

Local smoke/heat detectors in Automatic sprinkler (Unit 2 two-story office bldg. at Byron suppression Zone 32)

Note 1 Unit 2 Detection Zone 1 Turbine Building elevator shaft Automatic sprinkler system (2-story office structure) 8.7 A-0 None None 190 Low (Byron)

Station Auxiliary Low (Braidwood)

Diesel Generator Room 8.7 B-0 Automatic sprinkler (Unit 2 None 341 High (Byron)

Station Auxiliary suppression Zone 32) High (Braidwood)

Diesel Oil Tank Note 1 Room 9.1-1 Automatic total flooding CO2 Fenwal thermal & ultraviolet 2,200 Moderate (Byron)

Diesel Generator system (Unit 1 suppression (Unit 1 detection Zone 71) Moderate (Braidwood) 1B Room Zone 37) 2.2-40

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 9.1-2 Automatic total flooding CO2 Fenwal thermal & ultraviolet 2,200 Moderate (Byron)

Diesel Generator system (Unit 2 suppression (Unit 2 detection Zone 71) Moderate (Braidwood) 2B Room zone 37) 9.2-1 Automatic total flooding CO2 Fenwal thermal & ultraviolet (Unit 2,500 Moderate (Byron)

Diesel Generator system (Unit 1 suppression 1 detection Zone 72) Moderate (Braidwood) 1A Room Zone 38) 9.2-2 Automatic total flooding CO2 Fenwal thermal & ultraviolet (Unit 2,500 Moderate (Byron)

Diesel Generator system (Unit 2 suppression 2 detection Zone 72) Moderate (Braidwood) 2A Room Zone 38) 9.3-1 Automatic total flooding CO2 Fenwal thermal 44 High (Byron)

Diesel Generator system (Unit 1 suppression High (Braidwood) 1A Day Tank Room Zone 40) 9.3-2 Automatic total flooding CO2 Fenwal thermal 44 High (Byron)

Diesel Generator system (Unit 2 suppression High (Braidwood) 2A Day Tank Room Zone 40) 9.4-1 Automatic total flooding CO2 Fenwal thermal 44 High (Byron)

Diesel Generator system (Unit 1 suppression High (Braidwood) 1B Day Tank Room Zone 39) 9.4-2 Automatic total flooding CO2 Fenwal thermal 44 High (Byron)

Diesel Generator system (Unit 2 suppression High (Braidwood) 2B Day Tank Room Zone 39) 2.2-41

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 10.1-1 Manual Fluoro protein foam Byron: Fenwal rate 809 High (Byron)

Diesel Fuel Oil extinguishing system via spray compensating detectors High (Braidwood)

Storage Tank 1B nozzles (Unit 1 suppression ionization (or photoelectric)

Zone 27) detection (Unit 1) detection Zone 10 Braidwood: Fenwal thermal detection 10.1-2 Manual Fluoro protein foam Byron: Fenwal rate 853 High (Byron)

Diesel Fuel Oil extinguishing system via spray compensating detectors High (Braidwood)

Storage Tank 2B nozzles (Unit 2 suppression ionization (or photoelectric)

Zone 27) detection (Unit 2) detection Zone 10 Braidwood: Fenwal thermal detection 10.2-1 Manual Fluoro protein foam Bryon: Fenwal rate 974 High (Byron)

Diesel Fuel Oil extinguishing system via spray compensating detectors High (Braidwood)

Storage Tank 1A nozzles (Unit 1 suppression ionization (or photoelectric)

Zone 28) detection (Unit 1) detection Zone 10 Braidwood: Fenwal thermal detection 10.2-2 Manual Fluoro protein foam Byron: Fenwal rate 1,103 High (Byron)

Diesel Fuel Oil extinguishing system via spray compensating detectors High (Braidwood)

Storage Tank 2A nozzles (Unit 2 suppression ionization (or photoelectric)

Zone 28) detection (Unit 2) detection Zone 10 Braidwood: Fenwal thermal detection 2.2-42

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.1 A-0 Note 1 Ionization (or photoelectric) 4,826 Low (Byron)

Unit 1 Auxiliary detection (Unit 2 detection Zone Low (Braidwood)

Building Basement 11)

El 330' 11.1 B-0 Note 1 Ionization (or photoelectric) 4,942 Low (Byron)

Unit 2 Auxiliary detection (Unit 2 detection Zone Low (Braidwood)

Building Basement 11)

EL. 330' 11.2-0 Auxiliary Note 1 Ionization (or photoelectric) 26,979 Low (Byron)

Building General Automatic Sprinkler Stairway detection (Unit 2 detection Zones Low (Braidwood)

Area El. 346' (Unit 2 Suppression Zone 54) 17 and 40) 11.2A-1 Note 1 Ionization (or photoelectric) 366 Low (Byron)

Residual Hear detection (Unit 1 detection Zone Low (Braidwood)

Removal Pump 1A 21)

Room 11.2A-2 Note 1 Ionization (or photoelectric) 366 Low (Byron)

Residual Heat detection (Unit 2 detection Zone Low (Braidwood)

Removal Pump 2A 21)

Room 11.2B-1 Note 1 Ionization (or photoelectric) 506.5 Low (Byron)

Containment Spray detection (Unit 1 detection Zone Low (Braidwood)

Pump 1A Room 21) 2.2-43

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.2B-2 Note 1 Ionization (or photoelectric) 506.5 Low (Byron)

Containment Spray detection (Unit 2 detection Zone Low (Braidwood)

Pump 2A Room 21) 11.2C-1 Note 1 Ionization (or photoelectric) 439.5 Low (Byron)

Containment Spray detection (Unit 1 detection Zone Low (Braidwood)

Pump 1B Room 20) 11.2C-2 Note 1 Ionization (or photoelectric) 439.5 Low (Byron)

Containment Spray detection (Unit 2 detection Zone Low (Braidwood)

Pump 2B Room 20) 11.2D-1 Note 1 Ionization (or photoelectric) 300 Negligible (Byron)

Residual Heat detection (Unit 1 detection Zone Low (Braidwood)

Removal Pump 1B 20)

Room 11.2D-2 Note 1 Ionization (or photoelectric) 300 Negligible (Byron)

Residual Heat detection (Unit 2 detection Zone Low (Braidwood)

Removal Pump 2B 20)

Room 11.3-0 Note 1 Ionization (or photoelectric) 20,065 Low (Byron)

Auxiliary Building Automatic sprinkler (Unit 1 detection (Unit 1 detection Zones Low (Braidwood)

General Area El. suppression Zone 59) 17 and 40) 364' Stairway and Open Hatch (Unit 2 suppression Zone 54) 2.2-44

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.3-1 Note 1 Ionization (or photoelectric) 3,531 Low (Byron)

Unit 1 Containment Automatic sprinkler (Unit 1 detection (Unit 1 detection Zone Low (Braidwood)

Pipe Penetration suppression Zone 60) 18)

Area 11.3-2 Note 1 Ionization (or photoelectric) 3,531 Low (Byron)

Unit 2 Containment Automatic sprinkler (Unit 2 detection (Unit 2 detection Zone Low (Braidwood)

Pipe Penetration suppression Zone 53) 18)

Area 11.3A-1 Note 1 Ionization (or photoelectric) 422 Low (Byron)

Safety Injection detection (Unit 1 detection Zone Low (Braidwood)

Pump 1A Room 18) 11.3A-2 Note 1 Ionization (or photoelectric) 422 Low (Byron)

Safety Injection detection (Unit 2 detection Zone Low (Braidwood)

Pump 2A Room 18) 11.3B-1 Note 1 None 260 Negligible (Byron)

Residual Heat Negligible (Braidwood)

Removal HX 1A Room 11.3B-2 Note 1 None 260 Negligible (Byron)

Residual Heat Negligible (Braidwood)

Removal HX 2A Room 2.2-45

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.3C-1 Note 1 Ionization (or photoelectric) 424 Low (Byron)

Unit 1 Positive detection (Unit 1 detection Zone Low (Braidwood)

Displacement 19)

Charging Pump Room 11.3C-2 Note 1 Ionization (or photoelectric) 424 Low (Byron)

Unit 2 Positive detection (Unit 2 detection Zone Low (Braidwood)

Displacement 19)

Charging Pump Room 11.3D-1 Note 1 Ionization (or photoelectric) 369 Low (Byron)

Centrifugal detection (Unit 1 detection Zone Low (Braidwood)

Charging Pump 1A 19)

Room 11.3D-2 Note 1 Ionization (or photoelectric) 369 Low (Byron)

Centrifugal detection (Unit 2 detection Zone Low (Braidwood)

Charging Pump 2A 19)

Room 11.3E-1 Note 1 None 311 Negligible (Byron)

Residual Heat Negligible (Braidwood)

Removal HX 1B Room 2.2-46

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.3E-2 Note 1 None 311 Negligible (Byron)

Residual Heat Negligible (Braidwood)

Removal HX 2B Room 11.3F-1 Note 1 Ionization (or photoelectric) 980 Negligible (Byron)

Safety Injection detection (Unit 1 detection Zone Negligible (Braidwood)

Pump 1B Room 16) 11.3F-2 Note 1 Ionization (or photoelectric) 980 Negligible (Byron)

Safety Injection detection (Unit 2 detection Zone Negligible (Braidwood)

Pump 2B Room 16) 11.3G-1 Note 1 Ionization (or photoelectric) 247 Low (Byron)

Centrifugal detection (Unit 1 detection Zone Low (Braidwood)

Charging Pump 1B 16)

Room 11.3G-2 Note 1 Ionization (or photoelectric) 247 Low (Byron)

Centrifugal detection (Unit 2 detection Zone Low (Braidwood)

Charging Pump 2B 16)

Room 11.4-0 Automatic sprinkler stairway Ionization (or photoelectric) 17,407 Low (Byron)

Auxiliary Building and open hatch (Unit 2 detection (Unit 1 detection Low (Braidwood)

General Area El. suppression Zone 54) Zones 11 & 12) 383' 2.2-47

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.4A-0 Note 1 Ionization (or photoelectric) 1,199 Low (Byron)

Control Room detection (Unit 1 detection Zone Low (Braidwood)

Refrigeration 29)

Equipment Room 11.4B-0 Note 1 None 309 Low (Byron)

Radwaste / RSP Low (Braidwood)

Ventilation Control Room 11.4A-1 Automatic total flooding CO2 Byron: Fenwal thermal ionization 666 Moderate (Byron)

Unit 1 Auxiliary system (Unit 1 suppression (or photoelectric) detection (Unit Moderate (Braidwood)

Feedwater Pump Zones 41 and 42) 1 detection Zone 12) 1B Room Braidwood: Fenwal thermal detection 11.4A-2 Automatic total flooding CO2 Byron: Fenwal thermal ionization 724 Moderate (Byron)

Unit 2 Auxiliary system (Unit 2 suppression (or photoelectric) detection (Unit Moderate (Braidwood)

Feedwater Pump Zones 41 and 42) 1 detection Zone 12) Braidwood:

2B Room Fenwal thermal detection 11.4B-1 Note 1 None 234 Negligible (Byron)

Unit 1 Seal Water Negligible (Braidwood)

HX Room 11.4B-2 Note 1 None 234 Negligible (Byron)

Unit 2 Seal Water Negligible (Braidwood)

HX Room 2.2-48

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.4C-0 Note 1 Ionization (or photoelectric) 3,509 Low (Byron)

Radwaste/Remote detection (Unit 1 detection Zone Low (Braidwood)

Shutdown Control 13)

Room 11.4C-1 Note 1 None 175 Negligible (Byron)

Letdown HX 1A Negligible (Braidwood)

Room 11.4C-2 Note 1 None 175 Negligible (Byron)

Letdown HX 2A Negligible (Braidwood)

Room 11.4D-1 Note 1 None 165 Negligible (Byron)

Letdown HX 1B Negligible (Braidwood)

Room 11.4D-2 Note 1 None 165 Negligible (Byron)

Letdown HX 2B Negligible (Braidwood)

Room 11.5-0 Auxiliary Automatic sprinkler stairway Ionization (or photoelectric) 20,080 Low (Byron)

Building General and open hatch (Unit 2 detection (Unit 1 detection Zone Low (Braidwood)

Area EL. 401' suppression Zone 54) Aux. 8) bldg. waste oil drain tank (Unit 1 suppression Zone 57) 2.2-49

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.5-1 Note 1 Ionization (or photoelectric) 1,638 Low (Byron)

Unit 1 Containment detection (Unit 1 detection Zone Low (Braidwood)

Refrigeration 9)

Equipment Room 11.5-2 Note 1 Ionization (or photoelectric) 2,701 Low (Byron)

Unit 2 Containment detection (Unit 2 detection Zone Low (Braidwood)

Refrigeration 9)

Equipment Room 11.5A-0 Note 1 Ionization (or photoelectric) 1,177 Low (Byron)

Radiological detection (Unit 2 detection Zone Low (Braidwood)

Equipment 9)

Calibration Room 11.5A-1 Note 1 Ionization (or photoelectric) 3,489 Low (Byron)

Division 11 detection (Unit 1 detection Zone Low (Braidwood)

Containment 24)

Electrical Penetration Area, El. 414' 11.5A-2 Note 1 Ionization (or photoelectric) 3,489 Low (Byron)

Division 21 detection (Unit 2 detection Zone Low (Braidwood)

Containment 24)

Electrical Penetration Area, EL. 414' 2.2-50

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.5B-1 Note 1 Ionization (or photoelectric) 406 Low (Byron)

Division 12 Cable detection (Unit 1 detection Zone Low (Braidwood)

Riser Area 24) 11.5B-2 Note 1 Ionization (or photoelectric) 406 Low (Byron)

Division 22 Cable detection (Unit 2 detection Zone Low (Braidwood)

Riser Area 24) 11.6-0 Automatic sprinkler stairway to Ionization (or photoelectric) 7,872 Low (Byron)

Auxiliary Building open hatch (Unit 2 suppression detection (Unit 2 detection Zone Low (Braidwood)

General Area, El. Zones 54 and 55) 75) 426' 11.6-1 Note 1 Ionization (or photoelectric) 3,431 Low (Byron)

Division 12 detection (Unit 1 detection Zone Low (Braidwood)

Containment 76)

Electrical Penetration Area, El. 426' 11.6-2 Note 1 Ionization (or photoelectric) 3,401 Low (Byron)

Division 22 detection (Unit 2 detection Zone Low (Braidwood)

Containment 76)

Electrical Penetration Area, El. 426' 2.2-51

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.6A-0 Note 1 Ionization (or photoelectric) 1,808 Low (Byron)

Laboratory HVAC detection (Unit 2 detection Zone Low (Braidwood)

Equipment Room 75) 11.6A-1 Note 1 None 392.5 Negligible (Byron)

Unit 1 Volume Negligible (Braidwood)

Control Tank Room 11.6A-2 Note 1 None 387 Negligible (Byron)

Unit 2 Volume Negligible (Braidwood)

Control Tank Room 11.6B-0 Note 1 None 5,705 Low (Byron)

Auxiliary Building Low (Braidwood)

Offices, El. 426' 11.6C-0 Note 1 Ionization (or photoelectric) 829 Low (Byron)

Auxiliary Building detection (Unit 2 detection Zone Low (Braidwood)

Laundry Room, El. 75) 426' 2.2-52

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.6D-0 Note 1 Ionization (or photoelectric) 552 Low (Byron)

Auxiliary Building detection (Unit 1 detection Zone Low (Braidwood)

Hot Showers, 23)

Decontamination (Byron Only). Mask Cleaning and Issuance Room (Braidwood Only),

Change Areas (B/B), El. 426' 11.6E-0 Note 1 Ionization (or photoelectric) 676 Low (Byron)

Auxiliary Building detection (Unit 1 detection Zone Low (Braidwood)

Decontamination 23)

Pad and Storage (Byron Only), Tool Storage Room (Braidwood Only),

El. 426' 11.7-0 Manual charcoal deluge Temperature switch (in charcoal 7,147 Moderate (Byron)

Auxiliary Building system (Unit 1 suppression absorber) Moderate (Braidwood)

HVAC Exhaust Zones 1, 2, 3 and 10; Unit 2 Ionization (or photoelectric)

Complex suppression Zones 1, 2, 3, 8, detection (Unit 2 detection Zones 9, 10, 25, 26) 12, 22 and 62) 2.2-53

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 11.7-1 Manual charcoal deluge Temperature switch (in charcoal 2,860 Low (Byron)

Unit 1 Purge Room system (Unit 1 suppression absorber) Low (Braidwood)

Zone 7) Ionization (or photoelectric) detection (Unit 1 detection Zone 25) 11.7-2 Manual charcoal deluge Temperature switch (in charcoal 2,860 Low (Byron)

Unit 2 Purge Room system (Unit 2 suppression absorber) Low (Braidwood)

Zone 7) Ionization (or photoelectric) detection (Unit 2 detection Zone 25) 12.1-0 Note 1 Ionization (or photoelectric) 10,680 Low (Byron)

Fuel Handling detection (401'-0" and 426'-0" Low (Braidwood)

Building and Unit 1 detection Zone 39)

Ultraviolet detection (426'-0")

(Unit 1 detection Zone 38 Braidwood only) 13.0 Automatic total flooding Halon Ionization (or photoelectric) 816 High (Byron)

QA vault 1301 system (Unit 1 detection (Unit 1 detection Zones High (Braidwood) suppression Zone 53) 61 and 62) 14.1-0 Note 1 None 4,566 Low (Byron)

Radwaste Low (Braidwood)

Drumming Station and Tunnel 2.2-54

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 14.2-0 Note 1 None 1,433 Low (Byron)

Radwaste Negligible (Braidwood)

Evaporator Tank/Spent Resin Pump Room 14.3-0 Note 1 None 2,090 Low (Byron)

Surface Condenser Low (Braidwood)

Room 14.4-0 Note 1 None 716 Low (Byron)

Spent Resin Low (Braidwood)

Tank/Waste Gas Compressor Room 14.5-0 Note 1 None 1,940 Low (Byron)

Radwaste Low (Braidwood)

Evaporator Room 14.6-0 Partial coverage automatic Temperature switch (in charcoal 11,055 Low (Byron)

Radwaste Building sprinkler system; Manual absorber) Low (Braidwood)

Ground Floor charcoal deluge system (Unit 1 Ionization (or photoelectric) suppression Zones 32 and 58) detection (Unit 1 detection Zone Note 1 63) 16.1-1 Note 1 None N/A Low (Byron)

Unit 1 Refueling Low (Braidwood)

Water Storage Tank 2.2-55

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 16.1-2 Note 1 None N/A Low (Byron)

Unit 2 Refueling Low (Braidwood)

Water Storage Tank 17.1-0 Note 1 None N/A Low (Byron)

Open flume 17.1-1 Note 1 None 287,627 Moderate (Byron)

Natural Draft Cooling Tower -

Unit 1 17.1-2 Note 1 None 287,627 Moderate (Byron)

Natural Draft Cooling Tower -

Unit 2 17.2-1 Note 1 None 7,396 Low (Byron)

Essential Service Water (ESW)

Cooling Tower -

Division 12/22 (Byron) 2.2-56

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 17.2-2 Note 1 None 7,396 Low (Byron)

Essential Service Water (ESW)

Cooling Tower -

Division 11/21 (Byron) 18.1-1 Note 1 Ionization (or photoelectric) 297 Low (Byron)

Diesel-Generator detection in supply air duct Low (Braidwood) 1B and Switchgear Room Air Shaft 18.1-2 Note 1 Ionization (or photoelectric) 297 Low (Byron)

Diesel-Generator detection in supply air duct Low (Braidwood) 2B and Switchgear Room Air Shaft 18.2-1 Note 1 Ionization (or photoelectric) 141 Low (Byron)

Diesel-Generator detection in supply air duct Low (Braidwood) 1A and Switchgear Room Air Shaft 18.2-2 Note 1 Ionization (or photoelectric) 141 Low (Byron)

Diesel-Generator detection in supply air duct Low (Braidwood) 2A and Switchgear Room Air Shaft 2.2-57

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.3-1 Note 1 Ionization (or photoelectric) Tunnel Low (Byron)

Unit 1 Main Steam detection in safety valve 10,200; Low (Braidwood) and Auxiliary enclosures (Unit 1 detection Valve Feedwater Pipe Zones 14 and 15) enclosures Tunnel 1,719 18.3-2 Note 1 Ionization (or photoelectric) Tunnel Low (Byron)

Unit 2 Main Steam detection in safety valve 10,200; Low (Braidwood) and Auxiliary enclosures (Unit 2 detection Valve Feedwater Pipe Zones 14 and 15) enclosures Tunnel 1,719 18.4-1 Note 1 Temperature switch (in charcoal 1,433 Moderate (Byron)

Control Room Charcoal filter deluge system absorber) Moderate (Braidwood)

HVAC Equipment (Unit 1 suppression Zone 4) Ionization (or photoelectric)

Room, Train A detection (Unit 1 detection Zone 68) 18.4-2 Note 1 Temperature switch (in charcoal 1,530 Low (Byron)

Control Room Charcoal filter deluge system absorber) Ionization (or Low (Braidwood)

HVAC Equipment (Unit 2 suppression Zone 4) photoelectric) detection (Unit 2 Room, Train B detection Zone 68) 18.5-1 Note 1 None 846 Low (Byron)

Locker Room Area Low (Braidwood)

(Byron) and Kitchen/Locker Room Area (Braidwood) 2.2-58

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.5-2 Note 1 Ionization (or photoelectric) 734 Low (Byron)

Security Control detection (Unit 2 detection Zone Low (Braidwood)

Center and 69)

Electronics Shop 18.6-0 Note 4 Note 4 Note 4 Note 4 Service Building, Ground Floor 18.7-0 Note 4 Note 4 Note 4 Note 4 Service Building, Second Floor 18.8-0 Note 4 Note 4 Note 4 Note 4 Service Building, Third Floor 18.9-0 Note 4 Note 4 Note 4 Note 4 Service Building, Fourth Floor 18.10A-1 Deluge spray system electrical Thermistor wire (Unit 1 detection 1,530 High (Byron)

Main Power interlocks (Unit 1 Zone 14) Zone 30) High (Braidwood)

Transformer 1E 18.10A-2 Deluge spray system electrical Thermistor wire (Unit 2 detection 1,530 High (Byron)

Main Power interlocks (Unit 2 Zone 14) Zone 30) High (Braidwood)

Transformer 2E 2.2-59

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.10B-1 Deluge spray system electrical Thermistor wire (Unit 1 detection 1,530 High (Byron)

Main Power interlocks (Unit 1 Zone 13) Zone 31) High (Braidwood)

Transformer 1W 18.10B-2 Deluge spray system electrical Thermistor wire (Unit 2 detection 1,530 High (Byron)

Main Power interlocks (Unit 2 Zone 13) Zone 31) High (Braidwood)

Transformer 2W 18.10C-1 Deluge spray system electrical Thermistor wire (Unit 1 detection 905 High (Byron)

Unit Auxiliary interlocks (Unit 1 Zone 15) Zone 32) High (Braidwood)

Transformer 141-1 18.10C-2 Deluge spray system electrical Thermistor wire (Unit 2 detection 905 High (Byron)

Unit Auxiliary interlocks (Unit 2 Zone 15) Zone 32) High (Braidwood)

Transformer 241-1 18.10D-1 Deluge spray system electrical Thermistor wire (Unit 1 detection 905 High (Byron)

Unit Auxiliary interlocks (Unit 1 Zone 16) Zone 33) High (Braidwood)

Transformer 141-2 18.10D-2 Deluge spray system electrical Thermistor wire (Unit 2 detection 905 High (Byron)

Unit Auxiliary interlocks (Unit 2 Zone 16) Zone 33) High (Braidwood)

Transformer 241-2 18.10E-1 Deluge spray system electrical Thermistor wire (Unit 1 detection 1,476 High (Byron)

System Auxiliary interlocks (Unit 1 Zones 17 & Zones 34 & 35) High (Braidwood)

Transformers 142-1 18) and 142-2 2.2-60

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.10E-2 Deluge spray system electrical Thermistor wire (Unit 2 detection 1,476 High (Byron)

System Auxiliary interlocks (Unit 2 Zones 17 & Zones 34 & 35) High (Braidwood)

Transformer 242-1 18) and 242-2 18.11-0 Byron - partial low-pressure Byron: Ionization (or Byron Low (Byron)

River Screen local application CO2 system photoelectric) detection (Unit 1 7,855; Low (Braidwood)

House (Unit 1 Zone 52) - Note 1 detection Zone 79) Rate Braidwood compensated with CO2 system 7,871 Braidwood - Note 1 Braidwood: Ionization detection; Ultraviolet detection (Unit 1 detection Zone 79) 18.11-1 Total flooding CO2 system Rate compensated detectors 216 High (Byron)

Byron River Screen Ionization (or photoelectric)

House Diesel Oil detection (Unit 1 detection Zone Storage Tank 79)

Room 1 18.11-2 Total flooding CO2 system Rate compensated detectors 216 High (Byron)

Byron River Screen Ionization (or photoelectric)

House Diesel Oil detection (Unit 1 detection Zone Storage Tank 79)

Room 2 2.2-61

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.12-0 Note 1 Ionization (or photoelectric) and Byron Low (Byron)

Circulating Water U.V. detection (Unit 1 detection 11,697; Low (Braidwood)

Pump House Zone 22) Braidwood (Byron) Byron ionization (or 12,647 Lake Screen House photoelectric) and U.V. detection (Braidwood) (Unit 1 detection Zone 22)

Braidwood 18.13-0 Automatic sprinkler system Ionization (or photoelectric) Byron High (Byron)

Diesel Driven Fire (Unit 1 Zone 25) detection (Unit 1 detection Zone 267; High (Braidwood)

Pump Cubicle 22) Byron only Braidwood 302 18.14A-1 Note 1 Ionization (or photoelectric) 574 Low (Byron)

ESW Cooling detection (Unit 1 detection Zone Tower Electrical 26)

Substation 0B, Div.

12 (Byron Only) 18.14A-2 Note 1 Ionization (or photoelectric) 493 Low (Byron)

ESW Cooling detection (Unit 1 detection Zone Tower Electrical 26)

Substation 0B, Div.

22 (Byron Only) 2.2-62

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.14B-1 Note 1 Ionization (or photoelectric) 574 Low (Byron)

ESW Cooling detection (Unit 1 detection Zone Tower Electrical 26)

Substation 0A, Div.

11 (Byron Only) 18.14B-2 Note 1 Ionization (or photoelectric) 493 Low (Byron)

ESW Cooling detection (Unit 1 detection Zone Tower Electrical 26)

Substation 0A, Div.

21 (Byron Only) 18.15-0 Note 1 None 9,898 Low (Braidwood)

Makeup Demineralizer Building (Braidwood) 18.16-1 Dikes None N/A Negligible (Byron)

Sulfuric Acid Rank

1. 1 (Byron Only) 18.16-2 Dikes None N/A Negligible (Byron)

Sulfuric Acid Tank

1. 2 (Byron Only) 2.2-63

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.17-0 Note 1 None Note 4 Note 4 Hydrogen /

Nitrogen Storage Area 18.19-0 Dikes None N/A Negligible (Byron)

Sodium Hypochlorite Tank 18.20-0 Dikes None 1,240 High (Byron) 125,000 and (Tank and High (Braidwood) 50,000-gallon Fuel Berm)

Oil Storage Tanks 18.21-0 (Deleted) N/A N/A N/A N/A 18.22-0 Note 1 None 4,992 Low (Byron)

Makeup Demineralizer Building (Byron Only) 2.2-64

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.23-0 Note 1 None N/A Negligible (Byron)

Condensate Negligible (Braidwood)

Storage Tanks, Deep well, and Construction Fire Pump Area 18.24-0 Note 1 None 1,287 Low (Byron)

Turbine Building Low (Braidwood)

Sampling Room 18.25-1 Note 1 None N/A Negligible (Byron)

Primary Water Negligible (Braidwood)

Storage Tank #1 18.25-2 Note 1 None N/A Negligible (Byron)

Primary Water Negligible (Braidwood)

Storage Tank #2 18.26-0 Manual charcoal deluge Temperature switch (in charcoal 4,665 Low (Byron)

TSC/Condensate system; (Unit 2 suppression absorber) Low (Braidwood)

Cleanup Building Zone 57) 2.2-65

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.27-0 Note 1 None 351 High (Byron)

Level B Storage Low (Braidwood)

Building (Byron)

Bottle Storage Enclosure (Braidwood) 18.28-0 Note 1. Also, waste oil tank None 2,064 Low (Byron)

Waste Treatment has overhead sprinkler (Unit 2 Low (Braidwood)

Building Suppression Zone 52) 18.29-0 Fire Hydrants None N/A N/A Aboveground Vehicle Fuel Dispensing Areas 18.30-0 Fire Hydrants None New Oil High (Byron)

New and Used Oil Pad High (Braidwood)

Storage Pads 1,876; Used Oil Pad 346 18.31-0 Fire Hydrants None 216 Negligible (Byron)

Acid Pump House (Byron Only) 2.2-66

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.32-0 Note 1 None Byron Moderate (Byron)

Receiving Building Automatic sprinkler system and 30,380; Low (Braidwood) and Warehouse fire hydrants (Unit 1 Braidwood Suppression Zone 30) 4,876 18.33-0 Note 4 Note 4 Note 4 Note 4 Gatehouse 18.34-0 Fire Hydrants None 387 High (Byron)

Welding Gas High (Braidwood)

Storage Building 18.35-0 Note 1 Ionization (or photoelectric) 192.5 Low (Byron)

Security Diesel detection (Unit 2 detection Zone Low (Braidwood)

MCC 26) 18.36-0 None Ionization (or photoelectric) 2,024 Low (Byron)

Relay House detection (Unit 1 detection Zone Low (Braidwood) 80) 18.37-0 None None 1,765 Low (Byron)

Maintenance Low (Braidwood)

Building 18.38-0 Fire Hydrants Ionization (or photoelectric) Note 4 Note 4 Illinois Department detection of Nuclear Safety (IDNS) Building 2.2-67

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION FIRE AREA / FIRE PROTECTION FIRE DETECTION Floor Area FIRE LOAD ZONE NUMBER (ft2) CLASSIFICATION AND NAME 18.40-0 Automatic Sprinkler In-duct ionization (or Note 4 Note 4 Braidwood photoelectric) smoke detection electrical and instrument maintenance (EM/IM) shop building 18.41-0 Automatic Pre-Action Sprinkler Heat Detector 10,400 Moderate (Braidwood)

Unit 1 Containment Access Facility (Braidwood Only) 18.42-0 Automatic Pre-Action Sprinkler Heat Detector 10,400 Moderate (Braidwood)

Unit 2 Containment Access Facility (Braidwood Only) 18.43-0 Fire Hydrants None 10,325 Low (Braidwood)

Braidwood Radwaste Storage Tank 2.2-68

B/B - FPR AMENDMENT 29 DECEMBER 2020 TABLE 2.2-3 FIRE HAZARDS ANALYSIS EQUIPMENT TABULATION All fire zones are protected by manual extinguishing equipment. This includes manual hose stations (except Byron and Note 1 Braidwood river screen house) and portable fire extinguishers. See the figures listed on Table 2.2-2 for each zone, for the planned location for each piece of equipment.

An automatic deluge system is provided for the turbine oil storage tanks (Fire Zones 8.3-1 and 8.3-2), the hydrogen Note 2 seal oil units (Fire Zones 8.5-1 and 8.5-2), and the turbine oil bearings (Fire Zone 8.6-0). Fire detectors used for these hazards are Fenwal Rate Compensated detectors.

The ionization (or photoelectric) and Fenwal thermal detectors are cross zoned to require both an ionization (or photoelectric) and a heat detection of a fire to actuate the automatic fire suppression system. Each detection zone Note 3 provides an independent alarm of a fire (or detector trouble) to the main control room. The circuits are designed that if either of the circuits has a break or a ground fault in one of the signaling line circuits, the remaining detection circuit could then automatically actuate the fire suppression system if a fire was present The fire zone does not contain safety-related components or radioactive materials. The fire hazards in the zone are adequately protected and separated from areas that do contain safety-related components or radioactive materials.

Note 4 Therefore, descriptions of the fire protection, fire detection, combustible materials, floor area and fire load associated with the zone are not provided.

2.2-69

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3 FIRE AREA ANALYSIS 2.3.1 Containment Buildings Each primary containment has been divided into three zones for the fire area analysis.

The following material applies to the entire exterior containment structure.

Each primary Containment Building is a closed concrete cylinder with structural reinforced base slab, walls, and domed roof slab. These elements vary in thickness from 42 inches for the roof to 144 inches for the base slab. The roof slab and walls have been post-tensioned by means of steel tendons. The inside face of the entire building is lined with a 1/4-inch-thick steel plate liner.

Access to the Containment Building is through a 124-inch-diameter steel "personnel" air lock which leads to a weathertight, 3-hour fire rated enclosure of 36-inch-thick structural reinforced concrete walls, roof, and floor on the exterior of the building at elevation 401 feet 0 inch. There is a blast resistant vestibule, which is constructed of a steel shell filled with concrete, connected to the Emergency Airlock exit. The vestibule has a minimum thickness of 10.5 inches and contains a non-listed blast resistant door that provides a level of fire protection equivalent to a UL Label A fire door. The vestibule assembly provides a 3-hour fire resistance. Normal access is through a 225 inch-diameter steel "equipment" air lock which leads to the Fuel Handling Building at elevation 426 feet 0 inch. Both air locks are provided with airtight, removable covers of steel plate.

2.3.1.1 Unit 1 Containment Missile Shield Area (Fire Zone 1.1-1)

This zone is shown on Figures 2.3-10 (Sheet 1), 2.3-12 (Sheet 1), 2.3-13 (Sheet 1), and 2.3-15. It is shown in elevation on Figure 2.3-26 (Sheet 1). Electrical cable trays routed through this zone are shown on Figures 2.3-36 (Sheet 1), 2.3-37 (Sheet 1), and 2.3-38 (Sheet 1).

Fire Barrier Description A structural reinforced concrete cylinder with an inside diameter of 21 feet 0 inch and walls 108 inches thick surrounds the reactor cavity from elevation 348 feet 0 inch up to elevation 377 feet 0 inch. The structural reinforced concrete slab below this cylinder, which is the base slab of the Containment Building, is 39 feet 0 inch in diameter, and 108 inches thick. Access to the steam generator area at elevation 377 feet 0 inch from the reactor cavity is through a tunnel. The tunnel walls are structural reinforced concrete 36 inches thick. Both the tunnel and reactor cavity are provided with a 1/4-inch-thick steel liner plate. This tunnel is open to the steam generator area.

2.3-1

B/B - FPR AMENDMENT 29 DECEMBER 2020 Over the structural concrete described above are placed 24-inch-thick (reactor cavity walls), 30-inch-thick (reactor cavity and tunnel floor), and 24-inch-thick (tunnel walls) structural reinforced concrete topping.

From elevation 377 feet 0 inch to elevation 389 feet 6 inches, a structural reinforced concrete cylinder with an inside diameter of 17 feet 1 inch and walls 101 inches thick surrounds the reactor cavity.

From elevation 389 feet 6 inches to elevation 400 feet 10-1/2 inches a structural reinforced concrete cylinder of 25 feet 0 inch inside diameter and 54 inches thick surrounds the reactor cavity.

There are no floor drains in the reactor cavity or tunnel floor. A stainless-steel sump with pump is in the tunnel floor for the purpose of removing water to another sump on the reactor floor at elevation 368 feet 0 inch. There is also an oil separator and collection sump located in this zone.

Since this reactor cavity is open to the adjacent steam generator area, it is not considered to have fire rated walls.

The remainder of this zone is the area enclosed by the 36 inches to 45 inches thick structural reinforced concrete inner walls of the annular areas and the minimum 48 inches thick structural reinforced concrete walls enclosing the reactor cavity and refueling cavity. It extends from elevation 377 feet 0 inch up to elevation 426 feet 0 inch and has additional floor levels of steel grating supported by unprotected structural steel beams and columns at elevation 401 feet 0 inch and at elevation 390 feet 0 inch.

The floor of this zone is the previously described 108-inch-thick base slab of the Containment Building with an additional 36-inch-thick reinforced concrete finish slab. The ceiling slab at elevation 426 feet 0 inch, which is the floor slab of the operating area, is 60-inch-thick structural reinforced concrete, contains eight large openings for penetration of the steam generators and associated piping, and carries no fire rating.

Four-inch-diameter floor drains in this zone are routed to a sump at elevation 377 feet 0 inch.

Two nonrated doors are provided at elevation 377 feet 0 inch to the adjacent annular area.

2.3-2

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment All elements of the reactor coolant pressure boundary are in this zone. Cables and cable trays from both ESF divisions are present.

Protection Criteria and Measures The entire zone is separated from the remainder of the Containment Building by substantial concrete walls.

The design of the reactor coolant piping insulation results in a negligible probability of fire. The surface of the insulation will not exceed approximately 150 Degrees Fahrenheit. One of the prime considerations of reflective insulation design is the elimination of convective currents. Therefore, all seams are covered with metal flashings, reducing the possibility of oil seepage onto the pipe surface inside the insulation. The restriction of airflow also will prevent rapid combustion and spreading of the fire in the event oil is ignited at the pipe surface.

Combustible Materials Cable insulation, grease, hydraulic fluid, lube oil, miscellaneous and transient combustibles, polyester, rubber, and vinyl.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Four manual hose stations are provided within the adjacent zone. Portable fire extinguishers are available in the area.

Heat detectors are provided over the reactor coolant pumps which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone were consumed.

The effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.1.

The most likely fire would occur if all the lubricating oil in a single reactor coolant pump motor burned. If this happened, the reactor coolant pump motor would be rendered inoperative. This is assumed to be only one pump motor because of the large distances separating the motors. The ability to shut down the reactor would not be impaired by the loss of any or all motors as these motors are not safety-related and not necessary for a safe shutdown of the reactor.

2.3-3

B/B - FPR AMENDMENT 29 DECEMBER 2020 An analysis has been completed assuming that oil in a reactor coolant pump is ignited and all the oil (245 gallons) in the pump burns. The oil is assumed to burn at a rate of 6.5 gpm. The resulting maximum containment temperature (290 Degrees Fahrenheit) is lower than the temperature predicted after a main steam line break and is, therefore, within the design basis and the equipment qualification envelope. The only cable near the pumps, other than the cable to the reactor coolant pump itself, is routed on the walls near the pumps. These cables are a minimum of two feet from the outside surface of the pump and are enclosed in conduit or risers. There are no cables directly over the reactor coolant pumps.

The available heat sinks within the containment structure and the fan coolers will minimize any temperature or pressure rise resulting from a fire.

Portions of the Containment Building Ventilation System may be damaged, but these are not safety related. The design-basis fire is highly unlikely for the following reasons:

a. The Containment Building is a controlled access area.

b. Normally, all the lubricating oil is contained inside the pump motor casings.

c. Fire detection is provided.

Any fire in this zone would be detected and annunciated in the Control Room.

2.3.1.2 Unit 2 Containment Missile Shield Area (Fire Zone 1.1-2)

This zone is shown on Figures 2.3-10 (Sheet 3), 2.3-12 (Sheet 3), 2.3-13 (Sheet 2), 2.3-14 (Sheet 3), and 2.3-15. It is also shown in elevation on Figures 2.3-21 (Sheet 2) and 2.3-26 (Sheet 2). Electrical cable trays routed through this zone are shown on Figures 2.3-36 (Sheet 2), 2.3-37 (Sheet 2), and 2.3-38 (Sheet 2).

For details, see Subsection 2.3.1.1.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.2.

2.3-4

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.1.3 Unit 1 Annular Area (Fire Zone 1.2-1)

This zone is shown on Figures 2.3-12 (Sheet 1), 2.3-13 (Sheet 1), and 2.3-14 (Sheet 1) and in elevation on Figure 2.3-26 (Sheet 1). Electrical cable trays routed through this zone are shown on Figures 2.3-36 (Sheet 1), 2.3-37 (Sheet 1), and 2.3-38 (Sheet 1).

Fire Barrier Description This zone is an annular area between the exterior wall of the Containment Building and the 36-inch to 45-inch-thick structural reinforced concrete wall of the Missile Shield Area which extends up to the underside of the floor slab at elevation 426 feet 0 inch. The floor of this zone is the previously described 108-inch-thick base slab of the Containment Building with an additional 36-inch-thick reinforced concrete topping. The ceiling at elevation 426 feet 0 inch, which is the floor of the operating area above, is steel grating or a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by unprotected steel beams and carries no fire rating. Intermediate floor levels in this zone are elevation 390 feet 0 inch, elevation 399 feet 0 inch, elevation 407 feet 0 inch, and elevation 412 feet 0 inch; They are of similar construction, are open to one another and carry no fire rating.

There are two nonrated doors in the wall leading into the adjacent Missile Shield Area at elevation 377 feet 0 inch. An opening is provided in the wall in this area at elevation 401 feet 0 inch for access into the adjacent seal table cubicle.

Four-inch diameter floor drains in this zone are routed to a sump at elevation 377 feet 0 inch.

Safety-Related Equipment The following equipment is in this zone:

a. Reactor Containment Fan Cooler Units.

b. Various primary plant instrumentation equipment.

There are also cables and cable trays of both ESF divisions present.

Protection Criteria and Measures The safety-related equipment in this zone is widely spaced around the containment to preclude damage to redundant equipment.

The fire protection piping in this zone is all Category IC piping.

At Byron, the majority of the fire protection piping in this zone has been reclassified as Safety Category II, Quality Group D (ref. EC 626662); and remains classified as Seismic Category I.

2.3-5

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, flexible connections, gaskets, grease, miscellaneous and transient combustibles, polyester and vinyl.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Four manual hose stations are placed at equal intervals on each level (elevations 377 feet 0 inch, 401 feet 0 inch, and 426 feet 0 inch). Portable fire extinguishers are also available within the zone. One additional manual hose station is available outside the equipment hatch on elevation 426 feet 0 inch.

Ionization (or photoelectric) detectors are provided over the electrical penetration area which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned. With this the large distance between concentrations of combustibles, it is considered highly unlikely that more than one ESF division would be rendered inoperative.

This would, therefore, not prevent a reactor shutdown as the loss of any one ESF division is acceptable.

The analysis of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.1.

2.3.1.4 Unit 2 Annular Area (Fire Zone 1.2-2)

This zone is shown on Figures 2.3-12 (Sheet 3), 2.3-13 (Sheet 2), 2.3-14 (Sheet

3) and in elevation on Figures 2.3-21 (Sheet 2) and 2.3-26 (Sheet 2). Electrical cable trays routed through this zone are shown on Figures 2.3-36 (Sheet 2), 2.3-37 (Sheet 2), and 2.3-38 (Sheet 2).

For details, see Subsection 2.3.1.3.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.2.

2.3-6

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.1.5 Unit 1 Containment Upper Area (Fire Zone 1.3-1)

This zone is shown on Figures 2.3-8 (Sheet 1), 2.3-10 (Sheet 1), and 2.3-12 (Sheet 1) and in elevation on Figure 2.3-26 (Sheet 1). Electrical cable trays routed through this zone are shown on Figures 2.3-33 (Sheet 1) and 2.3-35 (Sheet 1).

Fire Barrier Description This zone includes the entire Containment Building, from elevation 426 feet 0 inch up to the domed roof slab at elevation 599 feet 0 inch, and the refueling cavity from elevation 390 feet 6 inches up to elevation 426 feet 0 inch.

The walls and floor slab of the refueling cavity are minimum 42-inch structural reinforced concrete. The entire cavity is lined with a 3/16-inch-thick stainless-steel plate liner.

The floor at elevation 426 feet 0 inch is a 60-inch-thick structural reinforced concrete slab in the portion over the steam generator and feed pump area and has several penetrations for equipment. The remaining portion, which is over an annular area, is steel grating or a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected structural steel beams and carries no fire rating. Structural reinforced concrete walls (36 feet high by 42 inches thick) completely enclose the portion of the four steam generators and the pressurizer that projects above the floor at elevation 426 feet 0 inch. Other piping and equipment are enclosed by 42-inch-thick structural reinforced concrete walls 9 feet high.

Four-inch-diameter floor drains are provided in concrete floor areas and are routed to the sump at elevation 377 feet 0 inch.

Safety-Related Equipment The safety injection accumulators are in this zone. Portions of the Containment Spray System and Reactor Containment Fan Cooler ductwork are safety related.

Protection Criteria and Measures Portable fire extinguishers are located at the overhead cranes and elsewhere in the zone.

2.3-7

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Charcoal, flexible connections, gaskets, grease, HEPA filters, lube oil, miscellaneous and transient combustibles, polyester, prefilters, PVC, and vinyl.

At Byron, there is plastic and rubber. Containment charcoal filter units have been abandoned in place with the Charcoal absorber filters removed from their HVAC plenum.

At Braidwood, there is HDPE and FRP. Containment charcoal filter units have been abandoned in place with the Pre-filters, HEPA filters, and Charcoal absorber filters removed from their HVAC plenum.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Four hose stations are located on the operating floor and four more hose stations are available from its fire zone below. Portable fire extinguishers are available in the Containment Building. If necessary, one additional hose could be brought in through the equipment hatch from the Fuel Handling Building.

Ionization (or photoelectric) detectors are provided over the electrical penetration area. They also alarm in the Control Room.

At Byron, the containment charcoal filter units have been abandoned in place with the charcoal filters removed from their HVAC plenum. The deluge supply has been manually isolated. A temperature switch is mounted in the charcoal absorber bank and will annunciate in the main control room but is no longer required.

At Braidwood, containment charcoal filter units have been abandoned in place with the Pre-filters, HEPA filters, and Charcoal absorber filters removed from their HVAC plenum. The deluge supply has been manually isolated and control room alarms to these units have been disabled.

Design-Basis Fire The design-basis fire would occur if all combustibles in the zone burned. Due to the physical arrangement of the combustibles, it is highly unlikely that the design-basis fire will occur. Safe shutdown of the reactor would not be affected.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.1.

2.3-8

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.1.6 Unit 2 Containment Upper Area (Fire Zone 1.3-2)

This zone is shown on Figures 2.3-8 (Sheet 3), 2.3-10 (Sheet 3), 2.3-12 (Sheet

3) and in elevation on Figures 2.3-21 (Sheet 2) and 2.3-26 (Sheet 2). Electrical cable trays routed through this zone are shown on Figures 2.3-33 (Sheet 2) and 2.3-35 (Sheet 2).

For details, see Subsection 2.3.1.5.

The analysis of the effects of fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.2.

2.3.2 Control Room Area 2.3.2.1 Control Room (Fire Zone 2.1-0)

This area is shown on Figure 2.3-8 (Sheets 1 and 3) and elevation views are shown on Figures 2.3-22 (Sheet 2) and 2.3-25 (Sheets 1 and 2). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor at elevation 451 feet 0 inch, which is the ceiling of the Lower Cable Spreading Room, is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and by structural steel columns protected with a 4-inch cover of solid masonry units or with a fire-resistant covering. The floor assembly carries a 3-hour fire rating.

The walls of the Control Room are 12-inch- thick solid masonry units or 42-inch-thick structural reinforced concrete and carry a 3-hour fire rating. These masonry walls extend up to within 1 inch of the ceiling above. This resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation. All doors leading from the Control Room are of "A" label construction.

The ceiling slab at elevation 463 feet 5 inches, which is the floor of the Upper Cable Spreading Room, is a 2-1/2- inch clear cover of reinforced concrete over 1-1/2-inch fluted steel decking. The underside of this decking, and the structural steel members which support this slab, are protected with a fire-resistant covering. The slab and supporting steel members carry a 3-hour fire rating. A metal egg crate suspended ceiling system is provided below the ceiling slab.

2.3-9

B/B - FPR AMENDMENT 29 DECEMBER 2020 The concrete ceiling and concrete floor separate the cable spreading rooms -

upper (ESF Divisions 11 and 21) and lower (ESF Divisions 12 and 22) - from the Control Room. Cable openings to the upper spreading area are fire stopped.

Cables from the Lower Cable Spreading Room enter the Control Room through fire-proofed openings located in the floor of the room.

All ventilation penetrations are in the ceiling slab and each is equipped with two curtain type 1-1/2-hour horizontal fire dampers in series per penetration.

Safety-Related Equipment Control panels, both safety-related and non-safety-related, which control all functions of the plant are in the Control Room. The following panels are safety-related:

a. Unit 1 equipment:

1. General and Auxiliary Power System Control Board, ESF Divisions 11 and 12, 1PM01J.

2. Reactor and Chemical Volume Control Board, ESF Divisions 11 and 12, 1PM05J.

3. Engineered Safety Features Control Board, ESF Divisions 11 and 12, 1PM06J.

4. Nuclear Instrumentation, ESF Divisions 11 and 12, 1PM07J.

5. Incore Instrumentation, ESF Divisions 11 and 12, 1PM08J.

6. Containment Isolation Control Board, ESF Divisions 11 and 12, 1PM11J.

b. Unit 2 equipment:

1. Same as Unit 1 equipment, except that ESF Divisions 11 and 12 are replaced by ESF Divisions 21 and 22, respectively, and the equipment numbers have a prefix of 2 instead of 1.

c. Common equipment:

1. General Services Control Board, ESF Divisions 11, 12, 21, and 22 -

0PM01J.

2. HVAC Control Board, ESF Divisions 11, 12, 21, and 22 - 0PM02J.

The safety-related ventilation equipment in this fire zone consists of portions of the Control Room Ventilation System.

2.3-10

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The fire dampers are provided with fusible links.

The amount of combustible material in the Control Room is minimized by administrative controls. Cables of the different ESF divisions are separated according to separation criteria presented in Appendix 5.2.

Cables of ESF Divisions 11 and 21 and 12 and 22 are separated by distance and enter the Control Room from the Upper and Lower Cable Spreading Rooms respectively. Separate risers and wireways for the different ESF divisions are used. Separation within the panels containing more than one ESF division is provided by metal barriers, switch modular housings, or by physical separation.

Combustible Materials Cable insulation, fiber optic cable, gaskets, insulation, paper, and plastic.

Earthstone solid surfaces are installed as desktops in the Control Room; these desktops have a flame spread less than 25 and a smoke development rating less than 450.

