ML18065A601

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Evaluation of Effects of Fire on West Wall of CCW Pump Room (Fire Area 16).
ML18065A601
Person / Time
Site: Palisades Entergy icon.png
Issue date: 03/22/1996
From: Young L
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18065A596 List:
References
EA-FPP-95-050, EA-FPP-95-050-R01, EA-FPP-95-50, EA-FPP-95-50-R1, NUDOCS 9604080140
Download: ML18065A601 (14)
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PALISADES NUCLEAR PLANT EA- FPP-95-050 ENGINEERING ANALYSIS COVER SHEET Total Number of Sheets IS

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  • 0 Initiated I nit Review Method Technically Reviewed Revr Rev Appd Appd CPCo
  1. Description By Detail* Qual By Appd By Date Alt Cale Review Test By Date 0 Original Issue LDYoung 12/12/95 DAC .,, RIJPhil ips 1/17/96 RLS PFB

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1.0 OBJECTIVE r The purpose of this Engineering Analysis is to show the impact of a fire on the barrier forming the west wall of the CompoQent Cooling Water Pump Room (EL. 590'-0"and 607'-6"). Specifically, the analysis will consider the equivalent fire resistance of the barriers, combustible loading within the rooms and suppression and detection. Through these considerations, this analysis will demonstrate the ability of the system as a

whole to Rreveiifthe-spread~of fire fro_m_one_area to another.

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'2.1 - Consumers Power Co. Palisades Nuclear Plant Drawings:

M-2, Rev. 19 Equipment Location - Aux. Bldg., Radwaste Modifications, Plan of EL. 590'-0" M-6, Rev. 14 Equipment Location, Reactor Building, Sections A-A, B-B, C-C,D-D&E-E

  • M-216, Sh. 5 .,

VEN 950*M66, Sh. 8/9 Rev. 2 Rev. 3 Fire Protection, Reactor Building, Plan of EL. 590'-0" "Automatic" Sprinkler Plans, Turbine Building 2.2 National Fire Protection Association, Fire Protection Handbook, 17th Edition.

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet ___z__ Rev # _,.><.-0_ _

2.3 Palisades Nuclear Plant Engineering Analysis EA-FPP-95-28, -Analysis of Combustible Loading for Fire Area 16, Component Cooling Pump Room.

2.4 Palisades Nuclear Plant Engineering Analysis EA-FPP-95-16, Analysis of Combustible Loading for Fire Area 23B, Steam Generator Feedpump Area.

2.5 Palisades Nuclear Plant Final Safety Analysis Report (FSAR).

2.6 Palisades Nuclear Plant Fire Hazards Analysis, Revision 2, February 1, 1989. \

2. 7 Palisades Nudear Plant Fire Protection Implementing Procedure FPIP-7, Fire.

Prevention Activities, Revision 9. .

2. 8 Palisades Nuclear Plant Fire Protection Program Report (FPPR), Volume 2, Section VIII; List of Changes to Appendix A to Branch Technical Position APCSB 9.5-1 and Regulatory Guide 1.78 and 1.101, Revision 1, October 26, 1989.

2.9 Palisades NuCiear Plant Fire Protection Program Report (FPPR), Vol~me 3, Section IX, #4 7.

/

7 2.10 U.S.* Nuclear Regulatory Commission (NRC) Generic Letter 86-10, Implementation of Fire Protection Requirements, April 24, 1986.

2.11 Palisades Nuclear Plant Engineering Analysis EA-APR-95-001, Rev. 0, Appendix R Safe Shutdown Equipment List and Logic Diagrams.

2.12 Methods of Quantitative Fire Hazard Analysis, EPRI Research Project 3000-37, by F.W. Mowrer, dated May.1992..

  • 2.13 Palisades Nuclear Plant Engineering Analysis EA-APR-95-024, Rev. 0, Auxiliary Feedwater Initiation, Main Steamline Isolation, and Steam Generator Blowdown Isolation Requirements Under Appendix R Conditions.