At Byron, acrylic and rubber.

At Braidwood, polyethylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities There is no automatic fire suppression system. Portable fire extinguishers are in the Control Room. Two manual hose stations are in the Turbine Building along column row L, which are available to fight a fire in this area. There are ionization or photoelectric detectors located above the metal egg crate ceiling, which alarm and annunciate locally.

In addition, the ionization (or photoelectric) detectors in the supply and exhaust ductwork for the control panels will alarm in the Control Room.

Design-Basis Fire The HVAC diffusers, which are aluminum, could be affected by a design-basis fire. The spread of heat and combustion products, if any, would be stopped by the fire dampers. The fire dampers will close when the temperature exceeds 165 Degrees Fahrenheit 2.3-11

B/B - FPR AMENDMENT 29 DECEMBER 2020 A design-basis fire could make the Control Room uninhabitable and may damage some portions of the cabinets and the Main Control Boards. Due to the low fire loading, the design-basis fire would be confined to the Control Room. A self-contained breathing apparatus with backup bottled air at Braidwood and backup reserve at Byron have been provided to allow operators to remain in the Control Room for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> during conditions which might otherwise force them to leave.

Any fire in the Control Room would be quickly detected by ionization (or photoelectric) detectors or the personnel in the room. The Control Room is continuously manned. Since most combustibles are either contained in cabinets or panels, any postulated fire will be localized and would be quickly extinguished using available manual firefighting equipment.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.3.

2.3.2.2 Record Storage Room (Fire Zone 2.1-1)

This area is shown on Figure 2.3-8 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor slab at elevation 451 feet 0 inch, which is the ceiling of the Lower Cable Spreading Room, is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and carries a 3-hour fire rating.

All walls are 12-inch hollow concrete masonry units and carry a 3-hour fire rating.

They extend up to within 1 inch of the ceiling above. This resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation. A 3-hour rated Label "A" fire door leads to the Control Room.

The ceiling slab at elevation 463 feet 5 inches, which is the floor of the Upper Cable Spreading Room, is a 1-1/2-inch clear cover of reinforced concrete over protected 1-1/2-inch fluted steel decking. It is supported by protected structural steel beams and carries a 3-hour fire rating. A 1/2-inch x 1/2-inch x 3/4-inch-thick aluminum egg crate suspended ceiling system is provided below the ceiling slab.

2.3-12

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment There is no safety-related or reactor shutdown and cooling equipment in this area.

Protection Criteria and Measures Combustibles in this room are subject to administrative controls.

Combustible Materials Gaskets, insulation, and paper.

The floor is covered with 1/8-inch-thick vinyl-asbestos tile and vinyl cove base is provided at the intersection of the walls and the floor. Fire hazard characteristics of vinyl-asbestos tile and cove base were obtained from tests in accordance with ASTM Test E-84. Vinyl-Asbestos Tile and Cove Base has a Flame spread less than 75, Fuel contribution of 0, and Smoke developed of 415.

At Byron, plastic.

At Braidwood, PMMA and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A portable fire extinguisher is in the room and a manual hose station can be brought in from the Turbine Building to fight a fire in this area.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would result if all the combustibles in this room burned. The furniture and other materials in this area would be destroyed.

This would not affect the ability to shut down and cool the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.4.

2.3-13

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.2.3 Storage and Toilet Room (Fire Zone 2.1-2)

This zone is shown on Figure 2.3-8 (Sheet 3).

Fire Barrier Description The floor slab at elevation 451 feet 0 inch, which is the ceiling of the Lower Cable Spreading Room, is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and carries a 3-hour fire rating.

All walls of the storage area are 12-inch-thick hollow concrete masonry units and carry a 3-hour fire rating and they extend up to within 1 inch of the ceiling above.

This resulting space is packed with a 1-inch-thick blanket of foil-backed Thermafiber insulation. A 3-hour rated Label "A" fire door leads to the Control Room.

The ceiling slab at elevation 463 feet 5 inches, which is the floor of the Upper Cable Spreading Room, is a 2-1/2-inch clear cover of reinforced concrete over 3-hour protected 1-1/2-inch fluted steel decking. It is supported by protected structural steel beams and carries a 3-hour fire rating. An acoustical tile suspended ceiling system is provided below the ceiling slab in the storage area.

Safety-Related Equipment For details, see Subsection 2.3.2.2.

Protection Criteria For details, see Subsection 2.3.2.2.

Combustible Materials Gaskets, insulation, and paper.

The storage area floor is covered with 1/8-inch-thick vinyl-asbestos tile and cove base is provided at the intersection of the walls and the floor.

At Byron, plastic.

At Braidwood, polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-14

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities For details, see Subsection 2.3.2.2.

Design-Basis Fire For details, see Subsection 2.3.2.2.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.5.

2.3.3 Cable Spreading Rooms The design includes several cable spreading rooms at elevations 439 feet 0 inch and 463 feet 4-1/2 inches. The rooms are designed such that redundant safe shutdown cabling is routed through separate rooms and isolated by 3-hour fire barriers.

NRC fire protection guidance contained in BTP CMEB 9.5-1 states that the primary fire suppression in cable spreading rooms should be an automatic water system. The primary fire suppression in the cable spreading rooms is automatic gaseous systems.

Exelon Generation Company believes that gaseous systems are an acceptable alternative because the reliability designed into them is equivalent to that which would be provided by an automatic water system. Modifications, described in Appendix A5.4, have significantly upgraded the reliability of these gaseous suppression systems.

Other design features provide additional protection against fire in the cable spreading rooms. The cable spreading rooms are physically separated from each other by 3-hour rated fire barriers. The upper cable spreading room, which contains only Division 11 cables, is further subdivided into four fire areas by 3-hour rated fire barriers. The lower cable spreading room, which primarily contains Division 12 cables, is further subdivided into four fire areas by 3-hour rated fire barriers. A loss of all the cables in any one of these fire areas will not prevent safe shutdown of the plant.

Each fire area within the cable spreading rooms is protected by redundant trains of fire detection circuits. The loss of any one detector will not result in loss of detection for a given fire area.

All cable used in the cable spreading rooms has passed the IEEE-383 flame propagation tests. The few numbers of power cables in the cable spreading rooms are in totally enclosed raceways.

All exterior and interior doors of the cable spreading rooms are electrically supervised to ensure they will not be left open inadvertently.

2.3-15

B/B - FPR AMENDMENT 29 DECEMBER 2020 An automatically actuated Halon system is the primary suppression for the upper cable spreading room. It is backed up by a manually actuated total flooding CO2 system. A water hose station is also available in each fire area of the upper cable spreading room.

In the lower cable spreading room, an automatic total flooding CO2 system provides the primary suppression.

This CO2 system can also be mechanically actuated manually through the initial discharge piping and withstand any single active failure when operated in this manual mode. An adequate supply of CO2 is available to discharge the design concentration into the largest hazard zone twice. A water hose station is also available in each fire area of the lower cable spreading room.

In the upper and lower cable spreading rooms, ionization (or photoelectric) detection is provided to alarm in the event of a small fire. The fire brigade would then be able to respond and take the appropriate actions without relying on the halon or CO2 system (which could still be actuated manually if necessary). Automatic actuation of the halon or CO2 system from both the ionization (or photoelectric) detectors and Fenwal thermal detectors is not the preferred method and is not necessary in the event of a small fire, as this could affect and have a more significant impact on plant operations. However, in the event the fire develops into a large fire or a design basis fire, which is also detected by the thermal detectors, the halon or CO2 system can operate automatically, which is consistent with the defense-in-depth approach. Based on the design features described above, it is evident that the defense in depth concept has been applied to fire protection for the upper and lower cable spreading rooms.

The design and installation of the carbon dioxide systems for the upper and lower cable spreading rooms and the modification to the lower cable spreading room CO2 system described in Appendix A5.4 have been reviewed in detail by the licensees fire protection consultant. The design and installation of the halon systems for the upper cable spreading rooms and the modifications to the upper cable spreading room halon system described in Appendix A5.4, have also been reviewed in detail by the licensees fire protection consultant. Carbon dioxide and halon fire extinguishing systems are an accepted method of providing fire protection for areas containing electrical cabling and have proven to be reliable and effective in the control and extinguishing of surface and deep-seated fire, both of which characterize a fire in a cable spreading area. Within cable spreading rooms, a carbon dioxide or halon fire protection system provides rapid response to a fire in the initial stages before reaching serious magnitude and will maintain a concentration over a predetermined time span necessary to effectively control and extinguish a deep-seated fire. A total flooding CO2 or halon system is recognized by NFPA Standard No. 12 and 12A as an adequate method of extinguishing deep-seated fire hazards.

2.3-16

B/B - FPR AMENDMENT 29 DECEMBER 2020 The carbon dioxide or halon fire extinguishing system protecting the upper or lower cable spreading room is also tested and maintained in accordance with NFPA Standard No. 12 and 12A. Adherence to the recommendations of the nationally recognized standard (NFPA) provides a degree of reliability in the design and effectiveness of a fire protection system. Periodic surveillances and testing of the carbon dioxide and halon systems provides added assurance of the operability and reliability of the systems.

In summary, cable spreading area fire protection system design ensures that a fire will not compromise plant safety. Use of automatic Halon or CO2 systems instead of water deluge reduces the probability of a plant shutdown or equipment damage in the event of spurious actuation. In the unlikely event that water is required, the area is well supplied with manual hose stations.

Refer to the following subsections for a detailed discussion of each fire zone.

2.3.3.1 Unit 1 Electrical Cable Tunnel (Fire Zone 3.1-1)

This zone is shown on Figure 2.3-12 (Sheet 1) and in elevation on Figure 2.3 25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-36, Sheet 1.

Fire Barrier Description The floor slab at elevation 415 feet 0 inch consists of a 5-inch to 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, which is supported by protected structural steel beams and hangers which carry a 3-hour rating. Three walls of the tunnel are structural rein-forced concrete varying in thickness from 12 inches to 36 inches. These carry a 3-hour fire rating.

The fourth wall is 12-inch-thick hollow concrete masonry units, extending up to within 1 inch of the ceiling or steel beam, and carries a 3-hour fire rating. The space at the top of the wall is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling at elevation 426 feet 0 inch, which is the floor of an ESF switchgear room, consists of a 5-inch clear cover of structural reinforced concrete with a 3-inch concrete topping over 3-inch fluted steel decking formwork. It is supported by steel beams protected with a fire-resistant covering and carries a 3-hour fire rating. The cable tunnel is divided into two parts consisting of the main cable tunnel room and a rear hatchway room on elevation 426 feet. The rear hatchway room is a 16 feet x 11 feet x 12 feet fully enclosed 3-hour rated room.

2.3-17

B/B - FPR AMENDMENT 29 DECEMBER 2020 Access to the room is by hatches from elevation 426 feet 0 inch that provide an equivalent 3-hour rating. The hatch that provides access from the ESF switchgear rooms is covered with 2 inches of Pyrocrete on 1/4-inch checkered plate, giving this hatch a 3-hour fire rating. The other hatch is in a 3-hour rated rear hatchway room.

Four 4-inch-diameter floor drains (90 gpm capacity each) are provided.

Safety-Related Equipment There is no safety-related equipment in this area. However, control instrumentation and power cables associated with ESF Divisions 11 and 12 are present.

Protection Criteria and Measures There is no fire protection piping in this area except for the primary fire protection system. The primary fire protection system for the main cable tunnel room is an automatic total flooding CO2 system designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The CO2 system does not extend into the rear hatchway room. The 10-ton low pressure CO2 storage tank is located at elevation 401 feet-0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment or systems which contain radioactive materials.

All air inlets and outlets ducted or non-ducted, to the rooms will be protected by fire dampers. Present layout shows there is one 3-hour damper (non-ducted) vertical mounted with electrothermal links and two 1-1/2-hour dampers (ducted) horizontal mounted with electrothermal links, galvanized steel fusible link fire dampers in this zone. Fusible link fire dampers are activated by temperatures exceeding 165 Degrees Fahrenheit or 281 Degrees Fahrenheit, as well as on initiation of a CO2 discharge.

Combustible Materials Cable insulation and gaskets.

At Byron, plastic.

At Braidwood, abandoned Thermo-Lag.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-18

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities The total flooding CO2 system will deliver sufficient quantity of CO2 to maintain a 50% concentration for 20 minutes. The CO2 system is actuated automatically by signals from one detector in each of the two trains, which annunciate and alarm in the control room. One detection train is comprised of thermal detectors; the other is comprised of ionization (or photoelectric) detectors. The rear hatchway rooms also have ionization (or photoelectric) and thermal detectors which annunciate and alarm in the control room. Pre-discharge alarms are provided locally and in the control room. Adjustable pre-discharge timers delay the discharge to allow personnel time to leave the area. After an automatic discharge the system is ready for immediate manual operation.

Hose stations and entry are available as shown on Figure 2.3-10 (elevation 426 feet 0 inch) and the zone is shown on Figure 2.3-12. Portable extinguishers are provided.

Design-Basis Fire The only combustible materials present in significant quantities are the cable insulation materials. The design-basis fire for this area is postulated to be the burning of all the cable insulation in the room. The fire would not spread out of this room, due to the substantial construction of the walls, floor, and ceiling, and that all penetrations and openings are sealed.

The design-basis fire is highly unlikely for the following reasons:

a. The Electrical Cable Tunnel is a controlled access area.

b. No significant quantities of combustible materials are stored in the cable tunnel.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

d. The main cable tunnel room is provided with two trains of detectors which annunciate in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the Control Room. The fire dampers would close, and the automatic fire suppression system would extinguish the fire and annunciate in the control room.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.6.

2.3-19

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.2 Unit 2 Electrical Cable Tunnel (Fire Zone 3.1-2)

This zone is shown on Figure 2.3-12 (Sheet 3) and in elevation on Figure 2.3 25 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-36, Sheet 2.

For details, see Subsection 2.3.3.1 except that:

a. Divisions 21 and 22 instead of Division 11 and 12 cabling are in this zone.

b. Fusible link fire dampers may also be activated by temperatures exceeding 281 Degrees Fahrenheit.

c. At Byron, Thermo-lag contributes to combustible material.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.7.

2.3.3.3 Auxiliary Building Elevation 439 feet 0 inch (Fire Zone 3.2-0)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-22 (Sheets 1 and 2). Electrical cable trays routed through this zone are shown on Figure 2.3-34.

Fire Barrier Description The floor slab at elevation 439 feet 0 inch consists of a 5-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork which is supported by protected steel beams and columns. Two 4-inch-diameter floor drains are provided. Three-hour rated, minimum 12-inch-thick hollow or solid concrete masonry unit walls separate this zone on three sides from the adjacent stairwells, elevator, cable spreading rooms, cable riser areas, and cable penetration areas. These walls extend up to within 1 inch of the ceiling above and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. Doors in these walls are Label "A" fire doors. This zone is open on the fourth side to the Auxiliary Building mezzanine floor.

The ceiling at elevation 451 feet 0 inch, which is the floor of the Computer Rooms, consists of a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by steel beams protected with a fire-resistant covering and carries a 3-hour fire rating. Exceptions are the area bounded by column row P and Q and 17.4 and 18.5, which carries no fire rating, and the area at Byron bounded by column row P-Q and 20-21, which is of fire-rated construction but contains nonrated penetration seals.

2.3-20

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment Safety-related cables and equipment associated with the auxiliary building ventilation system are in this zone. These are galvanized ductwork, dampers, and ductwork accessories.

Protection Criteria and Measures Fire dampers are not provided in the ventilation openings, penetrating walls or floors.

Combustible Materials Cable insulation, fiber optic cable, and gaskets.

At Byron, nylon, plastic, polypropylene, and Thermo-lag.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Ionization (or photoelectric) detectors are provided which annunciate and alarm in the control room.

Manual hose stations and portable fire extinguishers are available.

Design-Basis Fire If a fire were to occur in this area, the Auxiliary Building Supply Air System may be rendered inoperable. The fire in this area is highly unlikely due to the low fire loading.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Subsection 2.4.2.8.

2.3-21

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.4 Unit 1 Non-segregated Bus Duct Area (Fire Zone 3.2A-1)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-25 (Sheet 1).

Electrical cable trays routed through this zone are shown on Figure 2.3-34.

Fire Barrier Description The floor slab at elevation 439 feet 0 inch consists of 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, which is supported by protected structural steel. It carries a 3-hour fire rating, except at Byron in an area of the floor bounded by column row L-Q and 7.7-10, which is supported by structural steel with a 2.4-hour rating.

The walls enclosing Fire Zone 3.2A-1 are minimum 36-inch-thick structural reinforced concrete and carry a 3-hour fire rating except for the north wall, which is a minimum 30-inch-thick structural reinforced concrete and carries a 3-hour fire rating.

A portion of the west wall is 12-inch-thick reinforced concrete or hollow concrete masonry units and encloses two adjacent HVAC equipment rooms. It extends up to within 1 inch of steel beams of the ceiling above. This resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation, and the wall carries a 3-hour fire rating.

The ceiling at elevation 451 feet 0 inch, which is the floor of a non-ESF switchgear room and the battery rooms, consists of either a 9-inch clear cover of structural reinforced concrete with a 3-inch concrete topping over 3-inch fluted steel decking formwork or a 12-inch clear cover of structural reinforced concrete over 3-inch fluted steel framing deck work, depending on location. It is supported by structural steel beams protected with a fire rated material and carries a 3-hour fire rating. All freestanding structural columns are protected by a troweled-on fireproofing material and carry a 3-hour fire rating.

Two label "A" 3-hour fire rated doors are in the north wall and lead to an adjacent cable spreading room.

Nine 4-inch-diameter floor drains (90 gpm capacity each) are provided to remove firefighting water.

Three-hour labeled curtain-type galvanized steel vertical fire dampers are installed in the HVAC openings penetrating the fire walls. Electrothermal link fire dampers are activated by temperatures exceeding 165 F or 281 F, or by initiation of CO2 discharge.

2.3-22

B/B - FPR AMENDMENT 29 DECEMBER 2020 As Stated in Byron SSER 5, fire-rated seals are provided in bus duct penetrations at barriers that separate redundant shutdown-related systems (Fire Zones 3.2A-1/5.2-1). Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 3.2A-1/5.1-1, 3.2A-1/18.10C-1).

Safety-Related Equipment The safety-related equipment located in this fire zone consists of components of the Switchgear Ventilation System. These are galvanized ductwork, dampers, and ductwork accessories.

Control, instrumentation, and power cables associated with ESF Divisions 11 and 12 are present.

Protection Criteria and Measures As indicated in Figure 2.3-9, there is one manual hose station in this zone. The standpipe system is designed to ASME Section III standards and supported to withstand the safe shutdown earthquake (SSE). At Byron, the majority of the fire protection piping in this zone has been reclassified as Safety Category II, Quality Group D (ref. EC 626662); and remains classified as Seismic Category I.

The primary fire protection system is an automatic total flooding CO2 system, designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton low pressure CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

Combustible Materials Cable insulation, gaskets, and Thermo-Lag.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detection Capabilities The total flooding CO2 system will deliver a sufficient quantity of CO2 to maintain a 50% concentration for 20 minutes. The CO2 system is actuated automatically by signals from one detector in each of the two trains which annunciate and alarm in the control room. Pre-discharge alarms are provided locally and in the control room. Adjustable pre-discharge timers delay the discharge to allow 2.3-23

B/B - FPR AMENDMENT 29 DECEMBER 2020 personnel time to leave the area. After an automatic discharge, the system is ready for immediate manual operation.

As indicated in Figure 2.3-9, Fire Zone 3.2A-1 has one manual hose station located inside. Portable fire extinguishers are available as illustrated in Figure 2.3-9.

Design-Basis Fire The only combustible materials present in significant quantities are the cable insulation materials. The design-basis fire for this area is postulated to be the burning of all the cable insulation in the room. The fire would not spread out of this room, due to the substantial construction of the walls, floor, and ceiling, and all penetrations and openings are sealed.

The design-basis fire is highly unlikely for the following reasons:

a. This zone is a controlled access area.

b. No significant quantities of combustible materials are stored in this room.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

d. The room is provided with two trains of detectors which annunciate and alarm in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the Control Room. The fire dampers would close, and the automatic fire suppression system would extinguish the fire and annunciate in the Control Room.

In the event of a design-basis fire the ventilation system ductwork in this zone may be damaged. There will be no radioactive equipment in the area. The spread of heat and combustion products will be stopped by the fire dampers.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.9.

2.3-24

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.5 Unit 2 Non-segregated Bus Duct Area (Fire Zone 3.2A-2)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-21 (Sheet 1) and Figure 2.3-25 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-34.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems (Fire Zones 3.2A-2/5.2-2). Internal bus duct, fire-rate seals are not provided at barriers that do not separate redundant shutdown-related systems or do not affect safe shutdown as described in Section 2.4 (Fire Zones 3.2A-2/5.1-2, 3.2A-2/18.10C-2).

For details, see Subsection 2.3.3.4 except that:

a. Division 22 instead of Division 12 cabling is present

b. Electrothermal link fire dampers may also be activated by temperatures exceeding 281 Degrees Fahrenheit.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.10.

2.3.3.6 Lower Cable Spreading Area (Fire Zone 3.2B-1)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-25 (Sheet 1).

Fire Barrier Description The floor slab at elevation 439 feet 0 inch consists of a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, which is supported by protected structural steel and carries a 3-hour rating.

A portion of a structural beam enclosed in the block wall pipe chase in the Auxiliary Building laundry area is not coated.

The south, east, and west walls are structural reinforced concrete and vary in thickness from 30 inches to 42 inches. These walls carry a 3-hour fire rating and contain four Label "A" 3-hour fire rated doors. The north wall is 12-inch-thick hollow concrete masonry units, contains two Label "A" 3-hour fire rated doors and carries a 3-hour fire rating. A 12-inch-thick hollow concrete masonry unit wall encloses a stairway at the east portion of the room, contains an "A" Label construction door, and extends up to within 1 inch of the ceiling above. This 2.3-25

B/B - FPR AMENDMENT 29 DECEMBER 2020 resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation, and the wall carries a 3-hour fire rating.

The ceiling at elevation 451 feet-0 inch, which is the floor of the Auxiliary Electrical Equipment Room and the Air Conditioning Equipment Room, consists of a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire rated material with a 3-hour fire rating. (Three-hour labeled curtain type, galvanized steel dampers are installed in the ductwork passing through the walls.)

All freestanding structural steel columns are protected by a sprayed on 7/8-inch-thick cover of fire-resistant material and carry a 3-hour fire rating.

Seven 4-inch-diameter floor drains (90 gpm capacity each) are provided.

Safety-Related Equipment The safety-related equipment located in this fire zone consists of a portion of the Control Room HVAC System components. These components are dampers.

There is no safety-related equipment in this area. However, control and instrumentation cables associated with ESF Division 11 and Division 12 are present.

Protection Criteria and Measures There are two manual hose stations in this zone. The sandpipe system is designed in accordance with ASME Section III standards and supported to withstand the safe shutdown earthquake (SSE). The primary fire protection system, is an automatic total flooding CO2 system, designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton low pressure CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment or systems which contain radioactive materials. Three-hour labeled vertical fire dampers are installed in the fire walls. Horizontal fire dampers consist of two 1-1/2 labeled fire dampers in series and are inserted in the floor. Two fire dampers are electric-thermal link and the remaining three in the ductwork are fusible link. Electric-thermal link dampers are activated by the fire detection system and/or temperatures exceeding 165 Degrees Fahrenheit, while fusible link dampers are activated only by temperatures exceeding 165 Degrees Fahrenheit. The electric-thermal link dampers will close if operation of the fire protection system occurs. Portable fire extinguishers are also available.

As requested by NRC, all the existing woven-jacket fire hose in this zone has been replaced with a hard rubber-type fire hose.

2.3-26

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, fiber optic cable, gaskets, and insulation.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The total flooding CO2 system will deliver a sufficient quantity of CO2 to maintain a 50% concentration for 20 minutes. The CO2 system is actuated automatically by signals from one detector in each of the two trains, which annunciate the alarm in the Control Room. One detection train is comprised of thermal detectors; the other is comprised of ionization (or photoelectric) detectors. Local and control room pre-discharge alarms are provided. Adjustable pre-discharge timers delay the discharge to allow personnel time to leave the area. After an automatic discharge, the system is ready for immediate manual operation.

As indicated in Figure 2.3-9, two manual hose stations are located inside.

Portable fire extinguishers are also available as illustrated in Figure 2.3-9.

Design-Basis Fire The only combustible materials present in significant quantities are the cable insulation materials. The design-basis fire for this area is postulated to be the burning of all the cable insulation in the room. The design-basis fire is highly unlikely for the following reasons:

a. The cable spreading rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in the cable spreading rooms.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

d. The room is provided with two trains of detectors which annunciate and alarm in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

2.3-27

B/B - FPR AMENDMENT 29 DECEMBER 2020 If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the control room. The fire dampers would close, and the automatic fire suppression system would extinguish the fire and annunciate in the control room.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.11.

2.3.3.7 Lower Cable Spreading Room (Fire Zone 3.2B-2)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-25 (Sheet 2).

Electrical cable trays routed through this zone are shown on Figure 2.3-34.

For details, see Subsection 2.3.3.6 except that:

a. Division 22 instead of Division 12 cabling is present.

b. Flexible connections contribute to combustible loading.

c. At Braidwood, the north wall at column rows 23 and N-P is of 3-hour, fire-rated construction, but contains two nonrated fire seals (E0362059 and E0362060).

d. The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.12.

2.3.3.8 Lower Cable Spreading Area (Fire Zone 3.2C-1)

This zone is shown on Figure 2.3-9 and in elevation on Figures 2.3-22 (Sheet 2) and 2.3-25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-34.

Fire Barrier Description The floor slab at elevation 439 feet 0 inch consists of a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, which is supported by protected structural steel and carries a 3-hour rating.

At Byron, a portion of the structural steel supporting the common floor area between Fire Zones 3.2C-1, 3.2C-2, and 11.6B-0 is not fully protected with fireproofing material. An evaluation has been performed such that it is concluded that the level of fire barrier protection is commensurate with the fire hazard. This configuration is acceptable and does not adversely affect safe shutdown in the event of a fire.

2.3-28

B/B - FPR AMENDMENT 29 DECEMBER 2020 The walls are 12-inch-thick hollow concrete masonry units or 42-inch-thick structural reinforced concrete and carry a 3-hour fire rating. All doors are Label "A" fire doors.

The ceiling at elevation 451 feet 0 inch which is the floor of the control room, consists of a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected by a fire rated material and carries a 3-hour fire rating. All freestanding structural steel columns are protected by a 7/8-inch-thick cover of sprayed-on fire resistant material and carry a 3-hour fire rating. Fire dampers are provided at all ventilation openings and carry a 3-hour fire rating. One 4-inch-diameter floor drain (90 gpm capacity each) is provided.

Safety-Related Equipment The safety-related equipment located in this fire zone consists of a portion of the Control Room HVAC System components. These components are dampers.

There is no other safety-related equipment in this area. However, control and instrumentation cables associated with ESF Division 11 and Division 12 are present.

Protection Criteria and Measures There are two manual hose stations in this zone. The standpipe system is designed to ASME Section III standards and supported to withstand the safe shutdown earthquake (SSE). At Byron, the majority of the fire protection piping in this zone has been reclassified as Safety Category II, Quality Group D (ref. EC 626662); and remains classified as Seismic Category I.

The primary fire protection system, an automatic total flooding CO2 system, is designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton low-pressure storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

A 3-hour labeled electric-thermal link fire damper is installed in fire wall between this zone and Zone 3.2B-1. This vertical fire damper is energized by the fire detection system and/or temperatures exceeding 165 Degrees Fahrenheit.

As requested by NRC, all the existing woven-jacket fire hoses in this zone have been replaced with a hard rubber-type fire hose.

2.3-29

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, fiber optic cable.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The total flooding CO2 system will deliver a sufficient quantity of CO2 to maintain a 50% concentration for 20 minutes. The CO2 system is actuated automatically by signals from one detector in each of the two trains, which annunciate and alarm in the control room. One detection train is comprised of thermal detectors; the other is comprised of ionization (or photoelectric) detectors. Local and control room pre-discharge alarms are provided. Adjustable pre-discharge timers delay the discharge to allow personnel time to leave the area. After an automatic discharge, the system is ready for immediate manual operation.

As indicated in Figure 2.3-9, Fire Zone 3.2C-1 has two manual hose stations located inside. Portable fire extinguishers are also available.

Design-Basis Fire The only combustible materials present in significant quantities are the cable insulation materials. The design-basis fire for this zone is postulated to be the burning of all the cable insulation in the room. The fire would not spread out of this room due to the substantial construction of the walls, floor, and ceiling, and the fact that all penetrations and openings are sealed.

The design-basis fire is highly unlikely for the following reasons:

a. The cable spreading rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in the cable spreading rooms.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

d. The room is provided with two trains of detectors which annunciate in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the Control Room. The fire dampers would close, and the 2.3-30

B/B - FPR AMENDMENT 29 DECEMBER 2020 automatic fire suppression system would extinguish the fire and annunciate in the Control Room.

The Control Room HVAC System will not be shut down but will continue to operate and pressurize the Control Room and the zones surrounding the Control Room with this zone's fire dampers shut. There are no radioactive sources in this area.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.13.

2.3.3.9 Lower Cable Spreading Area (Fire Zone 3.2C-2)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-25 (Sheet 2).

Electrical cable trays routed through this zone are shown on Figure 2.3-34.

For details, see Subsection 2.3.3.8 except that:

a. Division 22 instead of Division 12 cabling is present.

b. At Braidwood, the south wall at column rows 23 and N-P is of 3-hour fire-rated construction but contains two nonrated fire seals (E0362059 and E0362060), which are constructed of Thermo-Lag, are abandoned in place and contribute to combustible loading.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.14.

2.3.3.10 Lower Cable Spreading Area (Fire Zone 3.2D-1)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-22 (Sheet 1).

Electrical cable trays routed through this zone are shown on Figure 2.3-34.

Fire Barrier Description The floor slab at elevation 439 feet 0 inch consists of a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, which is supported by protected structural steel and carries a 3-hour fire rating. One 4-inch-diameter floor drain is provided. The perimeter walls are 12-inch-thick hollow concrete masonry units and carry a 3-hour fire rating. They extend up to within 1 inch of the ceiling above and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. Doors in these are Label "A" fire doors.

2.3-31

B/B - FPR AMENDMENT 29 DECEMBER 2020 The ceiling at elevation 451 feet 0 inch, which is the floor of a storage room and a computer room, consists of a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by steel beams protected with a fire resistant covering and carries a 3-hour fire rating.

Safety-Related Equipment The safety-related equipment located in this zone consists of portions of the Control Room Ventilation System. These components are the dampers. There is no other safety-related equipment in this zone. However, control and instrumentation cables associated with ESF Division 12 are present.

Protection Criteria and Measures The zone is separated from the remainder of the plant by 3-hour rated fire barriers. Three-hour labeled vertical fire dampers are inserted in the fire walls separating this zone and Zone 3.2C-1. The fire dampers are electric-thermal link.

This type of damper is energized by the fire detection system and/or temperature exceeding 165 Degrees Fahrenheit.

There is one manual hose station in this zone. The standpipe system is designed to ASME Section III standards and supported to withstand the safe shutdown earthquake (SSE). At Byron, the majority of the fire protection piping in this zone has been reclassified as Safety Category II, Quality Group D (ref. EC 626662);

and remains classified as Seismic Category I.

The area is provided with ionization (or photoelectric) and thermal detectors, which annunciate in the Control Room. The primary fire suppression system is an automatic total flooding CO2 system, designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton low pressure CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

As requested by NRC, all the existing woven-jacket fire hose in this zone has been replaced with a hard rubber-type fire hose.

Combustible Materials Cable insulation and fiber optic cable.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-32

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities The total flooding CO2 system will deliver a sufficient quantity of CO2 to maintain a 50% concentration for 20 minutes. The CO2 system is actuated automatically by signals from one detector in each of the two trains. Local and control room pre-discharge alarms are provided. Adjustable pre-discharge timers delay the discharge to allow personnel time to leave the area. After an automatic discharge, the system is ready for immediate manual operation.

The area is provided with two trains of detectors which annunciate and alarm in the Control Room. One detection train is comprised of thermal detectors; the other is comprised of ionization (or photoelectric) detectors. As indicated in Figure 2.3-9, Fire Zone 3.2D-1 has one manual hose station located inside.

Portable fire extinguishers are also available as illustrated in Figure 2.3-9.

Design-Basis Fire The only combustible materials present in significant quantities are the cable insulation materials. The design-basis fire for this area is postulated to be the burning of all the cable insulation in the room. The results of this fire are acceptable since control and instrumentation cables of only one ESF division are routed through this room. Safe shutdown of the reactor can be achieved with components fed from the other ESF division.

The fire would not spread out of this room, due to the substantial construction of the walls, floor, and ceiling, and the fact that all penetrations and openings are sealed. The design-basis fire is highly unlikely for the following reasons:

a. The cable spreading rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in the cable spreading rooms.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

d. The room is provided with two trains of detectors which annunciate and alarm in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the Control Room. The fire dampers would close, and automatic fire suppression system would extinguish the fire and annunciate in the Control Room. If this zone is lost, sufficient redundancy exists in the engineered safety features electrical system that division may be lost and still have sufficient engineered safety features system auxiliaries in operation to control the plant under all modes of operation.

2.3-33

B/B - FPR AMENDMENT 29 DECEMBER 2020 The result of a fire in this zone is acceptable since only one ESF division will be lost. Sufficient redundancy exists in the engineered safety features fed from the other ESF division to achieve a reactor shutdown and to maintain the reactor in a safe shutdown condition.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.15.

2.3.3.11 Lower Cable Spreading Area (Fire Zone 3.2D-2)

This zone is shown on Figure 2.3-9 and in elevation on Figure 2.3-22 (Sheet 2).

Electrical cable trays routed through this zone are shown on Figure 2.3-34.

For details see Subsection 2.3.3.10 except that:

a. Division 22 instead of Division 12 cables are present.

The effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.16.

2.3.3.12 Division 11 Cable Riser (Fire Zone 3.2E-1)

This zone is shown on Figure 2.3-9. Electrical cable trays routed through this zone are shown on Figure 2.3-34.

Fire Barrier Description The floor slab at elevation 439 feet 0 inch consists of a 5-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork and is supported by protected steel beams and columns and carries a 3-hour fire rating.

The perimeter walls are minimum 12-inch-thick hollow or solid concrete masonry units and carry a 3-hour fire rating. They extend up to within 1 inch of the ceiling above and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. A Label "A" fire door is provided for access into this room.

The ceiling at elevation 451 feet 0 inch consists of a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by steel beams protected with a fire-resistant covering and carries a 3-hour fire rating.

2.3-34

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment There is no safety-related equipment in this zone. However, control and instrumentation cables are present.

Protection Criteria and Measures The zone is separated from the remainder of the plant by 3-hour rated fire barriers. The area is provided with two trains of detectors, one thermal and one ionization (or photoelectric), which annunciate and alarm in the Control Room.

The primary fire suppression system is an automatic total flooding CO2 system.

Combustible Materials There is cable insulation.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The total flooding CO2 system will deliver a sufficient quantity of CO2 to maintain a 50% concentration for 20 minutes. The CO2 system is actuated automatically by signals from one detector in each of the two trains. Local and control room pre-discharge alarms are provided. Adjustable pre-discharge timers delay the discharge to allow personnel time to leave the area. After an automatic discharge, the system is ready for immediate manual operation.

The area is provided with two trains of detectors which annunciate and alarm in the Control Room. One detection train is comprised of thermal detectors; the other is comprised of ionization (or photoelectric) detectors. One manual hose station is available in an adjacent zone to suppress a fire in this zone. Portable fire extinguishers are also available.

Design-Basis Fire If a fire was to start in one of the cable risers, at least one detector from each train would annunciate in the control room. The automatic fire suppression system would extinguish the fire and annunciate in the control room.

The only combustible materials present in significant quantities are the cable insulation materials. The design-basis fire for this area is postulated to be the burning of all the cable insulation in the room.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.17.

2.3-35

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.13 Division 21 Cable Riser (Fire Zone 3.2E-2)

This zone is shown on Figure 2.3-9.

Electrical cable trays routed through this zone are shown on Figure 2.3-34.

For details see Subsection 2.3.3.12 except that:

a. ESF Division 21 cables are present.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.18.

2.3.3.14 Control Room Upper Cable Spreading Area (Fire Zone 3.3A-1)

This zone is shown on Figure 2.3-7. Electrical cable trays routed through this zone are shown on Figure 2.3-32.

Fire Barrier Description Three-hour rated vertical fire dampers are installed with sleeves in the ductwork penetrations through the walls. Galvanized steel curtain-type vertical dampers are installed in the walls. Horizontal fire dampers, which consist of two 1-1/2-hour rated dampers in series, with sleeves, are installed for ductwork penetrations through the floors. The horizontal dampers close and lock with a stainless steel "negator" spring.

The north, south, east, and west walls are minimum 12-inch-thick structural reinforced concrete and carry a 3-hour fire rating. The walls extend up to within 1 inch of the ceiling above. This resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The floor slab at elevation 463 feet 5 inches is a 2-1/2-inch clear cover of reinforced concrete over 1-1/2-inch fluted steel decking which is covered with 9/16 inch of Pyrocrete and carries a 3-hour fire rating.

The room ceiling at elevation 477 feet 0 inch, which is the roof of the Auxiliary Building, consists of a 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-rated material and carries a 3-hour fire rating.

Label "A" 3-hour fire rated doors are in each of the north and west walls. The south wall contains one door with "A" Label construction.

Two 4-inch-diameter floor drains (90 gpm capacity each) are provided.

2.3-36

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The safety-related equipment located in this fire zone consists of portions of the Control Room Ventilation System. These are the galvanized ductwork, dampers, ductwork accessories, makeup air filter unit fan, and makeup air filter unit.

No other safety-related equipment is in this zone. However, control and instrumentation cables associated with ESF Division 11 are present.

Protection Criteria and Measures There is one manual hose station in this zone. The standpipe system is designed to ASME Section III standards and supported to withstand the safe shutdown earthquake (SSE). At Byron, the standpipe system in this zone has been reclassified as Safety Category II, Quality Group D (Ref. EC 626662); and remains classified as Seismic Category I.

As requested by NRC, all the existing woven-jacket fire hose in this zone has been replaced with a hard rubber-type fire hose.

The automatic total flooding Halon 1301 system is designed in accordance with NFPA Chapter 12A, "Standard for Halogenated Extinguishing Agent Systems-Ha1on 1301." The Halon 1301 storage containers are located at elevation 468 feet 4 inches in the Turbine Building. The containers will not damage safety-related equipment since they are in the Turbine Building. The total flooding manual CO2 system is designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton low pressure CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

The charcoal filters are protected by a manual deluge system. Fire dampers are provided in the fire walls. Fire dampers have electro-thermal or fusible links which are activated by fire detection system or temperatures greater than 165 Degrees Fahrenheit at the fire damper.

Combustible Materials Cable insulation, charcoal, flexible connections, gaskets, HEPA filters, insulation, lube oil and prefilters.

At Byron, plastic Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-37

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities The primary extinguishing system for this zone is an automatic total flooding Halon 1301 system at 6% concentration. The system is actuated automatically by signals from one detector in each of the two trains, which annunciate and alarm in the control room. Pre-discharge alarms are provided locally and in the control room. Pre-discharge timers delay the discharge to allow personnel time to leave the area. The Halon system can be initiated manually with or without electric power.

The backup system is a manually initiated (with or without electrical power) total flooding CO2 system at 50% concentration. Local and control room alarms are activated upon system discharge.

As indicated in Figure 2.3-7, Fire Zone 3.3A-1 has two manual hose stations located outside this zone and one inside. Portable fire extinguishers are also available as illustrated in Figure 2.3-7.

A temperature sensing device mounted in the charcoal filter bank will annunciate on the main control board. An operator can actuate the deluge line locally in the event of high temperature which annunciates in the control room.

Design-Basis Fire The combustibles present in this area are cable insulation, ductwork insulation, fiberglass filters, and charcoal filters. Ionization (or photoelectric) and thermal detectors for the room and temperature sensing devices for the filters have been provided to sense a fire and alarm in the Control Room. The automatic primary system (Halon 1301) and the manual backup system (CO2) can be actuated to extinguish a fire. With these methods of firefighting manual hose stations, and the early warning system, the potential for a major fire in this area is highly unlikely. The fire would not spread out of this room because of the substantial construction of the walls, floor, and ceiling. All penetrations and openings are sealed.

In the unlikely event a fire did start, and the three extinguishing systems failed to operate, the fire would be contained within the room by the fire barriers.

However, the Control Room HVAC ductwork inside the room may be damaged or the fusible link fire dampers inside the ductwork or electro-thermal link fire dampers would close and restrict the flow of air. The redundant train of the Control Room HVAC System could be started and supply air to the Control Room and surrounding areas except for the Unit 1 Auxiliary Electric Equipment Room and Record Storage Room. If necessary, these rooms could be ventilated with temporary fans.

2.3-38

B/B - FPR AMENDMENT 29 DECEMBER 2020 The design-basis fire is highly unlikely for the following reasons:

a. The cable insulation meets IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by division and function as described in Appendix 5.2.

b. The room is provided with two trains of detectors which annunciate in the Control Room.

c. Fire suppression systems including the charcoal filter deluge system are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector from each train would annunciate in the Control Room. The fire dampers would close and the automatic Halon fire suppression system and/or the manual backup CO2 system would extinguish the fire and annunciate in the Control Room The results of a fire in this zone are acceptable since only one ESF division will be lost. Sufficient redundancy exists in the engineered safety features fed from the other ESF division to achieve a reactor shutdown and to maintain the reactor in a safe shutdown condition.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.19.

2.3.3.15 Control Room Cable Spreading Area F (Fire Zone 3.3A-2)

This zone is shown on Figure 2.3-7. Electrical cable trays routed through this zone are shown on Figure 2.3-32.

For details, see Subsection 2.3.3.14, except that:

a. Division 21 cables instead of Division 11 cables are in this zone.

b. The areas whose supply air would be lost are the Unit 2 auxiliary electric room and toilet.

c. The zone also contains fiber optic cable.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.20.

2.3-39

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.16 Upper Cable Spreading Area B (Fire Zone 3.3B-1)

This zone is shown on Figure 2.3-7. Electrical cable trays routed through this zone are shown on Figure 2.3-32.

Fire Barrier Description The north, south, east, and west walls are a minimum of 12-inch-thick structural reinforced concrete and carry a 3-hour fire rating. The walls extend up to within 1 inch of the ceiling. This resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation. The west wall is 36-inch structural reinforced concrete and carries a 3-hour fire rating. A Label "A" 3-hour fire rated door is in the east wall and leads to an adjacent Cable Spreading Room.

The floor slab at elevation 463 feet 5 inches is a 2-1/2-inch clear cover of reinforced concrete over 1-1/2-inch structural fluted steel decking. The underside of this decking, and the structural steel members that support this slab, are protected with a fire-resistant covering. The slab and the supporting steel members carry a 3-hour fire rating.

The Cable Spreading Room ceiling at elevation 477 feet 0 inch, which is the roof of the Auxiliary Building, consists of a 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-rated material and carries a 3-hour fire rating.

Freestanding structural steel columns are protected by a sprayed-on fire-resistant material and carry a 3-hour fire rating.

Two 4-inch-diameter floor drains (90 gpm capacity each) are provided.

There are galvanized steel curtain 3-hour labeled vertical damper installations in the fire walls. The fire dampers in the horizontal barriers are galvanized steel curtain type and will close and lock by a stainless steel "negator spring."

Horizontal fire dampers are comprised of two 1-1/2-hour labeled dampers in series.

Safety-Related Cooling Equipment The safety-related equipment located in this fire zone consists of a portion of the Control Room HVAC System components. These are the galvanized ductwork, dampers, and ductwork accessories. Control and instrumentation cables associated with ESF Division 11 are present.

2.3-40

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures There is one manual hose station and fire protection piping in this zone. This hose station has been abandoned in place due to safety and accessibility concerns. The automatic total flooding Halon 1301 system is designed in accordance with NFPA Chapter 12A, "Standard for Halogenated Extinguishing Agent System-Halon 1301." The Halon 1301 storage containers are located at elevation 468 feet 4 inches in the Turbine Building. The containers will not damage safety-related equipment since they are in the Turbine Building.

As requested by NRC, all the existing woven-jacket fire hose in this zone have been replaced with a hard rubber-type fire hose.

Fire dampers are provided in the fire walls and floor. Fire dampers have electro-thermal or fusible links which are activated by either the fire detection system or temperatures exceeding 165 Degrees Fahrenheit. This zone is separated from the remainder of the plant by barriers of substantial construction.

The backup fire protection system, a manually initiated total flooding CO2 system, is designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

The area is provided with two trains of detectors, one thermal and one ionization (or photoelectric), which annunciate in the Control Room.

Combustible Materials Cable insulation, fiber optic cable, gaskets, flexible connections, insulation and lube oil.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The primary extinguishing system for this zone is an automatic total flooding Halon 1301 system at 6% concentration. The system is actuated automatically by signals from one detector in each of the two trains, which annunciate and alarm in the control room. Pre-discharge alarms are provided locally and in the control room. Pre-discharge timers delay the discharge to allow personnel time to leave the area.

2.3-41

B/B - FPR AMENDMENT 29 DECEMBER 2020 The Halon system can be initiated manually with or without electric power. This system is designed to maintain the Halon concentration above 6% for a minimum of 20 minutes. For this zone, this is accomplished by the initial discharge.

The backup system is a manually initiated (with or without electric power) total flooding CO2 system at 50% concentration. Local and control room alarms are activated upon system discharge. A pre-discharge alarm allows personnel to leave the room.

As indicated in Figure 2.3-7, Fire Zone 3.3B-1 has one manual hose station located inside. This hose station has been abandoned in place. The hose station immediately outside the door (in the adjacent zone) provides manual water suppression coverage of this zone. A portable fire extinguisher is available.

Design-Basis Fire The combustibles present in this zone are cable insulation and ductwork insulation. Ionization (or photoelectric) and thermal detectors have been provided to sense a fire and alarm in the Control Room. The automatic primary system (Halon 1301), and the manual backup system (CO2) or water from the manual hose station, can be actuated to extinguish a fire. With these three methods of firefighting and the early warning system, the potential for a fire in this zone is highly unlikely. The fire would not spread out of this room because of the substantial construction of the walls, floor, and ceiling and all penetrations and openings are sealed.

In the unlikely event a fire did start, and the two fixed extinguishing systems failed to operate, the fire would be contained within the room by the fire barriers.

The Control Room HVAC ductwork inside the room may be severely damaged or the fusible link fire dampers inside the ductwork or electro-thermal link fire dampers would close and restrict the flow of air. The redundant train of the Control Room HVAC System could be started to supply air to the Control Room and surrounding areas except for the Unit 1 Auxiliary Electric Equipment Room, Record Storage Room, and Upper Control Room HVAC Equipment Room. If necessary, this room could be ventilated with temporary fans.

The design-basis fire is highly unlikely for the following reasons:

a. The cable spreading rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in the Cable Spreading Room.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

2.3-42

B/B - FPR AMENDMENT 29 DECEMBER 2020

d. The room is provided with two trains of detectors which annunciate in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the Control Room. The fire dampers would close, and the automatic fire suppression system would extinguish the fire and annunciate in the control room. The results of a fire in this zone are acceptable since only one ESF division will be lost. Sufficient redundancy exists in the engineered safety features fed from the other ESF division to achieve a reactor shutdown and to maintain the reactor in a safe shutdown condition.

The Control Room HVAC System will not be shut down but will continue to operate and pressurize the Control Room and the zones surrounding the Control Room. The fire dampers have electro-thermal or fusible links which will close upon being energized by either the fire detection system temperatures exceeding 165 Degrees Fahrenheit.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.21.

2.3.3.17 Upper Cable Spreading Area (Fire Zone 3.3B-2)

This zone is shown in Figure 2.3-7 and in elevation on Figure 2.3-21 (Sheet 1).

Electrical cable trays routed through this zone are shown on Figure 2.3-32.

For details, see Subsection 2.3.3.16, except that:

a. Division 21 cabling instead of Division 11 cabling is present; however, at Byron Division 22 cabling is also present.

b. At Braidwood, the south wall at column rows 25 and N-P is of 3-hour fire-rated construction but contains a nonrated fire seal (E0383146).

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.22.

2.3-43

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.18 Unit 1 Upper Cable Spreading Area (Fire Zone 3.3C-1)

This zone is shown on Figure 2.3-7 and in elevation on Figures 2.3-22 (Sheet 2) and 2.3-25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-32.

Fire Barrier Description The north, south, east, and west walls are minimum 12-inch-thick structural reinforced concrete and carry a 3-hour fire rating. However, the east wall at Byron at column rows L and 16-17 and the east wall at Braidwood at column rows P and 13-14 are of 3-hour fire-rated construction but contain one nonrated penetration seal at Byron and two nonrated penetration seals (E0382487 and E0382488) at Braidwood. The walls extend up to within 1 inch of the ceiling above. This resulting space is packed with a 1-inch-thick blanket of foil-backed Thermafiber insulation. The floor slab at elevation 463 feet 5 inches is a 2-1/2-inch clear cover of reinforced concrete over 1-1/2-inch fluted steel decking. The underside of this decking, and the structural steel members that support this slab, are protected with fire-resistant covering. The slab and the supporting steel members carry a 3-hour fire rating.

The Cable Spreading Room ceiling at elevation 477 feet 0 inch, which is the roof of the Auxiliary Building, consists of a 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire rated material and carries a 3-hour fire rating. A Label "A" 3-hour fire rated door is in each of the north, south, and west walls.

Two 4-inch-diameter floor drains (90 gpm capacity each) are provided. Three-hour labeled curtain-type, galvanized steel, vertical fire dampers are installed in the ductwork passing through the fire walls. The fire dampers on the horizontal barriers are galvanized steel curtain type and will lock by a stainless steel "negator spring." Two 1-1/2-hour labeled dampers in series are installed for all ventilation openings penetrating a 3-hour horizontal fire barrier.