2.14 Palisades Nuclear Plant Engineering Analysis EA-APR-95-007, Rev. 0, 10CFR50, Appendix R Safe Shutdown Analysis.

2.15 Palisades Nuclear Plant Drawing M-3.02, Sh. 611. l thru 611.7, Piping Oil Drain Guard Layout.

  • ASSUMPTIONS None

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet ____l_ Rev # ----=-0_ _

4.0 ANALYSIS 4.1 General General Guidelines for Plant Protection are discussed in the List of Changes Reference 2.6, Page 27 and Response to Appendix A to BTP APCSB 9.5-1 and Regulatory Guide

1. 78 and 1. 101, Subsection D. l .j. The regulatory position states that concerning compartmentation "... Floors, walls and ceilings enclosing separate fire areas should have minimum fire rating of three hours." It then goes on to state that " ... The fire hazard in each area should be evaluated to determine barrier requirements." Also, ... "If barrier fire resistance cannot be made adequate, fire detection and suppression should be provided ... "

Based upon the above statements, it is apparent that the analysis of a specific barrier for acceptability should subsequently follow this order of importance:

a. The capability of the barrier must satisfy the minimum fire rating guideline of3-hours. If not then;
b. The barrier must be adequate to withstand the actual combustible

/

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~ loading in the fire areas separated by the barrier. If not then;

c. The actual configuration must be reviewed in order to take credit for other systems or circumstances that may increase the acceptability of the barrier (e.g. suppression, detection, etc ... ).

This analysis is based upon the above three criteria. It shall be used to demonstrate the capability of the fire barrier and its supporting systems to adequately prevent the spread offire across the barrier separating the Component Cooling Water Pump Room from the Turbine Building Feedwater Pump Area.

4.2 Description of the Fire Barrier The Component Cooling Water (CCW) Pump Room includes three elevations; 590'-0" EL., 607'-6" EL., and 625'-0" EL. The west and southwest walls that contain the openings in question are a minimum thickness of 24" and provide a portion ()f the barrier separating the seismic Auxiliary Building from the non-seismic Turbine Building. A 5-1/2" thick reinforced concrete floor is qualified for 3-hour fire rating, therefore, the 24" thick reinforced concrete wall is of 3-

  • hour fire rated barrier construction but has no rating because of openings .

. A 7 ft. X 9 ft. pressure release opening is located in the west wall to the Turbine Building at the 590'-0" elevation. This opening is required to provide pressure relief capability for postulated main steam or main feedwater line breaks in the CCW Pump Room. The pressure release opening is partially

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet __it_ Rev # -"'"o_ _

Kererence1cornmenc covered by metal blowout panels that provide a continuous seal over the lower half of the opening up to 5 feet high from the floor. The blowout panels also provide a water tight seal for flood protection from the Turbine Building side only. The remaining upper portion of the pressure release area is open With metal bars to provide security protection.

There are two main steam lines and two main feedwater lines that penetrate through the west and southwest walls. One main feedwater penetration is located approximately 5 feet above the 590'-0" floor elevation, while the other main feedwater line is located over 10 feet above the floor elevation. The two main steam line penetrations through a wall blockout are located approximately 5 feet above the 607'-6" grating floor elevation. These pipe penetrations are not sealed with fire rated material. The openings form gaps around the pipes that range from appro~ately I-inch to 5-inches wide on the two feedwater pipes. The feedwater line penetration at the lowest elevation of approximately 5 feet above the 590'-0" elevation has Kaowool installed into the annular gap

. to provide. a fire resistant seal, but this configuration does not meet the requirements for a rated fire seal. The main steam lines protrude through a single large opening that is blocked by massive steel supports on the Turbine Building side of the wall. The open spaces around the main steam pipes and .

supports range in size from approximately 2-inches to 9-inches wide.

The floor of the Turbine Building Steam Generator Feedpump Area adjacent to the CCW Pump Room is constructed of concrete. However, the Turbine Building area above, at the 607'-6" elevation, is metal grating. This allows any smoke or hot gases produced at the 590'-0" elevation to rise freely to the ceiling of the level above. There isa stairway opening in the ceiling of the 607'-6" elevation that opens into the upper level of the Turbine Building operating floor. This opening provides further venting of smoke and hot gases throughout the Turbine Building without allowing any significant buildup af the 590'-0" level.

In summary, the west and southwest wall of the CCW Pump Room provide either a 3-hour rated fire barrier or a radiant energy shield up to a 5 foot height above the 590'-0" elevation. The unsealed piping penetrations also provide an almost continuous line of sight radiant energy shield for a floor based fire at the 590'-0" elevation within 20 feet of the penetrations, due to the 24" wall thickness and size of the penetrating pipe filling _most of the opening area .

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4.3 Description of Combustible Loading

a. Component Cooling Pump Room The fire loading in Fire Area 16, the CCW Pump Room, results in an Reference 2.3 Equivalent Fire Severity ofless than one-minute. This area has a LOW Fire Loading Classification but realistically has a negligible fire loading.

The in-situ combustible materials are located primarily at the 590'-0" elevation and consist of a small quantity oflube oil associated with the CCW pumps, four I-gallon lube oil storage containers (NFPA 30 equivalent), and a small amount of cable insulation in cable trays located at the ceiling. The CCW pump lube oil is totally enclosed within the pump assembly and would not be expected to bum completely during a fire. The pumps are located approximately .21 ft. away from the pressure relief opening. in the west wall based on field measurements.

. The lube oil storage containers are located at the east wall approximately 30 ft. away from the pressure relief opening. There are

  • Reference 2.1 no significant combustibles located at the 607'-6" and 625'-0" elevations.

Transient combustibles are administratively controlled throughout the plant. The amount of transients that may be brought into the CCW Pump Room for maintenance and operating activities would be minimal based on the type of equipment located in the room .. Also, since this room does not provide an access path to surrounding rooms, there is further assurance that transients will be minimal .. The area near the pressure relief opening is congested by components such as the CCW heat exchanger, associated piping and air operated valves. No clear floor access is available to the area immediately adjacent to the pressure relief openi.ng. Therefore, it is

  • m physically impractical to place any significant transient combustibles this area as there is no open floor space to tise for storage.
b. Turbine Building Steam Generator Feedpump Area The Turbine Building area adjacent to the CCW Pump Room is part of Reference 2.4 Fire Zone 23B, the Turbine Building Steam Generator Feedpump Area.

The overall fire loading in this zone results in an Equivalent Fire Severity of 54 minutes. This results in a LOW Fire Loading Classification .

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet _1J.._ Rev # ~o __

Based on field walkdowns, the primary in-situ combustibles in the Turbine Building Steam Generator Feedpump area include two 480-V MCC's with associated cable trays and two 750 gallon lube oil reservoir tanks. The minimum distance to the MCC's from the pressure relief opening is approximately 31 ft., while the lube oil reservoirs are greater than 60 ft. away from the pressure relief opening._ The lube oil reservoir is also greater than 30 ft. away from the nearest feedwater pipe penetration in the southwest wall of the CCW Pump Room. Floor drains are located in this area around the lube oil reservoir tanks and in the space between the tanks and the pressure relief opening and feedwater line penetration. The floor is sloped away from the CCW wall and the drains would carry the lube oil to the Turbine Building Sump, away from the area of concern. There are no significant combustibles located above the floor levei on the 590'-0" elevation adjacent to any of the openings. The turbine lube oil return piping Reference 2 .15 located in this area is a double pipe arrangement that would require failure of two pipes before leakage could occur. Also, there are no significant combustibles located on the grating elevation (607'-6") above the pressure relief opening and near the main steam line penetrations

-1 located on that elevation.