Safety-Related Equipment Control and instrumentation cables associated with ESF Division 11 are present.

The safety-related equipment located in this fire zone consists of portions of the Control Room Ventilation System components. These are the galvanized ductwork, dampers, and ductwork accessories.

2.3-44

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures As indicated in Figure 2.3-7, Fire Zone 3.3C-1 has three manual hose stations located inside. Portable fire extinguishers are available as illustrated in Figure 2.3-7.

As requested by NRC, all the existing woven-jacket fire hose in this zone has been replaced with a hard rubber-type fire hose.

Inadvertent operation of the total flooding Halon 1301 or the CO2 flooding system would have no significant effect on the electrical cable in this zone because both extinguishing agents are electrically nonconductive inert gases. The automatic total flooding Halon 1301 system is designed in accordance with NFPA Chapter 12A, "Standard for Halogenated Extinguishing Agent Systems-Halon 1301." The Halon 1301 storage containers are located at elevation 468 feet 4 inches in the Turbine Building. The containers will not damage safety-related equipment since they are in the Turbine Building.

The backup fire protection system, a manually initiated total flooding CO2 system is designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

The area is provided with two trains of detectors, one thermal and one ionization (or photoelectric), which annunciate in the Control Room.

Combustible Materials Cable insulation, fiber optic cable, gaskets, and insulation.

At Byron, plastic and Thermo-lag.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The primary extinguishing system for this zone is an automatic total flooding Halon 1301 system at 6% concentration. The system is actuated automatically by signals from one detector in each of the two trains, which annunciate and alarm in the control room. Pre-discharge alarms are provided locally and in the control room. Pre-discharge timers delay the discharge to allow personnel time to leave the area.

2.3-45

B/B - FPR AMENDMENT 29 DECEMBER 2020 The Halon system can be initiated manually with or without electric power. This system is designed to maintain the Halon concentration above 6% for a minimum of 20 minutes. For this zone, this is accomplished by the initial discharge.

The backup system is a manually initiated (with or without electric power) total flooding CO2, system at 50% concentration. Local and control room alarms are activated upon system discharge. A pre-discharge alarm is provided to allow personnel to leave the room.

In addition, there are three fire hose stations located in this room and portable extinguishers are also available as shown on Figure 2.3-7.

Design-Basis Fire The combustibles present in this area are cable insulation and ductwork insulation. Ionization (or photoelectric) and thermal detectors for the room have been provided to sense a fire and alarm in the Control Room. The automatic primary system (Halon 1301) and the manual backup CO2 system or water from the manual hose station, or fire extinguishers, can be used to extinguish a fire.

With these methods of firefighting and the early warning system, the potential for a design-basis fire in this area is highly unlikely. The fire would not spread out of this room because of the substantial construction of the walls, floor, and ceiling and penetrations and openings are sealed, except as noted in the fire barrier description.

In the unlikely event a fire did start, and the two fixed extinguishing systems failed to operate, the fire would be contained within the room by the fire barriers.

However, the Control Room HVAC ductwork inside the room may be damaged and/or the fusible link fire dampers inside the ductwork or electrothermal link fire dampers would close and restrict the flow of air. The redundant train of the Control Room HVAC System could be started and supply air to the control room and surrounding areas except for the Unit 1 Auxiliary Electric Equipment Room, Record Storage Room, and Upper Control Room HVAC Equipment Room. If necessary, this room could be ventilated with temporary fans.

The design-basis fire is highly unlikely for the following reasons:

a. The cable spreading rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in the cable spreading rooms.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

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B/B - FPR AMENDMENT 29 DECEMBER 2020

d. The room is provided with two trains of detectors which annunciate in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the control room. The fire dampers would close, and the automatic fire suppression system would extinguish the fire and annunciate in the control room.

The results of a fire in this zone are acceptable since only one ESF division will be lost. Sufficient redundancy exists in the engineered safety features fed from the other ESF division to achieve a reactor shutdown and to maintain the reactor in a safe shutdown condition.

The Control Room HVAC System will not be shut down but will continue to operate and pressurize the Control Room and the zones surrounding the Control Room with one of the two HVAC trains in operation. The links of the fire dampers will close upon being energized by the control room fire detection system and/or temperatures exceeding 165 Degrees Fahrenheit. There are no radioactive sources in this zone.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.23.

2.3.3.19 Upper Cable Spreading Area H (Fire Zone 3.3C-2)

This zone is shown on Figure 2.3-7 and in elevation on Figure 2.3-25 (Sheet 2).

Electrical cable trays routed through this zone are shown on Figure 2.3-32.

For details, see Subsection 2.3.3.18, except that:

a. Division 21 instead of Division 11 cabling is present.

b. At Braidwood, Thermo-Lag contributes to combustible material.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.24.

2.3-47

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.20 Unit 1 Upper Cable Spreading Area D (Fire Zone 3.3D-1)

This zone is shown on Figure 2.3-7. Electrical cable trays routed through this zone are shown on Figure 2.3-32.

Fire Barrier Description The north and west walls are 24 inches thick and 36 inches thick, respectively and are solid concrete masonry units. The south and east walls are 12-inch-thick structural reinforced concrete and carry a 3-hour fire rating. However, the west wall at Braidwood at column rows P and 13-14 is of 3-hour fire-rated construction but contains two nonrated penetration seals (E0382487 and E0382488), which are constructed of Thermo-Lag and are abandoned in place. All walls extend up to within 1 inch of the ceiling above. The remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation, and the walls carry a 3-hour fire rating. A Label "A" 3-hour fire rated door is in the east wall and leads to an adjacent cable spreading room. At Byron, the north wall contains a fire door of "A" Label construction which leads to an enclosed stairwell. At Braidwood, this door is a Label "A" 3-hour fire rated door.

Two 4-inch-diameter floor drains (90 gpm capacity each) are provided.

Three-hour rated vertical fire dampers are installed with sleeves in the ductwork penetrations through the walls. There are horizontal fire dampers which consist of two 1-1/2-hour labeled dampers in series inserted in the floor. These dampers have electro-thermal or fusible links which are activated either from the fire detection system or when the temperatures exceed 165 Degrees Fahrenheit.

Safety-Related Equipment Control and instrumentation cables associated with ESF Division 11 are present.

The safety-related equipment located in this zone consists of a portion of the Control Room HVAC System components. These are the galvanized ductwork, ductwork accessories, and dampers.

Protection Criteria and Measures There is one manual hose station and fire protection piping designed in accordance with ASME Section III standards in this zone. At Byron, the manual hose station and fire protection piping in this zone has been reclassified as Safety Category II, Quality Group D (Ref. EC 636663); and remains classified as Seismic Category I.

As requested by NRC, all the existing woven-jacket fire hose in this zone has been replaced with a hard rubber-type fire hose.

2.3-48

B/B - FPR AMENDMENT 29 DECEMBER 2020 The automatic total flooding Halon 1301 system is designed in accordance with NFPA Chapter 12A, "Standard for Halogenated Extinguishing Agent Systems-Halon." This system is designed to maintain the Halon concentration above 6%

for a minimum of 20 minutes. For this zone, this is accomplished by the initial discharge.

The Halon 1301 storage containers are located at elevation 468 feet 4 inches in the Turbine Building. The Halon containers would not damage safety-related equipment since they are in the Turbine Building. Refer to Appendix A5.4 for a detailed description of the Halon system.

The backup fire protection system, a manually initiated total flooding CO2 system, is designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton low-pressure CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

Combustible Materials Cable insulation, fiber optic cable, gaskets, and insulation.

At Byron, plastic.

At Braidwood, Thermo-Lag.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The primary extinguishing system for this zone is an automatic total flooding Halon 1301 system at 6% concentration. The system is actuated automatically by signals from one detector in each of the two trains, which annunciate and alarm in the Control Room. Pre-discharge alarms are provided locally and in the control room. Pre-discharge timers delay the discharge to allow personnel time to leave the area. The Halon system can be initiated manually with or without electric power. This system is designed to maintain the Halon concentration above 6%

for a minimum of 20 minutes. For this zone, this is accomplished by the initial discharge.

The backup manually initiated, with or without electric power, total flooding CO2 system will deliver sufficient quantity of CO2 to achieve a 50% concentration.

Actuation of the system will alarm locally and in the control room. A pre-discharge alarm is provided.

2.3-49

B/B - FPR AMENDMENT 29 DECEMBER 2020 As indicated in Figure 2.3-7, Fire Zone 3.3D-1 has one manual hose station located inside. Portable CO2, extinguishers are also available.

Design-Basis Fire The only combustible materials present in significant quantities are the cable insulation materials. The design-basis fire for this area is postulated to be the burning of all the cable insulation in the room. The results of this fire are acceptable since control and instrumentation cables of only one ESF division are routed through this room. Safe shutdown and cooldown of the reactor can be achieved with components fed from the other ESF division. The fire would not spread out of this room, due to the substantial construction of the walls, floor, and ceiling, and the fact that all penetrations and openings are sealed.

The design-basis fire is highly unlikely for the following reasons:

a. The cable spreading rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in the cable spreading rooms.

c. The cable insulation meets the IEEE-383 criteria for cable fire test.

Additionally, the cables are separated by both division and function as described in Appendix 5.2.

d. The room is provided with two trains of detectors which annunciate in the Control Room.

e. The fire suppression systems are available to quickly extinguish any fire.

If a fire was to start in one of the cable trays, at least one detector in each train would annunciate in the Control Room. All fire dampers would close, and the automatic fire suppression system would extinguish the fire and annunciate in the Control Room. The results of a fire in this zone are acceptable since only one ESF division will be lost. Sufficient redundancy exists in the engineered safety features fed from the other ESF division to achieve a reactor shutdown to maintain the reactor in a safe shutdown condition.

The Control Room Ventilation System will not be shut down but will continue to operate and pressurize the Control Room and the surrounding zones.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.25.

2.3-50

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.3.21 Upper Cable Spreading Area (Fire Zone 3.3D-2)

This zone is shown on Figure 2.3-7. Electrical cable trays routed through this zone are shown on Figure 2.3-32.

For details, see Subsection 2.3.3.20, except that:

a. Division 21 cabling instead of Division 11 cabling is present.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.26.

2.3.3.22 Unit 1 Cable Riser Area (Fire Zone 3.4A-1)

This area is shown on Figure 2.3-8 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor at elevation 451 feet 0 inch, which is the ceiling of a lower cable riser area, is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams protected with spray-on fire-resistant material and carries a 3-hour fire rating.

Walls are 12-inch-thick hollow concrete masonry units, or 36-inch-thick structural reinforced concrete and carry a 3-hour fire rating. Masonry walls extend up to within 1 inch of the ceiling and this remaining space is packed with a 1-inch-thick blanket of foil-backed Thermafiber insulation. A Label "A" fire door leads to the Auxiliary Electric Equipment Room.

The ceiling at elevation 463 feet 5 inches, which is the floor of the Upper Cable Spreading Room, is a 2-1/2-inch clear cover of reinforced concrete over 1-1/2-inch fluted steel decking. The underside of the decking, and the structural steel members that support this slab are protected with a fire-resistant covering. The slab and the supporting steel members carry a 3-hour fire rating.

Safety-Related Equipment Cables in this zone are in risers and are ESF Division 11 and contain instrumentation and control cables.

Protection Criteria and Measures The Cable Spreading Room is separated from other portions of the floor by 3-hour fire walls. Entrance to this limited access area is provided through a fire door.

2.3-51

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Portable CO2 extinguishers are in adjacent rooms. This room is also within reach of manual hose station No. 16 in the turbine building. An ionization (or photoelectric) detector is provided which annunciates and alarms in the Control Room.

Design-Basis Fire The results of a fire in this zone are acceptable since only one ESF division will be lost. Sufficient redundancy exists in the engineered safety features fed from the other ESF division to achieve a reactor shutdown and to maintain the reactor in a safe shutdown condition.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.27.

2.3.3.23 Unit 2 Cable Riser Area (Fire Zone 3.4A-2)

This area is shown on Figure 2.3-8 (Sheet 3). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

This room is within reach of manual hose station No. 15 in the turbine building.

For details, see Subsection 2.3.3.22, except that:

a. Division 21 cabling instead of Division 11 is present.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.28.

2.3-52

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.4 Plant Computer Rooms 2.3.4.1 Unit 1 Computer Room (Fire Zone 4.1-1)

This room is shown on Figure 2.3-8 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor at elevation 451 feet 0 inch, which is the ceiling of the Lower Cable Spreading Room, is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams protected with a fire-resistant coating and carries a 3-hour fire rating. An architectural raised floor is provided in a portion of this room. The floor is of all-metal construction and is covered with Class 1 fire resistant carpeted floor tiles. Walls are 12-inch-thick hollow concrete masonry units, 24-inch-thick solid concrete masonry units or 36-inch-thick structural reinforced concrete and carry a 3-hour fire rating.

Masonry walls extend up to within 1-inch of the ceiling and this resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation. A door with "A" Label construction leads to the Control Room.

The ceiling at elevation 463 feet 5 inches, which is the floor of the Upper Cable Spreading Room, is a 2-1/2-inch clear cover of reinforced concrete over 1-1/2-inch fluted steel decking. The underside of this decking, and the structural steel members that support this slab, are protected with a fire-resistant covering. The slab and the supporting steel members carry a 3-hour fire rating. A nonrated acoustical tile suspended ceiling is provided below the ceiling slab. The floor is covered with approximately 800 ft2 of 1/8-inch-thick vinyl-asbestos tile. In addition, 106 lineal feet of 4-inch-high vinyl cove base is provided at the intersection of the walls and floor. These materials do not contribute significantly to the fire load in this room.

Fire dampers are installed in the ducts penetrating the fire walls and floors and are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. (Two 1-1/2-hour fire dampers are installed in floor openings to meet 3-hour rating.)

Safety-Related Equipment There is no safety-related equipment in this zone; however, safe shutdown cables are routed through this zone.

2.3-53

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The Computer Room is isolated from the rest of the elevation by walls with a 3-hour fire rating. One fire door provides entrance into this limited access area.

Fire dampers are provided in the fire walls and floors. The fire dampers are fusible link type which will close when the temperature exceeds 165 Degrees Fahrenheit.

Combustible Materials Cable insulation, fiber optic cable, gaskets, insulation, and paper.

At Byron, miscellaneous office material and plastic.

At Braidwood, polypropylene and wooden work tops.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Ionization (or photoelectric) detectors are located above and below the suspended ceiling which annunciate and alarm in the Control Room.

Portable extinguishers are in the room. Additional portable extinguishers are in adjacent rooms. A manual hose station located in the turbine building also has access to this room.

Design-Basis Fire The design-basis fire would result if all the combustibles in this room burned. The plant computer, which is non-safety-related, would be damaged. This would not affect the ability to shut down the reactor. The results of the design-basis fire are thus acceptable.

A fire in this room would be quickly detected by the ionization (or photoelectric) detectors.

If the temperature exceeds 165 Degrees Fahrenheit, the fusible links will melt, and the fire dampers will close. There is no radioactive HVAC equipment in this zone. The spread of hot air and combustion products will be mitigated by the fire dampers. All ductwork in this zone may be severely damaged in the event of a design basis fire; however, this will not affect the safe shutdown of the plant.

The analysis of the effects of a fire on cables required for safe shutdown in this zone is discussed in Section 2.4.2.29.

2.3-54

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.4.2 Unit 2 Computer Room (Fire Zone 4.1-2)

This room is shown on Figure 2.3-8 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

For details, see Subsection 2.3.4.1. except that:

a. At Byron, the floor area bounded by column row P-Q and 20-21 is of fire-rated construction but contains nonrated penetration seals.

See safe shutdown analysis Section 2.4.2.30.

2.3.5 Switchgear Areas 2.3.5.1 Division 12 ESF Switchgear Room (Fire Area 5.1-1)

This room is shown on Figure 2.3-10 (Sheet 1). An elevation view is shown on Figure 2.3-25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-35.

Fire Barrier Description The floor at elevation 426 feet 0 inch, which is the ceiling of a Diesel-Generator Room, is a 5-inch clear cover of structural reinforced concrete with a 3-inch concrete topping over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and carries a 3-hour fire rating. The walls of the switchgear room are minimum 12-inch-thick hollow concrete masonry units or minimum 12-inch-thick structural reinforced concrete and carry a 3-hour fire rating. Interior walls extend up to within 1 inch of the ceiling above. This resulting space is packed with a 1-inch thick blanket of Thermafiber insulation.

The single swing door at Braidwood and the double swing door at Byron leading from this switchgear room to the Turbine Building are non-labeled fire doors.

Steel plates have been bolted to the doors to reinforce the doors for HELB pressure loading. At Byron, horizontal stiffeners are added to the double swing door. The frames of these doors are also reinforced, and the hinges are heavy duty outer hinges. Door pulls have been added to these fire doors to facilitate door operation. The addition of door pulls does not affect the self-closing or latching performance of the doors. Refer to Braidwood EC EVAL 392603 and Byron EC-EVAL 392627. The door between this zone and the adjacent ESF switchgear room is a Label "A" door.

2.3-55

B/B - FPR AMENDMENT 29 DECEMBER 2020 The ceiling at elevation 439 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected by a fire-resistant covering and carries a 3-hour fire rating.

Three-hour rated galvanized steel vertical fire dampers are installed in the ventilation openings penetrating the fire walls.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 5.1-1/3.2A-1, 5.1-1/9.1-1).

Safety-Related Equipment The safety-related equipment located in this fire zone consists of ESF switchgear and the ESF switchgear room ventilation system.

These are specifically:

a. the galvanized ductwork

b. dampers

c. ductwork accessories

d. 4160-V ESF Switchgear 142, ESF Div. 12 1AP06E

e. 480-V ESF Unit Substation 132X, ESF Div. 12 1AP12E, and

f. components of the ventilation system for this room.

Protection Criteria and Measures Three-hour rated vertical fire dampers with 165 Degrees Fahrenheit or 286 Degrees Fahrenheit fusible links are installed in the ventilation openings penetrating the fire walls.

Combustible Material cable insulation and gaskets.

At Byron, acrylic and plastic.

At Braidwood, polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-56

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Portable fire extinguishers are in the room. Portable fire extinguishers are available outside the door in the Turbine Building. A manual hose station at column/row L-7 is available for backup.

Design-Basis Fire The design-basis fire is the fire that burns all the cable insulation and gasketing in the room. The design-basis fire would result in the incapacitation of the electrical equipment in the room. It would not spread to adjacent rooms, since the fire severity is less than the barrier rating. The results of this fire are acceptable, since the system design satisfies the single failure criteria in that any one of the two engineered safety features electrical system buses can be lost and still have sufficient engineered safety features system auxiliaries in operation to safely shut down the plant. The design-basis fire is highly unlikely for the following reasons:

a. These rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in these rooms.

c. The cable insulation meets the IEEE-383 criteria for non-self-propagation of fire. The cables are separated by both division and function as described in Appendix 5.2.

d. The room is provided with ionization (or photoelectric) detectors which annunciate and alarm in the Control Room.

In the event of a fire, the Control Room operators would be alerted by the ionization (or photoelectric) detectors. The fire would be quickly extinguished using available equipment.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.31.

2.3-57

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.5.2 Division 22 ESF Switchgear Room (Fire Area 5.1-2)

This room is shown on Figure 2.3-10 (Sheet 3). An elevation view is shown on Figure 2.3-25 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-35.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 5.1-2/3.2A-2, 5.1-2/9.1-2).

For details, see Subsection 2.3.5.1, except that:

a. The equipment is for Unit 2 (Division 22).

b. The manual hose station is located at column/row L-29.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.32.

2.3.5.3 Division 11 ESF Switchgear Room (Fire Area 5.2-1)

This room is shown on Figure 2.3-10 (Sheet 1). An elevation view is shown on Figure 2.3-25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-35.

Fire Barrier Description The ceiling at elevation 439 feet 0 inch is supported by structural steel beams protected with a fire-resistant covering and carries a 3-hour fire rating, except for one beam at Byron, which carries a 2.4-hour fire rating.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems (5.2-1/3.2A-1). Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 5.2-1/9.2-1).

For details, see Subsection 2.3.5.1.

2.3-58

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The safety-related equipment located in this fire zone consists of switchgear and the ESF Switchgear Room Ventilation System. These are specifically:

a. ductwork

b. dampers

c. ductwork accessories

d. 4160-V ESF Switchgear 141, ESF Div. 11 1AP05E,

e. 480-V ESF Unit Substation l31X, ESF Div. 11 1AP10E, and

f. components of the ventilation system for this room.

Protection Criteria and Measures Three-hour rated vertical fire dampers with 165 Degrees Fahrenheit or 286 Degrees Fahrenheit fusible links are installed in the ventilation openings penetrating the fire walls. Two 1-1/2-hour labeled fire dampers in series are installed in the ventilation openings penetrating fire rated floors.

Fire stops are provided for all bus duct penetrations between Fire Zones 3.2A 1 and 5.2-1 to protect redundant safe shutdown equipment located in these zones.

Combustible Materials Cable insulation and gaskets.

At Byron, acrylic, plastic and Thermo-Lag.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Portable fire extinguishers are in the room. A portable fire extinguisher is located outside the door in the Turbine Building. A manual hose station at column/row L-9 outside the room has access and can be used as a backup.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire For details, see Subsection 2.3.5.1.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Subsection 2.4.2.33.

2.3-59

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.5.4 Division 21 ESF Switchgear Room (Fire Area 5.2-2)

This room is shown on Figure 2.3-10 (Sheet 3). An elevation view is shown on Figure 2.3-25 (Sheet 2).

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Section 2.4.2.34.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems (5.2-2/3.2A-2). Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 5.2-2 and 9.2-2).

For details, see Subsection 2.3.5.3 except that:

a. The manual hose station is at column/row L-26.

b. The switchgear is for Division 21.

2.3.5.5 Unit 1 Nonessential Switchgear Room (Fire Area 5.3-1)

This room is shown on Figure 2.3-8 (Sheet 1). An elevation view is shown on Figure 2.3-25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor at elevation 451 feet 0 inch is a 9-inch clear cover of structural reinforced concrete with a 3-inch concrete topping over 3-inch fluted steel decking formwork and is supported by structural steel beams protected with a fire-resistant covering and carries a 3-hour fire rating. Three walls are a minimum 12-inch-thick hollow concrete masonry units or structural reinforced concrete and carry a 3-hour fire rating. Interior walls extend up to within 1 inch of the ceiling above. This remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. All doors leading from this switchgear room are Label "A" 3-hour rated fire doors. The ceiling at elevation 477 feet 0 inch, which is the roof of the Auxiliary Building, is a 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by protected structural steel beams and carries a 3-hour fire rating.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 5.3-1/18.10C-1).

2.3-60

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The safety-related equipment in this room consists of a portion of the ventilation system for the Division 12 Miscellaneous Electric Equipment and Battery Room.

Protection Criteria and Measures This zone is separated from the rest of the plant by barriers of substantial construction.

Combustible Materials Cable insulation and gaskets.

At Byron, acrylic and plastic.

At Braidwood, polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A fire hose station is in the room. A manual hose station is located at column/row L-6 in the Turbine Building and is available to suppress a fire in this room.

Portable extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire is the fire that burns all the cable insulation in the switchgear in this room. The design-basis fire is unlikely due to the small amount of combustible material present, and the resulting small fire loading. If a fire did occur, the safety-related ductwork might be damaged. A fire in this room would be quickly detected by the ionization (or photoelectric) detectors and annunciated in the Control Room. There would be no serious consequences from a fire in this room. The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.35.

2.3-61

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.5.6 Unit 2 Nonessential Switchgear Room (Fire Area 5.3-2)

This room is shown on Figure 2.3-8 (Sheet 3). An elevation view is shown on Figure 2.3-25 (Sheet 2).

Electrical cable trays routed through this zone are shown on Figure 2.3-33.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 5.3-2/18.10C-2).

For details, see Subsection 2.3.5.5 except that:

a. The fire hose station is located at column/row L-30 in the Turbine Building.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.36.

2.3.5.7 Division 12 Miscellaneous Electrical Equipment and Battery Room (Fire Area 5.4-1)

This room is shown on Figure 2.3-8 (Sheet 1) and in elevation on Figure 2.3 25.

Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor at elevation 451 feet 0 inch is a 12-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and carries a 3-hour fire rating.

All walls are a minimum 12-inch-thick hollow concrete masonry units or minimum 12-inch-thick structural reinforced concrete and carry a 3-hour fire rating. These walls extend up to within 1 inch of the ceiling above. This resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation. All doors leading from this equipment room are Label "A" 3-hour rated fire doors except for the door leading from the east wall of the equipment room which has "A" Label construction.

The two walls enclosing the batteries carry a 3-hour fire rating and extend up to 463 feet 0 inch. The ceiling of this enclosure carries no fire rating.

2.3-62

B/B - FPR AMENDMENT 29 DECEMBER 2020 The ceiling at elevation 477 feet 0 inch, which is the roof of the Auxiliary Building is a 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by protected structural steel beams and carries a 3-hour fire rating.

Safety-Related Equipment The following safety-related equipment is in this zone:

a. 125-Vdc Battery 112, 1DC02E

b. 125-Vdc Distribution Center 112, 1DC06E

c. Instrument Distribution Bus 112 Inverter, 1IP06E

d. Instrument Distribution Bus 114 Inverter, 1IP08E

e. Reactor Trip Switchgear, ESF Div. 11&2, 1RD05E

f. 125-Vdc Battery Charger 112, 1DC04E

g. Instrument Bus 112 Transformer, 1IP02E

h. Instrument Bus 114 Transformer, 1IP04E

i. Components of the ventilation system for this room

j. Spare cells and rack for 125-Vdc battery, 1DC10EA (Braidwood only)

k. Fuse box for spare cell charging cable (Braidwood only).

Protection Criteria and Measures The equipment is located on concrete pedestals. The batteries are located on steel racks. There are no fire protection lines routed through this room.

The ventilation system will maintain hydrogen concentration less than 2% by volume. This room is separated from the redundant battery by a 3-hour rated barrier. All ventilation openings are provided with 3-hour rated fire dampers.

Combustible Materials Acrylic, cable insulation, gaskets, lube oil, polycarbonate, plastic, and fire resistance PVC.

At Braidwood, grease, polyethylene, polypropylene, and Thermo-lag.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-63

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities Portable fire extinguishers are in the room. Fire extinguishers are also available from the adjacent area. One hose station at column/row L-10 in the Turbine Building has access to the room. Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would result if all the combustibles in the room burned. The reactor trip switchgear would be destroyed, as well as the battery. The ability to shut down the reactor would not be affected. A redundant dc power system can carry all necessary electrical loads. Because of the low fire loading this fire would not spread to adjacent zones. The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.37.

2.3.5.8 Division 22 Miscellaneous Electrical Equipment Room (Fire Area 5.4 2)

This room is shown on Figure 2.3-8 (Sheet 3) and in elevation on Figure 2.3 25.

Electrical cable trays routed through this zone are shown on Figure 2.3-33.

For details, see Subsection 2.3.5.7 except that:

a. Panels have a prefix of "2" instead of "1".

b. The hose station is at column/row L-26 in the Turbine Building.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.38.

2.3.5.9 Unit 1 Auxiliary Electrical Equipment Room (Fire Area 5.5-1)

This room is shown on Figure 2.3-8 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor at elevation 451 feet 0 inch is a 12-inch structural reinforced concrete slab on 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the zone below.

2.3-64

B/B - FPR AMENDMENT 29 DECEMBER 2020 All walls are minimum 12-inch-thick hollow concrete masonry units or minimum 12-inch-thick structural reinforced concrete and carry a 3-hour fire rating. These walls extend up to within 1 inch of the ceiling above at Byron and the remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. At Braidwood, these walls extend up to within 1 inch of the ceiling above, except for the north wall which is interrupted at elevation 459'-5-3/4" by a W18 x 60 structural steel beam to support a gallery at elevation 459'-7". This beam is protected to a 3-hour rating by a fire-resistant covering. The remainder of the north wall above the beam at elevation 459'-5-3/4" extending to within 1 inch of another structural steel beam above is comprised of 2-hour fire rated masonry with 1 layer each side of 7/8" metal furring channels and 1/2-inch fire rated gypsum wallboard. The remaining 1-inch space above the wall and between the structural steel beam is packed with a 1-inch-thick blanket of Thermafiber insulation. This portion of wall shall carry a minimum 3-hour fire rating. The beam is protected to a 3-hour rating by a fire-resistant covering. The ceiling structure above rests upon this structural steel beam. At Byron, a steel column at elevation 451 near N-13 is missing fire proofing at the top of the column but still maintains the required 3-hour barrier (EC 396395).

All doors leading from this equipment room are Label "A" 3-hour rated fire doors except for the door in the east wall which has "A" Label construction. The ceiling at elevation 463 feet 5 inches, which is the floor of an upper cable spreading room, is a 2-1/2-inch clear cover of reinforced concrete over 1-1/2-inch fluted steel decking. The underside of this decking and the structural steel members that support this slab are protected with a fire-resistant covering. The slab and the supporting steel members carry a 3-hour fire rating.

Safety-Related Equipment The following safety-related equipment is in this zone:

a. Process I&C Rack Protection Set I, Reactor Protection Channel I, 1PA01J

b. Process I&C Rack Protection Set II, Reactor Protection Channel II, 1PA02J

c. Process I&C Rack Protection Set III, Reactor Protection Channel III, 1PA03J

d. Process I&C Rack Protection Set II, Reactor Protection Channel IV, 1PA04J

e. Solid-State Protection System Cabinet Train A, ESF Div. 11, 1PA09J

f. Solid-State Protection System Cabinet Train B, ESF Div. 12, 1PA10J

g. Safeguard Test Cabinet Train A, ESF Div. 11, 1PA11J

h. Safeguard Test Cabinet Train B, ESF Div. 12, 1PA12J

i. ESF Sequencing and Actuating Cabinet Train A, ESF Div. 11, 1PA13J

j. ESF Sequencing and Actuation Cabinet Train B, ESF Div. 12, 1PA14J

k. Stop Valve Logic Cabinet Train A, ESF Div. 11, 1PA15J

l. Stop Valve Logic Cabinet Train B, ESF Div. 12, 1PA16J 2.3-65

B/B - FPR AMENDMENT 29 DECEMBER 2020

m. Auxiliary Safeguard Relay Rack Train A, ESF Div. 11, 1PA27J

n. Auxiliary Safeguard Relay Rack Train B, ESF Div. 12, 1PA28J

o. Annunciator Input Cabinet, ESF Div. 11, 1PA31J

p. Annunciator Input Cabinet, ESF Div. 12, 1PA32J

q. 120-Vac Instrument Distribution Cabinet, Reactor Protection Channel I, 1IP01J

r. 120-Vac Instrument Distribution Cabinet, Reactor Protection Channel II, 1IP02J

s. 120-Vac Instrument Distribution Cabinet, Reactor Protection Channel III, 1IP03J

t. 120-Vac Instrument Distribution Cabinet, Reactor Protection Channel IV, 1IP04J

u. Control System Cabinet, ESF Div. 11, 1PA33J

v. Control System Cabinet, ESF Div. 12, 1PA34J

w. Components of the ventilation system for this room.

Protection Criteria and Measures One manual hose station and portable fire extinguishers are available to fight a fire in this room. This room is separated from the remainder of the plant by 3-hour rated fire barriers. This zone is a controlled access area.

Combustible Materials Cable insulation, gaskets and insulation.

At Byron, acrylic and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Portable fire extinguishers are in the room. Additional fire extinguishers are in adjacent rooms. A hose station at column/row L-11 can be used as backup protection. Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire for this zone is considered the burning of all the cable insulation in the room. This fire should not spread to other fire zones due to the substantial fire rating of the walls. Control and instrumentation cables from both engineered safety features divisions are in the Auxiliary Electric Equipment Room, along with the other listed safety-related equipment.

2.3-66

B/B - FPR AMENDMENT 29 DECEMBER 2020 The design-basis fire is highly unlikely for the following reasons:

a. The auxiliary electric equipment rooms are controlled access areas, thus limiting the transient combustibles which may be present.

b. No significant quantities of combustible materials are stored in these rooms.

c. The cable insulation is in panels or cabinets and is thus afforded some protection from the effects of a nearby fire. Panels would minimize the propagation of fire from one panel to another. Additionally, the cables in the cable trays are separated by both division and function as described in Appendix 5.2.

d. The room is provided with ionization (or photoelectric) detectors which annunciate in the Control Room.

Cable insulation is the only combustible material of any consequence in this zone.

This material meets the IEEE-383 criteria for cable fire test. For these reasons, any fire that may start in this zone is likely to grow and spread quite slowly. The ionization (or photoelectric) detectors would alert the Control Room operators, who would promptly initiate corrective actions. The fire would most likely be extinguished in a short time using available equipment, before it became very serious.

The existing detection and manual suppression capability are adequate to protect against any fire likely to occur.

All the cables in these safety-related cabinets are either control or instrumentation cables. The potential for fire initiation due to short circuit conditions or electrical arcing is minimal. All relaying and instrumentation racks are enclosed in locked steel cabinets, and all cable penetrations into these cabinets have firestops.

These cabinets do not contain equipment or cables from more than one safety-related cable division. Safety-related cabinets pertaining to ESF Division 12 are fed from the room below this zone and the cabinets designated ESF Division 11 are fed from the upper floor through the ceiling of this room. Any fire which could credibly initiate in one of these cabinets would be of relatively low intensity, would be confined within the cabinet, and would not affect redundant safety-related systems.

It should be noted that all reactor protection circuitry located in these rooms is designed to automatically shut down the associated reactor when the circuitry is de-energized, which is the condition most likely to result from a circuit component failure, cabling short circuit, or a resulting fire. Thus, a single fire in any of the Auxiliary Electrical Equipment Room cabinets will not compromise the ability to safely shut down and cool the reactors.

2.3-67

B/B - FPR AMENDMENT 29 DECEMBER 2020 Since the auxiliary electrical equipment rooms are provided with ionization(or photoelectric) type smoke detectors which annunciate in the Control Room, additional fixed automatic fire suppression equipment for these rooms is not required in order to assure the availability of redundant safe shutdown systems in the event of a single credible fire. Early detection of a possible fire will afford a sufficient amount of time to allow extinguishment by means of portable extinguishers located in this area. As a last resort, the manual hose station in the Turbine Building could be used to extinguish the fire.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.39.

2.3.5.10 Unit 2 Auxiliary Electrical Equipment Room (Fire Area 5.5-2)

This room is shown on Figure 2.3-8 (Sheet 3). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

For details, see Subsection 2.3.5.9 except that:

a. Equipment is Unit 2 electrical equipment.

b. The fire hose station is at column/row L-25.

c. The door in the east wall is a Label "A" door.

d. At Braidwood, the block wall at the north side of the area is interrupted at elevation 459 feet 5 3/4 inches by a W18 X55 Structural steel beam.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.40.

2.3.5.11 Division 11 Miscellaneous Electrical Equipment and Battery Room (Fire Area 5.6-1)

This room is shown on Figure 2.3-8 (Sheet 1). An elevation view is shown on Figure 2.3-25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

Fire Barrier Description The floor at elevation 451 feet 0 inch is a 12-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the zone below.

2.3-68

B/B - FPR AMENDMENT 29 DECEMBER 2020 Three walls of this room are minimum 12-inch thick hollow concrete masonry units or minimum 12-inch thick structural reinforced concrete and carry a 3-hour fire rating. These walls extend up to within 1 inch of the ceiling above. This remaining space is packed with a 1-inch thick blanket of Thermafiber insulation.

All doors leading from this equipment room are Label "A" 3-hour rated fire doors.

The ceiling at elevation 477 feet 0 inch, which is the room of the Auxiliary Building is a 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by protected structural steel beams and carries a 3-hour fire rating.

The wall enclosing the batteries carries a 3-hour fire rating and extends up to 463 feet 0 inch. The ceiling of this enclosure carries no fire rating.

Three-hour galvanized steel vertical fire dampers are installed in the ventilation openings penetrating the fire walls. These dampers have fusible links which activate when the temperature exceeds 165 Degrees Fahrenheit.

Safety-Related Equipment The following safety equipment is in this zone:

a. 125-Vdc Battery 111, 1DC01E

b. 125-Vdc Distribution Center 111, 1DC05E

c. Instrument Distribution Bus 111 Inverter, 1IP05E

d. Instrument Distribution Bus 113 Inverter, 1IP07E

e. 125-Vdc Battery Charger 111, 1DC03E

f. Instrument Bus 111 Transformer, 1IP01E

g. Instrument Bus 113 Transformer, 1IP03E, and

h. Components of the ventilation system for this room.

Protection Criteria and Measures The batteries are on steel racks.

No fire protection lines are routed through this room.

Combustible Materials Acrylic, cable insulation, gaskets, plastic, polycarbonate, and fire resistance PVC.

At Braidwood, polyethylene and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-69

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities A portable fire extinguisher is in the room. Additional fire extinguishers are in adjacent rooms. A hose station at column/row L 10 in the Turbine Building is available for backup protection. Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire is the fire that burns all the cable insulation in the room.

The design-basis fire is assumed to result in the incapacitation of the electrical equipment in the room. It would not spread to adjacent rooms, since the fire loading is small and the barriers of substantial construction.

The results of this fire are acceptable, since the system design satisfies the single failure criteria in that any one engineered safety feature electrical system buses can be lost and still have sufficient engineered safety features system auxiliaries in operation to safely control the plant (only ESF Division 11 equipment is in this zone). The design-basis fire is highly unlikely for the following reasons:

a. These rooms are controlled access areas.

b. No significant quantities of combustible materials are stored in these rooms.

c. The cable insulation meets the IEEE-383 criteria for non-self-propagation of fire. The cables are separated by both division and function as described in Appendix 5.2.

d. The room is provided with ionization (or photoelectric) detectors which annunciate in the Control Room.

In the event of a fire, the Control Room operators would be alerted by the ionization (or photoelectric) detectors and would promptly take corrective actions.

The fire would be quickly extinguished using available equipment.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.41.

2.3-70

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.5.12 Division 21 Miscellaneous Electrical Equipment and Battery Room (Fire Area 5.6-2)

This room is shown on Figure 2.3-8 (Sheet 3). An elevation view is shown on Figure 2.3-25 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-33.

For details, see Subsection 2.3.5.11 except that:

a. The panel numbers are preceded by a "2" instead of a "1."

b. A hose station at column/row L-26 can be used as backup protection.

c. The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.42.

2.3.6 Remote Safety-Related Panels This area is part of Fire Zone 11.4C-0 (Subsection 2.3.11.35).

2.3.7 Battery Rooms 2.3.7.1 Unit 1 BOP Battery Room (Fire Zone 7.1-1)

This zone is shown on Figure 2.3-12 (Sheet 2).

Fire Barrier Description The floor at elevation 401 feet 0 inch is a 7-inch concrete topping over a 109-inch-thick structural reinforced concrete base slab, which is the foundation of this portion of the Turbine Building. All walls are 12-inch-thick hollow concrete masonry units and carry a 3-hour fire rating. They extend up to within 1 inch of the ceiling above, and this resulting space is packed with a 1-inch-thick blanket of foil-backed Thermafiber insulation. A label "A" 3-hour rated fire door is provided for access to this room.

The ceiling slab at elevation 413 feet 9 inches is a 6-inch clear cover of structural reinforced concrete over a 3-inch fluted steel decking formwork, is supported by protected steel beams, and carries a 3-hour fire rating.

Safety-Related Equipment No safety-related equipment is in this room.

2.3-71

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The ventilation system will maintain the hydrogen concentration less than 2% by volume.

Three-hour galvanized steel fire dampers are installed in ventilation openings penetrating the fire walls. These dampers have fusible links which activate when temperatures exceed 165 Degrees Fahrenheit.

Combustible Materials Acrylic and plastic.

At Braidwood, cable insulation and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Four manual hose stations and portable fire extinguishers are available in the Turbine Building to combat a fire in this zone. Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire A fire in this BOP Battery Room would have no effect on any safety-related equipment or preclude a reactor shutdown.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.43.

2.3.7.2 Unit 2 BOP Battery Room (Fire Zone 7.1-2)

This zone is shown on Figure 2.3-12 (Sheet 4) and in elevation on Figure 2.3 22 (Sheet 1).

For details, see Subsection 2.3.7.1.

The analysis of the effects of a fire in this zone on cable required for safe shutdown is discussed in Subsection 2.4.2.44.

2.3-72

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.8 Turbine Building The major design factors of the automatic sprinklers and deluge systems are given in Appendix 5.4.

There is no safety-related equipment located in the Turbine Building. Any fire therefore would not affect safety-related equipment.

Damage to the fire protection systems (CO2 or Halon) would not affect safety-related equipment, although the event might disable portions of the system which protect safety-related areas. If a Turbine Building fire were to cause short circuits in the CO2 panels for the safety-related diesel generator (DG) rooms, it is possible that one or more fire dampers for the DG rooms may close. The closure of the fire dampers could cause the DG ventilation fan to trip on high differential pressure across the fan. However, an analysis has shown that sufficient time (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) is available to perform manual actions to restore ventilation to the DG rooms prior to potential DG damage occurring.

Therefore, the DGs would not be affected by a fire in the Turbine Building. Sprinkler or deluge system operation will alarm both locally and in the Control Room.

The Turbine Building enclosure from elevation 357 feet 0 inch up to elevation 401 feet 0 inch is entirely of structural reinforced concrete and is considered the basement of the building. The enclosure above elevation 401 feet 0 inch consists of reinforced concrete walls, hollow or solid concrete masonry unit walls, insulated metal siding walls, and 3-1/2-inch precast concrete channel roof slabs at elevation 426 feet 0 inch, 451 feet 0 inch, 475 feet 0 inch, and 534 feet 0 inch. All metal siding and roof slabs are exposed to the exterior and are supported by unprotected steel beams, girts, and columns. All of these roof slabs and much of the metal siding carry no fire rating, although 2-hour fire rated metal siding is provided adjacent to the auxiliary transformers (at column row "L" between column rows "1-6" and "30 35") from elevation 401 feet 0 inch up to elevation 454 feet 0 inch.

The north and east walls of the Turbine Building enclosure, along column rows "37" and "C" and "E" respectively, are almost entirely of non-rated insulated metal siding with the exception of the fire barriers separating it from the Radwaste/Service Building and contain continuous bands of plastic glazed motor-operated windows at elevation 411 feet 6 inches, elevation 454 feet 0 inch, and elevation 511 feet 1 inch. The walls that separate the Turbine Building from the Auxiliary Boiler rooms carry a 2-hour fire rating.

The south wall at column row "1," consists of insulated metal siding from elevation 401 feet 0 inch up to the roof at elevation 534 feet 0 inch. This wall also contains a continuous band of plastic glazed motor-operated windows and several fixed louvers.

2.3-73

B/B - FPR AMENDMENT 29 DECEMBER 2020 The west wall of the enclosure, at column row "L" consists of insulated metal siding and structural reinforced concrete. The portion of this wall from column row "6" to column row "30" and from elevation 401 feet 0 inch up to elevation 477 feet 0 inch is structural reinforced concrete and separates the Turbine Building from the Auxiliary Building. The remainder of this wall is insulated metal siding up to the roof at elevation 534 feet 0 inch. It contains bands of plastic glazed motor-operated windows at elevation 454 feet 0 inch and elevation 511 feet 1 inch.

The lower portion of the north wall is 12-inch-thick hollow concrete masonry units and separates the Turbine Building from the Service Building from elevation 401 feet 0 inch up to elevation 467 feet 0 inch.

Most of the steel beams and columns in the Turbine Building are unprotected against fire. The roof contains UL-approved smoke and heat vents.

2.3.8.1 Clean and Dirty Oil Tank Room (Fire Zone 8.1-0)

This zone is shown in Figure 2.3-14 (Sheet 2) and in elevation on Figure 2.3 22 (Sheet 1) and Figure 2.3-24 (Sheet 1).

Fire Barrier Description The floor at elevation 369 feet 0 inch is an 8-inch concrete topping over a 72-inch-thick structural reinforced concrete base slab. One 4-inch-diameter floor drain (90 gpm capacity) is provided. All walls are 12-inch-thick hollow concrete masonry units and carry a 3-hour fire rating. They extend up to within 1 inch of the ceiling slab, and this resulting space is packed with a 1-inch-thick blanket of foil-backed Thermafiber insulation. Two steel grating platforms and two Label "A" 3-hour rated fire doors lead to the turbine building basement and are located 4 feet 6 inches above the floor to contain an oil spill. The ceiling slab at elevation 401 feet 0 inch is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected by a fire-resistant covering which carries a 3-hour fire rating.

Two 6-inch-diameter drains of 300 gpm capacity each are provided. The fire dampers installed in the horizontal ducts penetrating the fire walls are of galvanized steel and are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

Safety-Related Equipment No safety-related equipment is in this zone.

2.3-74

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The room is enclosed by 3-hour rated fire walls. Fire dampers are provided in the fire walls. The fire dampers are thermal link type. This room is designed to contain any spill.

Combustible Materials Gaskets, grease, and lube oi.

At Byron, acrylic, plastic, and polypropylene.

At Braidwood, PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities An automatic sprinkler system is provided as the primary fire protection.

Activation of the sprinkler system will annunciate and alarm in the Control Room.

The five manual hose stations which provide the backup are each within 50 feet of one of the two entrances to the room. Two additional hose stations can be made available from Unit 2. Portable extinguishers are provided as shown in Figure 2.3-l4 (Sheets 2 and 4). Ionization (or photoelectric) detectors are provided at Byron which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would occur if the contents of the tank were ignited. This is highly unlikely as there is no ignition source present. The fire would not spread to other areas because of the fire barrier. The equipment in the room would be heavily damaged.

Safety-related equipment would not be affected. The automatic wet pipe sprinkler system would suppress the fire.

The fire dampers have electro-thermal links which are activated by the fire detection system. The spread of heat and combustion products will be stopped by the fire dampers. All ductwork in this zone may be severely damaged in the event of a design-basis fire; however, this will not affect the safe shutdown of the plant.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.45.

2.3-75

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.8.2 Turbine Building Basement - Unit 1 (Fire Zone 8.2-1)

This zone is shown on Figure 2.3-l4 (Sheet 2) and in elevation on Figure 2.3 22 (Sheet 1), Figure 2.3-23 (Sheet 1), and Figure 2.3-24 (Sheet 1).

Fire Barrier Description The floor at elevation 369 feet 0 inch is an 8-inch-thick concrete topping over a structural reinforced concrete base slab which varies in thickness from 20 inches to 132 inches. Several 4-inch-diameter floor drains are provided (90 gpm capacity each). Three walls of this zone are the west, east, and south walls of the Turbine Building enclosure as previously described. The west wall, at column row "L," is 36-inch-thick structural reinforced concrete, carries a 3-hour fire rating except for exterior portions that are below grade, and separates the Turbine Building from the Auxiliary Building. The north wall at column row "18" is 12-inch-thick hollow concrete masonry units and separates Unit 1 from Unit 2. It contains several structural steel beams and columns which are protected by a fire-resistant covering and carries a 3-hour fire rating. Doors provided in this wall are Label "A" 3-hour rated fire doors. Several open stairways are provided in this zone for access to other floor levels. An elevator is also provided in this zone and is enclosed by 12-inch-thick hollow concrete masonry unit walls which carry a 2-hour fire rating.

The ceiling at elevation 401 feet 0 inch is an 8-inch concrete topping over a structural reinforced concrete slab which varies in thickness from 36 inches to 72 inches, or a 9-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork supported by unprotected structural steel beams.

There are no fire dampers installed in the ventilation openings penetrating the ceiling.

Safety-Related Equipment No safety-related equipment is present in this area.

Protection Criteria and Measures All walls are 3-hour rated. A curb is in place around the 3,000-gallon lube oil drain tank sufficiently high to contain the contents of the tank if it should leak.

As requested by NRC, additional sprinkler protection has been provided to the lube oil drain tank which is in this zone.

2.3-76

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, fiber optic cable, lube oil, gaskets, grease, miscellaneous and transient combustibles, plastic, and polypropylene.

At Byron, acrylic, FRP, nylon, polyethylene, PVC, and rubber.

At Braidwood, flammable fluids, plexiglass, PMMA, and staging area.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities An automatic sprinkler system, which annunciates locally and in the control room when operated, covers the entire floor area. Seven hose stations are in the zone and two additional hose stations are available in the adjacent zone. Portable extinguishers are provided.

Design-Basis Fire A design-basis fire would occur if the 3,000-gallon lube oil tank ruptured and started a fire. The fire would damage everything in the condensate pit. In the event of a design fire, the ductwork and the ventilation equipment in this zone may be severely damaged; however, this will not affect the safe shutdown of the plant. The sprinkler system would reduce the effects of a fire.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.46.

2.3.8.3 Turbine Building Basement, Unit 2 (Fire Zone 8.2-2)

This zone is shown on Figure 2.3-14 (Sheet 4), Figure 2.3-21 (Sheet 1), Figure 2.3-23 (Sheet 2), and Figure 2.3-24 (Sheet 2).

For details, see Subsection 2.3.8.2.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.47.

2.3-77

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.8.4 Turbine Building, Grade Level - Unit 1 (Fire Zone 8.3-1)

This zone is shown on Figure 2.3-12 (Sheet 2) and in elevation on Figure 2.3-23 (Sheet 1) and Figure 2.3-24 (Sheet 1).

Fire Barrier Description The floor at elevation 401 feet 0 inch is an 8-inch concrete topping over a structural reinforced concrete slab which varies in thickness from 36 inches to 72 inches, or a 12-inch cover of structural reinforced concrete on 3-inch fluted steel decking formwork supported by unprotected structural steel beams. Several 4-inch-diameter floor drains (90 gpm capacity each) is provided.