Transient combustibles are administratively controlled throughout the plant. The area adjacent to the pressure relief opening is blocked by the aq~;:;;s stairway to the 607'-6" elevation. There is limited clearance around the stairway precluding storage of material. The remainder of the area near the pressure relief opening is the walkway to the stairway which would not be suitable for storage or staging of material as this would*block an already limited access pathway. A feedwater heater and associated piping generally blocks the area adjacent to the two feedwater pipe penetrations such that it would be impractical to store any significant amount of transient combustibles below these openings. A flammable liquids storage locker that meets NFPA 30 requirements is located within approximately 5 ft. of the southwest feedwater piping penetration to house chemicals used

.for water treatment. This condition does not cause an exposure hazard to this penetration due to the fire rated design of the storage locker. No additional transient combustible controls, above those already in place, are deemed necessary for this area due to the height of the pressure relief and piping penetration openings above the floor.

c. Combustible Loading Summary

'.} The in-situ combustible loading of less than one-minute in the CCW Pump Room is negligible and does not pose a significant exposure hazard to the pressure relief opening or piping penetrations. The greater than 20 ft.

distance separating the in-situ combustibles from the openings in the west wall will further decrease the concern for potential fire spread across the

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet _7_ Rev# __,,O_ _

non-fire rated openings into the adjoining fire area. The equipment congestion and lack of open floor space near the pressure relief opening in the CCW Pump Room also ensures that credible transient combustibles used in this area will not present an exposure fire hazard to the adjacent fire area.

The in-situ combustible loading of 54 minutes in the Turbine Building

. Steam Generator Feedpump Area could pose a significant exposure hazard to the pressure relief opening and piping penetrations. However, the greater than 30 ft. separation of the in-situ combustibles from any of these openings combined with the floor slope away from the CCW wall and floor drains to limit pool fire spread significantly decreases the concern for potential fire spread across the non-fire rated openings into the adjoining fire area. The lack of significant combustibles on the CCW Pump Room side of the non-fJre rated openings for over 20 ft. behind the openings further decreases the concern for potential fire spread or smoke and hot gas damage to equipment in the CCW Pump Room. The equipment* located near the non-fire rated openings are substantial metal components that are not vulnerable to smoke and hot gas damage. These same factors ensure that credible amounts of transient combustibles located on the Turbine

~----- ----- Building-side.ofthe_pr_essg~ re~~f_opening or pipe penetrations would not present an exposure fire hazard to equlpmenflocatecrinthe-ecw-Room~----- ----*----------*--- _

The largest credible Turbine Building fire near the CCW* Pump Room would be a Main Feedpump lube oil fire from a rupture or leak of the reservoir. Such a fire would vent smoke and hot gasses throughout the Turbine Building without appreciable buildup near the CCW Pump Room openings. The remaining hazard would be from the radiant energy of such a postulated fire. Based on the spacing of floor drains located in the area around the lube oil reservoir, a postulated 10 foot diameter pool fire is analyzed in Attachment 'A' using data from Reference 2.12. This pool fire is located on the north side of the lube oil reservoir extending 10 feet toward the CCW Pump Room opening (worst case position). The only CCW Pump Room opening which may directly expose cable located in conduit to the radiant energy of such a fire would be the pressure release opening. These cables were conservatively assumed to be unprotected by conduit and located at the opening versus a few feet inside the room. The results indicate that with conservative assumptions there would not be sufficient energy in such a fire to damage unprotected IEEE-383 cable located just inside the pressure release opening. There are no intervening combustibles between the postulated fire and the CCW Room opening.

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet __JL_ Rev # __._O_ _

4.4 Description of Suppression and Detection

a. Suppression The CCW Pump Room is not equipped with automatic suppression.

Manual hose stations are provided in the access hallway outside the Auxiliary Building entry door and in the Turbine Building outside the pressure relief opening.

The Tu.rbine Building Steam Generator Feedpump Area contains partial automatic suppression above the 607'-6" elevation. The automatic suppression is provided over the combustible hazard areas such as the cable trays near the MCC's and the main feedpump lube oil reservoir area on the 590'-0" elevation. The floor grating at the 607'-6"- elevation is open over the feedpump areas so there is no blockage of the sprinkler spray pattern from the ceiling of the 607'-6" elevation down to the floor Reference 2.1 of the 590'-0" elevation. The sprinkler spacing is consistent with that required of an extra hazard occupancy and the existing obstructions to the spray pattern are within NFPA-13 allowables, based* on observations made during a plant walkdown.