Three walls of this zone are the west, east, and south wall of the Turbine Building enclosure as previously described in Subsection 2.3.8. A portion of the west wall, at column row "L," is 36-inch-thick structural reinforced concrete, separates the Turbine Building from the Auxiliary Building, and carries a 3-hour fire rating. The remaining exterior walls are of metal siding and carry a 2-hour fire rating. All doors in this wall are Label "A" 3-hour rated fire doors, except for the door which is between column rows 1O and 11 which is Label "A" construction. The unit dividing wall at column row "18" is 12-inch-thick hollow concrete masonry units and separates Unit 1 from Unit 2. It contains several structural steel beams and columns which are protected by a fire-resistive cover of masonry or Thermafiber and carries a 3-hour fire rating. Doors provided in this wall are Label "A" 3-hour rated fire doors. Several open stairways and equipment are provided in this zone for access to other floor levels. An elevator is also provided in this zone and is enclosed by 12-inch-thick hollow concrete masonry unit walls which carry a 2-hour fire rating.

Located within this zone between column rows 12-16 and F-G is the 15,000-gallon turbine oil storage tank. The floor slab in this area is a 9-inch clear cover of structural decking formwork which is supported by unprotected structural steel beams and columns. This slab provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the spread of fire to the Turbine Building floor level below. Two 4-inch-diameter floor drains (90 gpm capacity each) are provided to remove oil and fire protection water. A 3-foot-high curb is provided around this area to contain an oil spill.

The ceiling slab at elevation 426 feet 0 inch is a 4-inch clear cover of structural reinforced concrete over 2-inch fluted steel decking formwork supported by unprotected structural steel beams.

2.3-78

B/B - FPR AMENDMENT 29 DECEMBER 2020 A chemical storage area is located against the wall of the heating steam boiler room near column row 6 between column rows C and E. The chemical storage area consists of five separate rooms. Each room has 3-hour rated fire walls, label A fire doors and 3-hour rated fire dampers in the ceiling and walls. Each room has a 6-inch curb and ramp to contain spills.

Safety-Related Reactor Shutdown and Cooling Equipment No safety-related equipment is in this zone.

Protection Criteria and Measures All walls are 3-hour rated except as discussed previously in Subsection 2.3.8. A curb is provided around the turbine oil storage tank to contain a spill.

The chemical storage area rooms have 3-hour rated enclosures. Each room has a separate ventilation system exhausting to the atmosphere. The exhaust fans are Class I Division 2. Fan running and differential pressure alarms are provided on a local panel with a common "trouble" alarm in the control room. Lighting inside the rooms is explosion-proof.

Combustible Materials Cable insulation, fiber optic cable, gaskets, grease, hydrazine, lube oil, Kevlar, miscellaneous and transient combustibles, nylon, plastic, phosphate ester, polyethylene, polypropylene, and PVC.

At Byron, acrylic and sealant.

At Braidwood, amine, fluoropolymer, plexiglass, PMMA and staging area.

None of the chemicals stored in the chemical storage area are classified as combustible or flammable liquids and are not included.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities An automatic sprinkler system, which annunciates locally and in the control room when operated, is provided which covers the entire area.

At Byron, nine hose stations are in this zone.

At Braidwood, ten hose stations are in this zone.

Additional fire hoses can be brought in from Unit 2. Portable extinguishers are available as shown on Figure 2.3-12 (Sheet 2).

2.3-79

B/B - FPR AMENDMENT 29 DECEMBER 2020 An automatic deluge system, which alarms locally and in the control room when operated, is provided to protect the turbine oil storage area. The deluge system may be operated by use of local pushbuttons. Rate compensated detectors actuate this system.

At Byron, Ionization (or photoelectric) detection, which annunciates and alarms in the Control Room, is provided for a Dry Resin Storage Area located in the Condenser Tube Pull Area.

Design-Basis Fire The design-basis fire would occur if all the combustibles were ignited. Since most of the combustible materials are distributed over a very widely spaced area, it is unlikely any significant damage would be done if one of the components should catch fire. Any fire would be limited to the affected Turbine Building unit side.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.48.

2.3.8.5 Turbine Building, Grade Level - Unit 2 (Fire Zone 8.3-2)

This zone is shown on Figures 2.3-12 (Sheet 4) and 2.3-12a and in elevation on Figure 2.3 21 (Sheet 1), Figure 2.3-23 (Sheet 2), and Figure 2.3-24 (Sheet 2).

For details, see Subsection 2.3.8.4 except that:

a. No elevator is included in this zone.

b. Three walls of this zone are the unit dividing wall and west and east walls of the Turbine Building enclosure as previously described.

c. The 37-line wall of this zone consists of a 36-inch-thick reinforced concrete wall and a 12-inch-thick concrete masonry wall, which extends from elevation 401 feet 0 inch to elevation 467 feet 0 inch and separates this zone from the radwaste service building. An opening is provided in the wall at column-row 35 to 36 and G from elevation 401 feet 0 inch up to elevation 433 feet 0 inch for movement of equipment from the Turbine Building to the Service Building machine shop. It is protected by a self-closing rolling steel door which is certified to be of UL Label "A" construction.

d. At Byron, there are 10 hose stations located in this zone.

e. At Braidwood, there are 11 hose stations located in this zone.

2.3-80

B/B - FPR AMENDMENT 29 DECEMBER 2020

f. At Byron, the IM/EM shop contains paper, cloth, rubber, plastic, polypropylene, polyurethane foam, gaskets, wood, miscellaneous and transient combustibles., paint, paint thinner, solvents, gasoline, grease, lube oil, cable insulation, hydrazine, Nylon, and Kevlar.

g. A 3-hour rated fire wall extending up to 418 feet 0 inch separates this zone from the Station Auxiliary Diesel Generator and its fuel oil tanks. See Subsections 2.3.8.11 and 2.3.8.12 for details.

h. The double and single swing personnel fire doors in the L-line wall between columns 20 and 21 that separate this fire zone and the Auxiliary Building (Fire Zone 11.5-0) are non-labeled fire doors. Steel plates have been bolted to the doors and horizontal stiffeners have been added to one leaf of the double swing door to reinforce the doors for HELB pressure loading. The frames of these doors are also reinforced, and the hinges are heavy duty outer hinges. Door pulls have been added to these fire doors to facilitate door operation. The addition of door pulls does not affect the self-closing or latching performance of the doors. Refer to Braidwood EC-EVAL 393561 and Byron EC-EVAL 393650.

i. As requested by NRC, additional sprinkler protection has been provided to the lube oil drain tank which is in this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.49.

2.3.8.6 Unit 1 Auxiliary Boiler Room (Fire Zone 8.4-1)

This zone is shown on Figure 2.3-12 (Sheet 2) and in elevation on Figure 2.3 23 (Sheet 1).

Fire Barrier Description The floor at elevation 401 feet 0 inch is an 8-inch concrete topping over a 36-inch structural reinforced concrete slab. Three 4-inch-diameter floor drains are provided (90 gpm capacity each).

Three walls are 12-inch-thick hollow concrete masonry units and carry a 2-hour fire rating. They extend up to within 1 inch of the ceiling slab, and this resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation. The fourth wall, an exterior wall, is insulated metal siding supported by unprotected steel girts and carries no fire rating. Two Label "B" 1-1/2-hour rated fire doors lead to the turbine building ground floor. The ceiling slab at elevation 426 feet 0 inch is a 4-inch clear cover of structural reinforced concrete over 2-inch fluted steel decking formwork. It is supported by structural steel beams protected by a fire-resistant material and carries a 2-hour fire rating.

2.3-81

B/B - FPR AMENDMENT 29 DECEMBER 2020 Freestanding columns are enclosed by 4-inch-thick solid concrete masonry units and carry a 2-hour fire rating. At Byron, there is a portion of missing masonry block on column E/5. The 2-hour fire rating remains the same for this column.

Reference EC 394239 for details.

Safety-Related Equipment No safety-related equipment is in this zone.

Protection Criteria and Measures Fusible link fire dampers are installed in the north wall.

Combustible Materials Diesel fuel oil, gaskets, grease, insulation, lube oil, and miscellaneous and transient combustibles.

At Byron, acrylic, nylon, plastic, polypropylene, and propane.

At Braidwood PMMA and plexiglass.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Automatic sprinklers which alarm locally and in the Control Room, are provided as the primary means of fire protection. Electrical detectors are not provided.

Two hose stations are each located within 50 feet of one of the two entrances to the room. Portable extinguishers are also available.

Design-Basis Fire The design-basis fire would occur if one of the oil pipes ruptured while the boiler was in operation and ignited the entire contents of the room. The sprinkler system would extinguish the fire.

The fuel oil pumps secure if the supply line breaks or the sprinkler system initiates.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.50.

2.3-82

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.8.7 Unit 2 Auxiliary Boiler Room (Fire Zone 8.4-2)

This zone is shown on Figure 2.3-12 (Sheet 4) and in elevation on Figure 2.3 21 (Sheet 1) and Figure 2.3-23 (Sheet 2).

For details, see Subsection 2.3.8.6 except that:

a. zone is of opposite hand.

b. There is a non-fire-rated door to the exterior.

c. One Label "B" door to the turbine building ground floor.

d. A common 3-hour rated wall between the auxiliary boiler room and station auxiliary diesel oil tank room.

e. At Byron, there is a portion of missing masonry block on column E/31. The 2-hour fire rating remains the same for this column. Reference EC 394239 for details.

The Analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.51.

2.3.8.8 Unit 1 Mezzanine Floor (Fire Zone 8.5-1)

This zone is shown on Figure 2.3-10 (Sheet 2) and in elevation on Figure 2.3 22 (Sheet 1), Figure 2.3-23 (Sheet 1), and Figure 2.3-24 (Sheet 1).

Fire Barrier Description The floor slab at elevation 426 feet 0 inch and 418 feet 0 inch is either a 4-inch clear cover of structural reinforced concrete over 2-inch fluted steel decking formwork, an 11-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, or a 4-inch clear cover of structural reinforced concrete over 2-inch fluted steel decking, and is supported by unprotected structural steel beams. Several 4-inch-diameter floor drains (90 gpm capacity each) are provided.

Three walls of this zone are the west, east, and south walls of the Turbine Building enclosure as previously described. A portion of the west wall, at column row "L," is 42-inch-thick structural reinforced concrete, separates the Turbine Building from the Auxiliary Building, and carries a 3-hour fire rating. The remaining exterior walls are of metal siding and carry a 2-hour fire rating. All doors in this wall are Label "A" 3-hour rated fire doors or are of Label "A" construction. The north wall at column row "18" is 12-inch-thick hollow concrete masonry units and separates Unit 1 from Unit 2. It contains structural steel beams, columns and bracing which are protected by a fire-resistive cover which carries a 3-hour fire rating.

2.3-83

B/B - FPR AMENDMENT 29 DECEMBER 2020 Doors provided in this wall are Label "A" 3-hour rated fire doors. Several open stairways and equipment hatches are provided in this zone for access to other floor levels. An elevator is also provided in this zone and is enclosed by 12-inch-thick hollow concrete masonry units walls which carry a 2-hour fire rating.

The ceiling slab at elevation 451 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking or a 4-inch clear cover of structural reinforced concrete over 2-inch fluted steel decking formwork supported by unprotected structural steel beams.

Offices constructed of hollow block walls and precast concrete roof slabs are located within this zone between column rows G-J/1-2.

Safety-Related Equipment No safety-related equipment is in this fire zone.

Protection Criteria and Measures For details, see Subsection 2.3.8.4.

Combustible Materials Cable insulation, fiber optic cable, gaskets, grease, Kevlar, lube oil, miscellaneous and transient combustibles, nylon, polycarbonate, polypropylene, and rubber.

At Byron, acrylic, butene, plastic, and PVC.

At Braidwood, plexiglass, PMMA, and visco-fluid.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The automatic sprinklers, which alarm locally and in the Control Room, cover from column/rows E to K and 3 to 18. The seal oil units are protected by their own water deluge system, which alarms locally and in the Control Room, are actuated by rate compensated detectors. The deluge system may be operated using local pushbuttons. Ten manual hose stations are distributed throughout the zone as noted on Figure 2.3-10 (Sheet 2). Portable extinguishers are also located in the zone.

2.3-84

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would occur if all the combustibles in the area were ignited.

Such a fire is extremely unlikely due to the distances separating the combustible materials. Also, the installed sprinkler system or hose stations would be more than adequate to contain such a fire in a small area.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.52.

2.3.8.9 Unit 2 Mezzanine Floor (Fire Zone 8.5-2)

This zone is shown on Figures 2.3-10 (Sheet 4), 2.3-10a, and 2.3-10b and in elevation on Figure 2.3 21 (Sheet 1), Figure 2.3-23 (Sheet 2), and Figure 2.3-24 (Sheet 2).

For details, see Subsection 2.3.8.8 except that:

a. No elevator is included in this zone.

b. There are thirteen hose stations are in this zone.

c. Located in this zone are the TSC, station security battery room, and the security diesel MCC room (Fire Zone 18.35-0).

d. At Byron, the IM/EM shop contains cable insulation, gaskets, lube oil, nylon, paint, paper, plastic, polypropylene, polyurethane, and wood.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.53.

2.3.8.10 Turbine Building Main Floor (Fire Zone 8.6-0)

This zone is shown on Figure 2.3-8 (Sheets 2 and 4) and in elevation on Figure 2.3-21 (Sheet 1), Figure 2.3-22 (Sheet 1) Figure 2.3-23 (Sheets 1 and 2), and Figure 2.3-24 (Sheets 1 and 2).

Fire Barrier Description This zone includes the operating areas for Units 1 and 2.

The floor slab at elevation 451 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by unprotected structural steel beams and columns, and carries no fire rating.

Several 4-inch-diameter floor drains (90 gpm capacity each) are provided.

2.3-85

B/B - FPR AMENDMENT 29 DECEMBER 2020 All walls of this zone are the walls of the Turbine Building enclosure as previously described. A portion of the west wall, at column row "L," is 42-inch-thick structural reinforced concrete and separates the Turbine Building from the Auxiliary Building and carries a 3-hour fire rating. At Byron, the west wall at column row L and 16-17 is of fire-rated construction but contains a nonrated penetration seal.

The remaining exterior walls are of metal siding and carry a 2-hour fire rating. All doors in this portion of the west wall are "A" Label construction.

The lower portion of the north wall, at column row "37," is minimum 12-inch-thick hollow concrete masonry units from elevation 451 feet 0 inch up to elevation 467 feet 0 inch, and separates the Turbine Building from the Radwaste/Service Building. It contains several structural steel beams and columns which are protected by a fire-resistive cover which carries a 3-hour fire rating. All doors in this portion of the north wall are "A" Label construction.

Several open stairways and equipment hatches are provided in this zone for access to other floor levels. An elevator is also provided and is enclosed by 12-inch-thick hollow concrete masonry unit walls, which carry a 2-hour fire rating, below elevation 468 feet 2 inches. Above elevation 468 feet 2 inches, the block wall in the elevator machine room is not fire rated because of unsealed openings in the block wall.

The Safety Valve Penthouses, located at elevation 477 feet 0 inch at column rows "L-10" and "L-25," are included in this fire zone 8.6-0. The floor slab is a 1-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork and is supported by unprotected steel beams. This slab provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the spread of fire from the penthouses to the equipment rooms (Auxiliary Building) below. Insulated metal siding exterior walls enclose each penthouse on three sides, while the fourth side is open to the Turbine Building.

The ceiling of Fire Zone 8.6-0 is the roof of the Turbine Building enclosure as previously described. It contains UL-approved automatic smoke and heat vents.

Safety-Related Equipment No safety-related equipment is in this fire zone.

Protection Criteria and Measures This is a large fire zone and the combustibles within it are separated by large distances.

2.3-86

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Acrylic, cable insulation, gaskets, grease, hydrogen, insulation, Kevlar, lube oil, miscellaneous and transient combustibles, nylon, paper, plastic, polyester, polyethylene, polypropylene, rubber, and wood.

At Byron, butene, charcoal, fiberglass, FRP, and PVC.

At Braidwood, plexiglass, PMMA, and visco-fluid.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detection Capabilities There are 20 manual hose stations in this zone as shown on Figure 2.3-8 (Sheet 2 and 4). Portable extinguishers are also available in this and adjacent zones. At Byron only, a manual deluge system is provided for the off-gas charcoal filter unit. A temperature switch mounted in the filter bank will annunciate in the control room. An automatic pre-action sprinkler system, which alarms locally and in the control room when operated, is provided for the turbine bearings. The pre-action sprinkler system may be operated by local pushbuttons. Rate compensating detectors are provided to actuate the reaction sprinkler system. No credit is taken for the CO2 generator purging system. The chance of a fire starting and continuing for any length of time without being noticed is very remote.

An automatic sprinkler system that alarms both locally and in the Work Execution Center is provided for the two-story office structure (coordinate F/18).

Design-Basis Fire The design-basis fire would occur if a turbine bearing oil line ruptured and sprayed oil over the area. Most of the fire damage would likely occur on one of the lower elevations; however, some damage would occur on this floor. The pre-action sprinkler system would reduce or eliminate the fire. Safe shutdown of both reactors would not be affected by any fire in this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.54.

2.3-87

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.8.11 Station Auxiliary Diesel Generator Room (Fire Zone 8.7A-0)

This zone is shown on Figure 2.3-12 (Sheet 4).

Fire Barrier Description The floor at elevation 401 feet 0 inch is an 8-inch concrete topping over a 36-inch-deep structural reinforced concrete slab which is the foundation for the heater bay. The south, west, and north perimeter walls are 11-5/8-inch-thick hollow concrete block walls and are 3-hour rated.

The doors and other masonry openings in these walls are also 3-hour fire rated openings. The walls extend to within 1 inch of the bottom of the steel deck above.

The resulting space is packed with Thermafiber insulation. The ceiling above this area is the underside of a floor which is a 4-inch clear cover of concrete over a 2-inch-deep fluted steel deck. The deck is covered with a fire protection coating and is supported by protected steel framing. The floor assembly carries a 3-hour rating.

Safety-Related Equipment None Protection Criteria and Measures None Combustible Materials Gaskets, grease, and lube oil.

At Byron, acrylic, nylon, plastic, and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One hose station is available to fight a fire in this room. Portable extinguishers are also available. Fire detectors are not provided. An automatic sprinkler system, which alarms locally and in the control room when operated, is provided as the primary fire protection.

2.3-88

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would occur if the fuel oil line ruptured and started a fire while the diesel generator was in operation. The fuel oil tanks would gravity drain into the area. The overhead sprinkler system would be quickly activated and would extinguish the fire.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.55.

2.3.8.12 Station Auxiliary Diesel Oil Tank Room (Fire Zone 8.7B-0)

This zone is shown on Figure 2.3-12 (Sheet 4).

Fire Barrier Description The floor at elevation 401 feet 0 inch is an 8-inch concrete topping over a 36-inch-deep structural concrete slab which is the foundation of the heater bay.

There is a 12-inch high structural reinforced concrete curb in the slab which surrounds the diesel fuel tank.

The south and west perimeter walls are 3-hour fire rated. The door and other masonry openings in those walls are 3-hour fire-rated. The north wall is an 11-5/8-inch-thick hollow concrete block wall which is 3-hour rated.

The masonry openings in the wall are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The east wall is an insulated metal siding exterior wall with louvers. This wall has no rating.

All three walls extend to within 1 inch of the bottom of the ceiling above. The resulting space is packed with 1 inch of Thermafiber insulation. The ceiling above is the underside of a 4-inch clear cover of concrete over a 2-inch-deep structural concrete deck. This deck is coated with a fire protection covering and supported by protected steel framing. The ceiling carries a 3-hour rating.

Safety-Related Equipment None.

Protection Criteria and Measures The oil tank is surrounded by a curb large enough to contain the entire contents of the tanks.

2.3-89

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Material Diesel fuel and gaskets.

At Byron, plastic and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities An automatic sprinkler system, which alarms locally and in the control room when operated, is provided for this zone. In addition, one manual hose station and portable extinguishers are available as shown on Figure 2.3-12 (Sheet 4 of 4).

Fire detectors are not provided.

Design-Basis Fire The design-basis fire would occur if the tank ruptured, the contents spilled out of the tank, and were ignited. This is highly unlikely since there are no heat sources inside the tank room in a position to ignite the fuel oil. The tank is provided with a curb which will contain the entire contents of the tank should it be ruptured. The automatic sprinkler system would extinguish any fire in this room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.56.

2.3.9 Diesel-Generator Areas 2.3.9.1 Diesel-Generator Room 1B (Fire Area 9.1-1)

This room is shown on Figure 2.3-12 (Sheet 1). An elevation view is shown on Figure 2.3-25.

Electrical cable trays routed through this zone are shown on Figure 2.3-36.

Fire Barrier Description The floor at elevation 401 feet 0 inch, which is the ceiling of the Diesel Oil Storage Tank Room, is a 48-inch-thick structural reinforced concrete slab and carries a 3-hour fire rating. Five 4-inch-diameter floor drains are provided.

2.3-90

B/B - FPR AMENDMENT 29 DECEMBER 2020 All walls are minimum 12-inch-thick hollow concrete masonry units or minimum 36-inch-thick structural reinforced concrete. They carry a 3-hour fire rating. The L-line wall contains a Label (A) rolling steel fire door and a non-labeled personnel fire door. Steel plates have been bolted to the personnel door to reinforce it for HELB pressure loading. The personnel door frame has also been reinforced and the hinges are heavy duty outer hinges. A door pull has been added to this personnel fire door to facilitate door operation. The addition of the door pull does not affect the self-closing or latching performance of the door. Refer to the Braidwood EC-EVAL 392603 and Byron EC-EVAL 392627. A curb has been installed at the door opening to limit the potential fuel and fire propagation in the diesel-generator room up to elevation 401 feet 3/4 inch. All other doors in this zone are Label "A" fire doors. Masonry walls extend up to within 1 inch of the ceiling or the protected steel beams above. This remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling at elevation 426 feet 0 inch, which is the floor of an ESF switchgear room, is a 5-inch clear cover of structural reinforced concrete with a 3-inch concrete topping over 3-inch fluted steel decking formwork. It is supported by steel beams protected with a fire-resistant covering and carries a 3-hour fire rating.

An enclosed electrical cable tunnel is suspended from the steel beams supporting the ceiling. (For details see Subsection 2.3.3.1, Fire Zone 3.1 1.)

There are eight galvanized steel curtain type vertical damper installations in the fire walls each with one 3-hour equivalent damper. The fire dampers in the horizontal fire barriers are galvanized steel curtain type and will close and lock by a stainless steel "negator spring."

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 9.1-1/5.1-1).

Safety-Related Equipment Safety-related equipment located in this room consists of:

a. Diesel Generator

b. Portions of Diesel-Generator auxiliary equipment

c. Diesel-Generator Control Panel

d. Diesel-Generator Startup Panel

e. Diesel-Generator Neutral Grounding Cabinet

f. Diesel-Generator Ventilation Panel 2.3-91

B/B - FPR AMENDMENT 29 DECEMBER 2020 The safety-related HVAC equipment located in this fire zone consists of the Diesel-Generator Room Ventilation System components. These are galvanized ductwork, dampers, and ductwork accessories.

Protection Criteria and Measures All equipment and cabling in the room are only associated with one ESF division.

All cables routed in the room are in conduit except for the EDG monitoring system and the Station Wi-Fi cabling. Portions of the monitoring system wiring, and Wi-Fi wiring are not routed in conduit. Some diesel oil piping associated with one ESF train is routed through the redundant train's room. Calculations have been performed to determine that even if this DO piping is unprotected, a fire in this zone does not affect the operability of the redundant diesel generator; therefore, a fire in this zone would not affect the ability to shut down the plant safely (reference Calculations MAD 90-0079 and 3C8-0890-001). However, fire wrap was added as a conservative measure on most DO lines associated with the ESF train credited for safe shutdown.

The primary fire protection system is an automatic total flooding CO2 system designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." The 10-ton CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column/row L/18. (At this location, a rupture of the storage tank would not damage any safety-related equipment or systems which contain radioactive materials.)

The diesel-generator rooms carry a 3-hour fire rating. Fire dampers are provided in the fire walls. The fire dampers are electric-thermal link and are actuated by the fire detection system. The ventilation fans will shut off due to pressure differential upon activation of the fire detection system. A high room temperature alarm is provided in the room's ventilation control panel to alarm this condition.

Inadvertent operation of the Cardox system would not affect the equipment in the room. A pre-discharge alarm is provided to warn personnel to evacuate the room in the event of system actuation.

Combustible Materials Cable insulation, grease, gaskets, lube oil, miscellaneous and transient combustibles, and plastic.

At Byron, acrylic, nylon, and polypropylene.

At Braidwood, fluoropolymer, and polyethylene.

2.3-92

B/B - FPR AMENDMENT 29 DECEMBER 2020 Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The total flooding CO2 system will deliver sufficient quantity of CO2 to maintain a 34% concentration for 10 minutes. Actuation of the system will alarm locally and in the Control Room.

The CO2 system is initiated by Fenwal Thermal detectors. The area selector valves are automatically controlled by adjustable timers. Pre-discharge alarms with adjustable timers are provided to allow personnel to leave this area before the CO2 is discharged. After automatic discharge, the system is ready for immediate manual operation. The CO2 system can be manually actuated with or without electric power using local switches.

As indicated in Figure 2.3-12 (Sheet 2), there is a manual hose station in the Turbine Building along column/row L, which can be used as a backup fire suppression system. Portable fire extinguishers are also available. One ultraviolet fire detector is in the room. It annunciates and alarms in the Control Room.

Design-Basis Fire The design-basis fire would result if all the lubricating oil in the diesel spilled and ignited and the resulting fire ignited all other combustibles in the room. The fire would disable the diesel-generator but would not affect safe shutdown as sufficient redundancy exists to ensure an adequate supply of power.

This equipment is required for reactor shutdown if offsite power is not available.

A redundant diesel generator is provided. This satisfies the single failure criteria in that one of the two engineered safety features electrical system buses, including its control power, can be lost and still have sufficient engineered safety features system auxiliaries in operation to safely control the plant.

If the fire detection/protection system does not function as designed, the ventilation system components may be damaged. The ventilation system will not be affected if the fire detection/protection system functions as designed (Fire dampers close, ventilation fan trips and the fire is suppressed). The spread of hot air and combustion products will be stopped by the fire dampers.

If the design-basis fire occurs, all the equipment in this room is considered inoperable, but since redundant equipment is available, this would not affect the ability to shut down the reactor.

2.3-93

B/B - FPR AMENDMENT 29 DECEMBER 2020 The Cardox system is designed to quickly extinguish any fire.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.57.

2.3.9.2 Diesel-Generator Room 2B (Fire Zone 9.1-2)

This room is shown on Figure 2.3-12 (Sheet 3). An elevation view is shown on Figure 2.3-25. Electrical cable trays routed through this zone are shown on Figure 2.3-36.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 9.1-2/5.1-2).

For details, see Subsection 2.3.9.1 except that:

a. There are four 4-inch-diameter floor drains.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.58.

2.3.9.3 Diesel-Generator Room 1A (Fire Area 9.2-1)

This room is shown on Figure 2.3-12 (Sheet 1). An elevation view is shown on Figure 2.3-25. Electrical cable trays routed through this zone are shown on Figure 2.3-36.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 9.2-1/5.2-1).

For details, see Subsection 2.3.9.1.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.59.

2.3-94

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.9.4 Diesel-Generator Room 2A (Fire Area 9.2-2)

This room is shown on Figure 2.3-12 (Sheet 3). An elevation view is shown on Figure 2.3-25. Electrical cable trays routed through this zone are shown on Figure 2.3-36.

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations at barriers that separate redundant shutdown-related systems.

Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 9.2-2/5.2-2).

For details, see Subsection 2.3.9.1 except that

a. At Byron, there are five 4-inch-diameter floor drains are provided.

b. At Braidwood, there are four 4-inch-diameter floor drains are provided.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.60.

2.3.9.5 Diesel-Generator Day Tank Room 1A (Fire Area 9.3-1)

This zone is shown on Figure 2.3-12 (Sheet 1).

Fire Barrier Description The floor slab at elevation 401 feet 0 inch, which is the ceiling of the Diesel Oil Storage Tank Room, is 48-inch-thick structural reinforced concrete and carries a 3-hour fire rating. All walls are 12-inch-thick hollow concrete masonry units and carry a 3-hour fire rating. A 24-inch-high concrete curb is provided under the walls to contain an oil spill from a tank rupture. A label "A" 3-hour rated fire door on top of this curb leads to an adjacent diesel-generator room.

The ceiling at elevation 410 feet 0 inch is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork and carries a 3-hour fire rating.

Safety-Related Equipment The only safety-related equipment located in this room is the diesel-generator day tank. This tank may be required for reactor shutdown if offsite power is not available.

2.3-95

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures All equipment and cabling in the room are only associated with one safety division. Some diesel oil piping associated with one ESF train is routed through the redundant train's room. Calculations have been performed to determine that even if this DO piping is unprotected, a fire in this zone does not affect the operability of the redundant diesel generator; therefore, a fire in this zone would not affect the ability to shut down the plant safely (reference Calculations MAD 90-0079 and 3C8-0890-001). However, fire wrap was added as a conservative measure on most DO lines associated with the ESF train credited for safe shutdown.

All cables routed in the room are in rigid steel conduit. The day tank is vented to outside of the building and vent line is equipped with a flame arrester. The day tank is separated from the diesel generator by a 3-hour barrier including 3-hour fire dampers which are actuated by the fire detection system.

The primary fire protection system is an automatic total flooding CO2 system designed in accordance with NFPA Chapter 12, "Standard for Carbon Dioxide Extinguishing Systems." This system is a subsystem of the Diesel-Generator Automatic Total Flooding CO2 System. The 10-ton CO2 storage tank is located at elevation 401 feet 0 inch in the Turbine Building at column/row L/18. At this location, a rupture of the storage tank would not damage any safety-related equipment.

Inadvertent operation of the Cardox system would not affect the equipment in the room. A local alarm is provided to warn personnel to evacuate the room in the event of system actuation.

Combustible Materials Diesel fuel oil.

At Byron, plastic and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-96

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities The total flooding CO2 system will deliver sufficient quantity of CO2 to maintain a 34% concentration for 10 minutes. Actuation of the system will alarm locally and in the Control Room. The CO2 system is initiated by Fenwal Thermal detectors.

The CO2 system can be actuated manually with or without electric power using local switches.

The Day Tank Room CO2 system is also a subsystem of the main CO2 system of the diesel-generator rooms and as such a discharge in the Diesel Room would automatically cause a discharge in the Day Tank Room. A discharge in the Day Tank Room would not cause a discharge in the Diesel Room. Each day tank room CO2 system is independent of the other day tank room system.

As indicated in Figure 2.3-12 (Sheet 2) there is a manual hose station in the Turbine Building along column/row L which can be used as a backup fire suppression system. Portable fire extinguishers are also available.

Design-Basis Fire The design-basis fire would result if all the fuel oil in the day tank spilled and ignited. The fire should not affect adjacent rooms. No fuel to the diesel generator would be available from the day tanks, but since redundant equipment is available, this would not affect the ability to safely shut down the reactor.

A redundant diesel generator and its day tank are provided. This satisfies the single failure criteria in that any of the two engineered safety feature electrical system buses, including its control power, can be lost and still have sufficient engineered safety features system auxiliaries in operation to safely control the plant.

The Cardox system is designed to quickly extinguish the fire and its operation would mitigate the consequences of any fire.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.61.

2.3-97

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.9.6 Diesel-Generator Day Tank Room 2A (Fire Area 9.3-2)

This room is shown on Figure 2.3-12 (Sheet 3).

For details, see Subsection 2.3.9.5.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.62.

2.3.9.7 Diesel-Generator Day Tank Room 1B (Fire Area 9.4-1)

This room is shown on Figure 2.3-12 (Sheet 1).

For details, see Subsection 2.3.9.5.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.63.

2.3.9.8 Diesel-Generator Day Tank Room 2B (Fire Area 9.4-2)

This room is shown on Figure 2.3-12 (Sheet 3).

For details, see Subsection 2.3.9.5, except gaskets contribute to combustible loading.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.64.

2.3.10 Diesel-Fuel Oil Storage Areas 2.3.10.1 Diesel-Fuel Oil Storage Room 1B (Fire Zone 10.1-1)

This room is shown on Figure 2.3-13 (Sheet 1). An elevation view is shown on Figure 2.3-25 (Sheet 1).

Fire Barrier Description All boundaries except for the base slab and the south wall are 3-hour fire rated.

The base slab of Diesel-Fuel Oil Storage Room 1B is a 36-inch structural reinforced concrete slab. The south and west walls are 36-inch structural reinforced concrete, the east wall is 42 inches and the north wall is 24-inch structural reinforced concrete.

2.3-98

B/B - FPR AMENDMENT 29 DECEMBER 2020 The roof at elevation 401 feet-0 inch, which is the Diesel-Generator Room floor, is a 48-inch structural reinforced concrete slab. A Label "A" fire door is provided in the east wall and a Label "A" fire door is provided in the north wall. The doors are located 8 feet-0 inch above the floor line to contain the oil in the room in case of a tank rupture. A grating stair is provided at the east wall door and a steel ladder and grating platform are provided for the door in the north wall. Two 4-inch-diameter floor drains are provided. The drains are routed to a sump pit in the corner of the room. The spillage into this sump in turn is routed to the Turbine Building fire sump by two submersible sump pumps.

The fire dampers are curtain type, frame type A. There are two vertical damper installations in this zone each consisting of one 3-hour labeled damper.

Safety-Related Equipment The safety-related equipment located in this fire zone consists of components of the Diesel-Oil Storage Room Ventilation System. These are vane axial fans, galvanized ductwork, dampers, and ductwork accessories. The two 25,000-gallon capacity Diesel-Fuel Oil Storage Tanks in this room (or the 50,000-gallon tank in the Unit 2 rooms) are safety-related, as are the two 20 gpm transfer pumps.

This equipment may be required for reactor shutdown if offsite power is not available.

Protection Criteria and Measures Fire dampers are provided in the fire walls except for the smoke and heat vent above the door in the east wall. Diesel-oil storage exhaust fans will also trip upon activation of the fire detection system.

A ventilation system is provided which exhausts smoke and fumes.

The room is protected by a manual Fluoro protein foam-water extinguishing system. The 100-gallon foam storage tank is located at column/row 7/K at elevation 401 feet 0 inch in the Turbine Building. At this location, a rupture of the storage tank would not damage any safety-related equipment or systems which contain radioactive materials. The diaphragm foam storage tank is not pressurized.

In response to FSAR Question 280.1, the original automatic foam system has been modified to require manual actuation. This modification eliminated the possibility of a spurious actuation.

2.3-99

B/B - FPR AMENDMENT 29 DECEMBER 2020 All equipment and cabling in this room are only associated with one safety division. All cable routed in the room are in conduit. Some diesel oil piping associated with one ESF train is routed through the redundant train's room.

Calculations have been performed to determine that even if this DO piping is unprotected, a fire in this zone does not affect the operability of the redundant diesel generator; therefore, a fire in this zone would not affect the ability to shut down the plant safely (reference Calculations MAD 90-0079 and 3C8-0890-001).

However, fire wrap was added as a conservative measure on most DO lines associated with the ESF train credited for safe shutdown.

Fill lines, vent openings, and vent pipes are of ample sizes to prevent abnormal pressure in the tank during filling. Fill and vent lines terminate outside the building at a point of safe discharge. The vent line is equipped with a flame arrester.

Combustible Materials Diesel fuel oil, gaskets, grease, and flexible connections.

At Byron, polypropylene, acrylic, nylon and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The primary extinguishing system for this area is a manual Fluoro protein foam water system which will deliver a foam water mixture through foam water sprinklers.

After the contents of the diaphragm foam storage tank are exhausted, the system will continue to deliver water until it is manually shut off.

Manual actuation of the suppression system will sound an alarm in the Control Room identifying the vicinity of the hazard and locally. At Byron there are ionization (or photoelectric) detectors provided which annunciate the alarm in the Control Room. At Braidwood, Fenwal heat detectors will alarm and annunciate in the control room.

As indicated in Figure 2.3-14 (Sheet 2), there is a standpipe with 200 feet of 1 1/2-inch hose located outside of the room at elevation 357 feet 6 inch in the Turbine Building Condensate Pit. At Byron, the hose and associated hose reel has been removed per EC 626870. Portable fire extinguishers are also available.

The fire dampers will stop the spread of heat and combustion products. A separate heat and smoke removal system will vent these to the atmosphere.

2.3-100

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The fuel oil storage tanks are constructed of steel in two sizes, 25,000 gallons (in Unit 1) and 50,000 gallons (in Unit 2). The tanks are enclosed in four rooms of reinforced concrete construction of minimum 3-hour fire resistance with 50,000 gallons in each room.

The walls are a minimum of 4-foot-thick reinforced concrete for the rooms containing the 50,000-gallon storage tanks (Unit 2) and a minimum of 3-feet-thick reinforced concrete for the rooms containing the 25,000-gallon storage tanks (Unit 1). The rooms having the 25,000-gallon tanks are adjacent and separated by a 2-foot-thick reinforced concrete wall (Unit 1). The rooms containing the 50,000-gallon storage tanks are separated by a 5-foot-thick reinforced concrete wall. The floor/ceiling assembly above all rooms is 4-foot-thick reinforced concrete and the slab below all rooms is 4-foot-thick reinforced concrete on grade. Entry into the rooms is by means of a fire door of Label "A" construction and metal stairs. The door sill is 8 feet above the floor of the vault room and forms a dike large enough to contain 50,000 gallons.

Each room contains two 20 gpm fuel transfer pumps, a 100-gpm and 250-gpm submersible sump pump, air duct supply fan, ductwork, and electrical lighting, and power supply to the pumps. The likelihood of ignition is extremely low for the following reasons:

a. The room is a controlled access area.

b. The fuel oil storage areas by their design, construction, and use under normal conditions contain no heat sources.

c. A rupture of a tank is unlikely since there will be no movable equipment within the room.

d. It is a Class IC tank designed to Section III requirements.

Number 2 diesel-fuel oil is a flammable liquid which is not easily ignitable. It has a flashpoint of 125 Degrees Fahrenheit minimum and an ignition temperature of 494 Degrees Fahrenheit. It has a suggested hazard identification of 2 based on NFPA Standard 325M, "Properties of Flammable Gases and Volatile Solids,"

which are defined as "materials which must be moderately heated before ignition will occur..." In general, NFPA 30, "Properties of Flammable and Combustible Liquids Code," describes methods for safe storage and handling.

2.3-101

B/B - FPR AMENDMENT 29 DECEMBER 2020 For a fire to occur, four events must take place at the same time. These are:

a. tank rupture or leakage

b. presence of a heat source to heat the fuel oil vapor locally to at least 125 Degrees Fahrenheit

c. presence of an ignition source

d. sump pump failure.

The likelihood of a fire occurring in the fuel-oil storage area specifically, considering the above conditions which must occur, is extremely low. The likelihood that a rupture of the tank and a resultant spill would occur at the same time the sump pump fails, heat is present to preheat the fuel oil, and that there is an ignition source present is extremely low; there have been no reported fires in fuel oil storage tanks within buildings.

If it is assumed that all the above events occur at the same time (the worst possible postulated fire condition), and an actual fire occurs, the following would occur:

a. Because the tank is seismically qualified, a complete rupture is not likely. The probable maximum expected leak will be less than 100 gpm. Assuming this spill rate, the stored fuel would be emptied from the tank in 500 minutes or 8-1/3 hours.

b. In the worst room configuration, oil may burn over an area of 880 ft2 at a rate of 73 gpm. Assuming an unlimited air supply of 109,000 cfm, the oil would burn out in approximately 11-1/2 hours. The walls and ceilings are of adequate thickness to contain a fire for this duration.

Locating the diesel-oil storage tanks below the Diesel-Generator Room is an acceptable hazard because adequate measures have been taken to separate the areas with a minimum of 3-hour fire protection, install a fire protection system, and provide adequate drainage to a non-safety-related area.

The engineered safety features systems by design provide for independence and physical separation of components such that no single failure will result in the loss of more than one of the two systems or divisions.

Heat and smoke venting are provided to exhaust the heat and smoke from the room. Airflow will be about 300 scfm for each 200 ft2 of floor area.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.65.

2.3-102

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.10.2 Diesel-Fuel Oil Storage Room 2B (Fire Zone 10.1-2)

This room is shown on Figure 2.3-13 (Sheet 2). An elevation view is shown on Figure 2.3-25 (Sheet 2).

Fire Barrier Description All barriers except for the base slab and north wall are 3-hour fire rated. The base slab of diesel-oil storage room 2B is a 36-inch structural reinforced concrete slab. The east and west walls are 48-inch structural reinforced concrete. The north wall is 36-inch structural reinforced concrete and the south wall is 63-inch structural reinforced concrete. The roof at elevation 401 feet 0 inch, which is the floor of a diesel-generator room, is a 36-inch structural reinforced concrete slab.

A Label "A" fire-rated door is in the south wall and a Label "A" fire-rated door is in the east wall. The doors are located 8 feet 0 inch above the floor line to contain the oil in the room in case of a tank rupture. A grating stair is provided at the east wall door and a steel ladder and grating platform are provided for the door in the south wall. Three 4-inch-diameter floor drains are provided and route liquids to a sump pit in the southwest section of the room. This sump in turn is routed to a non-safety-related area sump.

Safety-Related Equipment For details, see Subsection 2.3.10.1 except that:

a. The room contains one 50,000-gallon capacity diesel-fuel oil storage tank.

Protection Criteria and Measures For details, see Subsection 2.3.10.1, except that the 100-gallon foam storage tank is located at column row 26/K at elevation 401 feet 0 inch in the Turbine Building.

Combustible Materials For details, see Subsection 2.3.10.1.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities For details, see Subsection 2.3.10.1.

As indicated in Figure 2.3-14 (Sheet 4), there is a standpipe with 200 feet of 1-1/2-inch hose located outside of the room at elevation 357 feet 6 inch in the Turbine Building Condensate Pit. At Byron, the hose and associated hose reel has been removed per EC 626870.

2.3-103

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire For details, see Subsection 2.3.10.1. The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.66.

2.3.10.3 Diesel-Fuel Oil Storage Room 1A (Fire Zone 10.2-1)

This room is shown on Figure 2.3-13 (Sheet 1). An elevation view is shown on Figure 2.3-25 (Sheet 1).

Fire Barrier Description All barriers except for the base slab are 3-hour fire rated. The base slab of Diesel Oil Storage Room 1A is a 36-inch structural reinforced concrete slab.

The north wall and the west wall are 36-inch structural reinforced concrete, the south wall is 24-inch structural reinforced concrete and the east wall is 42-inch structural reinforced concrete. The roof at elevation 401 feet 0 inch, which is the diesel-generator floor, is a 48-inch structural reinforced concrete slab. Label "A" fire-rated doors are in the east and south walls. The doors are located 8 feet 0 inch above the floor line to contain the oil in the room in case the oil tanks rupture. A grating stair is provided at the east wall door and a steel ladder and grating platform is provided at the south wall door. Three 4-inch-diameter floor drains are provided and route liquids to a sump in the northwest corner of the room. This sump in turn is routed to a non-safety-related area.

The fire dampers are curtain type, frame type A. There are two vertical damper installations in this zone each consisting of one 3-hour labeled damper.

Safety-Related Equipment For details, see Subsection 2.3.10.1.

Protection Criteria and Measures For details, see Subsection 2.3.10.1.

Combustible Materials For details, see Subsection 2.3.10.1.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities For details, see Subsection 2.3.10.1.

2.3-104

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire For details, see Subsection 2.3.10.1.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.67.

2.3.10.4 Diesel-Fuel Oil Storage Room 2A (Fire Zone 10.2-2)

This room is shown on Figure 2.3-13 (Sheet 4) and the elevation view is given on Figure 2.3-25 (Sheet 2).

Fire Barrier Description All barriers except for the base slab are 3-hour fire rated. The base slab of Diesel-Fuel Oil Storage Room 2A is a 36-inch structural reinforced concrete slab.

The south and west walls are 48-inch structural reinforced concrete. The north wall is 63-inch structural reinforced concrete and the east wall is 42-inch structural reinforced concrete. The roof at elevation 401 feet 0 inch, which is the floor of a diesel-generator room, is a 48-inch structural reinforced concrete slab.

A Label "A" fire door is in the east wall and a Label "A" fire door is in the north wall. The doors are located 8 feet-0 inch above the floor line to contain the oil in the room in case of a tank rupture. A grating stair is provided at the east wall door and a ladder and grating platform is provided for the door in the north wall.

Four 4-inch-diameter drains are provided and route liquids to a sump pit in the southeast corner of the room. This sump in turn is routed to the Turbine Building fire sump which in turn is pumped to the outside storm system which passes through an oil separator.

The fire dampers are curtain type, frame type A. There are two vertical damper installations in this zone each consisting of one 3-hour labeled damper.

Safety-Related Equipment For details, see Subsection 2.3.10.1.

Protection Criteria and Measures For details, see Subsection 2.3.10.1 except that:

a. The 100-gallon foam storage tank is located at column row 29/K at elevation 401 feet 0 inch in the turbine building.

Combustible Materials For details, see Subsection 2.3.10.1.

2.3-105

B/B - FPR AMENDMENT 29 DECEMBER 2020 Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities For details, see Subsection 2.3.10.1.

Design-Basis Fire For details, see Subsection 2.3.10.1.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.68.

2.3.11 Auxiliary Building 2.3.11.1 Unit 1 Auxiliary Building Basement (Fire Zone 11.1A-0)

This zone is shown on Figure 2.3-16, Figure 2.3-25 (Sheet 1), and Figure 2.3 26 (Sheet 2).

Electrical cable trays routed through this zone are shown on Figure 2.3-40.

Fire Barrier Description The floor at elevation 330 feet 0 inch is an 8-inch concrete topping over a 72-inch-thick structural reinforced concrete base slab. Four-inch-diameter floor drains are provided to remove oil spills and water.

All perimeter walls are structural reinforced concrete and vary in thickness from 12 inches to 63 inches. The wall at column/row l8 carries a 3-hour fire rating. The stairway and elevator hoist way included in this zone are enclosed by walls of 12-inch-thick reinforced concrete, which carry a 2-hour fire rating. The stairways also contain Label "B" fire doors. They extend up to within 1 inch of the ceiling above, and this space is packed with a 1-inch-thick blanket of foil-backed Thermafiber insulation. The ceiling at elevation 346 feet 0 inch is a 12-inch or 40-inch-thick structural reinforced concrete slab. It carries no fire rating, as it contains several openings for equipment removal which are covered by unprotected steel plates.

An oil separator and an oil storage vault (collection sump) are in this zone.

There are no fire dampers installed in the ducts penetrating the floor at elevation 346 feet 0 inch.

2.3-106

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The safety-related equipment in this zone is:

a. Auxiliary Building Ventilation System and coolers,

b. ESW Pump and Strainer 1A,

c. ESW Pump and Strainer 2A, and

d. ESF cabling, Divisions 11 and 21.

Protection Criteria and Measures This zone contains one ESW pump and strainer from each unit. The two replicate pumps and strainers are in Fire Zone 11.1B-0. These two zones are separated by a flood-proof fire wall. Either zone will provide full operational capability for both units.

If the fire protection piping breaks and floods the entire fire zone, the two essential service water pumps will be disabled. However, the Essential Service Water System is single-failure proof. That is, all components, including pumps, are multiple and redundant. The flooding of either Zone 11.1A-0 or 11.1B-0 will not affect plant operation as redundant equipment exists in the other zone.

Combustible Materials Cable insulation, grease, gaskets, insulation, lube oil and polypropylene.

At Byron, acrylic, nylon and plastic.

At Braidwood, lead shielding, miscellaneous and transient combustibles, and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Two manual hose stations are located within the zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

2.3-107

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The cubicle coolers are required to support the ESW system for safe shutdown of the plant; however, they are not designed to operate during or after a fire.

Redundant cubicle coolers in Zone 11.1B-0 are provided for the redundant essential service water pumps. In the event of a design fire, the cubicle cooler components and ductwork may be damaged.

The design-basis fire would occur if all oil in the area ignites. The motor of the essential service water pumps would be damaged. The fire would not spread, since the area is surrounded by either fire walls or walls of substantial construction. A fire would not affect plant operation, since the two essential service water pumps in Fire Zone 11.1B-0 would carry the plant ESW system demand in the event of a fire The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.69.

2.3.11.2 Unit 2 Auxiliary Building Basement (Fire Zone 11.1B-0)

This zone is shown on Figure 2.3-16 and in elevation on Figure 2.3-25 (Sheet 2) and Figure 2.3-26 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-40.

For details, see Subsection 2.3.11.1, except that:

a. No elevator hoist way is in this zone.

b. The ESW equipment is:

a. essential service water pump 1B and strainer 1B

b. essential service water pump 2B and strainer 2B

c. ESF Divisions 22 and 12 cabling.

c. At Byron, lead shielding contributes to combustible materials.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.70.

2.3-108

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.3 Auxiliary Building General Area, Elevation 346 feet 0 inch (Fire Zone 11.2-0)

This zone is shown on Figure 2.3-15 and in elevation on Figures 2.3-22 (Sheet 2), 2.3-25, and 2.3-26. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

Fire Barrier Description The floor at elevation 346 feet 0 inch is an 8-inch concrete topping over a 72-inch-thick structural reinforced concrete base slab or a minimum 12-inch structural reinforced concrete slab supported by concrete beams and columns. It carries no fire rating, as it contains several openings for equipment removal which are covered by unprotected steel plates. Four-inch-diameter floor drains are provided. All perimeter walls are structural reinforced concrete or solid concrete masonry units and vary in thickness from 36 inches to 66 inches. Two stairways and an elevator hoist way included in this zone are enclosed by walls of 12-inch-thick hollow concrete masonry units, which carry a 2-hour fire rating and contain Label "B" fire doors. They extend up to within 1 inch of the ceiling above, and this space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling at elevation 364 feet 0 inch is a 12-inch or 36-inch structural reinforced concrete slab supported by concrete beams and columns. It contains several large openings for equipment removal and for an open stairway. At Braidwood, portions of the ceiling carry a 3-hour rating. Specifically, as identified on Figure 2.3-14, Sheets 1 and 3, the area between column rows L/M-16/20, M/P-15/20, and P/Q-15/18 carries a 3-hour rating. The portion of the ceiling which carries the 3-hour rating contains some sealed but unrated penetrations at Braidwood. The permanent equipment removal hatch at N/18 will be covered with removable concrete plugs that are caulked in place with sealant.

Within this general area is an equipment decontamination room consisting of 12-inch reinforced solid concrete masonry walls with a minimum 8-inch-thick reinforced concrete roof slab. The room contains a washdown pad lined with stainless steel and capped with stainless steel grating. A sump with a pump is provided to remove liquid used in the decontamination process. Walls surrounding the pad are also lined with stainless steel. The floor of this room consists of an 8-inch concrete topping over a 72-inch-thick structural reinforced concrete slab. At Braidwood, the walls, floor, and roof are not fire rated.

2.3-109

B/B - FPR AMENDMENT 29 DECEMBER 2020 Within this general area is a station tool decontamination area consisting of a 5-foot 0-inch partial height hollow reinforced concrete masonry wall. At Byron, a concrete ramp is provided at the entrance to the decontamination area for the purpose of containing fluids in the area.

Safety-Related Equipment The following safety-related equipment is in this zone:

a. recycle evaporation feed pumps

b. gas decay tanks

c. recycle waste evaporators

d. moderating heat exchangers

e. letdown reheat heat exchangers;

f. letdown chiller heat exchangers;

g. Auxiliary Building Ventilation System;

h. RPS channel I instrument panel, Unit 1, 1PL82JA;

i. RPS channel I instrument panel, Unit 2, 2PL82JA;

j. RPS channel II instrument panel, Unit 1, 1PL82JB;

k. RPS channel II instrument panel, Unit 2, 2PL82JA;

l. local instrument panels 1PL81JB, 2PL81JB; and

m. cables and cable trays associated with ESF Divisions 11, 12, 21, and 22 are present.

Protection Criteria and Measures This fire zone is separated from adjacent zones by barriers of substantial construction. The zone itself is large so that equipment is physically separated.

Additionally, physical separation of safety-related equipment is provided by placing all such equipment in concrete cubicles. In addition, at Braidwood, a three-hour fire wrap is used to protect power and control cables associated with both the Division 21 and the Division 22 SX strainer and backwash valve such that the function of either the Division 21 or the Division 22 SX pump, strainer, and backwash valve may be credited in the event the other division pump power cable is damaged by fire and the pump cannot be credited.

2.3-110

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, gaskets, lead shielding, lube oil, miscellaneous and transient combustibles, nylon, plastic, and polypropylene.

At Byron, acrylic, cloth, fiberglass, grease, office material, paint, paint thinner, polyethylene, rubber, and towels.

AT Braidwood, flammable gas, plexiglass, and polycarbonate.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities An automatic sprinkler system is provided around the stairwell at P/18. In addition, minimum 18-inch deep draft stops are provided around the stairwell at P/18.

Ten manual hose stations are located within this zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

The fire protection piping in this zone is routed to avoid damage to any safety-related equipment if a failure should occur.

Design-Basis Fire The design-basis fire would occur if all combustible material in this zone ignited.

Since the combustible materials are spread throughout the room, it is unlikely that the design-basis fire will occur. The physical separation provided for by the size of this zone, and the concrete or masonry cubicles within it, reduces the likelihood of damage to safety-related equipment.

In the event of a fire, the ventilation equipment and ductwork in this zone might be damaged.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.71.

2.3-111

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.4 Residual Heat Removal Pump 1A Room (Fire Zone 11.2A-1)

This zone is shown on Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

Fire Barrier Description The floor slab at elevation 343 feet 0 inch, the mat foundation of the Auxiliary Building, is 72-inch-thick structural reinforced concrete with an 8-inch-thick separate concrete finish. A 4-inch-diameter leak detection sump drain (90 gpm) is provided. All walls are structural reinforced concrete or solid concrete masonry units and vary in thickness from 12 inches to 36 inches. Masonry walls extend up to within 1 inch of the ceiling and the resulting joint is packed with a 1-inch-thick blanket of Thermafiber insulation. A nonrated door leads from this room into an adjacent Containment Spray Pump Room.

The ceiling at elevation 364 feet 0 inch, which is the floor of the reactor containment fan cooler area, is 36-inch-thick structural reinforced concrete with two 36-inch-thick removable concrete slabs.

Safety-Related Equipment The safety-related equipment located in this zone consists of components of the Auxiliary Building Ventilation System. These are galvanized ductwork, dampers, ductwork accessories, and cubicle coolers.

The residual heat removal pump 1A and its unit cooler are also located in this room.

Cable trays associated with ESF Division 11 are present.

Protection Criteria and Measures The RHR pump and unit cooler are physically separated from other equipment and materials by structurally reinforced concrete or masonry walls and by distance. A redundant pump is provided in another fire zone, so that if one is rendered inoperative, the other is available.

Combustible Materials Cable insulation, grease, gaskets, and lube oil.

At Byron, acrylic, nylon, plastic, and polypropylene.

At Braidwood, lead shielding and PMMA.

2.3-112

B/B - FPR AMENDMENT 29 DECEMBER 2020 Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is within 50 feet of the room. Portable fire extinguishers are available from another zone. Ionization (or photoelectric) detection is installed which alarms and annunciates in the Control Room.

Design-Basis Fire The design-basis fire would occur if all combustibles burn. In this case, the pump would be rendered inoperative. A redundant RHR pump is provided in a physically separated area and can provide all necessary RHR pumping requirements. Because of the small amount of combustibles in the room, the fire would be confined to the immediate area.

The cubicle coolers are required for safe shutdown of the plant if the associated RHR pump is operating. The cooler is not designed to operate during or after a fire. In the event of a design fire, the cubicle cooler components and ductwork may be damaged; however, the redundant RHR pump and its cooler can function to shut down the plant. No fire dampers are provided; therefore, the spread of fire, heat, and products of combustion will be exhausted through HEPA filters via the Auxiliary Building Ventilation System. Radiation monitors are in the exhaust stack which will alarm in the Control Room if high radiation is present in the Auxiliary Building exhaust air. The Control Room operator can manually shut down the ventilation system to limit the exhaust of radioactive products.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.72.

2.3.11.5 Residual Heat Removal Pump 2A Room (Fire Zone 11.2A-2)

This zone is shown on Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

For details, see Subsection 2.3.11.4 except that:

a. RHR pump 2A and its cooler and cables of ESF Division 21 are in the room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.73.

2.3-113

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.6 Containment Spray Pump 1A Room (Fire Zone 11.2B-1)

This zone is shown in Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

Fire Barrier Description The floor slab at elevation 343 feet 0 inch, the mat foundation of the Auxiliary Building, is 72-inch-thick structural reinforced concrete with an 8-inch-thick separate concrete finish. Two 4-inch-diameter leak detection sump drains (each 90 gpm capacity) are provided.

All walls are structural reinforced concrete or solid concrete masonry units and vary in thickness from 12 inches to 36 inches. Masonry walls extend up to within 1 inch of the ceiling and the remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. A nonrated door leads into a residual heat removal pump room.

The concrete walls between Zones 11.2C-1 and 11.2B-1 and 11.2C-2 and 11.2B-2 are 2-hour fire barriers. A door which leads to another containment spray pump room and to the Auxiliary Building basement is rated as Label "B."

The ceiling at elevation 364 feet 0 inch, which is the floor of the Spray Additive Tank Room, is 36-inch-thick structural reinforced concrete with two 36-inch-thick removable concrete slabs.

Safety-Related Equipment The Containment Spray Pump 1A and its unit cooler are in this room. Cables and cable trays associated with ESF Division 11 are present.

Protection Criteria and Measures The containment spray pump and unit cooler are physically separated from other equipment in the building by concrete or masonry walls and distance. Two containment spray pumps are provided and physically separated so that if one is inoperative, the other will provide full operational capability.

Combustible Materials Cable insulation, gaskets, grease, and lube oil.

At Byron, nylon, plastic, and polypropylene.

At Braidwood, lead shielding and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-114

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities A manual hose station is located within this fire zone. Portable fire extinguishers are also available from adjacent zones.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The cubicle cooler is required for safe shutdown of the plant only if the associated spray pump is operating. It is not designed to operate if a fire occurs.

The design-basis fire would occur if all combustibles in the room burn. In this case, the pump and cooler would be damaged and assumed inoperative. A duplicate pump and cooler are available if required. With the low fire loading, and the distance and barriers between pumps, only one pump could be incapacitated.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.74.

2.3.11.7 Containment Spray Pump 2A Room (Fire Zone 11.2B-2)

This zone is shown on Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

For details, see Subsection 2.3.11.6 except that:

a. Pump 2A, its cooler and cables of ESF Division 21 are in this room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.75.

2.3.11.8 Containment Spray Pump 1B Room (Fire Zone 11.2C-1)

This zone is shown on Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

For details, see Subsection 2.3.11.6, except that:

a. No direct access to Auxiliary Building General area, elevation 346 feet 0 inch is provided.

b. Pump 1B, its cooler and cables of ESF Division 12 are in this room.

c. The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.76.

2.3-115

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.9 Containment Spray Pump 2B Room (Fire Zone 11.2C-2)

This zone is shown on Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

For details, see Subsection 2.3.11.6 except that:

a. No direct access to the basement is provided.

b. Pump 2B, its cooler and cables of ESF Division 22 are in this room.

c. The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.77.

2.3.11.10 Residual Heat Removal Pump 1B Room (Fire Zone 11.2D-1)

This zone is shown on Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

For details, see Subsection 2.3.11.4 except that:

a. RHR pump 1B and its cooler are in this room.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.78.

2.3.11.11 Residual Heat Removal Pump 2B Room (Fire Zone 11.2D-2)

This zone is shown on Figure 2.3-15. Electrical cable trays routed through this zone are shown on Figure 2.3-39.

For details, see Subsection 2.3.11.5 except that:

a. RHR pump 2B and its cooler are in this room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.79.

2.3-116

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.12 Auxiliary Building General Area Level 364 feet 0 inch (Fire Zone 11.3-0)

This fire zone is shown on Figure 2.3-l4 (Sheets 1 and 3) and in elevation on Figures 2.3-22 (Sheet 2), 2.3-25, and 2.3-26. Electrical cable trays routed through this zone are shown on Figure 2.3-38.

Fire Barrier Description The floor of the recycle hold-up tanks at elevation 346 feet 0 inch is a 72-inch-thick reinforced concrete slab with an 8-inch-thick finish. The walls are a minimum 36-inch-thick reinforced concrete or solid concrete masonry units. The ceiling for the tanks is the same ceiling described later in this section.

The floor at elevation 364 feet 0 inch is a 12-inch to 36-inch-thick structural reinforced concrete slab supported by concrete beams and columns. It contains several large openings for equipment removal and for an open stairway. At Braidwood, portions of the slab carry a 3-hour rating. Specifically, as identified on Figure 2.3-14, Sheets 1 and 3, the area between column rows L/M-16/20, M/P-15/20, and P/Q-15/18 carries a 3-hour rating at Braidwood. Four-inch-diameter floor drains are provided. Perimeter walls are structural reinforced concrete or solid concrete masonry units of minimum 20-inch-thickness. Walls common to the main steam pipe tunnels, Turbine Building basement, and to this zone carry a 3-hour fire rating. The floor slab at column-row N/18 contains a permanent equipment removal hatch which will be covered with removable concrete plugs that will be caulked in place with sealant. Walls common to this zone and the following safety-related cubicles are of 3-hour rated construction but contain nonrated doors or removable masonry areas, and thus carry no fire rating.

a. the Safety Injection Pump Rooms 1 and 2

b. Residual Heat Removal Heat Exchanger Rooms 1 and 2

c. the Positive Displacement Charging Pump Rooms 1 and 2

d. the Centrifugal Charging Pump Rooms 1 and 2

e. the Residual Heat Removal Pump Rooms 1 and 2

f. the Containment Pipe Penetration Areas 1 and 2.

Two stairways and an elevator hoist way included in this zone are enclosed by walls of 12-inch-thick hollow concrete masonry units, which carry a 2-hour fire rating and contain Label "B" fire doors. All masonry walls extend up to within 1 inch of the ceiling above, and this space is packed with a 1-inch-thick blanket of Thermafiber insulation.

2.3-117

B/B - FPR AMENDMENT 29 DECEMBER 2020 A pipe tunnel to the Unit 1 Containment Pipe Penetration Area is suspended from the ceiling slab of this zone by structural steel hangers; these hangers are encased in the minimum 32-inch-thick solid masonry unit (3-hour fire rated) walls of the tunnel. The floor of the tunnel at elevation 374 feet 6 inches is a 30-inch-thick structural reinforced concrete slab and carries a 3-hour fire rating. The ends of the tunnel are sealed and carry no fire rating. The 4-inch-diameter floor drains are provided in this tunnel. Another pipe tunnel, which connects the containment pipe penetration areas, is suspended from the ceiling slab of this zone by structural steel hangers and supported by unprotected steel beams. The walls are 32-inch-thick solid concrete masonry units and carry a 3-hour fire rating. Both ends of this pipe tunnel are sealed with non-rated closures.

The floor slab of the tunnel at elevation 375 feet 6 inches is a 27-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams which are protected with a fire-resistant covering and carry a minimum 2-hour fire rating. The floor slab itself carries no fire rating. Four 4-inch-diameter floor drains are provided in this tunnel.

The ceiling of this zone is a 12-inch or 36-inch-thick structural reinforced concrete slab supported by concrete beams and columns. It contains several 12-inch-thick removable concrete slabs, several openings for equipment removal, and an unenclosed stairway. Portions of the ceiling carry a 3-hour rating. Specifically, as shown on Figure 2.3-13, Sheets 1 and 2, the area between column rows L/N-12/20 and N/Q-16/20 carries a 3-hour rating. The portion of the ceiling which carries a 3-hour rating contains some sealed but nonrated penetrations.

The removable concrete slabs above at column N-18 are caulked with sealant.

Safety-Related Equipment The following safety-related equipment is in this fire zone:

a. component cooling heat exchangers and pumps

b. recycle holdup tank

c. Auxiliary Building Ventilation System

d. MCC-132X1 (ESF Div. 12)-1AP23E

e. cables and cable trays associated with ESF Divisions 11, 12, 21, and 22 are present.

f. remote shutdown panel - 1PL05JA 2.3-118

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The fire protection piping in this zone is routed to avoid damage to any safety-related equipment if a failure should occur.

Partial height walls have been provided between component cooling pumps for protection against exposure fire. Spray shields are provided for the component cooling pump motors to protect them in the event of an inadvertent suppression system actuation.

Combustible Materials Cable insulation, fiber optic cable, gaskets, insulation, lube oil, miscellaneous and transient combustibles, nylon, office material, polypropylene, and plastic.

At Byron, acrylic.

At Braidwood, flammable gas, plexiglass and polycarbonate.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Nine manual hose stations are provided within this zone. Portable fire extinguishers are available throughout the fire zone and from adjacent areas.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

An automatic sprinkler system has been provided for the component cooling pumps which annunciates and alarms in the control room. A sprinkler system has also been provided around the stairwell at P-18 per NRC request. In addition, minimum 18-inch-deep draft stops are also provided around the stairwell at P-18.

Design-Basis Fire The fire zone is large and equipment, especially safety-related or radioactive equipment, is well separated. Mechanical fire hazards are limited to oil lubricants in the following pumps:

a. Regeneration Waste Drain Pump

b. Component Cooling Water Pumps

c. Auxiliary Building Floor Drain Pumps

d. Recycle Evaporator Monitor Pumps

e. Primary Water Makeup Pumps

f. Chemical Drain Pump.

2.3-119

B/B - FPR AMENDMENT 29 DECEMBER 2020 None of these pumps has more than 1 gallon of oil lubricant. The pumps are all situated so that groups of pumps are separated by at least 35 feet. The small amount of oil per pump and the separation of combustibles would make a severe fire unlikely. The pumps in each group (e.g., a., b., c., etc.) are usually placed close together. The only safety-related group of pumps used for reactor shutdown are the component cooling water pumps. They contain a negligible amount of lubricant oil.

A severe fire in this area is highly unlikely because of the separation of combustibles. This area is administratively supervised, and access is controlled; therefore, a situation resulting in the initiation of fire is highly unlikely. Detectors are provided over the component cooling pumps and other portions of this area.

These detectors would notify the station operators of any incipient fire. The automatic sprinkler system could rapidly extinguish any fire at the component cooling pumps. Portable extinguishers and manual hose stations are also available.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.80.

2.3.11.13 Unit 1 Containment Pipe Penetration Area (Fire Zone 11.3-1)

This zone is shown on Figure 2.3-14 (Sheet 1) and in elevation on Figure 2.3 26 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-38 (Sheet 1).

Fire Barrier Description The floor at elevation 364 feet 0 inch is the ceiling of the Residual Heat Removal Pump Rooms, the Containment Spray Pump Rooms, and the Collection Drain Tank Pump Room. It is a 36-inch-thick structural reinforced concrete slab supported by concrete beams and columns and contains several 36-inch-thick removable concrete slabs. At Byron, five 4-inch-diameter floor drains are provided to remove oil spills and water. At Braidwood, there are four floor drains.

Perimeter walls are minimum 20-inch-thick structural reinforced concrete or solid concrete masonry units. Walls common to this zone, other Auxiliary Building floor levels, and to adjacent safety-related cubicles are of 3-hour rated construction but may contain open passageways, nonrated doors or removable masonry areas, and thus carry no fire rating. The ceiling of this zone is at elevation 401 feet 0 inch and at elevation 414 feet 0 inch.

2.3-120

B/B - FPR AMENDMENT 29 DECEMBER 2020 The slab at elevation 401 feet 0 inch, which is the floor of the Reactor Containment Chiller Pump Room, is a minimum 25-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams which are protected with a fire-resistant covering and carry a minimum 2-hour fire rating. The slab itself carries no fire rating.

The slab at elevation 414 feet 0 inch is the same construction and rating as at elevation 401 feet 0 inch.

The exterior seismic gap joint seal system installed and enclosed by buttress enclosure #1 on unit 1 is adequate barrier between Containment Building and Aux Building as is. The installation of Cerablanket (exterior side) for this seal is not required (Refer EC 369257)

Protection Criteria and Measures Except for the Containment Spray Additive Tank and associated motor control center, there is no safety-related equipment in this zone. There is a considerable amount of safety-related piping associated with the safety injection, containment spray, and essential service water systems among others. There is no fire hazard in this zone severe enough to damage the containment spray tank or any piping.

Electrical equipment from only one ESF division is in this zone. Loss of this equipment will not prevent a safe shutdown of the reactor.

The zone's boundaries are of substantial construction. Additionally, the zone is large and the combustibles well separated, making the design-basis fire highly unlikely.

Safety-Related Equipment The Spray Additive Tank is safety related. Piping associated with the safety injection, containment spray, and essential service water is in this zone and is safety related. MCC 131X1 (1AP21E) from ESF Division 11 is also safety-related equipment.

Combustible Materials Cable insulation, gaskets, insulation, lube oil, miscellaneous and transient combustibles, nylon, plastic, and polypropylene.

At Byron, acrylic and hydraulic fluid.

At Braidwood, lead shielding, plexiglass, and polycarbonate.

2.3-121

B/B - FPR AMENDMENT 29 DECEMBER 2020 Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Two hose stations are located inside this zone and two additional hoses may be brought in from adjacent zones. Portable extinguishers are also provided.

Ionization (or photoelectric) detectors are provided, which annunciate and alarm in the Control Room.

An automatic sprinkler system has been installed to protect the area bounded by column rows U and Y and 12 and 15 in the zone. This sprinkler system deviates from NFPA 13, Article 4-3, regarding the position of sprinklers in that the sprinklers are located substantially below the ceiling height in order to avoid obstructions and adequately cover the floor area. This system is described further in Subsection A5.8.13.

Design-Basis Fire The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.81.

2.3.11.14 Unit 2 Containment Pipe Penetration Area (Fire Zone 11.3-2)

This zone is shown on Figure 2.3-14 (Sheet 3) and in elevation on Figure 2.3 26 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-38 (Sheet 2).

For details, see Subsection 2.3.11.13 except that:

a. The exterior seismic gap joint seal system installed and enclosed by buttress enclosure #5 on unit 2 is adequate barrier between Containment Building and Aux. Building as is. The installation of Cerablanket (exterior side) for this seal is not required (Refer EC 369257).

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.82.

2.3-122

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.15 Safety Injection Pump 1A Room (Fire Zone 11.3A-1)

This room is shown on Figure 2.3-14.

Fire Barrier Description The floor at elevation 364 feet 0 inch is a 33-inch-thick structural reinforced concrete slab supported by concrete beams and columns. One 4-inch-diameter floor drain is provided.

All walls are minimum 28-inch-thick structural reinforced concrete or solid concrete masonry units. Masonry walls extend to within 1-inch of the ceiling above, and this resulting space is packed with a 1-inch blanket of foil-backed Thermafiber insulation.

The ceiling at elevation 383 feet 0 inch is a 33-inch-thick structural reinforced concrete slab supported by concrete beams and columns.

Safety-Related Equipment Safety Injection Pump 1A and its unit cooler are in this room.

Portions of the Auxiliary Building Ventilation System are safety related.

Protection Criteria and Measures The fire zone is isolated from the rest of the equipment on this level by walls of substantial construction.

Combustible Materials Gaskets, grease and lube oil.

At Byron, acrylic, nylon, plastic, and polypropylene.

At Braidwood, PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual hose station is located within 30 feet of the safety injection pump room.

Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the control room.

2.3-123

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire is minimal but would occur if the lubricant oil in the pump burned. In this case, the pump might conceivably be unable to operate. The chances of this happening are remote. If the pump does become inoperable as a result of a fire, the safety function of the Safety Injection System (SIS) will not be impaired. The SIS is designed to tolerate a single failure without loss of its reactor protective functions. This single failure includes an active failure during the short-term injection phase following a LOCA.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.83.

2.3.11.16 Safety Injection Pump 2A Room (Fire Zone 11.3A-2)

This room is shown on Figure 2.3-14.

For details, see Subsection 2.3.11.15 except that;

a. safety injection pump 2A and its unit cooler are in this room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.84.

2.3.11.17 Residual Heat Removal Heat Exchanger 1A Room (Fire Zone 11.3B-1)

This room is shown on Figure 2.3-14.

Fire Barrier Description The floor slab at elevation 364 feet 0 inch is 33-inch structural reinforced concrete and is supported by concrete beams and columns. A pit, at elevation 357 feet 0 inch, is located within this room and is provided with a 4-inch leak detection sump drain (90 gpm capacity). All walls are structural reinforced concrete or solid concrete masonry units of minimum 28-inch thickness. Masonry walls extend to within 1 inch of the ceiling above, and this resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling at elevation 401 feet 0 inch is a 24-inch-thick structural reinforced concrete slab supported by concrete beams and columns. It contains three 24-inch-thick removable concrete slabs.

2.3-124

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The safety-related equipment located in this zone consists of components of the Auxiliary Building Ventilation System. These are galvanized ductwork, dampers, and ductwork accessories.

Residual Heat Removal Heat Exchanger 1A is also located in this room.

Protection Criteria and Measures The RHR heat exchanger is in a structurally reinforced concrete room and is physically separated from other equipment on the floor.

Combustible Material Gaskets At Byron, cable insulation, nylon, plastic and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is available for use in this zone. Portable fire extinguishers are also available from the adjacent areas.

Design-Basis Fire In the event of a design fire, the galvanized ductwork, dampers, and ductwork accessories located in this zone may be damaged. Any radioactive products of combustion will be exhausted through HEPA filters by the Auxiliary Building Ventilation Exhaust System and discharged to the atmosphere. Radiation monitors have been provided in the exhaust stack.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Subsection 2.4.2.85.

2.3-125

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.18 Residual Heat Removal Heat Exchanger 2A Room (Fire Zone 11.3B-2)

This room is shown on Figure 2.3-14.

For details, see Subsection 2.3.11.17 except that:

a. RHR heat exchanger 2A is in this room.

Also, the analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.86.

2.3.11.19 Unit 1 Positive Displacement Charging Pump Room (Fire Zone 11.3C-1)

This room is shown on Figure 2.3-14 (Sheet 1) and in elevation on Figure 2.3 22 (Sheet 2).

Fire Barrier Description The floor at elevation 364 feet 0 inch is 33-inch structural reinforced concrete slab supported by concrete beams and columns. Two 4-inch-diameter floor drains are provided.

All walls are minimum 20-inch-thick structural reinforced concrete or solid concrete masonry units. Masonry walls extend to within 1 inch of the ceiling above, and this resulting space is packed with a 1-inch-thick blanket of foil-backed Thermafiber insulation.

The ceiling at elevation 383 feet 0 inch is a 24-inch-thick structural reinforced concrete slab supported by concrete beams and columns.

Safety-Related Equipment The Positive Displacement Charging Pump is safety related.

Protection Criteria and Measures This room is of structural reinforced concrete or solid concrete masonry walls and physically isolates the pump from all other equipment.

Combustible Materials Gaskets, grease, lube oil At Byron, acrylic, nylon, plastic and polypropylene.

At Braidwood, polycarbonate.

2.3-126

B/B - FPR AMENDMENT 29 DECEMBER 2020 Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is located within reach of this room. Portable fire extinguishers are also available from the adjacent areas.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the room burned. In this case, the equipment in the room would be rendered inoperable. However, the loss of this pump would not affect either plant operation or plant shutdown because redundant pumps are provided.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.87.

2.3.11.20 Unit 2 Positive Displacement Charging Pump Room (Fire Zone 11.3C-2)

This room is shown on Figure 2.3-14 (Sheet 3).

For details, see Subsection 2.3.11.19 except that:

a. Unit 2 pump is in this zone.

b. At Braidwood, lead shielding contributes to combustible materials.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.88.

2.3-127

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.21 Centrifugal Charging Pump 1A Room (Fire Zone 11.3D-1)

This room is shown on Figure 2.3-14 (Sheet 1) and in elevation on Figure 2.3 22 (Sheet 2).

Fire Barrier Description The floor slab at elevation 364 feet 0 inch is 33-inch structural reinforced concrete supported by concrete beams and columns. One 4-inch-diameter floor drain is provided. All walls are minimum 20-inch-thick structural reinforced concrete or solid concrete masonry units. Masonry walls extend up to within 1 inch of the ceiling, and this resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation. The ceiling at elevation 383 feet 0 inch is a 24-inch-thick structural reinforced concrete slab supported by concrete beams and columns.

Safety-Related Equipment Centrifugal Charging Pump 1A and its unit cooler are in this room. Portions of the Auxiliary Building Ventilation System are safety related.

Protection Criteria and Measures The charging pump is physically separated from other equipment on the floor by structurally reinforced concrete walls.

Combustible Materials Gaskets, grease, and lube oil.

At Byron, acrylic, nylon, plastic, and polypropylene.

At Braidwood, PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is within reach of this zone. Portable fire extinguishers are available from the adjacent areas.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

2.3-128

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would occur if all the oil in the pump burned. If this happened, the pump will be rendered inoperable. Redundant pumps are provided in case a charging pump fails.

The cubicle coolers are required for safe shutdown of the plant if the associated RHR pump is operating. The cooler is not designed to operate during or after a fire. In the event of a design fire, the cubicle cooler components and ductwork may be damaged; however, the redundant pump and its cooler can function to shut down the reactor. No fire dampers are provided; therefore, the spread of fire, heat, and products of combustion will be exhausted through HEPA filters via the Auxiliary Building Ventilation System. Radiation monitors are in the exhaust stack which will alarm in the Control Room if high radiation is present in the Auxiliary Building exhaust air. The Control Room operator can manually shut down the ventilation system to limit the exhaust of radioactive products.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.89.

2.3.11.22 Centrifugal Charging Pump 2A Room (Fire Zone 11.3D-2)

This room is shown on Figure 2.3-14 (Sheet 3).

For details, see Subsection 2.3.11.21, except that:

a. Centrifugal Charging Pump 2A and its unit cooler are in this room.

b. At Braidwood, rubber hoses are stored in a metal box in the zone and contribute to combustible materials.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.90.

2.3-129

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.23 Residual Heat Removal Heat Exchanger 1B Room (Fire Zone 11.3E-1)

This room is shown on Figures 2.3-13 (Sheet 1) and 2.3-14 (Sheet 1) and in elevation on Figure 2.3-22 (Sheet 2).

Fire Barrier Description The floor slab at elevation 364 feet 0 inch is 33-inch-thick structural reinforced concrete supported by concrete beams and columns. One 4-inch-diameter leak detection sump drain is provided.

All walls are minimum 36-inch-thick structural reinforced concrete or solid concrete masonry units. Masonry walls extend up to within 1 inch of the ceiling, and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The wall common to this zone and to the Fuel Handling Building carries a 3-hour fire rating. All other walls, while of 3-hour construction, contain nonrated doors or penetrations and carry no fire rating.

The ceiling at elevation 401 feet 0 inch is a 24-inch-thick structural reinforced concrete slab supported by concrete beams and columns.

For further details, see Subsection 2.3.11.17 except the RHR Heat Exchanger 1B in this room.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Subsection 2.4.2.41.

2.3.11.24 Residual Heat Removal Heat Exchanger 2B Room (Fire Zone 11.3E-2)

This room is shown on Figures 2.3-13, (Sheet 2) and 2.3-14 (Sheet 3).

For details, see Subsection 2.3.11.17, except that:

a. RHR Heat Exchanger 2B is in this room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.92.

2.3-130

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.25 Safety Injection Pump 1B Room (Fire Zone 11.3F-1)

This room is shown in Figure 2.3-14 (Sheet 1).

Fire Barrier Description The floor at elevation 364 feet 0 inch is a 72-inch-thick structural reinforced concrete base slab with an 8-inch concrete topping. A 4-inch-diameter floor drain is provided.

The perimeter walls of this zone are minimum 30-inch-thick structural reinforced concrete walls or 20-inch-thick solid concrete masonry unit walls, which contain a removable masonry area and a nonrated door and carry no fire rating. The ceiling at elevation 388 feet 6 inches is a 30-inch-thick structural reinforced concrete slab. Also included in the zone is the tunnel for the refueling water pipe.

It extends at elevation 379 feet 6 inches from the Safety Injection Pump Room to the Refueling Water Tanks and is constructed of minimum 24-inch-thick structural reinforced concrete floor and ceiling slabs, and walls. These elements carry no fire rating.

Safety-Related Equipment Safety Injection Pump 1B and its unit cooler are in this room.

Portions of the Auxiliary Building Ventilation System are safety related.

Combustible Materials Gaskets, grease, and lube oil.

At Byron, acrylic, nylon, plastic, and polypropylene.

At Braidwood, PMMA Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual hose station is located within reach of this room. Portable fire extinguishers are also available from the adjacent areas.

Ionization (or photoelectric) detectors are provided in the pump room portion of this fire zone. The RWST pipe tunnel portion of this fire zone does not have any ionization (or photoelectric) detectors; however, smoke from a potential fire in the RWST would migrate into the pump room and be detected by the ionization (or photoelectric) detectors in the pump room.

2.3-131

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.93. For further details, see Subsection 2.3.11.15.

2.3.11.26 Safety Injection Pump 2B Room (Fire Zone 11.3F-2)

This room is shown in Figure 2.3-14.

For details, see Subsection 2.3.11.25 except that:

a. Safety Injection Pump 2B and its unit cooler are in this room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.94.

2.3.11.27 Centrifugal Charging Pump 1B Room (Fire Zone 11.3G-1)

The room is shown on Figure 2.3-14 (Sheet 1) and in elevation on Figure 2.3-22 (Sheet 2).

The floor at elevation 364 feet 0 inch is a 72-inch-thick structural reinforced concrete base slab with an 8-inch concrete topping. A 4-inch-diameter floor drain is provided. The perimeter walls of the zone are minimum 30-inch-thick structural reinforced concrete walls or 20-inch-thick solid concrete masonry unit walls, which contain a removable masonry area and a nonrated door and carry no fire rating. The ceiling at elevation 388 feet 6 inches is a 30-inch-thick structural reinforced concrete slab.

For details, see Subsection 2.3.11.21 except that:

a. Centrifugal Charging Pump 1B and its unit cooler are in this room.

b. No fire protection piping passes through this zone.

c. Rubber hose contributes to combustible materials.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.95.

2.3-132

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.28 Centrifugal Charging Pump 2B Room (Fire Zone 11.3G-2)

The room is shown on Figure 2.3-14.

For details, see Subsection 2.3.11.27 except that:

a. Centrifugal Charging Pump 2B and its unit cooler are in this room.

b. No fire protection piping passes through this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.96.

2.3.11.29 Auxiliary Building Elevation 383 feet 0 inch (Fire Zone 11.4-0)

This zone is shown on Figure 2.3-13 and in elevation on Figures 2.3-25 and 2.3-

26. Electrical cable trays routed through this zone are shown on Figure 2.3-37.

Fire Barrier Description The floor at elevation 383 feet 0 inch is a 12-inch to 48-inch-thick structural reinforced concrete slab supported by concrete beams and columns. It contains several 12-inch-thick removable concrete slabs, several openings for equipment removal and for an open stairway, and portions of the slab carry a 3-hour rating.

Specifically, as shown on Figure 2.3-13, Sheets 1 and 2, the area between column rows L/N-12/20 and N/Q-16/20 carries a 3-hour rating. Four-inch-diameter floor drains are provided.

The removable concrete slabs at column N-18 are caulked with sealant.

Perimeter walls are structural reinforced concrete or solid concrete masonry units and are minimum 36 inches thick. Walls common to the Fuel Handling Building, the Turbine Building Basement, and this zone carry a 3-hour fire rating. Walls common to this zone and the following cubicles are of 3-hour rated construction but contain nonrated doors or removable masonry areas, and thus carry no fire rating:

a. Seal Water Heat Exchanger Rooms 1 and 2

b. Letdown Heat Exchanger Rooms 1, 2, 3, 4

c. Containment Pipe Penetration Areas; and

d. The Residual Heat Removal Heat Exchanger Rooms.

Three stairways and an elevator hoist way included in this zone are enclosed by walls of 12-inch-thick hollow concrete masonry units, which carry a 2-hour fire rating and contain Label "B" fire doors. All masonry walls extend up to within 1 inch of the ceiling above, and this space is packed with a 1-inch-thick blanket of Thermafiber insulation.

2.3-133

B/B - FPR AMENDMENT 29 DECEMBER 2020 A pipe tunnel, which connects the containment pipe penetration areas, is suspended from the ceiling slab of this zone by structural steel hangers and supported by unprotected steel beams. The 32-inch-thick walls are solid concrete masonry units and carry no fire rating.

The floor slab of the tunnel at elevation 394 feet 6 inches is a 27-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and carries no fire rating. Four 4-inch-diameter floor drains are provided.

A pipe tunnel to the Unit 1 Containment Pipe Penetration Area is suspended from the ceiling slab of this zone by structural steel hangers. These hangers are encased in the minimum 32-inch-thick solid masonry unit walls (3-hour fire-rated) of the tunnel. The floor of the tunnel at elevation 394 feet 0 inch is a 30-inch-thick structural reinforced concrete slab and carries no fire rating. Two 4-inch-diameter floor drains are provided.

The ceiling at elevation 401 feet 0 inch is a minimum 12-inch-thick structural reinforced concrete slab supported by concrete beams and columns. It contains several large openings for equipment removal and for an open stairway and carries no fire rating.

The removable concrete slabs above at column N-18 are caulked with sealant.

Safety-Related Equipment The following safety-related equipment is in this zone:

a. reactor coolant filters

b. Seal Water Filter

c. Seal Water Injection Filter

d. Recycle Evaporator Feed Filter

e. auxiliary feedwater motor-driven pumps

f. MCC-131X3 (ESF Division 11)-1AP22E

g. MCC-132X3 (ESF Division 12)-1AP24E

h. MCC-232-X1 (ESF Division 22)-2AP23E

i. MCC-232X3 (ESF Division 22)-2AP24E

j. cables and cable trays ESF Divisions 11, 12, 21, and 22 are present

k. portions of the Auxiliary Building Ventilation System.

Protection Criteria and Measures All equipment on this level with significant quantities of lubricating oil are physically isolated from the central area.

2.3-134

B/B - FPR AMENDMENT 29 DECEMBER 2020 Class IC fire protection piping is routed through this zone. At Byron, the fire protection piping in this zone has been reclassified as Safety Category II, Quality Group D (Ref. EC 636663): and remains classified as Seismic Category I.

Combustible Materials Cable insulation, fiber optic cable, grease, insulation, lube oil, miscellaneous and transient combustibles, nylon, paper, plastic, polypropylene, waste oil and solvents, and wood.

At Byron, acrylic, buckets, diesel fuel oil, FRP, pig pans, and rubber.

At Braidwood, flammable gas, lead shielding, plexiglass, polycarbonate, and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Seven manual hose stations are located within this fire zone. Portable fire extinguishers are also provided.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Automatic sprinklers are provided around the stairwell at P-18 per NRC request.

In addition, minimum 18-inch deep draft stops are provided around the stairwell at P-18.

Design-Basis Fire The design-basis fire in this area is the burning of all the combustibles in the zone. If this fire occurs the filters would not be damaged, since they are in cubicles of substantial construction. The motor-driven auxiliary feedwater pump could be damaged, but its loss is acceptable since a diesel-driven feedwater pump is available as backup protection in another zone. Sufficient extinguishing capability is provided to control and contain this postulated fire.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.97.

2.3-135

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.30 Control Room Refrigeration Equipment Room (Fire Zone 11.4A-0)

This room is shown on Figure 2.3-13 (Sheet 1) and in elevation on Figure 2.3 25 (Sheet 1).

Fire Barrier Description The floor at elevation 383 feet 0 inch is a 48-inch-thick structural reinforced concrete slab and carries a 3-hour rating. Four-inch-diameter floor drains are provided. The perimeter walls of the zone are minimum 36-inch-thick structural reinforced concrete. The walls common to this zone and to the Diesel Oil Storage Tank Room 1A, to the Pipe Tunnel, and to the Turbine Building carry a 3-hour fire rating. The fourth wall contains an open passageway to the rest of the Auxiliary Building floor at elevation 383 feet 0 inch and thus carries no fire rating.

The ceiling at elevation 401 feet 0 inch is a 48-inch-thick structural reinforced concrete slab and carries a 3-hour fire rating.

Safety-Related Equipment The safety-related equipment located in this zone consists of components of the Auxiliary Building Ventilation System and the Control Room Refrigeration System. These are galvanized ductwork, dampers, ductwork accessories, chillers, and pumps.

Protection Criteria and Measures Due to arrangement, the equipment in this zone is separated from other areas by either fire-rated barriers or distance.

Combustible Materials Gaskets, grease, and lube oil.

At Byron, acrylic, nylon, plastic, and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detection Capabilities One manual hose station is in this room. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

2.3-136

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire A partition separates the two redundant refrigeration trains; however, it is not a fire barrier. In the event of a fire, the galvanized ductwork, ductwork accessories, dampers, refrigeration equipment, and pumps may be damaged. However, this equipment is not required for safe shutdown of the plant.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.98.

2.3.11.31 Unit 1 Auxiliary Feedwater Diesel-Driven Pump Room Fire (Zone 11.4A-1)

This zone is shown on Figure 2.3-13 (Sheet 1) and in elevation on Figures 2.3 22 (Sheet 2) and 2.3-25 (Sheet 1).

Fire Barrier Description The floor at elevation 383 feet 0 inch is an 18-inch-thick structural reinforced concrete slab and carries a 3-hour fire rating. One 4-inch-diameter leak detection sump drain is provided. As requested by the NRC, a curb has been installed at the door opening to limit the potential fuel and fire propagation up to elevation 383 feet 7 inches.

The perimeter walls of this zone are 12-inch-thick hollow (Byron) or solid (Braidwood) concrete masonry units or 42-inch-thick structural reinforced concrete and carry a 3-hour fire rating. Masonry walls extend up to within 1 inch of the ceiling above, and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. All doors in this perimeter wall are Label "A" fire doors except at Braidwood the door in the south wall is of Label "A" construction.

The ceiling of this fire zone, at elevation 401 feet 0 inch, is a 24-inch-thick structural reinforced concrete slab supported by concrete beams and columns and carries a 3-hour fire rating.

The fire dampers installed in the ducts penetrating the fire walls are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

The day tank cubicle walls are 12-inch-thick hollow concrete units and carry a 3-hour rating. They extend up to the ceiling at elevation 391 feet 0 inch.

2.3-137

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The safety-related equipment located in this fire area consists of components of the Auxiliary Building Ventilation System. These are galvanized ductwork, ventilation ductwork accessories, cubicle coolers, and vane-axial fans. The diesel-driven pump and the diesel's 500-gallon day tank are also safety-related.

Protection Criteria and Measures This room is physically separated from the remainder of the plant by 3-hour rated fire barriers.

Fire dampers are provided in all the fire walls. Fire dampers are electro-thermal link type which will close when the temperature exceeds 165 Degrees Fahrenheit.

Combustible Materials Diesel fuel oil, gaskets, grease, lube oil, miscellaneous and transient combustibles, and polypropylene.

At Byron, acrylic, nylon, plastic, and wood.

At Braidwood, instrument cable, polycarbonate and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Two manual hose stations are located within reach of this room. Portable fire extinguishers are also available.

A total flooding low-pressure CO2 system is provided which actuates automatically from Fenwal thermal detectors. At Byron, Ionization (or photoelectric) detectors are provided which annunciate and alarm in the control room. Manual actuation, with or without electric power, is available through local switches. Actuation of the system will alarm locally and in the control room. The day tank room CO2 system is also a subsystem of the main CO2 of the diesel-driven auxiliary feedwater pump room and, as such, a discharge in the feedwater pump room would automatically cause a discharge in the day tank room. A discharge in the day tank room would not cause a discharge in the feedwater pump room.

2.3-138

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would result if all the combustibles in the zone burned. The probable results of such a fire would be the incapacitation of the auxiliary feedwater diesel-driven pump and the cubicle cooler. Because of the fire rated barriers, the fire would not spread. The loss of the pump is acceptable as a redundant pump is provided.

The design-basis fire is highly unlikely since the combustibles are enclosed in the motor casing and tank. Because this is a controlled access area, transient loads are not considered. The total flooding CO2 system will extinguish the postulated fire and limit fire damage to this area. The redundant motor-driven auxiliary feedwater pump would not be damaged and would be available to safely shut down the reactor.

The design-basis fire is highly unlikely since most of the combustibles are enclosed in the motor casings or the tank.

This room is a controlled access area.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.99.

2.3.11.32 Unit 2 Auxiliary Feedwater Diesel-Driven Pump Room (Fire Zone 11.4A-2)

This zone is shown on Figure 2.3-13 (Sheet 2) and in elevation on Figure 2.3 25 (Sheet 2).

For details, see Subsection 2.3.11.31.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.100.

2.3.11.33 Radwaste and Remote Shutdown Panel Ventilation Control Room (Fire Zone 11.4B-0)

This zone is shown on Figure 2.3-13 (Sheet 2).

Fire Barrier Description The floor at elevation 383 feet 0 inch is an 18-inch-thick structural reinforced concrete slab supported by concrete beams and columns. It carries a 3-hour fire rating. It contains a 4-inch-diameter floor drain.

2.3-139

B/B - FPR AMENDMENT 29 DECEMBER 2020 All walls in this zone are 12-inch-thick solid concrete masonry units and carry a 3-hour fire rating. The walls extend up to within 1 inch of the beam above and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. Both doors into this zone are label "A" fire doors.

The ceiling at elevation 392 feet 4 inches is a 12-inch-thick structural reinforced concrete slab supported by concrete beams and columns and carries a 3-hour fire rating.

Mechanical and electrical penetrations through the walls, floor, and ceiling are provided with rated fire seals. Ventilation ductwork penetrations are equipped with electro-thermal or fusible link fire dampers which are activated by either the fire detection system or when the temperature exceeds 165 F.

Safety-Related Equipment There is no safety-related equipment within this room.

Protection Criteria and Measures This room is separated from other plant areas by a 3-hour rated fire barrier.

Combustible Materials Cable insulation, filters, flexible connections, gaskets, insulation, lube oil and polypropylene.

At Byron, acrylic, and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capability No fire detectors are provided. Portable extinguishers are provided in the general area. Two manual hose stations are within 50 feet of this room.

Design-Basis Fire Due to the low fire loading in this room and to the fact that no safety-related equipment is present, the design basis fire is of no consequence and would not affect the ability to safely shut down the plant.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Subsection 2.4.2.101.

2.3-140

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.34 Unit 1 Seal Water Heat Exchanger Room (Fire Zone 11.4B-1)

This zone is shown in Figure 2.3-13 (Sheet 1) and in elevation on Figures 2.3 22 (Sheet 2) and 2.3-36 (Sheet 1).

Fire Barrier Description The floor at elevation 383 feet 0 inch is a 24-inch-thick structural reinforced concrete slab. It contains a 4-inch-diameter floor drain.

All walls are minimum 24-inch-thick structural reinforced concrete or 36-inch-thick solid concrete masonry units. The masonry walls extend up to within 1 inch of the ceiling above and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. The walls, although of 3-hour rated construction, may contain nonrated doors or penetrations, or removable masonry areas, and do not carry a fire rating.

The ceiling at elevation 401 feet 0 inch is a 28-inch-thick structural reinforced concrete slab.

Safety-Related Equipment The seal water heat exchanger is safety related.

Combustible Materials Gaskets.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is available for use in this room. Portable fire extinguishers are available from the adjacent areas.

Design-Basis Fire The design-basis fire would not affect the safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.102.

2.3-141

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.35 Unit 2 Seal Water Heat Exchanger Room (Fire Zone 11.4B-2)

This zone is shown on Figure 2.3-13 (Sheet 2) and in elevation on Figure 2.3 26 (Sheet 2).

For details, see Subsection 2.3.11.34.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.103.

2.3.11.36 Radwaste and Remote Shutdown Control Room (Fire Zone 11.4C-0)

This zone is shown on Figure 2.3-13 (Sheet 2) and in elevation on Figure 2.3 25 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-37.

Fire Barrier Description The floor at elevation 383 feet 0 inch is an 18-inch-thick structural reinforced concrete slab supported by concrete beams and columns and carries a 3-hour fire rating.

The perimeter walls of this zone are 42-inch-thick structural reinforced concrete or minimum 12-inch-thick solid masonry units and carry a 3-hour fire rating.

Masonry walls extend up to within 1 inch of the ceiling above and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. Both doors into this zone are Label "A" fire doors. Twelve-inch-thick solid reinforced masonry unit walls (non-fire-rated) separate the shutdown control panels into rooms within the fire zone.

The ceiling at elevation 401 feet 0 inch is a minimum 30-inch-thick structural reinforced concrete slab supported by concrete beams and columns and carries a 3-hour fire rating.

The fire dampers installed in the horizontal ducts penetrating the fire walls are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

Safety-Related Equipment The following equipment in this room is safety-related:

a. Unit 1, remote shutdown control panel, Division 11, 1PL04J.

b. Unit 1, remote shutdown control panel, Division 12, 1PL05J.

c. Unit 2, remote shutdown control panel, Division 21, 2PL04J.

d. Unit 2, remote shutdown control panel, Division 22, 2PL05J.

2.3-142

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The room is physically separated from the rest of the plant by fire barriers.

Combustible Materials Cable insulation, fiber optic cable, gaskets, insulation, and plastic.

At Byron, acrylic, nylon, and office material.

At Braidwood, paper and wood.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is located within the zone. Portable fire extinguishers are also available. One manual hose station is situated just outside the room entrance. Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the room burned.

The Unit 1 and Unit 2 remote shutdown panels are located on opposite ends of the room, separated by approximately 90 feet and by 12-inch-thick solid reinforced masonry walls. The radwaste panels are between them. Should a fire initiate in any panel only one unit's panel could be affected.

The shutdown panels are further divided into Division 1 BOP, and Division 2 sections, separated by metal barriers. Therefore, a fire in a panel should only damage one section, leaving at least one ESF division of that panel intact and available for shutting down the reactor.

The Unit 2 panel is located 20 feet from any other panel. The Unit 1 panel is approximately 7 feet from the closest panel.

The design-basis fire is highly unlikely. The room is physically separated from the rest of the plant by 3-hour fire barriers. The major combustible in the zone is the cable insulation. These panels are constructed to contain a fire and minimize the fire's spread.

2.3-143

B/B - FPR AMENDMENT 29 DECEMBER 2020 Cable trays are separated both by division and by function as discussed in Appendix 5.2. All cable insulation is fire resistant.

Ionization (or photoelectric) detectors are located at various points in the room and would alert station personnel if a fire started.

No transient load is considered as this is a controlled access area.

In summary, the design-basis fire is unlikely for the following reasons:

a. The zone is a controlled access area.

b. This is a noncombustible storage area.

c. The panels are separated by considerable distances.

d. The panels are subdivided by ESF division and safety classification.

e. The room is usually occupied.

f. Fire detection is installed which annunciates in the control room.

g. Fire extinguishing equipment is readily available.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.104.

2.3.11.37 Letdown Heat Exchanger 1A Room (Fire Zone 11.4C-1)

This room is shown on Figure 2.3-13 (Sheet 1) and in elevation on Figure 2.3 22 (Sheet 2).

Fire Barrier Description The floor at elevation 383 feet 0 inch is a 24-inch-thick structural reinforced concrete slab. One 4-inch-diameter floor drain is provided in each room.

The perimeter walls of this zone are minimum 24-inch-thick structural reinforced concrete or 16-inch-thick solid concrete masonry units. A 24-inch-thick masonry wall also separates the two rooms within the zone. The masonry walls extend up to within 1 inch of the ceiling above and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. The walls, although of 3-hour rated construction, may contain nonrated doors or penetrations, or removable masonry areas, and do not carry a fire rating.

The ceiling of the Valve Aisle Area is a 24-inch-thick structural reinforced concrete slab. The ceiling of the Letdown Heat Exchanger Room, at elevation 401 feet 0 inch is a 28-inch-thick structural reinforced concrete slab.

2.3-144

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment Letdown Heat Exchanger 1A is in this room.

Protection Criteria and Measures The letdown heat exchanger is physically separated from other equipment on the floor by barrier of substantial construction.

Combustible Materials Gaskets.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is located within 30 feet of this room as well as portable fire extinguishers.