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The Turbine Building Steam Generator Feedpump Area is also supplied with two hose stations. These are capable of reaching the pressure release opening in the west wall of the CCW Pµmp Room. In addition, a wheeled dry chemical extinguisher is located close to the southwest CCW Pump Room wall near the flammable storage locker, and fire fighting foam

  • equipment is located west of this area on the 590'-0" 'elevation. Outside
  • access to the main feedpump area is provided by a roll-up door on the south side of the Turbine Building. - This opening provides the fire brigade
  • access from a hydrant hose house.
b. Detection The detection system in the CCW Pump Room provides partial coverage as the detectors are installed only above the 590'-0" elevation. The smoke detectors are considered adequately positioned to take into account the potential fire sources in the room and will perform satisfactorily to provide early warning of a fire. The adequacy of the partial detection has been reviewed and approved by the NRC in a letter dated March 30, 1989, that closed Unresolved Item 255/86022-04.

L .

1 The partial area automatic suppression system in the Turbine Building Steam Generator Feedpump Area includes a watertlow switch .. The switch provides an alarm signal to the Control Room, thus providing_ indication of a fire in this area.

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c. Fire Brigade/Equipment The plant fire brigade training program includes actual involvement with fighting flarrimable liquid fires during the live fire training. The 590'-0" elevation of the Turbine Building contains one of the fire brigade depot
  • areas for equipment storage providing ready access to equipment for a fire in this area. Equipment such as self-contained vent fans capable of delivering 16, 000 CFM are also located nearby the CCW Pump Room west wall in the Turbine Building. As mentioned above, the area also contains fire fighting foam equipment for a potential lube oil fire.

.4.5 Description of HVAC for Each Area

a. CCW Pump Room The Penetration and Fan Room HVAC System provides ventilation requirements for all three levels of the CCW Pump Room (Fire Area 16).

This system, as described in Design Basis Document 1. 07, provides a balanced ventilation air flow of 10,000 CFM supply and exhaust. The supply and eXhaust fans operate as a single unit and start or stop at preset

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thermostat settings. During fan operation the system is designed to be air balanced for neutral air flow to or from adjacent areas.

b. Turbine Building Area Per the System Operating Procedure (SOP-24), the Turbine Building ventilation is adjusted to be air balanced during normal plant operation, similar to the CCW Pump Room. *However, the Turbine Building is a large area served by several independently controlled fans and the individual cycling may periodically cause the Turbine Building to be at a positive or negative pressure with respect to the CCW Pump Room. The Turbine Building ventilation system is designed, with all fans operating, to provide a negative pressure condition due to an excess of30,000 CFM exhaust flow.

The likelihood of operating the Turbine Building at a positive pressure, due to independent fan cycling, is a low probability event.

C. HVAC Summary The CCW Pump Room ventilation system is designed to ensure an air balanced condition at all times with respect to adjacent areas. For the purposes of this evaluation, the Turbine Building will be assumed to be air balanced with respect to air exchanges with the CCW Pump Room, since this is the normal proceduralized mode of operation. The design of the Turbine Building ventilation is to provide a negative pressure, but this would be non-conservative with respect to the concern for a fire spreading from the Turbine Building to the CCW Pump Room. The only realistic

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet _JQ_ Rev # _...o_ _

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concern is for a Turbine Building fire to spread into the CCW Pump Room based on the fire loading and type of combustible materials in each area, as described in Section 4.3, above. Although the operation of the Turbine Building in a positive pressure mode is conservative for the purposes of this calculation, it is considered a low probability event that would not provide a realistic measure of the risks involved.