Design-Basis Fire The design-basis fire would not affect the safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.105.

2.3.11.38 Letdown Heat Exchanger 2A Room (Fire Zone 11.4C-2)

This zone is shown on Figure 2.3-13 (Sheet 2).

For details, see Subsection 2.3.11.39.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.108.

2.3-145

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.39 Letdown Heat Exchanger 1B Room (Fire Zone 11.4D-1)

This zone is shown on Figure 2.3-13 (Sheet 1) and in elevation on Figure 2.3 22 (Sheet 2).

Fire Barrier Description The floor at elevation 383 feet 0 inch is a 24-inch structural reinforced concrete slab. It contains a 4-inch-diameter floor drain.

All walls are minimum 24-inch-thick structural reinforced concrete or 16-inch-thick solid concrete masonry units. Masonry walls extend up to within 1 inch of the ceiling above and the remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. The walls, although of 3-hour rated construction, may contain nonrated doors or penetrations, or removable masonry areas, and do not carry a fire rating.

The ceiling at elevation 401 feet 0 inch is a 28-inch structural reinforced concrete slab.

For further details, see Subsection 2.3.11.37 The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.107.

2.3.11.40 Letdown Heat Exchanger 2B Room (Fire Zone 11.4D-2)

This zone is shown on Figure 2.3-13.

For details, see Subsection 2.3.11.39.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.108.

2.3-146

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.41 Auxiliary Building Elevation 401 feet 0 inch (Fire Zone 11.5-0)

This zone is shown on Figure 2.3-12 (Sheets 1 and 3) and in elevation on Figures 2.3-25 and 2.3-26. Electrical cable trays routed through this zone are shown on Figure 2.3-36.

Fire Barrier Description The floor at elevation 401 feet 0 inch is a 12-inch to 48-inch structural reinforced concrete slab supported by concrete beams and columns. The floor contains several openings for equipment removal, for an open stairway, and; therefore, carries no fire rating. Several 4-inch-diameter floor drains are provided.

The removable concrete slabs at column N-18 are caulked with sealant.

The perimeter walls of this zone are minimum 12-inch-thick hollow concrete masonry units or 30-inch-thick structural reinforced concrete. The wall common to this zone and the Turbine Building ground floor, the Fuel Handling Building, and the Diesel Generator Rooms carry a 3-hour fire rating. Fire doors in these walls are either Label 'A" doors or "doors of label A construction, with the exception of the double and single swing personnel fire doors in the L-line wall between columns 20 and 21 that separate this fire zone and the Turbine Building (Fire Zone 8.3-2). These two doors are non-labeled fire doors: steel plates have been bolted to the doors and horizontal stiffeners have been added to one leaf of the double swing door to reinforce the doors for HELB pressure loading. The frames of these doors are also reinforced, and the hinges are heavy duty outer hinges. Door pulls have been added to these fire doors to facilitate door operation. The addition of door pulls does not affect the self-closing or latching performance of the doors. Refer to Braidwood EC-EVAL393561 and Byron EC-EVAL 393650.

Three stairways and an elevator hoist way included in this zone are enclosed by 12-inch-thick hollow concrete masonry unit walls, which contain Label "B" fire doors and carry a 2-hour fire rating. The walls and door for the dumbwaiter in the primary sample room carry a 2-hour fire rating.

All masonry walls extend up to within 1 inch of the ceiling above, and the remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation.

2.3-147

B/B - FPR AMENDMENT 29 DECEMBER 2020 The ceiling slab at elevation 426 feet 0 inch is 36-inch-thick structural reinforced concrete or a 5-inch to 41-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. Between column-rows Q and L, the structural steel columns and the main beams (at column lines only) which support this ceiling slab and the control room complex at elevation 451 feet 0 inch above are protected by a fire-resistant covering to a rating of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The secondary steel beams and columns in the area between column-rows 10 and 23 are protected by a fire-resistant covering and carry a minimum 2-hour fire rating.

The ceiling slab contains a permanent equipment removal hatch at column-row Q/12 which is covered with removable concrete plugs that are caulked in place with sealant.

The portion of this ceiling between column-rows Q and V is supported by unprotected steel beams and columns and carries no fire rating. Except for the area beneath the Unit 1 and 2 volume control tank rooms and valve aisles at elevation 426 feet 0 inch, the steel beams in that area are protected with a fire-resistant covering and carry a minimum 2-hour fire rating. The portion of this ceiling between column-rows V and W is supported by protected steel beams and columns and carries a 3-hour rating.

Safety-Related Equipment The safety-related equipment in this zone consists of components of the Auxiliary Building Ventilation System. These are galvanized ductwork, dampers, and ductwork accessories.

The following additional safety-related equipment is also located in this zone:

a. Boron Thermal Regenerative Demineralizers 1A, 1B, 1C, 1D, 2A, 2B, 2C, and 2D

b. cation bed demineralizers

c. mixed bed demineralizers

d. recycle evaporator feed demineralizers

e. Boric Acid Tanks

f. boric acid transfer pumps

g. boric acid filters

h. control panel 231Y1

i. Hydrogen Recombiners

j. MCC-231X3 (Division 21)-2AP22E

k. cable and cable trays associated with ESF Divisions 11, 12, 21, and 22 are present.

2.3-148

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures This zone is separated from the remainder of the plant by either rated fire barriers or barriers of substantial construction. The large extent of this zone results in large distances between the safety-related equipment. All the demineralizers are contained within individual concrete structures, and all the tanks contain some amount of water. Note that the Hydrogen Recombiners are no longer required for combustible gas control systems and have been abandoned in place.

Combustible Materials Anti-C clothing, cable insulation, electric cords, electric motors, flammable gas, fiber optic cable, gaskets, grease, insulation, lube oil, miscellaneous and transient combustibles, nylon, office material, paper, plastic, polypropylene, and wood.

At Byron, acrylic, methane, and PVC.

At Braidwood, EPDM, lead shielding, plexiglass, polycarbonate, polyethylene, and SOOW.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Eight manual hose stations are in this zone. Portable fire extinguishers are available throughout the zone.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Automatic sprinklers are provided around the stairwell at P-18 per NRC request.

In addition, minimum 18-inch-deep draft stops are provided around the stairwell at P-18. Sprinklers are also provided over the waste oil tank.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone were ignited.

The only safety-related equipment which could be affected by a fire are the boric acid transfer pumps. Failure of both recombiners would be acceptable since it is only required for use after a LOCA, which is more than adequate time to repair or replace it. Loss of all three boric acid transfer pumps is acceptable since the safe shutdown analysis credits the borated water inventory in the RWST for providing the boration required to reach the cold shutdown condition.

2.3-149

B/B - FPR AMENDMENT 29 DECEMBER 2020 The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.109.

2.3.11.42 Unit 1 Containment Refrigeration Equipment Room (Fire Zone 11.5-1)

This zone is shown on Figure 2.3-12 (Sheet 1) and in elevation on Figure 2.3 26.

Electrical cable trays routed through this zone are shown on Figure 2.3-36.

Fire Barrier Description The floor at elevation 401 feet 0 inch is a minimum 25-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams which are protected by a fire-resistant covering and carry a minimum 2-hour fire rating. The slab itself carries no fire rating. Four 4-inch-diameter floor drains are provided in the Reactor Containment Chiller Pump Room 1. The perimeter walls of this zone are minimum 24-inch-thick structural reinforced concrete or solid concrete masonry units. All masonry walls extend up to within 1 inch of the ceiling above, and the remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling slab at elevation 414 feet 0 inch is a 5-inch to 33-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. This slab contains a large opening for equipment removal, is supported by steel beams and columns, which are protected by a fire-resistant covering and carry a minimum 2-hour fire rating. The slab itself carries no fire rating.

Safety-Related Equipment The safety-related equipment located in this zone are portions of the Auxiliary Building Ventilation System.

Protection Criteria and Measures This zone is physically isolated from the rest of the plant by concrete barriers or distance.

2.3-150

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, fiber optic cable, gaskets, grease, lube oil, miscellaneous and transient combustibles, and plastic.

At Byron, acrylic, aerosol cans, buffing pads, buckeye blue, ear plugs, geyser pump, nylon, polypropylene and vinegar.

At Braidwood, polycarbonate.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Portable fire extinguishers are available in this room and adjacent zone. Two manual hose stations are positioned within reach of the room.

Ionization (or photoelectric) detectors are provided, which annunciate and alarm in the Control Room.

Design-Basis Fire If a fire should occur in this room, the ventilation system may be damaged. The loss of the room would not prevent a safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.110.

2.3.11.43 Unit 2 Containment Chillers Room (Fire Zone 11.5-2)

This zone is shown on Figure 2.3-12 (Sheet 3) and in elevation on Figures 2.3 21 (Sheet 2) and 2.3-26 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-36.

For details, see Subsection 2.3.11.42 except that:

a. Two 4-inch-diameter drains are provided in the HVAC filter room and four in the reactor containment chiller pump room 2.

b. HEPA filters and prefilter modules contribute to combustible materials.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.111.

2.3-151

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.44 Radiological Instrument Calibration Room (Fire Zone 11.5A-0)

This zone is shown on Figure 2.3-12 (Sheet 1).

Fire Barrier Description The floor at elevation 401 feet 0 inch is a 33-inch clear cover of structural reinforced concrete over a 3-inch fluted steel decking formwork. It is supported by steel beams which are protected by a fire-resistant covering and carry a minimum 2-hour fire rating. Two 4-inch-diameter floor drains are provided in this area.

The walls common to this zone and to the containment chiller pump room are 2 feet 11-5/8-inch-thick solid concrete masonry which contain nonrated penetrations. Masonry walls extend up to within 1 inch of the structural slab above and the remaining space is packed with a 1-inch-thick blanket of the Thermafiber insulation. The wall common to this zone and to the auxiliary building along column row "Q" is 36-inch-thick structural reinforced concrete and contains a nonrated metal personnel door.

The ceiling slab at elevation 414 feet 0 inch is a 33-inch clear cover of structural reinforced concrete over a 3-inch fluted steel decking formwork. This slab contains two floor openings (1 foot) 3 inches x 1 foot 3 inches and 1 foot 11 inches x 2 feet 5 inches) and is supported by steel beams and columns which are protected with a fire-resistant covering and carry a minimum 2-hour fire rating.

The slab itself carries no fire rating.

Safety-Related Equipment Safety-related cables run in conduit are routed through this zone. No safety-related equipment is in this room.

Protection Criteria and Measures This room is separated from other plant areas by barriers of substantial construction.

Combustible Materials Cable insulation, cotton, gaskets, lube oil, plastic, rope, and rubber.

At Braidwood, polycarbonate, polypropylene and polyester.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-152

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capability Ionization (or photoelectric) detectors are provided which annunciate and alarm in the control room.

Two manual hose stations are within 50 feet of this room. Portable extinguishers are available.

Design-Basis Fire The design-basis fire would not affect the safe shutdown of the reactor.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Section 2.4.2.112.

2.3.11.45 Division 11 Cable Penetration Area (Fire Zone 11.5A-1)

This zone is shown on Figure 2.3-11.

Fire Barrier Description The floor at elevation 414 feet 0 inch, which is the ceiling of the Reactor Containment Chiller Pump Room, is a 5-inch to 33-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It contains a non-rated penetration, and a large opening for equipment removal. The floor is supported by steel beams and columns which are protected with a fire-resistant covering and carry a minimum 2-hour fire rating. Due to the opening for equipment removal and non-rated penetration, the floor carries no fire rating. Six 4-inch-diameter floor drains are provided. The perimeter walls of this zone are minimum 24-inch-thick structural reinforced concrete. Walls which are common to the diesel generator rooms, diesel fuel oil storage tank rooms, pipe tunnels, and safety valve rooms carry a 3-hour fire rating. A stairway up to elevation 426 feet 0 inch is included in this zone and is enclosed by 12-inch-thick hollow concrete masonry unit walls which carry a 2-hour fire rating. A door of Label "A" construction leads to this stairway.

The ceiling at elevation 426 feet 0 inch is a 5-inch to 15-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork. It is supported by steel beams and columns which are protected to a minimum 2-hour rating with a fire-resistant covering. Ceiling penetrations, except for the equipment hatch at column-row 13-15/U-V, are provided with 3-hour rated fire seals. The equipment hatch is covered by a non-rated hatch cover. Due to the non-rated hatch cover, the ceiling carries no fire rating.

2.3-153

B/B - FPR AMENDMENT 29 DECEMBER 2020 The equipment hatch at column and row 13-15/U-V is covered with removable steel plates, which are caulked into place with sealant.

Fire Zone 11.5A-1 extends below floor elevation 414 feet 0 inch between column rows Q and S and between column rows 7 to 10 and 26 to 29 and continues down to floor elevation 377 feet 0 inch. Access to this portion of the zone is by ladder at elevation 414 feet 0 inch. All walls surrounding this area are minimum 24-inch-thick structural reinforced concrete. Walls which are common to the diesel generator rooms, diesel fuel oil storage tank rooms, pipe tunnels, and safety valve rooms carry a 3-hour fire rating. The floor at elevation 377 feet 0 inch is a 36-inch-thick reinforced concrete slab.

Safety-Related Equipment The safety-related equipment in this zone is:

a. portions of the Auxiliary Building Ventilation System,

b. Motor Control Centers-131X2 and 131X4 (ESF Division 11), and

c. cable and cable raceways associated with ESF Division 11 and Division 12.

d. UPS and battery for 1D SG PORV power supply (ESF Division 11).

e. UPS and battery for 2D SG PORV power supply (ESF Division 21).

Protection Criteria and Measures Only Division 11 components are in this fire zone.

Combustible Materials Cable insulation, gaskets, insulation, polyethylene, and Styrofoam, and vinyl.

At Byron, fiber optic cable and polycarbonate.

At Braidwood, acrylic, battery cells and plexiglass.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Two manual hose stations are in this zone. Portable fire extinguishers are also available. Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.113 2.3-154

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.46 Division 21 Cable Penetration Area (Fire Zone 11.5A-2)

This zone is shown on Figure 2.3-11.

For details, see Subsection 2.3.11.45 except that:

a. Division 21 is in this zone.

b. At Braidwood, from the 414 foot 0 inch elevation to the 426 foot 0 inch elevation a three-hour fire wrap is used to protect power and control cables associated with the Division 22 SX strainer and backwash valve such that the function of the Division 22 SX pump, strainer, and backwash valve may be credited if Division 21 is unavailable.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.114.

2.3.11.47 Division 12 Cable Riser Area (Fire Zone 11.5B-1)

This zone is shown on Figure 2.3-11.

Fire Barrier Description The floor at elevation 414 feet 0 inch is a 5-inch to 25-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams and columns, which are protected by a fire-resistant covering and carry a minimum 2-hour fire rating. One 4-inch-diameter floor drain is provided. The walls between this zone and the containment area are 42-inch-thick structural reinforced concrete. There is a Label "A" door in the east wall.

The other two perimeter walls of this zone are 12-inch-thick concrete block masonry, which carry a 3-hour fire rating.

The ceiling at elevation 426 feet 0 inch is a 5-inch to 15-inch clear cover of structural reinforced concrete on a 3-inch fluted steel decking formwork.

It is supported by steel beams and columns, which are protected with a fire-resistant covering and carry a minimum 3-hour fire rating. The ceiling itself carries a 3-hour fire rating.

Safety-Related Equipment The safety-related equipment in this zone consists of cables and cable raceways associated with ESF Division 11 and Division 12.

Protection Criteria and Measures This room is separated from other plant areas by barriers of substantial construction.

2.3-155

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A portable extinguisher is provided in this zone. A manual hose station is also available nearby.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.115.

2.3.11.48 Division 22 Cable Riser Area (Fire Zone 11.5B-2)

This zone is shown on Figure 2.3-11.

For details, see Subsection 2.3.11.47, except that:

a. Division 22 cables and cable trays are in this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.116.

2.3-156

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.49 Auxiliary Building Elevation 426 feet 0 inch (Fire Zone 11.6-0)

This zone is shown on Figure 2.3-10 (Sheets 1 and 3) and in elevation on Figures 2.3-22 (Sheet 2), 2.3-25, and 2.3-26. Electrical cable trays routed through this zone are shown on Figure 2.3-35.

Fire Barrier Description The floor slab at elevation 426 feet 0 inch is 36-inch-thick structural reinforced concrete or a 5-inch to 33-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It contains openings for equipment removal and two open stairways. Between column-rows Q and L, the structural steel column and main beams (at column lines only) which support this floor slab and the control room complex above are protected by a fire-resistant covering to a 3-hour fire rating. The secondary beams and columns in this area are protected by a fire-resistant covering which carries a minimum 2-hour fire rating, except for those between column-rows 23 and 26 which are not fire-rated. Four-inch-diameter floor drains are provided. The perimeter walls of this zone are minimum 12-inch-thick solid concrete masonry units or minimum 27-inch (Byron) or 30-inch (Braidwood)-thick structural reinforced concrete. The walls common to this zone and to the ESF switchgear rooms carry a 3-hour fire rating. The wall common to this zone and the Fuel Handling Building is of 3-hour rated construction and contains two pairs of equipment access doors that are of Label "A" construction.

At Braidwood, the walls common to the Division 12 cable penetration area are of 3-hour fire-rated construction but contain one or more nonrated penetrations.

Therefore, these walls at Braidwood do not carry a fire rating.

An elevator hoist way included in this zone is enclosed by 12-inch-thick hollow concrete masonry unit walls, which contain Label "B" fire doors and carry a 2-hour fire rating.

The floor slab also contains a permanent equipment removal hatch near column-rows Q/12, which is covered with removable concrete plugs that are caulked into place with sealant.

The masonry walls in this zone extend to within 1 inch of the ceiling above, and this resulting space is packed with a 1-inch-thick blanket of Thermafiber insulation.

2.3-157

B/B - FPR AMENDMENT 29 DECEMBER 2020 The ceiling slab at elevation 439 feet 0 inch between column rows Q and L is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, except for one 33-inch slab (Byron only). It is supported by steel beams and columns, protected by a fire-resistant covering, and carries a 3-hour rating. At elevation 451 feet 0 inch and between column-rows Q and V the ceiling is a minimum 9-inch cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and columns and carries no fire rating. The main steel and header beams, which support the control facilities above are protected with a 3-hour rated covering.

Safety-Related Equipment The following safety-related equipment is in this zone:

a. portions of the Auxiliary Building Ventilation System

b. Motor Control Centers 131X5 (Div. 11), 231X5 (Div. 21), 132X5 (Div. 12),

and 232X5 (Div. 22)

c. component cooling surge tanks

d. cable and cable trays associated with ESF Divisions 11, 12, 21, and 22 are present.

e. UPS and battery for 1C (Div. 12) and 2C (Div. 22) SG PORV power supplies.

Protection Criteria and Measures Most of the zone is broken into sectors by concrete walls and the equipment separated by these walls and distance. Five manual hose stations and portable fire extinguishers are located within this zone.

Combustible Materials Acrylic, cable insulation, fiber optic cable, gaskets, insulation, lube oil, methane, miscellaneous and transient combustibles, nylon, plastic, polycarbonate, polyethylene, polypropylene, Styrofoam, and vinyl At Byron, office material.

At Braidwood, anti-c sets, battery cells, paints, plexiglass, and solvents.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-158

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities Four manual hose stations are located within this zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Automatic sprinklers are provided around the stairwell at P-18 per NRC request.

In addition, minimum 18-inch-deep draft stops are provided around this stairwell at P-18.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned. The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.117.

2.3.11.50 Division 12 Cable Penetration Area (Fire Zone 11.6-1)

This zone is shown on Figure 2.3-10 (Sheet 1) and in elevation on Figure 2.3 26 (Sheet 1).

Electrical cable trays routed through this zone are shown on Figure 2.3-35.

Fire Barrier Description The floor at elevation 426 feet 0 inch, which is the ceiling of the Cable Penetration Area, Division 11, is a 5-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork. It is supported by steel beams and columns protected to a 2-hour rating by a fire-resistant covering. The equipment hatch located at column-row 13-15/U-V is covered by a non-rated steel plate hatch cover which is caulked into place with sealant. All other floor penetrations are sealed by 3-hour rated fire seals. Because of the non-rated hatch cover, this floor carries no fire rating. Five 4-inch-diameter floor drains are provided.

2.3-159

B/B - FPR AMENDMENT 29 DECEMBER 2020 The perimeter walls of this zone are minimum 36-inch-thick solid concrete masonry units or 24-inch-thick structural reinforced concrete. These walls carry a 3-hour fire rating except for the walls common to this zone and to the Auxiliary Building Mezzanine Floor which are of 3-hour rated construction but contain one or more non-rated penetrations and thus do not carry a fire rating. At Braidwood, the west wall at column rows Q and 12-13, approximately at elevation 436 feet 0 inch, contains a non-rated fire seal (E0351073), which is constructed of Thermo-Lag 330-1 material and is abandoned in place. A stairway is provided in this zone which is enclosed in a 2-hour rated masonry barrier from elevation 426 feet 0 inch down to elevation 414 feet 0 inch, and which is open to elevation 439 feet 0 inch. Masonry walls extend up to within 1 inch of the ceiling and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. Label "A" fire doors are provided for access to the Fuel Handling Building. The ceiling at elevation 451 feet 0 inch is a minimum 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, which is supported by unprotected steel beams and columns, and does not carry a fire rating.

Safety-Related Equipment MCC 132X2 (ESF Div. 12), MCC 132X4 (ESF Div. 12), and ESF Division 12 cables are present in this zone.

Protection Criteria and Measures This zone is separated from the other ESF division by a 2-hour rated fire barrier.

Combustible Materials Cable insulation, gaskets, insulation, miscellaneous and transient combustibles, wood shelving At Byron, plastic At Braidwood, plexiglass and polycarbonate Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Two manual hose stations are in this zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

2.3-160

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The loss of ESF Division 12 is acceptable, as sufficient redundancy exists in the other division to safely shut down the reactor.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.118.

2.3.11.51 Division 22 Cable Penetration Area (Fire Zone 11.6-2)

This zone is shown on Figure 2.3-10 (Sheet 3) and in elevation on Figures 2.3 21 (Sheet 2) and 2.3-22 (Sheet 2). Electrical cable trays routed through this zone are shown on Figure 2.3-35.

For details, see Subsection 2.3.11.50, except that:

a. Division 22 cables and panels are present

b. There are two hose stations in this zone.

c. Nylon strips, electrical cords, and rubber hoses contribute to combustible material.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.119.

2.3.11.52 Laboratory/HVAC Equipment Room (Fire Zone 11.6A-0)

This zone is shown on Figure 2.3-10 (Sheet 1) and in elevation on Figure 2.3 25 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-35.

Fire Barrier Description The floor at elevation 426 feet 0 inch is a 5-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork. The structural steel columns and the main beams (at column lines only) which support this floor and the control room complex at elevation 451 feet 0 inch are protected with a fire-resistant coating to a rating of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The intermediate supporting beams for this floor are protected with a fire-resistant covering and carry a minimum 2-hour fire rating. The floor itself carries no fire rating. Three 4-inch-diameter floor drains are provided.

2.3-161

B/B - FPR AMENDMENT 29 DECEMBER 2020 The perimeter walls are minimum 30-inch-thick structural reinforced concrete or minimum 12-inch-thick hollow or solid concrete masonry units. The walls common to this zone and to the Turbine Building Mezzanine Floor and the Division 11 ESF Switchgear Room carry a 3-hour fire rating. Walls common to this zone and to the enclosed stairway at column row L-12 carry a 2-hour fire rating. The other perimeter walls contain non-rated doors or penetrations and do not carry a fire rating. Masonry walls extend up to within 1 inch of the ceiling above, and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling at elevation 439 feet 0 inch, which is the floor of a Lower Cable Spreading Room, is a 5-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork, is supported by steel beams protected with a fire-resistant covering, and carries a 3-hour fire rating.

Safety-Related Equipment For Byron, cables and cable trays associated with ESF Divisions 11 are present; for Braidwood, cables and cable trays associated with ESF Divisions 11 and 12 are present.

Protection Criteria and Measures This room is separated from the remainder of the plant by barriers of substantial construction.

Combustible Materials Cable insulation, lube oil, flexible connections, HEPA filters, gaskets, prefilters, and silencing mat.

At Byron, acrylic, nylon, plastic, and polypropylene.

At Braidwood, polycarbonate.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguisher and Detecting Capabilities One manual hose station is available for use in this zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

2.3-162

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The equipment located in this zone is not required for safe shutdown of the plant.

In the event of a fire, the galvanized ductwork, ductwork accessories, dampers, and other HVAC non-safety-related equipment may be damaged. The radioactive substances generated when HEPA filters burn will be exhausted to the atmosphere through the main stacks. There are no provisions for holdup of the exhaust air; however, radiation monitors in the exhaust duct are provided, and the Auxiliary Building Ventilation System may be secured.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.120.

2.3.11.53 Unit 1 Volume Control Tank Room (Fire Zone 11.6A-1)

This fire zone is shown on Figure 2.3-13 (Sheet 1). An elevation view is shown on Figure 2.3-26 (Sheet 1).

Fire Barrier Description The floor slab at elevation 426 feet 0 inch is a 29-inch to 57-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams and columns, which are protected by a fire-resistant covering and carry a minimum 2-hour fire rating. One 4-inch-diameter floor drain is provided along with a 3 feet 3 inches by 4 feet 6 inches framed opening in the slab.

The perimeter walls of this zone are minimum 32-inch- to 56-inch-thick high-density concrete masonry unit walls or 56-inch-thick structural reinforced concrete. Also, a 56-inch-thick removable concrete block wall is provided. These walls are of a 3-hour rated construction but contain one or more non-rated penetrations and thus do not carry a fire rating. Columns on row "Q" at rows 15, 17, 19, and 21 are protected by a fire-resistant covering to a 3-hour fire rating up to elevation 439 feet 0 inch. Except for the masonry walls supporting the labyrinth roofs, all masonry walls extend to within 1 inch of the ceiling above, and this resulting space is packed with a 1-inch blanket of Thermafiber insulation.

The labyrinth roofs at elevation 438 feet 6 inches and 442 feet 0 inch are a 27-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. At elevation 451 feet 0 inch the ceiling for the volume control tank room is a 60-inch cover of structural reinforced concrete over 3-inch fluted decking formwork. It is supported by steel beams and columns which are protected by a fire-resistant covering and carry a minimum 2-hour fire rating.

2.3-163

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The volume control tank with associated piping and valves is safety-related and located in this zone.

Protection Criteria and Measures This fire zone is separated from other areas by thick shielding walls.

Combustible Materials Gaskets.

At Byron, nylon, plastic, and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capability There are three portable extinguishers and two hose stations located nearby.

Design-Basis Fire The design-basis fire for this zone is negligible. The ability to safely shut down the plant would not be affected by a fire in this zone.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Subsection 2.4.2.121.

2.3.11.54 Unit 2 Volume Control Tank Room (Fire Zone 11.6A-2)

This zone is shown on Figure 2.3-13 (Sheet 3) and in elevation on Figure 2.3-26 (Sheet 2)

For details, see Subsection 2.3.11.53.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.122.

2.3-164

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.55 Auxiliary Building Offices - Elevation 426 feet 0 inch (Fire Zone 11.6B-0)

This zone is shown on Figure 2.3-10 (Sheets 1 and 3) and in elevation on Figures 2.3-22 (Sheet 2) and 2.3-25 (Sheet 1) Electrical cable trays routed through this zone are shown on Figure 2.3-35.

Fire Barrier Description The floor at elevation 426 feet 0 inch is a 5-inch to 27-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. The steel beams and columns which support this floor, are protected with a fire-resistant covering to a 3-hour fire rating. The secondary beams and columns in this area are protected by a fire-resistant covering, which carries a minimum 2-hour fire rating. The floor itself carries no fire rating. Four-inch-diameter floor drains are provided.

This zone includes the following rooms which are separated from each other by minimum 12-inch-thick hollow and solid concrete masonry walls: High Level Laboratory, Counting Room, Radiation Supervisor's Office, Supply Room, Supervisor's Office, and Hot Instrument Room. At Braidwood, the Radiation Supervisor's Office, Supply Room, and Supervisor's Office are used as Chemistry Offices. Most of these rooms have vinyl asbestos tile applied to the floor (4200 ft2) suspended acoustical ceiling (1500 ft), and 4-inch vinyl cove base (300 ft2) is provided at wall base. The masonry walls in this zone extend to within 1 inch of the ceiling slab above. This resultant space is packed with a 1-inch-thick blanket of Thermafiber insulation. The walls surrounding the dumbwaiter carry a 2-hour fire rating. In addition, this zone has a minimum 36-inch thick structural reinforced concrete wall common to this zone and to the Turbine Building. Label A fire doors are provided in the Turbine Building wall. Walls common to this zone and to the enclosed stairway at column row L-23 carry a 2-hour fire rating, and a Label B fire door is also provided for this enclosed stairway.

The ceiling slab at elevation 439 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams and columns, which are protected by a fire-resistant covering and carries a 3-hour fire rating. At Byron, a portion of the structural steel supporting the common floor area between Fire Zones 3.2C-1, 3.2C-2, and 11.6B-0 is not fully protected with fireproofing material. A fire hazards analysis was performed from which it was determined that the level of fire protection is commensurate with the fire hazard. This configuration is acceptable and does not adversely affect safe shutdown in the event of a fire.

2.3-165

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment The safety-related equipment in this zone consists of cables and cable trays associated with ESF Divisions 11 and 21.

Protection Criteria and Measures This zone consists of rooms, which are separated from each other by minimum 12-inch-thick hollow and solid concrete masonry walls.

Combustible Materials Cable insulation, compressed gas cylinders, gaskets, insulation, lube oil, miscellaneous and transient combustibles., paper, and plastic.

At Byron, acrylic, aerosol cans, RPMS, garbage bags, buffing pads.

At Braidwood, polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual hose station is located within this zone. Portable fire extinguishers are available nearby.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned. The ability to safely shut down the plant would not be affected by a fire in this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.123.

2.3-166

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.56 Auxiliary Building Laundry Room - Elevation 426 feet 0 inch (Fire Zone 11.6C-0)

This zone is shown on Figure 2.3-10 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-35 (Sheet 1).

Fire Barrier Description The floor slab at elevation 426 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. The steel beams and columns which support the slab are protected by a fire-resistant covering to a 3-hour fire rating. The secondary beams and columns in this area are protected by a fire-resistant covering which carries a minimum 2-hour fire rating. The floor itself carries no fire rating. Two 4-inch-diameter floor drains are provided.

Two of the boundary walls in this zone are 16-inch-thick solid concrete block walls and are not rated. The 36-inch-thick structural reinforced concrete walls along column 10 are 3-hour fire-rated.

The ceiling slab at elevation 439 feet 0 inch is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. The slab is supported by steel beams and columns which are protected with a fire- resistant coating and carry a 3-hour fire rating. A portion of a structural beam enclosed in the block wall pipe chase is not coated.

Safety-Related Equipment The safety-related equipment in this zone consists of cables and cable raceways associated with ESF Division 11 and Division 12.

Protection Criteria and Measures This zone is separated from the adjacent ESF Division 11 switchgear room by a 3-hour fire-rated wall and from the remainder of the plant by barriers of substantial construction.

Combustible Materials Cable insulation, gaskets, insulation, and miscellaneous and transient combustibles.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-167

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities Ionization (or photoelectric) detection is provided which annunciates and alarms in the control room. A manual hose station is located within 10 feet of this zone.

Portable fire extinguishers are also available.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned. The ability to safely shut down the plant would not be affected by a fire in this zone.

The analysis of the effect of a fire in this zone on cables and equipment required for safe shutdown is discussed in Subsection 2.4.2.124.

2.3.11.57 Auxiliary Building Hot Showers, Decontamination (Byron only), Mask Cleaning and Issuance Room (Braidwood) and Change Areas (Byron/Braidwood) - Elevation 426 feet 0 inch (Fire Zone 11.6D-0)

This zone is shown on Figure 2.3-10 (Sheet 1). Electrical cable trays routed through this zone are shown on Figure 2.3-35 (Sheet 1)

Fire Barrier Description The floor at elevation 426 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork.

The steel beams and columns which support this floor are unprotected and carry no fire rating. Two 4-inch floor drains are provided.

The solid concrete masonry wall between this zone and the adjacent Fire Zone 12.1-0 is 3-hour rated. The other two solid concrete block walls and the combined concrete/concrete block wall have no fire rating. There is a Label "A" door in the west wall.

The ceiling at elevation 439 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by steel beams, which are unprotected and carry no fire rating.

Safety-Related Equipment The safety-related equipment in this zone consists of cables and cable trays associated with ESF Division 11.

2.3-168

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures This zone is separated from the adjacent Fire Zone 12.1-0 by a 3-hour fire-rated wall and from the remainder of the plant by barriers of substantial construction.

Combustible Materials Cable insulation, clothing, gaskets, insulation, miscellaneous and transient combustibles, and plastic.

At Braidwood, polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual hose station is located within 10 feet of this zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the control room.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned. The ability to safely shut down the plant would not be affected by a fire in this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.125.

2.3.11.58 Byron Auxiliary Building Decontamination Pad and Storage, Braidwood Auxiliary Building Tool Room - Elevation 426 feet 0 inch (Fire Zone 11.6E-0)

This zone is shown on Figure 2.3-10 (Sheet 3). Electrical cable trays routed through this zone are shown on Figure 2.3-35 (Sheet 3).

Fire Barrier Description The floor at elevation 426 feet 0 inch is a 5-inch-thick clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. The steel beams and columns which support the slab are unprotected and do not carry a fire rating. Two 4-inch-diameter floor drains are provided.

2.3-169

B/B - FPR AMENDMENT 29 DECEMBER 2020 Three of the four perimeter walls in this zone are 12-inch-thick solid concrete block masonry walls. The wall along column row V is 3-hour fire rated. The other 2 walls are not rated. The fourth wall is an 18-inch-thick structural reinforced concrete wall.

The ceiling slab at elevation 439 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over a 3-inch steel fluted decking formwork.

The steel beams and columns which support the slab, are unprotected and carry no fire rating.

Safety-Related Equipment The safety-related equipment in this zone consists of cables and cable trays associated with ESF Division 21.

Protection Criteria and Measures This zone is separated from the adjacent Fire Zones 12.1-0 and 11.6-2 by 3-hour fire-rated walls and from the remainder of the plant by barriers of substantial construction.

Combustible Materials Cable insulation, clothing, gaskets, lube oil, insulation, miscellaneous and transient combustibles, and plastic.

At Braidwood, nylon, polypropylene, and rubber.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual hose station is located within 25 feet of this zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the control room.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned. The ability to safely shut down the plant would not be affected by a fire in this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.126.

2.3-170

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.59 Auxiliary Building Elevations 451 feet 0 inch, 459 feet 0 inch, 463 feet 0 inch, 467 feet 4 inches, and 475 feet 6 inches (Fire Zone 11.7-0)

This zone is shown on Figures 2.3-8 (Sheets 1 and 3), 2.3-4, 2.3-5, and 2.3-6.

Elevation views are shown on Figures 2.3-21, 2.3-22 (Sheet 2), and 2.3-26.

Fire Barrier Description The floor slab at elevation 451 feet 0 inch is a 5-inch to 57-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and columns except for the area bounded by column rows V and W and 15 and 21 which is supported by steel beams which are protected by a fire-resistant covering and carries a 3-hour fire rating.

The remainder of the slab contains several penetrations and carries no fire rating. Several 4-inch-diameter floor drains are provided. The perimeter walls are minimum 12-inch-thick hollow concrete masonry unit walls or minimum 24-inch-thick structural reinforced concrete walls. Perimeter walls common to this zone and to the computer rooms, enclosed stairway, Upper Cable Spreading Area, the control panels at elevation 467 feet 4 inches, and the Fuel Handling Building carry a 3-hour fire rating. At Byron, a portion of the 3-hour firewall located in the Unit 2 Control Panel Room does not meet the 3-hour fire rating. The 3-hour firewall has a hollow block chipped away on the bottom 1/2 inch and is hollow on the inside (not filled in with grout). There is a 4-inch floor drain located partially under the 3-hour firewall. Generic Letter (GL) 86-10 Evaluation of EC 369384, Evaluate 3 Hr. Fire Wall with Partial Floor Drain, concluded that the existing configuration does not adversely affect the ability to achieve and maintain safe shutdown in the event of a fire. At Braidwood, the walls separating the control panel rooms from other portions of the fire zone contain unprotected structural steel. Other perimeter walls contain non-rated doors or openings and carry no fire rating. The ceilings at elevation 477 feet 0 inch and elevation 485 feet 0 inch, which are a part of the Auxiliary Building roof, are an 11-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, are supported by unprotected steel beams and columns and carries a 3-hour fire rating from external exposure fires.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 This zone is subdivided into several interior ventilation "levels" by concrete floors at elevation 459 feet 2 inches, elevation 463 feet 0 inch, elevation 467 feet 4 inches, and elevation 475 feet 6 inches. The area above the Upper Cable Spreading area, which includes the Auxiliary Building tank vent filter unit floor, the Exhaust Tunnels, and the Elevator Machine Room, is included in this zone.

These levels are open to one another by grating covered floor openings or open stairways and carry no fire rating. These levels are further subdivided into plenums by metal walls or hollow concrete masonry unit walls. These walls carry no fire rating except for the enclosure walls of the elevator machine room and the auxiliary building dumbwaiter, which carry a 2-hour fire rating. At Braidwood, the walls of the auxiliary building dumbwaiter contain unprotected structural steel.

Safety-Related Equipment The safety-related equipment located in this zone consists of components of the auxiliary building HVAC system. These are galvanized ductwork filters and fans.

Combustible Materials Cable insulation, charcoal, gaskets, grease, HEPA filters, lube oil, insulation, miscellaneous and transient combustibles, and prefilters.

At Byron, acrylic and polypropylene.

At Braidwood, polycarbonate.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual water spray system is provided for the charcoal filters. A temperature switch mounted in the absorber bank will annunciate in the Control Room. An operator can actuate the deluge valves locally in the event of high temperature or fire, which will annunciate in the control room.

Five manual hose stations are provided in this zone. Portable fire extinguishers are also available.

Ionization (or photoelectric) detection is provided which annunciates and alarms in the Control Room (except on elevation 475 feet 0 inch).

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire for this area is postulated to be the burning of all the prefilters, HEPA filters, charcoal filters and lube oil in this area.

The design-basis fire is highly unlikely for the following reasons:

a. The filter areas are controlled access areas.

b. The filter plenums are enclosed in the 1/4-inch steel plate housings, which will inhibit the spread of fire.

c. Temperature sensors are located downstream of each charcoal filter and on high temperature (below the ignition point of charcoal) will annunciate and alarm in the main Control Room. Water spray systems are provided for each charcoal filter.

d. Manual hose stations and portable fire extinguishers are provided on each level.

In the event of a fire, the charcoal filter temperature sensors would alarm in the Control Room and the plant fire brigade would be dispatched to the area.

In the event a fire did start, the Auxiliary Building Ventilation System might be rendered inoperable. The loss of the entire Auxiliary Building Ventilation System would not prevent the safe shutdown of the reactor. No fire dampers are provided; therefore, the spread of fire, heat, and products of combustion will be exhausted through HEPA filters via the Auxiliary Building Ventilation System.

Radiation monitors are in the exhaust stack, which alarm in the Control Room if high radiation is present in the Auxiliary Building exhaust air. The Control Room operator can manually shut down the ventilation system to limit the exhaust of radioactive products.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsections 2.4.2.127.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.11.60 Auxiliary Building, Unit 1 Purge Room, Elevations 451 feet 0 inch and 467 feet 0 inch (Fire Zone 11.7-1)

This zone is shown on Figures 2.3-8 (Sheet 1) and 2.3-5 and in elevation on Figure 2.3-26 (Sheet 1).

Fire Barrier Description The floor slab at elevation 451 feet 0 inch is a 5-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by unprotected steel beams and columns, and with the exception of the 3-hour rated floor west of column row "V," carries no fire rating. Seven 4-inch-diameter floor drains are provided. The perimeter walls are minimum 12-inch-thick hollow concrete masonry unit walls or minimum 24-inch-thick structural reinforced concrete walls. Perimeter walls common to this zone and to the Auxiliary Building main floor carry a 3-hour fire rating. Other perimeter walls contain non-rated doors or openings and carry no fire rating.

The ceiling at elevation 477 feet 0 inch is part of the auxiliary building roof, is an 11-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by unprotected steel beams and columns, and carries a 3-hour fire rating from external exposure fires.

This zone is subdivided into several levels by grating or concrete slab floors at elevation 459 feet 0 inch and elevation 467 feet 0 inch. These levels are open to one another or connected by open stairways and grating covered floor openings and carry no fire rating.

Safety-Related Equipment The containment isolation valves are safety related.

Protection Criteria and Measures All combustibles in this zone are separated from each other. Most of the combustibles are contained in separate portions of the ductwork and are isolated from the zone's environment. It is therefore exceedingly difficult for a fire to spread, if one starts.

Combustible Materials Charcoal, gaskets, HEPA filters, lube oil, and prefilters.

At Byron, acrylic, nylon, plastic and polypropylene.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual water spray system is provided for the charcoal filter units. A temperature switch mounted in the charcoal absorber bank will annunciate in the Control Room. An operator can actuate the deluge valve locally in the fire water supply line to the charcoal bank in the event of high temperature, which will annunciate in the control room.

One manual hose station is provided near the filter plenums. Portable fire extinguishers are also available.

Ionization (or photoelectric) detectors are provided on elevation 467 feet 0 inch which annunciate and alarm in the Control Room.

Design-Basis Fire The design basis fire for this area is postulated to be the burning of all the prefilters, HEPA filters, charcoal filters, and lube oil in this area.

Radiation monitors and samplers are present in the plant vent stacks and will aid in detection.

The design-basis fire is highly unlikely for the following reasons:

a. The filter areas are controlled access areas.

b. The filter plenums are enclosed in the 1/4-inch steel plate housings, which will retard the spread of fire.

c. Temperature sensors are located downstream of each charcoal filter and on high temperature (below the ignition point of charcoal) will annunciate in the control room. Manual water spray systems are provided for each charcoal filter.

d. Manual hose stations are additionally provided near each filter plenum as well as fire extinguishers.

In the unlikely event a fire did start, and the charcoal water spray system or fire brigade failed to extinguish the fire, the containment purge systems would be rendered inoperable. The loss of the Containment Purge System would not prevent the safe shutdown of the reactor. The radioactive substances generated when the charcoal filters, HEPA filters, and prefilters burn will be exhausted to the atmosphere through the plant vent stacks. The securing of the fans will mitigate this problem.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 In the event of a fire, the charcoal filter temperature sensors would alarm in the control room and the plant fire brigade would be dispatched to the area to extinguish the fire before it spread.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.128.

2.3.11.61 Auxiliary Building Unit 2 Purge Room, Elevations 451 feet 0 inch and 467 feet 0 inch (Fire Zone 11.7-2)

This zone is shown on Figures 2.3-8 (Sheet 3) and 2.3-5 and in elevation on Figure 2.3-26 (Sheet 2).

For details see Subsection 2.3.11.60.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.129.

2.3.12 Fuel Handling Building 2.3.12.1 Fuel Handling Building (Fire Zone 12.1-0)

This zone is shown on Figures 2.3-19 and 2.3-20 and in elevation on Figure 2.3-22 (Sheet 2).

Fire Barrier Description All slabs and exterior walls in the Fuel Handling Building are structural reinforced concrete. The floor slab at elevation 401 feet 0 inch varies from 55 inches to 96 inches thick structural reinforced concrete and is the foundation. The floor slab at elevation 411 feet 0 inch, which is the fuel unloading platform, is 18-inch structural reinforced concrete and is between columns 17 and 19.6. The platform is supported by concrete columns.

This platform extends to row Y, but is covered by the new fuel storage area at elevation 426 feet 0 inch from row Y to Z.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 The north, south, and west exterior walls are 36-inch-thick structural reinforced concrete. The north and west walls carry a 3-hour fire rating. The east wall, which includes the Fuel Transfer Canal wall up to elevation 426 feet 0 inch, is structural reinforced concrete or solid concrete masonry units and varies in thickness from 12 inches to 84 inches. It separates the Fuel Handling Building from the Auxiliary Building and carries a 3-hour fire rating. It contains three Label "A" fire doors, and two pairs of doors which are either of Label "A" construction which close tightly around a continuous steel trolley beam (Byron), or are Label "A" fire doors (Braidwood). A portion of the auxiliary building floor slabs at elevation 451 feet 0 inch and elevation 426 feet 0 inch also separates the Fuel Handling Building from the Auxiliary Building. These slabs are a minimum 15-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, supported by steel beams protected by a fire-resistant covering and columns, and carry a 3-hour fire rating.

All exterior walls extend up to and are dowelled into the roof slab. The roof slab at elevation 474 feet 6 inches is 14-inch over 3-inch metal decking, which is supported by unprotected structural steel beams and columns.

The Spent Fuel Storage Pool extends from elevation 385 feet 0 inch to elevation 426 feet 0 inch and is open to the operating floor. The floor slab and walls of the pool are structural reinforced concrete. The thickness of the walls varies from 60 inches to 84 inches, and the floor slab is 65 inches thick with a 7-inch concrete topping. A continuous stainless-steel liner plate is anchored to the floor slab and walls of the pool.

The floor level at elevation 401 feet 0 inch includes the following areas:

a. Heat Exchanger Area The walls are minimum 20-inch-thick solid concrete masonry units, structural reinforced concrete, or removable solid concrete masonry units. The floor slab is an 8-inch concrete topping over a 55-inch-thick structural reinforced concrete which is the grade foundation.

Two 36-inch by 36-inch drainage sumps are in the northwest and southwest corners of the heat exchanger areas.

b. Spent Fuel Pump Room The walls are minimum 20-inch-thick solid concrete masonry units.

The base slab at elevation 401 feet 4 inches is an 8-inch concrete topping over 64-inch-thick structural reinforced concrete.

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B/B - FPR AMENDMENT 29 DECEMBER 2020

c. Decontamination Area The decontamination area extends from elevation 401 feet 0 inch up to elevation 426 feet 0 inch and is open to the operating floor.

The floor slab at elevation 401 feet 0 inch is 62-inch structural reinforced concrete. The walls are 24-inch-thick structural reinforced concrete. A continuous stainless-steel plate is anchored to the walls and floor slab of the decontamination pit. A 36-inch by 36-inch drainage sump is in the northeast corner of this area.

Sixteen 4-inch floor drains (90 gpm capacity each) are provided in the heat exchanger area, spent fuel pump room, fuel unloading area, and the railroad track area. These drains flow to the heat exchanger area sump and are then routed to the Radwaste Building.

The intermediate floor level at elevation 411 feet 0 inch, which includes the new fuel unloading area and new fuel storage area, is an 18-inch structural reinforced concrete slab and is the roof of the heat exchanger and spent fuel pump areas.

This slab is supported by concrete columns. A 4-inch concrete curb is provided at the edge of the slab as well as removable handrails. Two 4-inch-diameter drains are provided in the new fuel unloading area, and four drains (90 gpm each) in the new fuel storage area. These drains flow to the heat exchanger area sump.

The new fuel storage area is enclosed by minimum 24-inch-thick structural reinforced concrete walls which extend up to and are dowelled into the floor slab at elevation 426 feet 0 inch.

The operating floor level at elevation 426 feet 0 inch is an 18-inch-thick structural reinforced concrete slab. There are several openings through this floor slab. The openings to the spent fuel transfer canal and the new fuel storage area are covered by removable checkered plates. The other openings are to equipment cubicles and are covered by removable concrete slabs.

The railroad car shed is attached to the Fuel Handling Building. The floor slab of the car shed area at elevation 401 feet 0 inch is 36-inch-thick structural reinforced concrete and the walls are insulated metal siding. The roof slab at elevation 426 feet 0 inch is precast concrete roof slab supported by unprotected structural steel beams and columns. Two nonrated rolling steel doors are provided in the car shed and lead to the Fuel Handling Building and to the outside respectively. The railroad tracks run through the car shed and into the Fuel Handling Building.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 (Braidwood Only) There is a Ballistic Resistant Enclosure (BRE) installed in the east wall of the railroad car shed attached to the Fuel Handling Building. The BRE is constructed of steel on all sides and completely self-contained. Although the BRE itself may contain minor amounts combustible material, due to the construction, a fire inside of the structure will not propagate to fire zone 12.1-0.

As such, the BRE does not contribute to the combustible loading of the area.

Duct penetrations in the floors and walls which separate this zone from zones 11.3-1 and 11.3-2 do not have fire dampers installed. It has been determined this lack of dampers will not prevent safe shutdown and is deemed satisfactory. Fire dampers are provided in the fire wall separating the fuel handling building and the auxiliary building.

Piping penetrations are sealed.

Safety-Related Equipment Safety-related equipment located in the Fuel Handling Building consists of the components of the Auxiliary Building Ventilation System, the 125-ton fuel handling crane, spent fuel pit heat exchanger, and the fuel pit sump pump. Only the spent fuel pit heat exchanger and pumps are needed to maintain fuel pool temperature. The cranes, spent fuel pit heat exchangers, and pumps are designed as Seismic Category I.

The HVAC safety-related equipment located in this fire area are components of the Auxiliary Building Ventilation System. These include galvanized ductwork, ductwork accessories, and cubicle coolers.

Protection Criteria and Measures The protection measures for this area consist of separation of the area from the rest of the plant by a fire barrier. The new fuel storage racks are designed to preclude criticality problems when subjected to water spray. Nonfogging type nozzles are used for the manual hose station located in this area to preclude conditions of optimum moderation for the new fuel storage racks.

If a rupture should occur, no safety-related equipment is likely to be damaged.

Fire dampers are provided in the fire wall except as noted under section entitled Fire Barrier Description. Fire dampers are fusible link type which will be closed when the temperature exceeds 165 Degrees Fahrenheit.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Acrylic, cable insulation, epoxy, gaskets, grease, hydraulic oil, lube oil, miscellaneous and transient combustibles, rubber, plastic, polypropylene, and wood.

At Byron, diesel fuel oil, and nylon.