4.6 Post-Fire Safe Shutdown Equipment Due to the unpredictable size and location of the fire in the Turbine Building, an evaluation of the more heat sensitive safe shutdown components and manual operator actions within the CCW Pump Room was performed. The more sensitive eiectrical components within this area include electrical cables and electric motors. The remaining components such as the pumps and valves are substantial metal components not easily damaged by smoke and hot gases that may enter the CCW Pump Room from a massive Turbine Building fire. The systems identified as containing electrical cables or motors and requiring actions within the CCW Pump Room include the Component Cooling Water System, Auxiliary Feedwater System and the Main Steam System. Other systems may have electrical cabling within the area, but the Appendix R safe shutdown analysis credits actions outside either the CCW Pump Room or Turbine Building to mitigate any damage consequences.

The Component Cooling Water System compon~nts include the electrical cables and motors for the CCW pumps. This system is only required to support the decay heat removal function of the shutdown cooling system. A Reference 2.14 repair is proceduralized to provide a replacement spare motor and cabling to restore this function for a fire in this area, and this could be used for damage from a Turbine Building fire as well. The CCW flow to two of the three charging pumps, which are hot shutdown components, is not required as they can be cycled alternatively to keep the lube oil temperatures below vendor recommendations. Even if this function were to be lost the use of a piggy-back arrangement of HPSI pumps and Containment Spray pumps remains available as a further defense-in-depth measure for primary inventory control. All of these features ensure that any damage caused by smoke and hot gases entering the CCW Pump Room from aTurbine Building fire would be mitigated by either repairs or multiple methods of providing primary inventory control.

PALISADES NUCLEAR PLANT EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet ......1L Rev # _...Q_ _

  • '. e erence/ ornmen The Turbine Building fire evaluation shows that Auxiliary Feedwater Pump P-8A could be lost. The remaining Auxiliary Feedwater System components located in the CCW Pump Room include the steam supply valve and flow control valve and their associated circuits that support P-8B, and electrical cables for P-8C and its associated flow control valves. If
  • smoke and hot gas damage to electrical circuits occurs, then manual actions for the steam supply and flow control valves for P-8B would be taken inside the CCW Pump Room. These actions are not required prior to 4 7 minutes Reference 2.13 after reactor trip to ensure an unrecoverable condition does not occur. This provides adequate time to restore access to the CCW Pump Room from the potential smoke and hot gases entering from a Turbine Building fire.

Standard industry practice in evaluating manual actions inside an area where a fire occurs allows a one-hour time period before actions may be assumed.

However, in this case the fire is outside the fire area with the concern addressing smoke and hot gases only. Therefore, it is* reasonable to assume manual actions can be performed within the 47 minute limit established 1n the functional requirements evaluation.

The Main Steam System components requiring operation include the Atmospheric Steam Dump Valves (ASDV's) and the Main Steam Isolation Valve (MSIV) bypass valves. The ASDV's and the MSIV bypass valves are physically located on the upper levels of the CCW Pump Room, but have electrical control cables routed through the lower elevation or Turbine Building. The motive air/nitrogen supplies for the ASDV's are considered lost due to the fire in the Turbine Building. The other method of secondary steam release is the Hogging Air Ejector also located in the Turbine Building. The Hogging Air EjeCtor relies on the MSIV bypass valves to be opened.

  • Therefore, the control of secondary steam pressure will rely on the main steam safety valves until access to the Turbine Building is restored. This situation is considered acceptable for an extended period of time, greater than one hour, allowing time for fife fighting activities ~o extinguish or control the fire such that access is restored to allow manual operation of the Hogging Air Ejector and MSIV bypass valves. Manual operation of these components will then allow secondary side heat removal to continue and to transition the plant to cold shutdown.

5.0 CONCLUSION

The CCW Pump Room boundary with the Turbine Building Steam Generator Feedpump Area provides reasonable assurance that a realistic in-situ or transient combustible material fire on either side of this wall will not propagate across the pressure relief opening or various piping penetrations such that equipment will be damaged in both fire areas from a single exposure fire. The key factors that ensure the defense-in-depth protection for this area includes:

PALISADES NUCLEAR PLANT. EA- FPP-95-050 ANALYSIS CONTINUATION SHEET Sheet _.1L Rev # __,.O_ _

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  • The construction features of the pressure relief opening with water tight metal plates on the lower 5 *feet of the opening and physical location of the piping penetrations at least 5 feet above floor level,
  • the location of in-situ combustibles at least 20 feet away from these openings on both sides (greater than 40 feet overall separation) and location of floor drains in the intervening space to remove the most likely fuel source on the Turbine Building side,
  • the large area volume and ceiling height above the openings on the Turbine Building side to dissipate smoke and hot gases from the relatively larger fire loading on this side,
  • practical limitations on the location and amount of transient combustibles that may be stored near the barrier openings,
  • reasonable assumptions on the lack of forced air flow between the two ateas of concern,
  • and lack of significant intervening combustible materials or smoke and hot

. ..__~/ gas sensitive equipment Within 20 feet on either side of the boundary wall.

If electrical cable or motor damage in the CCW Room should occur in spite of these features, due to smoke and hot gases entering the pressure release opening from a massive Turbine Building fire, then the defense-in-depth features of the safe shutdown components will ensure adequate equipment remains available as discussed in Section 4.6, above. For the purposes of the Appendix R safe shutdown analysis this scenario is not considered credible and plant procedures ~11 not reflect this scenario. The evaluation presented here is to provide further assurance of plant safety for a worst case fire that is not considered realistic. The CCW Pump Room west wall is considered adequate to withstand the hazards associated with the fire area and, as necessary, to protect important equipment within the fire area from a fire outside the area.

6.0 ATTACHMENTS Attachment A - Radiant Energy Calculation for a Lube Oil Fire Near the CCW West Wall

EA-FPP-95-050 Page 1of1 ATTACHMENT A Radiant Energy Calculation for Lube Oil Fire Near CCW West Wall The largest single fire load potential near the CCW Pump Room west wall is a Main Feedwater Pump lube oil spill on the Turbine Building side. The radiant energy from such a fire could directly expose conduit located inside the CCW Pump Room near the pressure relief opening.*

The other openings do not provide a line of sight target from a such a floor based fire to conduit inside the CCW Pump Room. The distance from the closest Main F eedwater Pump lube oil tank to the pressure relief opening is greater than 60 feet. Assuming a 10 foot diameter lube oil spill for a practical fire size would leave 50 feet of separation from the edge of the postulated fire to .

the pressure relief opening. Using Table 2 data from Reference 2.12, the Heat Release Rate (HRR) of a 10 foot diameter fuel oil fire (this is more conservative than lube oil) would be:

10 ft. X 0.3048 m/ft.= 3.1 meters; Area= ((1t)d 2)/4 = (3.1416 X (3.1) 2)/4 = 7.5 m2 HRR from Heavy Fuel Oil from Table 2 = 1,251 kW/ m2 Therefore, the total HRR would be= 1~251 kW/ m2 X 7.5 m2 = 9,383 kW The target of concern is a cable inside a conduit near the pressure release opening that is greater than 50 feet from the edge of a 9,383 kW fire. From Table 1 of Reference 2.12, the critical flux to cause damage to a cable that is not protected by a conduit is conservatively set at 10 kW/ m2 for IEEE-383 cable. Equation (56) of Reference 2.12, can be rearranged to solve for the Heat Release Rate required .to reach a 10 kW/ m2 critical flux at a distance of 50 feet (15 .2 m) as follows:

Qc = Heat Release Rate cm= Critical Flux (set at 10 kW/ m2)

R =Radius (15.2 m) XR = 0. 4 from Fig. 13 (Percent of HRR that is Radiant Energy)

Qc = (10 kW/ m2(41t(15.2 m) 2))/0.4 =.29,033 kW/0.4 = 72,583 kW The amount of energy required to damage unprotected cable is 72,583 kW, while the amount of energy available is only 9,383 kW. Therefore, the radiant energy of a postulated lube oil fire near the Main Feedwater Pump lube oil tank would not have sufficient energy to damage unprotected cables located at the pressure release opening in the CCW Pump Room.

EA-FPP-95-050 Pages 14 through 19 intentionally omitted

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