At Braidwood, Anti-C clothing, plexiglass, polycarbonate, polyester, and vinyl.

Fire Loading Most of the combustible materials are in an 87-foot by 72-foot area bounded by column rows Y and BB and 15 and 21 at elevation 401 feet 0 inch. See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detection Capability Portable fire extinguishers and four manual hose stations are located at elevation 426 feet 0-inch, Figure 2.3-19 and Figure 2.3-10, sheets 1 and 3, and two manual hose stations and portable fire extinguishers are provided at elevation 401 feet 0-inch, Figure 2.3-20.

Similar equipment can be brought in from the Auxiliary Building at elevation 426 feet 0 inch if needed.

Ionization (or photoelectric) detectors are provided for elevation 401 feet 0 inch, 411 feet 0 inch and 426 feet 0 inch which alarm and annunciate in the Control Room. At Braidwood, the large area above elevation 426 feet 0 inch is provided with ultraviolet detectors which alarm and annunciate in the Control Room.

Design-Basis Fire Due to the quantity of combustibles present, the design-basis fire would be localized to the floor area at elevation 401 feet 0 inch and of short duration. The spread of heat and combustion products would be mitigated by the fire barriers.

The available manual extinguishing equipment is capable of rapidly extinguishing the design-basis fire.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.130.

The only equipment that would conceivably be damaged by the design-basis fire would be the safety-related Fuel Handling Building Ventilation System. These systems and components are not required for safe shutdown and cooldown of the reactor. If the temperature exceeds 165 Degrees Fahrenheit, the fusible links will melt, and the fire dampers will close.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.13 QA Vault (Fire Zone 13)

This area is shown on Figure 2.3-17.

Fire Barrier Description The floor slab at elevation 433 feet 0 inch is 37-inch cover of reinforced concrete on 3-inch fluted steel decking formwork and is supported by unprotected steel beams and columns. It provides a resistance of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to the spread of fire to the radwaste area below. The ceiling slab at elevation 443 feet 0 inch, and all walls are as a minimum 12-inch-thick structural reinforced concrete and carry a 4-hour fire rating. A Label "A" fire door leads to the adjacent Service Building corridor.

Safety-Related Equipment There is no safety-related equipment in this area. Records associated with safety-related equipment are kept in this area.

Protection Criteria and Measures Should a fire occur in the room, operation of the plant would not be affected.

However, access to quality assurance records may be disrupted.

Combustible Materials Gaskets, insulation, paper, and transient combustibles.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Manual hose stations and portable extinguishers are available.

An automatic one-shot Halon system is provided for the area. Ionization or photoelectric detectors that annunciate and alarm locally and in the Control Room will actuate the system. Approximately 288 pounds of Halon will be available for injection into the room and will be delivered within 10 seconds. A maximum of 160 pounds of Halon is required. The Halon supply will be in the HVAC Ventilation Equipment Room on elevation 433 feet 0 inch. The system can be manually initiated at the Halon tank and by a toggle switch located just outside the room which will alarm in the control room. Inadvertent operation or damage to the Halon system would not affect plant operation.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would occur if everything in the room was ignited. Under this assumption, most of the station's quality assurance records would be destroyed. The Halon system would extinguish the fire in the QA vault. Manual suppression systems are also available.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.131.

2.3.14 Radwaste Areas 2.3.14.1 Radwaste Drumming Station and Tunnel (Fire Zone 14.1-0)

This zone is shown on Figure 2.3-13 (Sheet 2).

Fire Barrier Description The floor, which slopes up from elevation 383 feet 0 inch to elevation 388 feet 0 inch, is a minimum 20-inch-thick structural reinforced concrete slab with a 5-inch concrete topping. Seven (Byron) 4-inch-diameter floor drains are provided which are routed to a sump in a drum fill area of this zone. At Braidwood, there are six floor drains.

All walls are minimum 12-inch-thick structural reinforced concrete or solid concrete masonry units. All perimeter walls carry a 3-hour fire rating except the wall common to this zone and to the Auxiliary Building, elevation 383 feet 0 inch, which contains a nonrated door and carries no fire rating. Masonry walls extend up to within 1 inch of the ceiling above, and this space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling, which slopes up from elevation 391 feet 8 inches to elevation 396 feet 0 inch in the tunnel area, is a minimum 20-inch-thick structural reinforced concrete slab and carries a 3-hour fire rating.

Safety-Related Equipment No safety-related equipment is in this zone.

Protection Criteria and Measures This fire zone is separated from the remainder of the plant by thick shielding walls.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, DAW bags, gaskets, grease, lube oil, miscellaneous and transient combustibles, and polypropylene.

At Byron, plastic.

At Braidwood, plexiglass, polyethylene, and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is available in the zone. Portable fire extinguishers are available from adjacent zones.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned. Safe shutdown of the reactor would not be affected. Radioactive products may be released, but all air leaving this zone is vented through HEPA filters, which are monitored by radiation detectors.

The design-basis fire is considered unlikely due to the physical separation of the combustibles. A fire in this zone would not affect safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.132.

2.3.14.2 Radwaste Evaporator Monitor Tank Room and Spent Resin Pump Room (Fire Zone 14.2-0)

This zone is shown on Figure 2.3-12 (Sheet 3). An elevation view is shown on Figure 2.3-25 (Sheet 2).

Fire Barrier Description The floor at elevation 401 feet 0 inch is a 30-inch-thick reinforced concrete slab supported by concrete beams and columns and carries a 3-hour fire rating. Four-inch-diameter floor drains are provided. All walls are 12-inch-thick hollow concrete masonry units, minimum 36-inch-thick solid concrete masonry units, or 42-inch-thick structural reinforced concrete. Walls common to this zone and to the Diesel-Generator 2A Room carry a 3-hour fire rating. The walls separating this zone from the stairway at column L/24 are 2-hour rated.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 All the remaining walls in this zone are of 3-hour rated construction but contain non-rated doors leading to the Auxiliary Building ground floor. All masonry walls extend up to within 1 inch of the ceiling above, and this space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling at elevation 426 feet 0 inch is a minimum 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. The structural steel columns and the main beams (at the main column lines only) which support the ceiling and the control room complex at elevation 451 feet 0 inch above are protected by a fire-resistant covering to a rating of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

However, intermediate supporting beams are unprotected in remaining areas of the ceiling and those areas of the ceiling carry no fire rating. A portion of the Radwaste Monitor Tank Room extends up the ceiling slab at elevation 439 feet 0 inch.

Safety-Related Equipment Portions of the Auxiliary Building Ventilation System in this zone are safety related. These are sections of the galvanized ductwork, dampers, and ductwork accessories.

Protection Criteria and Measures This fire zone is separated from the remainder of the plant by thick shielding walls.

Combustible Materials Gaskets, grease, lube oil.

At Byron, Plastic and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is located within 50 feet of the zone. Portable fire extinguishers are available in adjacent areas.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire for this zone is negligible. It would occur if all the combustibles in the zone burned. If any radioactive products were released, they would pass through HEPA filters, which are monitored by radiation detectors.

The negligible design-basis fire is considered unlikely due to spatial arrangement and lack of combustibles. Any fire in this zone would not affect the safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.133.

2.3.14.3 Surface Condenser Rooms (Fire Zone 14.3-0)

This zone is shown on Figure 2.3-12 (Sheet 3).

Fire Barrier Description This zone includes Surface Condenser Rooms "A," "B," and "C."

The floor of this zone at elevation 401 feet 0 inch is a minimum 36-inch structural reinforced concrete slab supported by concrete beams and columns. One 4-inch-diameter floor drain is provided in each room.

The perimeter walls of this zone are minimum 12-inch-thick structural reinforced concrete. Walls common to this zone and to the exterior of the Diesel-Generator 2A Room carry a 3-hour fire rating. Other perimeter walls are of 3-hour rated construction but contain nonrated doors leading to the Auxiliary Building ground floor. The rooms are separated from each other by 12-inch-thick solid concrete masonry unit walls, which also enclose in each room a stair leading up to the radwaste evaporator rooms above. All masonry walls extend up to within 1 inch of the ceiling or structural steel above, and this space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling at 414 feet 0 inch is a 29-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and carries no fire rating.

Safety-Related Equipment There is no safety-related equipment in this zone.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures This fire zone is separated from the remainder of the plant by thick shielding walls.

Combustible Materials Cable insulation and lube oil.

At Byron miscellaneous and transient combustibles, plastic and polypropylene.

At Braidwood acetone, cotton, grease, and polycarbonate.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is located within 50 feet of the zone. Portable fire extinguishers are available in adjacent areas.

Design-Basis Fire The design-basis fire for this zone is negligible. It would occur if all the combustibles in the zone burned. If any radioactive products were released, they would pass through HEPA filters, which are monitored by radiation detectors.

The negligible design-basis fire is considered unlikely due to spatial arrangement and lack of combustibles. Any fire in this zone would not affect the safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.134.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.14.4 Spent Resin Storage Tank, Concentrates Holding Tank, and Waste Gas Compressor Rooms (Fire Zone 14.4-0)

This zone is shown on Figure 2.3-10 (Sheet 3) and elevation on Figure 2.3-25 (Sheet 2).

Fire Barrier Description This zone includes the Waste Gas Compressor Cubicles, the Spent Resin Storage Tank Room, and the Concentrates Holding Tank Room.

The floor slab at elevation 414 feet 0 inch, the floor of the Spent Resin Tank Room and the Concentrates Holding Tank Room, is a minimum 33-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, and is supported by unprotected steel beams with the exception of the main header beams and columns which support the Control Room complex, and protected with a fire-resistant covering to a 3-hour rating. The portion of the floor at the Concentrates Holding Tank Room provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the spread of fire to the zone below. The floor at the Spent Resin Tank Room contains a nonrated penetration and carries no fire rating.

The floor slab at elevation 426 feet 0 inch, the floor of the Waste Gas Compressor Cubicles, is a minimum 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by unprotected steel beams and columns, and provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the spread of fire to the zone below. Four-inch-diameter floor drains are provided.

The perimeter walls of this zone are minimum 24-inch-thick solid concrete masonry units or minimum 42-inch-thick structural reinforced concrete. The walls common to this zone and to the Turbine Building basement and the ESF Switchgear Room - Division 21 carry a 3-hour fire rating. The remaining walls, which include separating walls between cubicles, are of 3-hour rated construction but contain nonrated doors leading to the Auxiliary Building mezzanine floor or nonrated penetrations.

The ceiling slab at elevation 439 feet 0 inch is a minimum 33-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by protected steel beams, and carries a 3-hour fire rating.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment Portions of the Auxiliary Building Ventilation System in this zone are safety related. These are sections of the galvanized ductwork, dampers, and ductwork accessories.

The spent resin storage tank in this zone is safety-related but is not required for reactor shutdown.

Protection Criteria and Measures This fire zone is separated from the remainder of the plant by thick shielding walls.

Combustible Materials Gaskets.

At Byron, flammable gas and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is located within 50 feet of this zone. Portable fire extinguishers are available from adjacent areas.

Design-Basis Fire The design-basis fire would occur if all the combustibles in the rooms burned.

Safe shutdown of the reactor would not be affected. Radioactive products may be released, but all air leaving this zone passes through HEPA filters, which are monitored by radiation detectors.

The design-basis fire is considered unlikely due to separation of the combustibles within this zone by thick shielding walls. Any fire in this zone would not affect safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe 2.3-188

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.14.5 Radwaste Evaporator Rooms (Fire Zone 14.5-0)

This zone is shown on Figure 2.3-10 (Sheet 3).

Fire Barrier Description This zone includes the Radwaste Evaporator Rooms "A," "B," and "C."

The floor slab at elevation 414 feet 0 inch, which is the ceiling of the Surface Condenser Rooms, is a 29-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and columns and contains several nonrated openings for ventilation ducts and a stairway in each room and carries no fire rating. Four-inch-diameter floor drains are provided in each room. The perimeter walls of the zone are minimum 32-inch-thick structural reinforced concrete. Walls common to this zone and to the ESF Switchgear Room - Division 21, the electrical penetration area - Division 22, and the cable riser area carry a 3-hour fire rating. The remaining perimeter walls are of 3-hour rated construction but contain nonrated penetrations which are in the process of being upgraded. The rooms are separated from each other by 32-inch-thick solid concrete masonry walls which also contain non-rated penetrations. All masonry walls extend up to within 1 inch of the ceiling above, and this space is packed with a 1-inch-thick blanket of Thermafiber insulation.

The ceiling slab at elevation 439 feet 0 inch is a 33-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, is supported by protected steel beams and columns, and carries a 3-hour fire rating.

Safety-Related Equipment No safety-related equipment is in this zone.

Protection Criteria and Measures This zone is separated from the remainder of the plant by thick shielding walls.

Combustible Materials Cable insulation, gaskets, grease, lube oil.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station is located within 50 feet of this zone. Portable fire extinguishers are also available.

2.3-189

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire for this zone is negligible. It would occur if all the combustibles in the zone burned. If any radioactive products were released, they would be exhausted through HEPA filters, which are monitored by radiation detectors.

Even the negligible design-basis fire is considered unlikely due to special arrangement of the combustibles. Any fire in this zone would not affect safe shutdown of the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.136.

2.3.14.6 Radwaste Building, Drum Storage Area (Fire Zone 14.6-0)

This zone is shown on Figure 2.3-18.

Fire Barrier Description This zone includes the high level and low-level storage areas, the empty drum storage and dry waste storage areas, the trucking aisle, and the radwaste control room.

The floor at elevation 397 feet 0 inch and at elevation 401 feet 0 inch is a minimum 36-inch-thick structural reinforced concrete slab and is the foundation of the Radwaste/Service Building complex. An 8-foot 0-inch by 15-foot 0-inch opening is provided in this slab for the transfer of drums from the Radwaste Tunnel (Fire Zone 14.1-0).

The perimeter walls of this zone are minimum 12-inch-thick structural reinforced concrete or 12-inch-thick solid concrete masonry units. Two walls (the separating walls between this zone and the adjacent Turbine Building and the machine shop) carry fire ratings. The east wall carries a 2-hour fire rating and the south wall carries a 3-hour fire rating. Label "A" fire doors are provided in these walls.

The exterior walls carry no fire rating. The interior walls in this zone which separate the storage areas are partial-height walls of structural reinforced concrete but carry no fire rating.

The ceiling slab at elevation 433 feet 0 inch is a minimum 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and columns and carries no fire rating.

2.3-190

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment No safety-related equipment is in this zone.

Protection Criteria and Measures Except for incoming dry active waste, all combustible materials are kept in enclosed containers or tanks.

Combustible Materials Cable insulation, catalyst, charcoal, DAW, gaskets, grease, insulation, lube oil, miscellaneous and transient combustibles, paper, polymer resin, promotor.

At Byron, acrylic, nylon, plastic, and polypropylene.

At Braidwood, caustic, polycarbonate and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A fixed automatic sprinkler system protects most of this zone. In addition, there are three manual hose stations in this zone. Portable extinguishers are also available. Two manual hose stations located nearby have access to this area also. A manual deluge system is provided for the charcoal filter units. A temperature switch mounted in the filter bank will annunciate in the control room.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the control room. This detection system covers the zone, except for the high-and low-level drum storage rooms located between column-rows 43 to 45 and H.4 to L.

Design-Basis Fire The design-basis fire would occur if all the combustibles in this zone burned.

There would be a considerable amount of radioactive particles released to the air in this zone or in the charcoal filters. Plant operation would not be affected.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.137.

2.3.15 Decontamination Area The area is found within various fire zones of Fire Area 11 (Subsection 2.3.11).

2.3-191

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.16 Safety-Related Water Tanks This area covers the safety-related water tanks located outside. All tanks located indoors are discussed elsewhere.

2.3.16.1 Refueling Water Storage Tank - Unit 1 (Fire Zone 16.1-1)

This tank is shown on Figures 2.3-1, 2.3-2, 2.3-19, and 2.3-20. An elevation view is shown on Figure 2.3-22 (Sheet 2).

Fire Barrier Description The 450,000-gallon tank is a 24-inch-thick closed, reinforced concrete cylinder, with a 1/4-inch-thick stainless-steel liner plate, on a 72-inch-thick structural reinforced concrete base slab, which is also the foundation of the Fuel Handing Building. The walls of the RWSTs are 3-hour rated fire barriers. This tank is connected at the base to an underground, reinforced concrete pipe tunnel, which leads to the Safety Injection Pump Room in the Auxiliary Building.

Safety-Related Equipment The tank is safety related.

Protection Criteria and Measures The tank is constructed of noncombustible materials and normally filled with 450,000 gallons of borated water.

Combustible Materials This zone contains no combustible materials.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Fire hydrants, which are part of the loop fire main, are available, if required.

Design-Basis Fire With no combustibles within this zone, there can be no fire.

The analysis of the effect of a fire in this zone on equipment required for safe shutdown is discussed in Subsection 2.4.2.138.

2.3-192

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.16.2 Refueling Water Storage Tank - Unit 2 (Fire Zone 16.1-2)

This zone is shown on Figures 2.3-1, 2.3-2, 2.3-19, and 2.3-20.

For details, see Subsection 2.3.16.1.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.139.

2.3.17 Cooling Towers Cooling Towers are only at the Byron Station.

2.3.17.1 Open Flume (Fire Zone 17.1-0)

The flume is shown on Figure 2.3-1.

Fire Barrier Description This flume is located between and attached to the circulating water-cooling towers and the circulating water pump house. It is entirely of minimum 12-inch-thick structural reinforced concrete construction.

Safety-Related Equipment No equipment in this zone is safety related.

Protection Criteria and Measures The flume is always filled with water when the towers are in operation and is constructed of nonflammable material. A failure of the flume would not affect safety-related equipment.

Combustible Materials This zone contains no combustible materials.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Fire hydrants are located nearby if ever needed.

Design-Basis Fire With no combustibles within the zone, there can be no fire.

2.3-193

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.17.2 Natural Draft Cooling Towers - Unit 1 (Fire Zone 17.1-1)

This zone is shown on Figure 2.3-1.

Fire Barrier Description This cooling tower is a hyperbolic shell of structural reinforced concrete that is 490 feet high and 450 feet in diameter at its widest point. The thickness of this shell varies from 8 inches to 36 inches. The tower is located on a reinforced concrete foundation and is adjacent to the circulating water pump house.

Safety-Related Equipment The tower is not safety related. There is no safety-related equipment in this zone.

Protection Criteria and Measures The tower is located so that any structural failure will not affect any safety-related structures.

Combustible Material ABS, FRP, neoprene, nylon, plastic, polypropylene, PVC, and rubber.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Fire hydrants are located nearby if ever needed.

Design-Basis Fire The design basis fire would occur if all the combustibles in the zone burn. The equipment located in this zone is not required for safe shutdown of the plant.

Therefore, the ability to shut down the plant safely is not affected by a fire in this zone.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.140.

2.3.17.3 Natural Draft Cooling Tower - Unit 2 (Fire Zone 17.1-2)

This tower is shown on Figure 2.3-1.

For details, see Subsection 2.3.17.2. The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.141.

2.3-194

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.17.4 Essential Service Water (ESW) Cooling Tower - Division 12/22 (Byron) (Fire Zone 17.2-1)

This tower is shown on Figures 2.3-1 and 2.3-31 (Sheet 2).

Fire Barrier Description The enclosure for the four forced-draft fans is constructed of structural reinforced concrete openings provided in the walls and roof for air intake and exhaust, respectively. Above normal water level, each fan is separated from adjacent fans by a reinforced concrete wall. The fan enclosure is separated from the adjacent electrical substations by a 3-hour rated firewall.

Safety-Related Equipment These cooling towers are safety related. The fans mounted on top of the cooling tower are also safety related.

There is also safety-related motor-operated valves in the valve houses associated with the Essential Service Water System.

Protection Criteria and Measures The cooling towers are over 100 feet from any other structures and are made of noncombustible materials.

Electrical ESF divisions in the towers are separated by distance and fire barriers.

All cabling in the towers is in conduit.

Combustible Materials Acrylic, cable insulation, FRP, grease, lube oil and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Three hydrants are located nearby.

Design-Basis Fire The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Section 2.4.2.142.

2.3-195

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.17.5 ESW Cooling Tower - Division 11/21 (Byron) (Fire Zone 17.2-2)

This tower is shown on Figures 2.3-1 and 2.3-31 (Sheet 1).

For details, see Subsection 2.3.17.4.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.143.

2.3.18 Miscellaneous Areas 2.3.18.1 Diesel-Generator 1B and Switchgear Room Air Shaft (Fire Zone 18.1-1)

This zone is shown on Figures 2.3-8 (Sheet 1), 2.3-10 (Sheet 1), and 2.3 12 (Sheet 1).

Fire Barrier Description This zone includes the Diesel-Generator Fan Room and Air Intake Plenum from elevation 401 feet 0 inch up to the louver penthouse on the Auxiliary Building Room at elevation 477 feet 0 inch. The floor at elevation 401 feet 0 inch is a 48-inch-thick structural reinforced concrete slab and carries a 3-hour fire rating. One 4-inch-diameter floor drain is provided. The perimeter walls of this zone are of minimum 12-inch-thick structural reinforced concrete or 12-inch hollow concrete masonry units and carry a 3-hour fire rating up to the Auxiliary Building Roof Level at elevation 477 feet 0 inch. Masonry walls extend up to within 1 inch of the Auxiliary Building floors or the protected steel beams at elevation 426 feet 0-inch, elevation 439 feet 0-inch, elevation 451 feet 0 inch, and elevation 477 feet 0 inch. This remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. Some steel beams partially embedded in the 3-hour barrier are not fireproofed. This is acceptable because the worst-case fire will not affect the structural integrity of these beams. The steel column at elevation 451 Q-7 is missing an approximate five-foot section of fire proofing just below the 451 floor grating (EC 371033). Intermediate floor levels of steel grating are provided in this plenum, are supported by unprotected steel beams and columns, and do not carry a fire rating. All doors leading into the plenum are Label "A" fire doors. The ceiling at elevation 477 feet 0 inch, which is the floor of the Air Intake Penthouse, is a 21-inch clear cover of structural reinforced concrete on 3-inch fluted steel decking formwork and is supported by protected steel beams and columns and carries a 3-hour rating.

2.3-196

B/B - FPR AMENDMENT 29 DECEMBER 2020 At Braidwood, the steel support members located between column/rows P.5-Q/6-7 at elevations 463-0 and 466-0 are not fireproofed. These support members are installed for HELB pressure loading combined with seismic loading under the new HELB design basis analysis and are attached to existing steel column 8AWC54 that forms a part of a 3-hour fire rated block wall. Generic Letter 86-10 Evaluation EC-EVAL 395459 was performed per EC 392489, which determined that the steel support members do not require fireproofing.

The Air Intake Penthouse is a nonrated enclosure entirely of minimum 14-inch-thick structural reinforced concrete walls and roof. The intake louvers are in this penthouse. The 12-inch-thick structural reinforced concrete shaft that contains the Diesel-Generator Exhaust Stack is also included in this zone. It extends from the Diesel-Generator Room at elevation 471 feet 0 1/4-inch up to the concrete enclosure around the exhaust silencers on the Auxiliary Building Room at elevation 490 feet 6 inches and carries a 3-hour fire rating.

The fire dampers installed in the horizontal ducts penetrating the fire walls are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

Safety-Related Equipment The safety-related equipment located in this zone consists of components of the Diesel-Generator and Switchgear Room Ventilation System. These are galvanized ductwork, dampers, ductwork accessories, fans, and filters.

Protection Criteria and Measures The insulation used to cover the diesel exhaust pipe is not combustible. The pipe is separated from the air shaft and both are separated from adjacent areas by fire-rated barriers.

Combustible Materials Cable insulation, flexible connections, gaskets, grease, and prefilters.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-197

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities At Byron and at Braidwood, an ionization (or photoelectric) detector is provided on the discharge side of each supply fan on the VD, VE and VX system ducts.

Portable extinguishers can be brought in from adjacent zones if required. Hose stations are also available in adjacent zones.

Design-Basis Fire The only material which might even remotely be flammable is the pipe insulation which is required to withstand the over 1,000 Degree Fahrenheit temperature of the exhaust.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.144.

2.3.18.2 Diesel-Generator 2B and Switchgear Room Air Shaft (Fire Zone 18.1-2)

This zone is shown on Figures 2.3-8 (Sheet 3), 2.3-10 (Sheet 3), and 2.3-12 (Sheet 3) and in elevation on Figure 2.3-21 (Sheet 2).

For details, see Subsection 2.3.18.1 except that:

a. The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.145.

b. The steel support members located between column/rows P.5-Q/29-30 at elevations 463 feet 0 inch and 466 feet 0 inch are not fireproofed. These support members are installed for HELB pressure loading combined with seismic loading under the new HELB design basis analysis and are attached to existing steel column 8AWC43 that forms a part of a 3-hour fire rated block wall. Generic Letter 86-10 Evaluations determined that the steel support members do not require fireproofing. Refer to Byron EC-EVAL 395449 and Braidwood EC-EVAL 395459.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.145.

2.3-198

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.3 Diesel-Generator 1A and Switchgear Room Air Shaft (Fire Zone 18.2-1)

This zone is shown on Figure 2.3-8 (Sheet 1), 2.3-10 (Sheet 1), and 2.3-12 (Sheet 1).

For details, see Subsection 2.3.18.1 except that:

a. There is a single Label "A" door on the east wall.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.146.

2.3.18.4 Diesel-Generator 2A and Switchgear Room Air Shaft (Fire Zone 18.2 2)

This zone is shown on Figures 2.3-8 (Sheet 3), 2.3-10 (Sheet 3), and 2.3-12 (Sheet 3).

For details, see Subsection 2.3.18.1 except that:

a. There is only one Label "A" door in the east wall.

b. The vent fan in this zone is coated with any epoxy coating. This material has a flame spread less than 25 and a smoke development rating less than 450.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.147.

2.3-199

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.5 Unit 1 Main Steam and Auxiliary Feedwater Pipe Tunnel (Fire Zone 18.3-1)

This zone is shown on Figures 2.3-13 (Sheet 1) and 2.3-14 (Sheet 1).

Fire Barrier Description The Auxiliary Feedwater Tunnel at elevation 357 feet 0 inch and the Main Steam Tunnel at elevation 377 feet 0 inch are constructed of minimum 24-inch-thick structural reinforced concrete. The walls separating these tunnels from the Auxiliary Building are 3-hour fire rated. They are separated from each other by a 48-inch-thick structural reinforced concrete slab, which is the ceiling of the Auxiliary Feedwater Tunnel and the floor of the Main Steam Tunnel. These tunnels lead to the Isolation Safety Valve Enclosures adjacent to the Containment Building, which are included as part of this fire zone. The Main Steam Tunnel is also open to the Turbine Building Basement.

The Isolation Safety Valve enclosures are constructed of structural reinforced concrete. The floor of the enclosures at elevation 377 feet 0 inch is 36 inches thick and is also the floor slab of the Main Steam Tunnel.

An opening is provided in this floor slab for access into the tendon tunnel below and is covered by a removable steel plate. The walls of the enclosures are a minimum 36 inches thick. A Label "B" door is provided in each enclosure and leads to the exterior.

The roof slab at elevation 423 feet 8 inches is a minimum of 20 inches thick and contains a 20-inch-thick removable concrete slab.

Each safety valve enclosure is divided into an upper and lower portion by a 48-inch-thick slab, which contains openings for access between portions.

Safety-Related Equipment The Hydraulic Operating System for the Main Steam Isolation Valves is safety related. Safety-related piping is in this zone.

Protection Criteria and Measures All electrical cables are in conduit, except for the cables for the ultrasonic feedwater flow instrumentation at Byron that are routed in free air.

2.3-200

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, Fyrquel, and polypropylene.

At Byron, acrylic, insulation, nylon, and plastic.

At Braidwood, polystyrene.

Fire Loading There is no fire loading in the tunnel. Isolation Safety Valve enclosures see Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities There are no automatic or manual fire suppression systems provided in the tunnel. Manual extinguishers can be brought in from adjacent zones if required.

One manual hose station is available to each valve enclosure.

Ionization (or photoelectric) detectors are provided in both valve enclosures. The remaining portions of the tunnel have no detection capability installed.

Design-Basis Fire If the design-basis fire occurs, loss of operability of the isolation valves would result. However, the valves fail safe and boundaries would remain intact.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.148.

2.3.18.6 Unit 2 Main Steam and Auxiliary Feedwater Pipe Tunnel (Fire Zone 18.3-2)

This zone is shown on Figures 2.3-13 (Sheet 2) and 2.3-14 (Sheet 3).

For details, see Subsection 2.3.18.5.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.149.

2.3-201

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.7 Control Room HVAC Equipment Room, Train A (Fire Zone 18.4-1)

This room is shown on Figure 2.3-8 (Sheet 1) and in elevation on Figure 2.3-25 (Sheet 1).

Fire Barrier Description The floor at elevation 451 feet 0 inch, which is the ceiling of a lower cable spreading room, is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the spread of fire to the zone below. Two floor drains are provided. Perimeter walls of this zone are minimum 12-inch-thick hollow concrete masonry units or minimum 30-inch-thick structural reinforced concrete. Masonry walls extend up to within 1 inch of the ceiling above, and this remaining space is packed with a 1-inch-thick blanket of Thermafiber insulation. All walls carry a 3-hour fire rating except for the exterior wall, which contains a nonrated opening for an air intake louver, and does not carry a fire rating and, at Braidwood, the south wall which is interrupted at elevation 459 feet 5 3/4 inches by a W18x60 structural steel beam to support a gallery at elevation 459 feet 7 inches. This beam is protected to a 3-hour rating by a fire-resistant covering. The remainder of the south wall above the beam at elevation 459 feet 5-3/4 inches extending to within 1 inch of the ceiling above is comprised of 2-hour fire rated masonry with one layer each side of 7/8-inch metal furring channels and 1/2-inch fire-rated gypsum wallboard. This portion of wall carries a minimum 3-hour fire rating. The remaining 1-inch space above the wall is packed with a 1-inch-thick blanket of Thermafiber insulation.

At Byron, the steel beams located along the Column-11 wall between rows L and Q at elevations 463-5 and 477-0 are not fireproofed on the Train A Control Room HVAC Equipment Room side of the beams. These beams are part of a fire wall that separates the Train A Control Room HVAC Equipment Room from adjacent fire zones. Generic Letter 86-10 Evaluation BYR-07-02 was performed per EC #366688, which determined that the fire loading in this zone would not cause the room to heat up to a degree that would challenge the integrity of the non-fireproofed structural steel beams.

As recommended by the Generic Letter 86 10 evaluation, transient combustible materials on the intermediate grating level are controlled and limited to minimize possible flame impingement to the non-fireproofed steel beams at Elevation 463-

5. Therefore, these steel beams do not require fireproofing, and the steel beams remain capable of functioning as a 3-hour fire barrier for the fire hazard present in this fire zone.

2.3-202

B/B - FPR AMENDMENT 29 DECEMBER 2020 All doors in this zone are Label A fire doors or are of 3-hour fire-rated construction. The ceiling at elevation 477 feet 0 inch, which is the roof of the Auxiliary Building, is a 21-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and does not carry a fire rating.

Fire dampers are installed in the horizontal ducts penetrating the fire walls and are 3-hour fire rated. The only exception to this is the wall bordering Fire Zone 8.6-0, where the existing damper is acceptable in lieu of a fire damper. It is acceptable since any fire spreading from Fire Zone 8.6-0 to the HVAC equipment room will be contained within the room and any fire in this room will not affect the components of the redundant HVAC train due to the physical separation (>200 feet) between the trains.

Safety-Related Equipment The safety-related equipment located in this zone consists of components of Train A of the Control Room Ventilation System. These are galvanized ductwork, dampers, ductwork accessories, fans, filters, and control panel 0VC01JA as well as the ESF Division tray.

Protection Criteria and Measures Fire dampers are provided in the fire walls. The fire dampers are fusible link type which will close when the temperature exceeds 165 Degrees Fahrenheit.

Combustible Materials Cable insulation, charcoal filters, flexible connections, gaskets, grease, insulation, miscellaneous and transient combustibles, and prefilters.

At Byron acrylic, nylon, plastic, and polypropylene.

At Braidwood hydraulic fluid and polycarbonate.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual deluge system is provided for the charcoal filters. A temperature switch mounted in the charcoal absorber bank annunciates in the Control Room. An operator can energize the deluge valve locally in the fire water supply line to the charcoal bank in the event of high temperature.

2.3-203

B/B - FPR AMENDMENT 29 DECEMBER 2020 One manual hose station and one portable fire extinguisher are available in the zone. Another hose station and additional extinguishers are available from outside the room.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The equipment in this zone is not necessary for safe shutdown of the reactor.

Also, a redundant train, Train B, is available in the event of a fire.

In the event of a fire, the galvanized ductwork, ductwork accessories, dampers, and HVAC equipment may be damaged. The spread of heat and the combustion products will be stopped by the fire dampers.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.150.

2.3.18.8 Control Room HVAC Equipment Room, Train B (Fire Zone 18.4-2)

This room is shown on Figure 2.3-8 (Sheet 3) and in elevation on Figure 2.3-25 (Sheet 2).

For details, see Subsection 2.3.18.7 except that:

a. Train "B" is present instead of train A in this zone.

b. At Byron, the steel beams located along the Column-25 wall between rows L and Q at Elevations 463 feet 5 inch and 477feet 0 inch are not fireproofed on the Train B Control Room HVAC Equipment Room side of the beams. These beams are part of a fire wall that separates the Train B Control Room HVAC Equipment Room from adjacent fire zones. Generic Letter 86-10 Evaluation BYR-07-02 was performed per EC #366688, which determined that the fire loading in this zone would not cause the room to heat up to a degree that would challenge the integrity of the non-fireproofed structural steel beams. As recommended by the Generic Letter 86-10 evaluation, transient combustible materials on the intermediate grating level are controlled and limited to minimize possible flame impingement to the non-fireproofed steel beams at Elevation 463 feet 5 inch. Therefore, these steel beams do not require fireproofing, and the steel beams remain capable of functioning as a 3-hour fire barrier for the fire hazard present in this fire zone.

2.3-204

B/B - FPR AMENDMENT 29 DECEMBER 2020

c. At Braidwood, the block wall at the north side of the area is interrupted at elevation 459 feet 5-3/4 inches by a W18x55 structural steel beam. Also, at Braidwood, the north wall at column rows 25 and N-P, approximately at elevation 467 feet 0 inch, is of 3-hour fire-rated construction, but contains a nonrated fire seal (E0383146), which is constructed of Thermo-Lag 330-1 material and is abandoned in place.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.151.

2.3.18.9 Locker Room Area (Byron) and Kitchen/Locker Room Area (Braidwood) (Fire Zone 18.5-1)

This zone is shown on Figure 2.3-8 (Sheet 1).

Fire Barrier Description The floor at elevation 451 feet 0 inch, which is the ceiling of a Lower Cable Spreading Room, is a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by structural steel beams protected with a fire-resistant covering and provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the spread of fire to the zone below.

The perimeter walls of this zone are of 12-inch-thick hollow concrete masonry units or 42-inch-thick structural reinforced concrete and carry a 3-hour fire rating, with the exception of the north wall at Braidwood which is interrupted at elevation 459 feet 5-3/4 inches by a W18x60 structural steel beam to support a gallery at elevation 459 feet 7 inches. This beam is protected to a 3-hour rating by a fire-resistant covering. The remainder of the south wall above the beam at elevation 459 feet 5-3/4 inches extending to within 1 inch of the ceiling above is comprised of 2-hour fire rated masonry with 1 layer each side of 7/8" metal furring channels and 1/2-inch fire rated gypsum wallboard. This portion of wall shall carry a minimum 3-hour fire rating. The remaining 1-inch space above the wall is packed with a 1-inch-thick blanket of Thermafiber insulation.

These masonry walls extend up to within 1 inch of the ceiling above, and this remaining space is packed with 1-inch-thick blanket of Thermafiber insulation.

Doors in these walls are Label "A" fire doors.

2.3-205

B/B - FPR AMENDMENT 29 DECEMBER 2020 This zone is divided into the following rooms by nonrated masonry walls:

a. Two Locker Rooms at Byron and a Kitchen/Locker Room at Braidwood.

b. Janitor's Closet.

c. Men's Restroom.

A suspended ceiling of plaster or acoustical tile is provided in all rooms except for the Janitor's Closet.

A stairwell is also included in this zone and is enclosed by 3-hour rated masonry or structural reinforced concrete walls and is open to the corridor.

The ceiling at elevation 463 feet 5 inches is also the floor of an upper cable spreading room. For Braidwood units, the ceiling is a 6-1/2-inch clear cover of reinforced concrete on a 1-1/2-inch structural fluted steel decking. For Byron units, it is a 5-inch clear cover of reinforced concrete on 3-inch structural fluted steel decking. For all units, the ceiling is supported by steel beams which are protected by a fire-resistant covering and carries a 3-hour fire rating.

There are 3-hour rated fire dampers in all fire barriers.

Safety-Related Equipment There is no safety-related equipment in this zone.

Protection Criteria and Measures Fire dampers are provided in fire walls and floor. The fire dampers are fusible link type which are activated by temperatures exceeding 165 Degrees Fahrenheit.

Combustible Materials Cloth, gaskets, insulation, lube oil, miscellaneous and transient combustibles, and paper.

At Byron, plastic and wood.

At Braidwood, polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A manual hose station and portable extinguishers located in adjacent zones are available.

2.3-206

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire A fire would make this zone uninhabitable; however, the fire would not spread to other areas because of the fire barrier.

The Control Room Ventilation System will continue to operate and pressurize the surrounding zones and the Control Room.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.152.

2.3.18.10 Security Control Center and Electronics Shop (Fire Zone 18.5-2)

This zone is shown on Figure 2.3-8 (Sheet 3).

Fire Barrier Description For details, see Fire Zone 18.5-1, except that the zone is the Security Control Center, Electronics Shop, and the 2-hour rated stairwell enclosure and the adjoining corridor. Also, at Braidwood, the north side of the area is interrupted at elevation 459 feet 5-3/4 inches by a W18X55 structural steel beam. There are 3-hour fire dampers in all fire barriers.

Safety-Related Equipment No safety-related equipment is in this zone.

Protection Criteria and Measures This zone is bounded by 3-hour barriers.

Combustible Materials Cable insulation, cloth, fiber optic cable, gaskets, insulation, lube oil, miscellaneous and transient combustibles, and paper.

At Byron, plastic.

At Braidwood, polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Portable extinguishers and one manual hose station are provided for the area.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

2.3-207

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would occur if everything combustible in the room was ignited. In the event of a fire the ductwork and its accessories may be damaged.

The spread of heat and combustion products will be stopped by the fire dampers.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.153.

2.3.18.11 Service Building, Ground Floor (Fire Zone 18.6-0)

This zone is shown on Figure 2.3-18.

Fire Barrier Description The floor at elevation 401 feet 0 inch is the minimum 30-inch-thick structural reinforced concrete base slab of the Service Building. The perimeter walls of this zone are 12-inch-thick hollow concrete masonry units or insulated metal siding on unprotected steel girts. The walls common to this zone, to the radwaste drum storage area and to the turbine building ground floor carry a 3-hour fire rating. All doors in these walls are Label "A" 3-hour fire doors. The other perimeter walls are exterior walls and do not carry a fire rating.

Safety-Related Equipment There is no safety-related equipment in the Service Building.

Combustible Materials Office/administrative areas mainly occupy the Service Building with other occupancies including tool room/workshop areas, building utility service areas (e.g. HVAC equipment rooms), and a paint/oil storage room. The combustible materials and fire load associated with the Service Building are typical for these types of occupancies.

Extinguishing and Detecting Capabilities Manual hose stations and portable extinguishers are in the fire zone. Specific fire hazards are protected as shown on plant drawings.

Design-Basis Fire Due to its location and separation from essential portions of the station, a fire in the Service Building will not affect safety-related structures or components.

2.3-208

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.12 Service Building, Second Floor (Fire Zone 18.7-0)

This zone is shown on Figure 2.3-18.

For details see Subsection 2.3.18.11.

2.3.18.13 Service Building, Third Floor (Fire Zone 18.8-0)

This zone is shown on Figure 2.3-17.

For details see Subsection 2.3.18.11.

2.3.18.14 Service Building, Fourth Floor (Fire Zone 18.9-0)

This zone is shown on Figure 2.3-17.

For details see Subsection 2.3.18.11.

2.3.18.15 Main Power Transformer 1E (Fire Zone 18.10A-1)

This zone is shown on Figure 2.3-1 and Figure 2.3-2.

Fire Barrier Description The transformer is placed on a structural reinforced concrete pad with a perimeter of crushed stone to prevent the spread of any spilled oil. It is separated from other adjacent transformers by a 3-hour structural reinforced concrete fire wall. Minimum 2-hr fire integrity rated firewall extension panels have been added to the firewalls that separate the 1E and 1W main power transformers from each other, from the adjacent unit auxiliary transformers 141-1/2, and from system auxiliary transformer 142-1. The panels are described in Section 2.1.4.1.

A minimum 2-hr fire integrity rated firewall extension panels have been added to the firewalls that separate the 2E and 2W main power transformers from each other, from the adjacent unit auxiliary transformers 241-1/2, and from system auxiliary transformer 242-1. The panels are described in Section 2.1.4.1.

Safety-Related Equipment The transformer is not safety-related, nor is any of its auxiliary equipment.

Protection Criteria and Measures No safety-related equipment is in this zone.

The grade is designed to keep liquids from flowing to nearby structures.

2.3-209

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Transformer oil.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities The transformer is protected by an automatic deluge water spray system actuated by differential relay. Alarms and interlocks are provided which annunciate locally and in the Control Room to indicate operation of the system.

Thermistor wire detection is provided independent of the deluge valve which annunciates and alarms in the Control Room.

Design-Basis Fire The design-basis fire would occur if the oil in a transformer ignited and burned.

The spilled oil would be localized because of the base fill and the fire walls which are provided.

If a fire started in a transformer, it would be quickly extinguished by the deluge system. It would not spread to the Turbine Building or the Auxiliary Building because of the area configuration. Loss of the transformer would not affect the ability to safely shut down the reactor.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.154.

2.3.18.16 Main Power Transformer 2E (Fire Zone 18.10A-2)

This zone is shown on Figures 2.3-1 and 2.3-2.

For details, see Subsection 2.3.18.15 except:

a. At Braidwood, there is cable insulation that contributes to combustible materials.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.155.

2.3-210

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.17 Main Power Transformer 1W (Fire Zone 18.10B-1)

This zone is shown on Figures 2.3-1 and 2.3-2.

For details, see Subsection 2.3.18.15.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.156.

2.3.18.18 Main Power Transformer 2W (Fire Zone 18.10B-2)

This zone is shown on Figures 2.3-1 and 2.3-2.

For details, see Subsection 2.3.18.15 except:

a. At Braidwood, there is cable insulation that contributes to combustible materials.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.157.

2.3.18.19 Unit Auxiliary Transformer 141-1 (Fire Zone 18.10C-1)

This zone is shown on Figures 2.3-10 (Sheet 1) and 2.3-12 (Sheet 1).

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations that separate redundant shutdown-related systems. Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 18.10C-1/3.2A-1, 18.10C-1/5.3-1).

For details, see Subsection 2.3.18.15 The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.158.

2.3.18.20 Unit Auxiliary Transformer 241-1 (Fire Zone 18.10C-2)

This zone is shown on Figures 2.3-10 (Sheet 3) and 2.3-12 (Sheet 3).

As stated in Byron SSER 5, fire-rated seals are only required in bus duct penetrations that separate redundant shutdown-related systems. Internal bus duct, fire-rated seals are not provided at barriers that do not separate redundant shutdown-related systems or do not adversely affect safe shutdown as described in Section 2.4 (Fire Zones 18.10C-2/3.2A-2, 18.10C-2/5.3-2).

2.3-211

B/B - FPR AMENDMENT 29 DECEMBER 2020 For details, see Subsection 2.3.18.15.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.159.

2.3.18.21 Unit Auxiliary Transformer 141-2 (Fire Zone 18.10D-1)

This zone is shown on Figures 2.3-10 (Sheet 1) and 2.3-12 (Sheet 1).

For details, see Subsection 2.3.18.15.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.160.

2.3.18.22 Unit Auxiliary Transformer 241-2 (Fire Zone 18.10D-2)

This zone is shown on Figures 2.3-10 (Sheet 3) and 2.3-12 (Sheet 3).

For details, see Subsection 2.3.18.15.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.161.

2.3.18.23 System Auxiliary Transformers 142-1 and 142-2 (Fire Zone 18.10E-1)

This zone is shown on Figures 2.3-10 (Sheet 1) and 2.3-12 (Sheet 1).

For details, see Subsection 2.3.18.15.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.162. The transformers are approximately 50 feet apart.

2.3.18.24 System Auxiliary Transformers 242-1 and 242-2 (Fire Zone 18.10E-2)

This zone is shown on Figures 2.3-10 (Sheet 3) and 2.3-12 (Sheet 3).

For details, see Subsection 2.3.18.15.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.163. The transformers are approximately 50 feet apart.

2.3-212

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.25 River Screen House (Fire Zone 18.11-0)

This house is shown on Figure 2.3-29 for Byron Station and Figure 2.3-30 for Braidwood Station.

Fire Barrier Description Braidwood River Screen House The entire River Screen House below elevation 557 feet 0 inch (that is, below grade) is constructed of minimum 36-inch-thick structural reinforced concrete.

There are several openings in the floor slab at elevation 557 feet 0 inch for the traveling screens, various pumps, and access ladders for personnel. Eight 4-inch-diameter floor drains are also provided in this floor slab.

The exterior walls of the River Screen House are double-tee, precast concrete insulated "sandwich" panels, supported by unprotected steel beams and columns, and do not carry a fire rating. Louvers are provided in three of the walls.

A Battery Room is in the corner of the building. The floor of this room is an 18-inch-thick structural reinforced concrete slab, the walls are of 12-inch-thick hollow concrete masonry units, and the ceiling is a 6-inch cover of structural reinforced concrete on fluted steel decking formwork supported by unprotected steel beams. The door providing access to the room is not fire rated, and the walls of the enclosure carry no rating. The roof of the building at elevation 586 feet 4 inches is of 3-1/2-inch-thick precast concrete channel slabs supported by unprotected steel beams and columns which do not carry a fire rating.

Byron River Screen House The entire River Screen House below elevation 687 feet 0 inch (that is, below grade) is constructed of minimum 36-inch-thick structural reinforced concrete.

There are several openings in the floor slab at elevation 686 feet 6 inches for the traveling screens, various pumps, and access ladders for personnel. Seven 4-inch-diameter floor drains are also provided in this floor slab.

The exterior walls of the River Screen House are insulated metal siding, supported by unprotected steel beams, girts and columns, and do not carry a fire rating. Pneumatic operated louvers are provided in three of the walls. A manually operated rolling steel door is provided in the south wall.

An intermediate floor is provided at elevation 702 feet 0 inch and consists of a 9-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork. It is supported by unprotected steel beams and columns but provides a resistance of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to the spread of fire from the Diesel Oil Storage Tank Rooms to the floor level below.

2.3-213

B/B - FPR AMENDMENT 29 DECEMBER 2020 The Essential Service Water Makeup Pump Areas, which are adjacent to the Diesel Oil Storage Tank Room, are enclosed by a minimum 48-inch-high, 12-inch-thick structural reinforced concrete barrier. Access to the areas is by means of a grating stair and platform over the top of the barrier.

One 4-inch-diameter floor drain is provided in each Essential Service Water Makeup Pump Area. Two 4-inch-diameter floor drains are provided in the remaining floor area at elevation 702 feet 0 inch.

The roof at elevation 716 feet 0 inch over the Diesel Oil Storage Tank Rooms, which is the roof of the River Screen House, is a 3-inch clear cover of structural reinforced concrete over 2-inch fluted steel decking and is supported by steel beams and columns protected with a 3-hour rated fire-resistant covering. Other portions of the River Screen House Roof are of similar construction but are supported by unprotected steel beams and columns which do not carry a fire rating.

The Battery Room is in the northeast corner of the River Screen House. The floor at elevation 686 feet 6 inches is a 36-inch-thick structural reinforced concrete slab and carries a 3-hour fire rating. Two walls are 12-inch-thick hollow concrete masonry units. The remaining two walls are exterior walls of the Screen House as previously described and do not carry a fire rating. The roof slab of the Battery Room at elevation 699 feet 0 inch is a 4-inch cover of concrete over 2-inch fluted steel decking formwork supported by steel beams.

Safety-Related Equipment There is no safety-related equipment at the Braidwood River Screen House. The Byron River Screen House contains two safety-related diesel-driven ESW makeup pumps and their respective diesel oil storage tanks.

Protection Criteria and Measures The Byron River Screen House, the ESW makeup pumps and the diesel oil storage tank rooms are protected by an automatic CO2 system. Fires in other components will not affect safety-related equipment. Fire dampers are installed in the ventilation openings at Byron around the Diesel Oil Storage Tank Room.

The Braidwood River Screen House is located away from any safety-related structure so a fire would have no effect on any safety-related equipment.

2.3-214

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Acrylic, cable insulation, gaskets, grease, insulation, lube oil, miscellaneous and transient combustibles.

At Byron, fiber optic cable, nylon, plastic, polypropylene, and polyethylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities At Braidwood, portable extinguishers are provided. Component fires would be detected by various equipment monitors as a malfunction in the equipment. At Byron, portable extinguishers are provided. In addition, the ESW makeup pumps and oil tank rooms are protected by an automatic CO2 system. The 2-ton CO2 storage tank is located near column/row 7-E. A rupture of the CO2 storage unit would not affect the safety-related equipment due to its location. The CO2 system is actuated by rate-compensating detectors.

Ionization (or photoelectric) detectors are provided at Byron which alarm and annunciate in the Control Room. Ionization and ultraviolet detectors are provided at Braidwood which alarm and annunciate in the Control Room. There are also ultraviolet detectors at Braidwood.

An automatic local application CO2 system protects the ESW makeup pumps.

Design-Basis Fire At Braidwood, the design-basis fire would occur if all the combustible materials in the zone burned. There would be no safety-related equipment or structures affected by the fire.

At Byron, the design-basis fire would occur if all the combustibles in the zone burned. The diesel driven ESW makeup pumps are separated by approximately 40 feet, part height walls, and are protected by a local application CO2 system.

Loss of one ESW makeup pump is acceptable since a redundant pump is available. This zone is also a controlled access area.

A fire at either location is considered highly unlikely due to the separation of the various components in the buildings.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.164.

2.3-215

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.26 Byron River Screen House Diesel Oil Storage Tank Room B (Fire Zone 18.11-1)

This room is shown on Figure 2.3-29.

Fire Barrier Description Each Diesel Storage Tank Room is enclosed by 12-inch-thick structural reinforced concrete walls which carry a 3-hour fire rating. A 15-inch-high concrete curb is provided under each of these walls to contain any oil in the event of a tank rupture. A Label "A" fire door is provided into the room at the top of the curb.

There are no dampers in the outside air exhaust ducts because the tank room is located well away from any safety-related structures. All interior walls are provided with fusible link fire dampers.

Safety-Related Equipment The 2000-gallon diesel oil storage tank in this room is safety-related.

Protection Criteria and Measures This zone is separated from all other areas in the building by 3-hour fire barriers.

Combustible Materials Cable insulation, diesel fuel oil, plastic, and PVC.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities An automatic total flooding CO2 system is provided for this zone. It is actuated by rate compensating detectors. Portable extinguishers are provided in the remainder.

Ionization (or photoelectric) detectors are provided which annunciate and alarm in the Control Room.

Design-Basis Fire The design-basis fire would occur if the contents of the tank were ignited. This is considered highly unlikely for the following reasons:

a. There is no ignition source present.

b. An automatic total flooding CO2 system is provided to extinguish any fire which does occur.

c. The zone is bounded by 3-hour fire barriers 2.3-216

B/B - FPR AMENDMENT 29 DECEMBER 2020 In the event of a fire, the fuel supply for one diesel ESW makeup pump could be unavailable thereby rendering one pump inoperable. A redundant pump and fuel oil supply is provided.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.165.

2.3.18.27 Byron River Screen House Diesel Oil Storage Tank Room A (Fire Zone 18.11-2)

This room is shown on Figure 2.3-29.

For details, see Subsection 2.3.18.26.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.166.

2.3.18.28 Circulating Water Pump House (Byron), Lake Screen House (Braidwood) (Fire Zone 18.12-0)

These houses are shown on Figures 2.3-27 and 2.3-28, respectively.

Fire Barrier Description The entire Lake Screen House and Circulating Water Pump House below grade level is constructed of minimum 48-inch-thick structural reinforced concrete. At the Byron units, the floor at grade level is a 40-inch-thick structural reinforced concrete slab with several openings for various pumps and access ladders for personnel. At the Braidwood units, the floor is the same except it is 42 inches thick. Four-inch-diameter floor drains are provided.

The exterior walls of both buildings are insulated metal siding, supported by unprotected steel beams, girts, and columns and do not carry a fire rating.

Pneumatic operated louvers are provided in two of the walls.

The roof of the buildings is of 3-1/2-inch-thick precast concrete channel slabs and is supported by unprotected steel beams and columns.

The fire dampers installed in the horizontal ducts penetrating the fire walls are galvanized steel and are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

2.3-217

B/B - FPR AMENDMENT 29 DECEMBER 2020 A chemical feed tank building directly adjoins the Lake Screen House at Braidwood. The construction is identical to the Lake Screen House except that the floor at grade is 46 inches thick. In addition, five chemical storage tanks and chemical injection feed equipment are located outside the Lake Screen House on the north and west sides of the building. The tanks and injection equipment do not contribute to the combustible loading of this fire zone.

Safety-Related Equipment At Byron, there is no safety-related equipment in this fire zone.

At Braidwood, six Essential Service Water pump suction header upstream isolation valves are in valve pits.

Protection Criteria and Measures Fire dampers are provided in the Diesel Oil Storage Tank Room fire walls. The fire dampers are fusible link type which will close when the temperature exceeds 165 Degrees Fahrenheit.

Both structures are situated at a considerable distance from safety-related structures. The safety related valves at Braidwood are each contained in a separate concrete valve pit with a steel cover. As described in EC 361785, these valves are normally open, manually operated gate valves, which are not susceptible to fire damage that could change their position or adversely affect the SX pump suction flow paths. Therefore, a fire will have no effect on safety-related components or structures.

Combustible Materials Acrylic, cable insulation, gaskets, grease, lube oil, miscellaneous and transient combustibles, nylon, plastic, and polypropylene.

At Byron, polyethylene.

At Braidwood, CPVC, Kynar, PFA, plexiglass, PMMA, PVC, PTFE, PVDF, and rubber Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Six hose stations are provided. Portable extinguishers are also available.

Ionization (or photoelectric) detectors are provided at Byron which annunciate and alarm in the Control Room. Ionization and ultraviolet detectors are provided at Braidwood which annunciate and alarm in the Control Room.

2.3-218

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would occur if the oil contained in the circulating water pump motors was ignited. Most of the building would probably be damaged; however, safe shutdown of the reactor would be unimpaired. The motor-driven fire pump might also be damaged as well as the jockey pumps; however, the diesel fire pump would still be available and capable of handling the entire system.

2.3.18.29 Diesel-Driven Fire Pump Cubicles (Fire Zone 18.13-0)

The cubicles are shown on Figures 2.3-27 and 2.3-28.

Fire Barrier Description The Diesel Oil Tank Room contains the diesel-driven fire pump and its diesel oil storage tank. At the Byron units, the floor is a 40-inch-thick structural reinforced concrete slab, the walls are of 12-inch-thick hollow concrete masonry units and the ceiling is an 8-inch cover of structural reinforced concrete supported by protected steel beams. At the Braidwood units, the room is the same except the floor is 42 inches thick. These enclosures carry a 3-hour fire rating. An 8-inch-high concrete curb is provided under each of the walls to contain any oil in the event of an oil tank rupture. A Label "A" fire door is provided for access into the room.

Three-hour rated fire dampers are installed in the roof.

Safety-Related Equipment There is no safety-related equipment contained in this fire zone.

At Byron, the east exterior 3-hour fire wall has a non-rated opening for a louver that does not carry a fire rating. See EC 397405 for details.

Protection Criteria and Measure The diesel fire pump is separated from the motor-driven fire pumps by over 120 feet and a 3-hour fire wall. It is unlikely a single fire could disable both pumps.

Combustible Materials Diesel fuel oil, grease, lube oil, and polypropylene.

At Byron, acrylic, nylon, and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-219

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities Automatic sprinklers are provided in this area. Portable extinguishers and a hose station are also available.

Ionization (or photoelectric) detectors are provided at Byron which alarm and annunciate in the Control Room.

Design-Basis Fire A fire would disable the diesel-driven fire pump; however, the motor-driven fire pump would be available. The sprinkler system would reduce the effects of the fire. Actuation of the sprinkler system would alarm in the Control Room.

If the temperature exceeds 165 Degrees Fahrenheit, the fusible links will melt, and the fire dampers will close. The spread of heat and combustion products will be stopped by the fire dampers. Ductwork in this zone may be damaged in the event of a design-basis fire; however, this will not affect the safe shutdown of the reactor.

2.3.18.30 ESW Cooling Tower Electrical Equipment Room, Division 12 (Fire Zone 18.14A-1)

This zone is shown in Figure 2.3-31 (Sheet 2).

Fire Barrier Description The floor at elevation 874 feet 6 inches is a 24-inch-thick structural reinforced concrete slab. A sump is provided in the corner of the room. The walls are 18-inch-thick structural reinforced concrete. The walls separating this area from the Unit 2 Electrical Equipment Room and the ramp area carry a 3-hour fire rating except for a portion of the wall that separates this area from the ramp area where there is a non-rated opening for an exhaust damper and does not carry a fire rating. Reference EC 395618 for details. Label "A" fire doors are provided and lead to an adjacent Electrical Equipment Room and to the exterior. The ceilings at elevation 895 feet 0 inch and at elevation 899 feet 0 inch are minimum 12-inch-thick structural reinforced concrete and are the roof of this building. This roof includes a concrete "penthouse" for ventilation louvers and does not carry a fire rating.

2.3-220

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment There are safety-related power and control cable trays in this zone. Safety related electrical equipment is contained in this zone as follows:

a. 132Z1-MCC-(1AP92E)

b. 480-V switchgear - 132Z

c. Cooling Tower Electrical Equipment Room Division 12 Ventilation System.

Protection Criteria and Measures This area is protected by one hydrant. This zone is separated from the ESW cooling towers by fire-rated walls and from the rest of the plant by over 100 feet of distance.

Combustible Materials Acrylic, cable insultation, gaskets, lube oil, plastic, and prefilters.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities This zone is equipped with ionization detectors which will annunciate in the Control Room.

Three hydrants are provided to protect the ESW cooling towers at least one of which has access to this fire zone.

Design-Basis Fire The design-basis fire would occur if all the combustible materials in the zone were ignited. The resulting fire would damage one of the two electrical divisions provided to power the cooling tower. The results of the fire would be acceptable since a redundant division is provided.

In the event of a design-basis fire, the ventilation system may be damaged. If it is damaged, the redundant cooling tower electrical equipment room and associated ventilation system would function to safely shut down the reactor.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.167.

2.3-221

B/B AMENDMENT 29 DECEMBER 2020 2.3.18.31 ESW Cooling Tower Electrical Equipment Room, Division 22 (Fire Zone 18.14A-2)

This zone is shown on Figure 2.3-31 (Sheet 2).

For details, see Subsection 2.3.18.30 except that:

a. The safety-related equipment is 232Z1-MCC-(2AP92E) and 480-V switchgear - 232Z.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.168.

2.3.18.32 ESW Cooling Tower Electrical Equipment Room, Division 11 (Fire Zone 18.14B-1)

This zone is shown on Figure 2.3-31 (Sheet 1).

For details, see Subsection 2.3.18.30 except that:

a. The safety-related equipment is 131Z1A-MCC-(1AP89E), 131Z1-MCC-(1AP03E), and 480-V switchgear - 131Z.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.169.

2.3.18.33 ESW Cooling Tower Electrical Equipment Room, Division 21 (Fire Zone 18.14B-2)

This zone is shown on Figure 2.3-31 (Sheet 1).

For details see Subsection 2.3.18.30 except that:

a. The safety-related equipment is 231Z1-MCC-(2AP93E) and 480-V switchgear - 213Z.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.170.

2.3-222

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.34 Makeup Demineralizer Building (Braidwood) (Fire Zone 18.15-0)

This building is shown on Figures 2.3-2, 2.3-10 (Sheet 2), 2.3-12 (Sheet 2) and 2.3-42.

Fire Barrier Description The floor at elevation 401 feet 0 inch is an 8-inch concrete topping on a 60-inch-thick structural reinforced concrete base slab. Several 4-inch-diameter floor drains are provided. The perimeter walls of this zone are of 12-inch-thick hollow concrete masonry units or insulated metal siding supported by unprotected steel beams, girts, and columns. The wall common to this zone and to the Auxiliary Boiler Room is a 2-hour rated masonry fire wall. The other perimeter walls, which are exterior walls or walls common to the Turbine Building Grade Level, do not carry a fire rating.

The second-floor level, at elevation 426 feet 0 inch, is a 4-inch clear cover of structural reinforced concrete on 2-inch fluted steel decking formwork, is supported by unprotected steel beams and columns and carries no fire rating.

Several 4-inch-diameter floor drains are provided. This floor level is entirely enclosed by insulated metal siding exterior walls.

The roofs of the building, at elevation 426 feet 0 inch and at elevation 451 feet 0 inch, are of 3-1/2-inch-thick precast concrete channel slabs and are supported by unprotected steel beams and columns.

Safety-Related Equipment There is no safety-related equipment in this zone.

Protection Criteria and Measures The building is separated from safety-related structures by over 100 feet.

Combustible Materials Cable insulation, charcoal, FRP, grease, HDPE, hydrazine, lube oil, miscellaneous and transient combustibles, plexiglass, PMMA, polyethylene, prefilters, PP, PPE, PVC, and rubber.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Twelve manual hose stations are provided throughout this zone. Also, one hose station can be brought in from the Turbine Building if required. Portable extinguishers are provided.

2.3-223

B/B - FPR AMENDMENT 29 DECEMBER 2020 Design-Basis Fire The design-basis fire would occur if all the combustibles in the zone burned.

Reactor shutdown and cooling would not be affected. No safety-related equipment or structures would be affected.

2.3.18.35 Sulfuric Acid Tank #1 (Byron) (Fire Zone 18.16-1)

This tank is shown on Figure 2.3-1.

Fire Barrier Description The two 50,000-gallon sulfuric acid tanks are of welded steel plates and stiffeners. Each tank is located on a structural reinforced concrete foundation.

The tank area is surrounded by a perimeter of crushed limestone and an earthen berm.

Safety-Related Equipment The tank is not safety related.

Protection Criteria and Measures The tank has a berm around it to contain the contents of the tank should a rupture occur. The tank is located well away from any safety-related structures.

Combustible Materials This zone contains no combustible materials Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A hydrant is in the general vicinity of the tank.

Design-Basis Fire A design-basis fire would occur if, due to a fire, the tank was damaged.

Failure of the sulfuric acid tanks would have no impact on safe shutdown and cooling of the reactor. These tanks have been abandoned in place.

2.3-224

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.36 Sulfuric Acid Tank #2 (Byron) (Fire Zone 18.16-2)

This tank is shown on Figure 2.3-1.

For details, see Subsection 2.3.18.35.

2.3.18.37 Hydrogen/Nitrogen Storage Area (Fire Zone 18.17-0)

This area is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description There are no walls enclosing this area. It is 100 feet away from the nearest source of combustible material, the 125,000-gallon diesel oil storage tank.

Safety-Related Equipment The hydrogen/nitrogen storage facility is not safety-related and there is no safety-related equipment within 100 feet.

Protection Criteria and Measures The nitrogen is stored in cryogenic form in a steel tank at 250 psi. The tank capacity is 3000 gallons.

The hydrogen storage facility is located outdoors over 100 feet away from the Turbine Building and well away from any safety-related structure or component.

The flow control system is provided with an excess flow manifold which will stop hydrogen flow if it exceeds 20,000 scfh. This feature is provided in the event the hydrogen supply line should break. The storage facility is mechanically separated into three segments. An active storage segment which consists of a 100,000 scf tube trailer (two stanchions), a reserve storage segment which consists of seven 7500 scf storage tubes, and a backup reserve segment which consists of two 7500 scf storage tubes. The segments are connected in such a manner that a single failure in the piping will only deplete one storage segment. The two reserve portions are stacked into a 3x3 vertical rack. The reserve facility is permanently installed.

Combustible Materials Hydrogen storage cylinders.

Fire Loading This is an outdoor area and fire loading is not calculated.

2.3-225

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detecting Capabilities Hydrants are in the general vicinity of the storage facility. Any large line break would be detected by pressure switches in the hydrogen piping and the line would be quickly shut off by the excess flow check valve. Since most of the hydrogen piping is either embedded in concrete or buried underground, it is unlikely any damage would be done.

Design-Basis Fire In the event of a line break in an exposed portion of piping, the hydrogen flow would be immediately halted by the excess flow check valve. A failure in the facility itself would not affect safety-related structures or components.

2.3.18.38 Sodium Hypochlorite Tank (Byron) (Fire Zone 18.19-0)

This tank is shown on Figure 2.3-1.

Fire Barrier Description The 60,000-gallon sodium hypochlorite tank is of welded steel plates and stiffeners and is located on a structural reinforced concrete foundation. The tank area is surrounded by an earthen berm.

For further details, see Subsection 2.3.18.35.

2.3.18.39 Fuel Oil Storage Tanks (Fire Zone 18.20-0)

This zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description The 125,000-gallon and 50,000-gallon fuel oil storage tanks are of welded steel plates and stiffeners and are located on a structural reinforced concrete foundation. The tank area is surrounded by an earthen berm and will be lined with asphalt or concrete.

Safety-Related Equipment No safety-related equipment is in this zone.

2.3-226

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The tanks are located outside approximately 100 feet from the Turbine Building and 50 and <100 feet for PWST and filtered water tanks from any other tanks or buildings. The outdoor diesel oil storage tanks are surrounded by a berm which can contain the entire 175,000 gallons of the tanks.

Combustible Materials Diesel fuel oil.

At Byron, plastic and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Hydrants are in the general vicinity of the tanks.

Design-Basis Fire The design-basis fire would result if the tanks ruptured and the oil ignited and burned. The burning oil would be contained within the berm. The fire would not spread to the adjacent structures due to the large distances. At Byron and Braidwood, hydrants and manual suppression capability will prevent the fire from spreading from the berm. The ability to safely shut down the reactor would not be affected by a rupture of both tanks or by any fire in this zone.

2.3.18.40 Demineralizer Building (Braidwood Only)

Refer to Subsection 2.3.18.34.

2.3-227

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.41 Makeup Demineralizer Building (Byron) (Fire Zone 18.22-0)

This building is shown on Figure 2.3-1.

Fire Barrier Description The floor at elevation 401 feet 0 inch is an 8-inch topping of finished concrete over a 60-inch-deep structural concrete pad. The exterior walls are insulated metal siding which carry no fire rating. There are no interior walls on the ground floor. The ceiling above this floor is the roof (elevation 426 feet 0 inch) of the Makeup Demineralizer Building. The exterior walls are insulated siding which have no fire rating. The roof is a series of 3-1/2-inch deep precast concrete slabs covered with 2 inches of sized insulation and supported by steel beams and columns which are unprotected and have no fire rating.

Safety-Related Equipment There is no safety-related equipment in this zone.

Protection Criteria and Measures This building is separated from safety-related components and structures by over 50 feet.

Combustible Materials Acrylic, cable insulation, gaskets, grease, lube oil, miscellaneous and transient combustibles, nylon, plastic, polyethylene, polypropylene, and rubber.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Hose stations are provided in this zone. Portable extinguishers are available in this zone and adjacent zones.

Design-Basis Fire The design-basis fire would occur if all the combustibles in this zone burned.

Reactor shutdown and cooling would not be affected. No safety-related equipment or structures would be affected.

2.3-228

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.42 Condensate Storage Tank Area (Fire Zone 18.23-0)

This fire zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description At each of the stations, the two condensate storage tanks are of welded aluminum plates and stiffeners. Each tank is located on a structural reinforced concrete foundation.

Safety-Related Equipment The storage area is not considered safety related. The two condensate storage tanks are capable of supplying water to the Auxiliary Feedwater System. A redundant supply is available from the Essential Service Water System.

For further details, see Subsection 2.3.18.35.

The analysis of the effect of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.171.

2.3.18.43 Turbine Building Sampling Room (Fire Zone 18.24-0)

This zone is shown on Figure 2.3-12 (Sheets 2 and 4).

Fire Barrier Description The floor at elevation 401 feet 0 inch is a 7-inch concrete topping over a 109-inch-thick structural reinforced concrete base slab, which is the foundation of this portion of the Turbine Building. Two 4-inch-diameter floor drains are provided in this room. Three of the perimeter walls are of 12-inch-thick hollow concrete masonry units and carry a 3-hour fire rating. They extend up to within 1 inch of the ceiling above, and this remaining space is packed with a 1-inch blanket of Thermafiber insulation. Label "A" fire doors are provided in these walls and lead to the Turbine Building Ground Floor Level of Unit 1 and Unit 2 respectively. The fourth wall is an insulated metal siding exterior wall, as previously described for the Turbine Building.

The ceiling slab at elevation 431 feet 9 inches is a 6-inch clear cover of structural reinforced concrete over 3-inch fluted steel decking formwork, supported by steel beams which are protected with a fire-resistant covering and carries a 3-hour rating.

The fire dampers installed in the horizontal ducts penetrating the fire walls are galvanized steel and are rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

Safety-Related Equipment There is no safety-related equipment in this zone.

2.3-229

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures This zone is separated from the rest of the plant by walls of substantial construction.

Fire dampers are provided in the fire walls. The fire dampers are fusible link type which close when the temperature exceeds 165 Degrees Fahrenheit.

Combustible Materials Cable insulation, gaskets, miscellaneous and transient combustibles, and polypropylene.

At Byron, acrylic, nylon, and plastic.

At Braidwood plexiglass and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Hose stations and portable extinguishers are available in adjacent zones.

Design-Basis Fire If the temperature exceeds 165 Degrees Fahrenheit, the fusible links will melt, and the fire dampers will close. There is no radioactive HVAC equipment in this zone. The spread of heat and combustion products will be stopped by the fire dampers. Some ductwork in this zone may be damaged in the event of a design-basis fire; however, this will not affect the safe shutdown of the plant.

2.3.18.44 Primary Water Storage Tank - Unit 1 (Fire Zone 18.25-1)

This tank is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description The tank is field-fabricated aluminum plates and stiffeners and is located on a structural reinforced concrete foundation. The tank and the foundation have been designed to resist seismic forces.

Safety-Related Equipment The tank is not safety related.

2.3-230

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures The tank is more than 50 feet from any fire hazard and well separated from the Turbine Auxiliary Buildings. The tank is normally kept full of water.

Combustible Materials This zone contains no combustible materials.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities One manual hose station, part of the loop fire main, is available if ever required.

Design-Basis Fire With no combustibles within the zone, there can be no fire.

2.3.18.45 Primary Water Storage Tank - Unit 2 (Fire Zone 18.25-2)

This tank is shown on Figures 2.3-1 and 2.3-2.

For details, see Subsection 2.3.18.44.

2.3.18.46 TSC/Condensate Cleanup Building (Fire Zone 18.26-0)

This zone is shown on Figures 2.3-1, 2.3-2, 2.3-12 (Sheet 2), and 2.3-41.

Fire Barrier Description Condensate Cleanup Building - Elevation 401 feet 0 inch The floor slab at elevation 401 feet 0 inch is an 8-inch clear concrete topping over a 36-inch deep structural slab which is the foundation of the building. Four-inch-diameter floor drains are provided to remove chemical spills and water. All perimeter walls are 12-inch-thick structural reinforced concrete. The east, south, and west walls are covered with uninsulated metal siding. The door in the north wall which leads to the Turbine Building is a Label "A" door and the wall carries a 3-hour fire rating. The other openings in the exterior walls are louvers, a rolling steel door, and a hollow metal door; none of which have a fire rating.

The ceiling above this area is a 9-inch clear cover of structural reinforced concrete over 3-inch deep fluted steel decking which is supported by unprotected steel beams and carries no rating.

2.3-231

B/B - FPR AMENDMENT 29 DECEMBER 2020 Technical Support Center - Elevation 435 feet 0 inch The floor at elevation 435 feet 0 inch is the ceiling above the Condensate Cleanup Area. The concrete slab in the monitor room is the same thickness as the rest of the floor and is recessed to an elevation of 434 feet 3 inches to allow a 9-inch deep access pit under a paneled floor which is flush with the other area at elevation 435 feet 0 inch.

The perimeter walls are 12-inch-thick structural reinforced concrete walls. Except for the north wall which carries a 3-hour fire rating, all the perimeter walls are covered with uninsulated metal siding. The interior walls are non-rated gypsum drywalls except for the concrete block stair hall enclosures which have a 2-hour rating. The door in the stair hall enclosure is a Label "B" door. None of the other interior doors are rated. The ceiling above elevation 435 feet 0 inch is a 9-inch clear cover of concrete over a 3-inch deep fluted steel deck. The interior drywell extends up to the bottom of the slabs.

Technical Support Center - Elevation 452 Feet The floor at elevation 452 feet is the ceiling above the floor at elevation 435 feet.

The exterior walls are 12-inch-thick structural reinforced concrete in the Technical Support Center Area. The east and west walls are covered with uninsulated metal siding. The south wall is adjacent to the HVAC room which is enclosed by uninsulated metal siding.

The single point of access to the Turbine Building from the Technical Support Center is through a vestibule which has a Label "A" door on the north wall. The single egress point from the HVAC room is a non-rated pair of doors which leads to the turbine building across the roof at another pair of non-rated doors. The ceiling above the area is a 9-inch clear cover of concrete over a 3-inch deep fluted steel deck. There are no openings in the roof other than roof drains.

Safety-Related Equipment None.

Protection Criteria and Measures This zone is separated from the Turbine Building by 3-hour fire walls.

2.3-232

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Cable insulation, charcoal, gaskets, grease, insulation, lube oil, miscellaneous and transient combustibles, plastic, paper, and polypropylene.

At Byron, acrylic and nylon.

At Braidwood, ABS and PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Six manual hose stations are provided in this fire zone. (There are 3 hose stations in the TSC and 3 hose stations in the condensate cleanup building.) A manual deluge system is provided for the HVAC charcoal filter unit. A temperature switch mounted in the charcoal bank will annunciate in the control room.

Design-Basis Fire A fire in the Condensate Cleanup Building might disable the pumps located therein. As the equipment located there is only used while the plant is shut down, there will be no effect on plant operations should the equipment be disabled.

The TSC is only required under accident conditions and has no impact on plant operations when activated. Therefore, a fire in this area will have no effect on the ability to safely shut down the plant.

2.3.18.47 Storage Zones 2.3.18.47.1 Level B Storage Building (Byron) (Fire Zone 18.27-0)

This zone is shown on Figure 2.3-1.

Fire Barrier Description The floor at elevation 400 feet 6 inches is a 15-inch-thick structural reinforced concrete slab which is supported by 33-inch deep footings. The exterior walls are 12-inch-thick structural reinforced concrete and the interior walls are 9 inches in thickness. The only opening in the wall is a pair of hollow metal doors which are not fire rated. The ceiling of the Storage Enclosure is a 9-inch-thick structural reinforced concrete roof slab.

2.3-233

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment None.

Protection Criteria and Measures This building is separated from the Turbine Building by walls of substantial construction.

Combustible Materials Battery cells, cable insulation, paint, paint thinner, and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A fire hydrant is located nearby, and hose stations are also accessible in the makeup demineralizer buildings. There is no fire detection.

Design-Basis Fire The design-basis fire would occur if all combustibles in the zone burned. This would not affect safe shutdown of the plant.

2.3.18.47.2 Bottle Storage Enclosure (Braidwood) (Fire Zone 18.27-0)

This zone is shown is on Figure 2.3-2.

Fire Barrier Description The floor at elevation 400 feet 6 inches is a 15-inch-thick structural reinforced concrete slab which is supported by 33-inch deep footings. The exterior walls are 12-inch-thick structural reinforced concrete and the interior walls are 9 inches in thickness. The only opening in the wall is a pair of hollow metal doors which are not fire rated. The ceiling of the Storage Enclosure is a 9-inch-thick structural reinforced concrete roof slab.

Safety-Related Equipment None.

Protection Criteria and Measures This building is separated from the Turbine Building by walls of substantial construction.

2.3-234

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials Gaskets, methane, and propane.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A fire hydrant is located nearby, and hose stations are also accessible in the Makeup Demineralizer Buildings. There is no fire detection.

Design-Basis Fire The design-basis fire would occur if all combustibles in the zone burned.

Instrumentation in the High-Level Laboratory and Counting Room would be disabled due to interruption of the gases. This would not affect safe shutdown of the plant.

2.3.18.48 Waste Treatment Building (Fire Zone 18.28-0)

This building is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description The bottom of the Clean Water Storage Area below grade in the Waste Treatment Building at elevation 390 feet 3 inches is an 18-inch-thick structural reinforced concrete pad. The walls are also 18-inch-thick structural reinforced concrete.

For Byron, the floor at elevation 401 feet 0 inch is a 54-inch-thick structural reinforced concrete pad which is the foundation of this building. For Braidwood, the floor is 21 inches thick. There are several openings and penetrations in the slab for piping and water treatment pits. There are 4-inch floor drains in the slab to remove chemicals and water.

The exterior walls of the Water Treatment Building are insulated metal siding which are supported by an unprotected girt framing system. The openings in the walls include a rolling steel door, a hollow metal door, and two 4-foot wide louvers.

The ceiling above is a roof which is a series of 3-1/2-inch-thick precast concrete slabs which are supported by unprotected steel roof framing and has no fire rating.

2.3-235

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment None.

Protection Criteria and Measures The waste oil tank is provided with a curb which will contain the contents of the tank should it rupture.

Combustible Materials Cable insulation, grease, lube oil, neoprene, plastic, and PVC.

At Byron, acrylic, nylon, and polypropylene.

At Braidwood, miscellaneous combustibles, plexiglass, PMMA, and polyethylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Two manual hose stations are located inside this building and fire hydrants are also located near the building. The waste oil tank is provided with an overhead sprinkler system which annunciates and alarms in the Control Room when actuated.

Design-Basis Fire The design-basis fire would occur if the entire contents of the building burned.

The loss of waste treatment would not have any effect on plant operations. The building is also located well away from the main plant so the fire will not spread beyond the building.

2.3.18.49 Aboveground Vehicle Fuel Dispensing Areas (Fire Zone 18.29-0)

These areas are shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description At Byron, the 2,000-gallon diesel fuel oil tank and the 2,500-gallon gasoline storage tank are concrete-encased aboveground tanks. In addition, the tanks are located at least 50 feet from the nearest permanent plant structure.

At Braidwood, two 2,500 gallon above ground storage tanks (split fuel 1,250-gallon diesel, 1,250-gallon gasoline) are installed. These tanks are located outside the protected area fencing and are not near any permanent plant structure.

2.3-236

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment None.

Protection Criteria and Measures Fire hydrants and fire extinguishers are in the vicinity of the tanks.

The vehicle aboveground gasoline and diesel fuel dispensing tanks are designed with features to reduce the potential for a gasoline or diesel fuel fire. Each tank is equipped with a secondary containment to prevent fuel leakage from being released to the surrounding area. The tanks are equipped with two types of leak detection equipment, a tank level probe and an interstitial sensor. The tanks are equipped with 7-gallon spill/overspill containments (Byron) and 5-gallon spill/overspill containments (Braidwood), overfill prevention valves on the fill tubes, and overfill alarms.

The gasoline tanks are equipped with Stage I and Stage II vapor recovery systems to prevent the release of gasoline vapors to the atmosphere in the area around the tanks. The aboveground tank assemblies (including the concrete encasement at Byron and integral secondary containment with thermal insulation at Braidwood) have a 2-hour fire rating. Collision protection is provided by concrete filled pipe bollards installed around the perimeter of each aboveground dispensing tank locations.

Combustible Materials Diesel fuel oil and gasoline.

Fire Loading This is an outdoor area and is not near any permanent structure. fire loading is not calculated.

Extinguishing and Detecting Capabilities Fire hydrants and fire extinguishers are available in the vicinity. There is no fire detection provided in this zone.

Design-Basis Fire The design-basis fire would occur if all 4,500 gallons of fuel oil at Byron or all 5,000 gallons of fuel oil at Braidwood were released from the tanks and ignited.

The fuel dispensing pumps would be inoperable but there would be no other effect on plant operations and shutdown.

2.3-237

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.50 New and Used Oil Storage Pads (Fire Zone 18.30-0)

This zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description New Oil Storage Pad The pad for New Oil Storage is a slopping concrete topping which varies from 3 1/2 inches to 2 inches over a 12-inch-thick structural reinforced concrete slab.

The thickness of the slab increases to 38 inches around the perimeter. There is a 6-inch-diameter floor drain in the center of the pad and a 9-1/2-inch-high structural reinforced concrete curb for the containment of possible oil spills.

Used Oil Storage Pad The pad for Used Oil Storage is a concrete topping which varies in thickness from 3-1/2 inches to 2 inches over a 12-inch-thick structural reinforced concrete slab. The perimeter of the slab is increased in depth to 38 inches to act as a footing for the pad. There is a 6-inch-diameter floor drain in the center of the pad and a 9-1/2-inch high, 8-inch-thick structural reinforced concrete curb for the containment of oil spills.

Safety-Related Equipment None.

Protection Criteria and Measures The new and used oil pads are separated from the remainder of the plant by about 50 feet. Fire hydrants are located nearby.

Combustible Materials Lube oil.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Fire hydrants are located nearby.

Design-Basis Fire The design-basis fire would occur if all the oil on both pads burned. As the pads are well away from the plant, there would be no effect on plant operation.

2.3-238

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.51 Acid Pump House (Byron) (Fire Zone 18.31-0)

This zone is shown on Figure 2.3-1.

Fire Barrier Description The floor is a 12-inch-thick structural reinforced concrete slab which is supported by a 48-inch-deep footing wall. There are no drains in the floor but there is a sump pit. The perimeter walls which are exterior walls are 12-inch-thick structural reinforced concrete block walls. There is a non-rated door located in the north wall. The ceiling above is a 9-inch-thick structural reinforced concrete roof slab.

Safety-Related Equipment None.

Protection Criteria and Measures This enclosure is separated from the main plant by over 100 feet.

Combustible Materials Acrylic, grease, nylon, plastic, and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities At least one fire hydrant is within 100 feet of this zone if ever required. There is no fire detection.

Design-Basis Fire If there is a fire, the pump will not function. This will not affect plant operation or shutdown.

2.3-239

B/B - FPR AMENDMENT 29 DECEMBER 2020 2.3.18.52 Receiving Building and Warehouse (Fire Zone 18.32-0)

This zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description The floor is a 54-inch-thick structural reinforced concrete slab which is the foundation of the receiving building. A 4-inch floor drain in the toilet is the only drain in the receiving building. The warehouse for Byron Station also has two floor drains. The perimeter walls are the exterior walls and are non-rated insulated metal siding up to the top of the parapet. The interior walls are hollow concrete block or solid concrete block and extend up to 1 inch from the bottom of the roof deck. The resulting space is packed with Thermafiber. Doors in these walls are not fire rated. At Byron, one interior wall is the former south side exterior wall of the warehouse and is not fire rated. The ceiling above is the roof which is a series of 3-1/2-inch deep precast concrete slabs supported by unprotected steel roof framing. There are four hose cabinets located around the inside of the perimeter walls of the receiving building. Four additional hose stations are in the warehouse.

Safety-Related Equipment None.

Protection Criteria and Measures This building is located about 50 feet away from the Service Building and is provided with hose stations inside the building and access to fire hydrants outside.

Combustible Materials Cable insulation, gaskets, insulation and miscellaneous and transient combustibles.

At Byron, paper and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

The Braidwood fire loading indicated is for the receiving building only.

Extinguishing and Detecting Capabilities An automatic sprinkler system is provided that alarms and annunciates in the Control Room. The receiving building office area is not covered by this system.

At Byron, the automatic sprinkler system for the warehouse addition on the south side of the warehouse is not installed to regulatory-related (augmented quality) 2.3-240

B/B - FPR AMENDMENT 29 DECEMBER 2020 requirements. A manual isolation valve provides a quality class break between the regulatory-related and non-regulatory-related fire protection lines.

There are eight manual hose stations located in this zone and two fire hydrants nearby outside the zone. There is no fire detection.

Design-Basis Fire If a fire occurs, whatever is currently located in the building may be damaged or destroyed. This will not affect safe shutdown or operation of the plant.

2.3.18.53 Gatehouse (Fire Zone 18.33-0)

This zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description Elevation 401 feet 6 inches The floor at elevation 401 feet 6 inches is an 8-inch concrete topping over a 12-inch-thick concrete base slab which is the foundation of the Gatehouse. The exterior walls are 11-5/8-inch-thick combination 3-5/8-inch face brick and 7-5/8-inch concrete insulated concrete block which extends up to elevation 416 feet-10 inches where the face brick ends. The wall is supported by an unprotected framing system of steel columns and beams and carries no rating. None of the doors in the exterior walls carry a fire rating. The interior walls are 7-5/8 inches thick hollow or solid concrete block.

The ceiling above at elevation 417 feet 0 inch is a 4-inch clear cover of structural reinforced concrete over a 2-inch deep fluted steel deck which is supported by unprotected steel framing and carries no rating.

Elevation 417 feet 0 inch The floor at elevation 417 feet 0 inch is the ceiling above the floor at elevation 401 feet 0 inch. The perimeter walls are 11-5/8-inch-thick insulated hollow concrete block and are covered with a cantilever supported system of uninsulated metal siding which extends up to the parapet cap. The interior walls are 7-5/8-inch-thick hollow concrete block and extend up to within 1 inch of the bottom of the roof deck. The resulting space is packed with Thermafiber. The ceiling above at elevation 432 feet 1-3/4 inches is a series of 3-1/2-inch-thick precast concrete roof slabs. There are four roof openings and three storm drains in the roof.

2.3-241

B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment None.

Protection Criteria and Measures The Gatehouse is located about 50 feet away from the Service Building and Receiving Building.

Combustible Materials Cable insulation, fiber optic cable, gaskets, insulation, and paper.

At Byron, acrylic, nylon, plastic and polypropylene.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Four manual hose stations are located inside the building and fire hydrants outside the building are also accessible.

Design-Basis Fire The Gatehouse contains no equipment required for plant operation or shutdown and, therefore, a fire in this zone will not affect the ability to safely shut down the plant.

2.3.18.54 Welding Gas Storage Building (Fire Zone 18.34-0)

This zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description The floor at elevation 401 feet 0 inch is a structural reinforced concrete slab which varies in thickness from 12 inches at the center to 48 inches at the perimeter and is the foundation for this building. The building is divided into six cubicles which are enclosed on three sides with hollow concrete block and are open on the fourth side. The entire structure is covered with a gable roof of 18-gauge galvanized metal deck. Framed openings are provided between adjacent cubicles to ensure proper ventilation of gases which may build up near the entrance of the building.

2.3-242

B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures This building is located over 50 feet away from the main plant and 20 feet away from the used oil pad. The fuel gases are separated from the oxidizer gases by an 8-inch block exposure wall.

Combustible Materials Fuel gases.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities A fire hydrant is available for fire suppression. There is no fire detection.

Design-Basis Fire The design-basis fire would occur if all the combustibles in this zone were ignited. As these gases are used only for welding, cutting and brazing, there will be no effect on plant operations. This building is located well away from the plant so any potential fire would not have any effect on safety-related structures or equipment.

2.3.18.55 Security Diesel Motor Control Center (Fire Zone 18.35-0)

This zone is shown on Figure 2.3-10 (Sheet 4).

Fire Barrier Description The floor at elevation 426 feet 0 inch is the mezzanine floor of the turbine building and is a 4-inch clear cover of concrete over a 2-inch-deep fluted steel deck which is supported by unprotected steel beams and carries no rating. The walls are 7-5/8-inch-thick hollow concrete block masonry with one non-rated door opening.

The ceiling above this area is a 3-inch clear cover of structural reinforced concrete over a 3-inch-deep fluted steel deck which is supported along its perimeter by the masonry walls and mid-span by an unprotected steel beam.

Safety-Related Equipment None.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures This zone is not located near safety-related equipment.

Combustible Materials Cable insulation.

At Byron, plastic.

At Braidwood, PMMA.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Manual hose stations and portable extinguishers are available from the surrounding area.

Ionization (or photoelectric) detection is provided which annunciates in the Control Room.

Design-Basis Fire The design-basis fire would disable the security system emergency power supply, but the fire would be confined to this zone. The ability to safely control and shut down the plant would not be affected.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.172.

2.3.18.56 Relay House (Fire Zone 18.36-0)

This zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description The floor is a 6-inch slab on 1-1/2-inch decking which is the ground floor of the relay house. The perimeter walls are exterior walls which are 11 5/8-inch-thick hollow concrete block. The north and south walls each have a non-rated double door and two non-rated louvers. The ceiling above the area is a series of 10-inch-deep precast concrete roof slabs.

Safety-Related Equipment None.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Protection Criteria and Measures This zone is well over 100 feet from the nearest safety-related structure.

Combustible Materials Miscellaneous combustibles.

At Byron, acrylic, cable insulation, and plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Ionization (or photoelectric) detection is provided and annunciates in the control room.

Design-Basis Fire The design-basis fire would destroy this structure. It would not spread to other zones due to the large distances to other structures. A fire in this zone would not have any effect on the ability to safely shut down the plant.

The analysis of the effects of a fire in this zone on cables required for safe shutdown is discussed in Subsection 2.4.2.173.

2.3.18.57 Maintenance Building (Fire Zone 18.37-0)

This zone is shown on Figures 2.3-1 and 2.3-2.

Fire Barrier Description The floor is a 12-inch-thick structural reinforced concrete slab and is the foundation of this building. There is a 4-inch diameter floor drain in this slab located in the toilet. The perimeter walls are exterior walls and are 11 5/8-inch-thick hollow concrete block masonry. Openings in the wall include a non-rated rolling steel door, two non-rated hollow metal doors, two non-rated louvers, and two non-rated ventilator openings.

The interior walls which are 7-5/8-inch-thick hollow concrete block masonry walls, extend up to 1 inch below the ceiling. The resulting space is packed with Thermafiber. The ceiling above the area is the underside of a series of 10-inch-deep precast slabs. These concrete slabs are supported by the masonry walls along the perimeter of the roof.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment None.

Protection Criteria and Measures This zone is well over 100 feet from the nearest safety-related structure.

Combustible Materials Miscellaneous combustibles.

At Byron, plastic.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities No extinguishing or detecting capability is provided.

Design-Basis Fire The design-basis fire would destroy the structure. It would not spread to other zones due to the large distances to other structures. A fire in this zone would not have any effect on the ability to safely shut down the plant.

2.3.18.58 Illinois Department of Nuclear Safety (IDNS) Building (Fire Zone 18.38-0)

This building is shown on Figures 2.2-1, 2.2-2, 2.3-1, and 2.3-2.

Fire Barrier Description The floor of the IDNS Building is a 6-inch concrete slab. The walls are metal siding and are supported by an unprotected framing system of steel columns and beams. The interior walls are constructed of fire-resistant gypsum board. The walls carry no rating. None of the doors in the exterior walls carry a fire rating.

The roof of the building is ribbed decking and carries no rating. There is an acoustic ceiling under the roof.

There is a 50-kW diesel generator located outside of the IDNS building. A 560-gallon fuel tank is buried next to the generator. In addition, there is a 75-kVA, oil-filled, pad-mounted transformer located outside of the IDNS building at Braidwood.

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B/B - FPR AMENDMENT 29 DECEMBER 2020 Safety-Related Equipment None.

Fire Protection Criteria and Measures The IDNS building and pad-mounted transformer at Braidwood are located within 50 feet of the Unit 2 RWST and the Fuel Handling Building, which are safety-related structures. The exterior walls of both structures are of 3-hour construction. As a result, the separation is acceptable.

Combustible Materials This fire zone does not contain safety related components or radioactive materials and the fire load is not calculated.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capabilities Two ionization (or photoelectric) -type fire detectors are in the IDNS building.

They alarm in the control room. Fire hydrants are located near the building.

Design-Basis Fire If a fire occurs, whatever is currently located in the building may be damaged or destroyed. This will not affect the safe shutdown or operation of the plant.

2.3.18.59 Braidwood Electrical and Instrument Maintenance (EM/IM) Shop (Fire Zone 18.40-0)

This zone is shown on Figures 2.3-3, 2.3-8, 2.3-10, and 2.3-12.

This zone consists of a free-standing building on the west side of the Unit 2 Turbine Building that is made up of three floors at elevations 401 feet 0 inch, 415 feet 6 inches, and 426 feet 0 inch, respectively. The three floors constitute the entire shop building structure.

Fire Barrier Description The floor at elevation 401 feet 0 inch is a 5-inch reinforced concrete slab on grade. The second and third floors at elevations 415 feet 6 inches and 426 feet 0 inch, respectively, are constructed of 8-inch hollow core precast slabs with a 2-inch concrete topping. Each of the three floors have two, 2-inch-diameter floor drains. Similarly, the roof at elevation 436 feet 4 inches is constructed of 8-inch 2.3-247

B/B - FPR AMENDMENT 29 DECEMBER 2020 hollow core precast slabs with 2-inch concrete topping. There are five, 4-inch-diameter roof drains provided near the west edge of the structure.

The three exterior walls that are adjacent to the Turbine Building, Heater Bay, and Service Building are 8-inch thick hollow masonry with vermiculite fill; these walls carry a 3-hour fire rating. The masonry extends up to and forms the roof parapet at approximately elevation 438 feet 4 inches. The fourth wall on the west side of the Braidwood EM/IM Shop Building is constructed of insulated metal siding supported on unprotected steel girts; this wall carries no fire rating.

Two, 3-hour-rated fire doors lead to the Turbine Building ground floor; one, 3-hour-rated fire door leads to the Service Building second floor at elevation 417 feet 0 inch; and one, 3-hour-rated fire door leads to the Turbine Building mezzanine floor at elevation 426 feet 0 inch.

The roof decking assembly consists of a design and materials classified as a UL-listed Class A or an FM Class I assembly.

Safety-Related Equipment No safety-related equipment is in this zone.

Protection Criteria and Measures The three exterior walls that are adjacent to the Turbine Building, Heater Bay, and Service Building are 8-inch-thick hollow masonry with vermiculite fill; these walls carry a 3-hour fire rating. Fire dampers are installed at all HVAC penetrations to existing buildings, and fire seals are provided at all piping and electrical conduit penetrations.

Combustible Materials and Fire Loading The EM/IM Shop Building is a commercial grade structure consisting of both office and shop space and has its own passive and active fire detection/suppression equipment. Due to the fire protection afforded by the 3-hour rated barriers and the fully automatic sprinkler system, the level of fire protection is greater than any fire hazard presented by the classification of occupancy. Therefore, no quantification of combustible materials is required.

Extinguishing and Detecting Capabilities Automatic sprinklers that alarm both locally and remotely in the Work Control Office are provided as the primary means of fire protection throughout each elevation of the Braidwood EM/IM Shop Building along with a portion of the Turbine Building at elevation 401 feet 0 inch (between rows E and F.2 and column lines 33 to 35). Electrical in-duct ionization (or photoelectric) detectors 2.3-248

B/B - FPR AMENDMENT 29 DECEMBER 2020 are provided that use closed loop initiating device circuits with individual zone supervision. Portable fire extinguishers are provided for manual firefighting.

Design Basis Fire If a fire occurs, the building structure and its contents may be damaged or destroyed; however, the sprinkler system would extinguish the fire. The 3-hour-rated fire barriers between this building and the adjacent structures would prevent the spread of fire from this zone. A fire in this zone will not affect the operation or safe shutdown of the plant.

2.3.18.60 Unit 1 Containment Access Facility (Braidwood) (Fire Zone 18.41-0)

This building is shown on Figures 2.3-1.

The Containment Access Facility (CAF) is a commercially designed metal frame and metal siding building. It is located outdoors adjacent to Unit 1 Containment to serve as an equipment and personnel staging area during outages.

Fire Barrier Description The building is of non-combustible construction with a concrete slab base, steel columns, steel beams, metal siding and metal roof, and has no fire rating. The building is located under 345kv transmission lines that connect System Auxiliary Transformers and Main Power Transformers to the switchyard. The building is greater than 50 feet away from the transformers. The building is separated from the Containment by concrete walls.

Safety-Related Equipment None.

Combustible Materials The building is occupied by personnel primarily during outage periods. The CAF has typical utilities for personnel occupied areas (HVAC equipment, electrical distribution and lighting equipment, tool storage). The building occupancy is classified as ordinary hazard group two; The combustible material is typical for the type of occupancy described and is considered a moderate fire load.

Fire Loading See Table 2.2-3 for Fire Load Classification.

2.3-249

B/B - FPR AMENDMENT 29 DECEMBER 2020 Extinguishing and Detection Capabilities The building is equipped with a heat detection and sprinkler system. An actuated heat detector initiates a local building alarm and a control room alarm via phone line. If a sprinkler head fuses after heat detection, water is discharged through all open sprinkler heads. The sprinkler system water source is supplied from the outdoor Fire Protection system header. An internal wall hydrant is available for exterior exposure fires.

Design Basis Fire The buildings metal structure and the fire protection features preclude a fire affecting the Containment, the 345 kv lines, or transformers. Due to its outdoor location, separation from adjacent structures, and fire protection features, a fire in the CAF will not affect safety-related structures or components.

2.3.18.61 Unit 2 Containment Access Facility (Braidwood) (Fire Zone 18.42-0)

For details, see Subsection 2.3.18.60.

2.3.18.62 Unit 0 Radwaste Storage Tank Bermed Wall Area (Braidwood)

(Fire Zone 18.43-0)

This zone is shown on Figure 2.3-2.

Fire Barrier Description The 500,000-gallon stainless steel insulated storage tank (45 diameter, 45 high) is constructed of welded steel plates and stiffeners and is located on a structural reinforced concrete foundation. It is located outdoors, southeast of the Main Access Facility and is surrounded by a 9 high concrete (berm) wall. The berm wall, earthen floor inside the berm, and exposes portion of the concrete foundation are lined with an HDPE material to contain any/all leakage from the tank, which will store tritiated water for future processing and prevent its runoff to area surface or ground water.

Safety Related Equipment None.

Protection Criteria and Measures The tanks are located outside approximately 250 feet from the Turbine and Radwaste Buildings. The tank insulation is covered with a metal lagging.

2.3-250

B/B - FPR AMENDMENT 29 DECEMBER 2020 Combustible Materials HDPE and polyisocyanurate foam.

Fire Loading See Table 2.2-3 for Fire Load Classification.

Extinguishing and Detecting Capability There is no fire detection equipment in the area. Two fire hydrants (0FP06S and 0FP07S) are located within approximately 100 feet of the berm area and provide sufficient water supply for manual firefighting.

Design-Basis Fire The design-basis fire would result if the berm liner ignited and burned, eventually involving the plastic overflow tank. The fire would not spread to adjacent structures due to the large distances and the 9-foot high concrete berm walls.

Given its relative location, the magnitude of the fire load inside the berm and the existing fir fighting capability in the area, a fire within this fire zone will have no adverse effects on equipment important to safety or the safe shutdown of the plant.

Note for 2.3 Figures:

Figures 2.3-1 through 2.3-42 are composite drawings, which were prepared from many different design documents. They represent an attempt to portray many of the plant's important fire protection related features on one set of drawings. In cases where specific details are difficult to interpret or in cases of apparent discrepancies between Figures 2.3-1 through 2.3-42 and design documents, the design documents shall be taken as the basis for plant design.

2.3-251