ML20134M836

Documents Results of Fire Hazards Analysis & Provides Details of Compensatory Actions Discussed in Conference Calls Re 961107 Event

ML20134M836
Person / Time
Site:	Byron
Issue date:	11/20/1996
From:	Kofron K COMMONWEALTH EDISON CO.
To:	NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BYRON-96-5188, NUDOCS 9611260055
Download: ML20134M836 (18)

Text

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I Cornmonw calth i:dison Company Ilyron Generating Mation i

, 4 45,0 North German Church Road

11) run, IL 61010 9794 TelHIS-L M 511i November 20,1996 LTR: BYRON-96-5188 FILE: 1.10.0101

, Office of Nuclear Reactor Regulation 4

U. S. Nuclear Regulatory Commission Washington, D. C. 20555-001 ATTENTION: Document Control Desk

SUBJECT:

Actions taken in Response to Fire Protection Report

, Safe Shutdown Analysis Deficiences Byron Nucbar Power Station Units 1 and 2 Facility Operating Licenses NPF-37 and NPF-66 NRC Docket Nos. 50-454 and 50-455

REFERENCES:

1. November 7,1996 Emergency Notification System (ENS) call regarding identified deficiencies in the Fire Protection Report Safe Shutdown Analysis (Update to Event # 29449)

2. November 8,1996, conference call between Comed and NRC concerning ENS Event #29449

3. November 12,1996, conference call between l Comed and NRC concerning ENS Event #29449 l continuing fire hazard analysis and compensatory actions l

4. November 13,1996, ccnferenco call between Comed and NRC concerning ENS Event #29449 final analyses and compensatory actions The purpose of this letter is to document the results of a Fire Hazards Analysis and provide details of compensatory actions discussed i during conference calls (References 2,3, and 4) with the NRC '

regarding an event reported by Byron Station on November 7,1996  :

(Reference 1), and discussed below. I  !

9611260055 961120 PDR

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ADOCK 05000454 F PDR p:\sec\byrttr'.06-9 i GO. doc A Iinicom Company

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BYRON LETTER 96-5188

November 20,-1996 Page 2 i

j Byron Station is presently implementing a Fire Protection Report Improvement Review. On November 7,1996, it was confirmed that the existing Safe Shutdown Analysis (SSA) of the Fire Protection Report (FPR) does not evaluate the potential for a single fire to result in the loss of both 4 KV ESF buses and both diesel generators (D/Gs) in Byron fire zones 3.2A-1 and 3.2A-2. This unanalyzed condition is not in compliance with 10CFR50, Appendix R.

In fire zone 3.2A-2, Division 21 safe shutdown equipment is relied upon for safe shutdown. In this zone, Bus 241 (Div. 21) normal and reserve DC control power supply cables are routed in conduits. A fire in this zone could damage these cables and interrupt all control power to Bus 241. This situation is addressed in the current FPR SSA, but the SSA does not address that loss of DC control power prevents Bus 241 breakers from opening to isolate cable faults. The power cable from Bus 241 cubicle #5 to the Essential Service Water (SX) Tower Unit Substation is also routed in conduit through zone 3.2A-2. Applying the assumptions of 10CFR50, Appendix R, a single fire could cause the loss of control power to Bus 241 and, subsequently, cause a fault on the cable from Bus 241 cubicle #5. If this ,

sequence of cable failures should occur such that the control power cable fails before the SX power cable fails, the fault current would not be interrupted (because control power is lost to trip the Bus 241 breakers) and damage could occur to the ESF bus and D/G 2A. By analysis, safe shutdown cannot be assured if either D/G 2A or Bus 241 is unavailable.

This concern also applies to Unit 1 fire zone 3.2A-1 for the corresponding cables and equipment.

It was determined that the existing plant configuration was not in full compliance with the requirements of Section Ill.G of 10CFR50, Appendix R and that this condition was reportable per 10CFR 50.72(b)(1)(ii). The i Reference ENS phone notification was made to the NRC on November 7, l 1996 (Reference 1), for an unanalyzed condition not in conformance with  ;

10CFR50, Appendix R. Additional details related to these deficiencies were I discussea with NRC staff members in conference calls held on November 8, '

12, and 13,1996 (References 2,3, and 4).

During the Reference 4 conference call, the NRC requested the following information to be placed on the Byron docket:

1. The Fire Hazard Analysis described in the Reference 3 call,

2. A summary of all compensatory actions taken since the event, p:\sec\byritr\96-5188. doc

l BYRON LETTER 96-5188 l November 20,1996 Page 3 9

3. The Operator action flow chart reflecting the Reference 4 agreed to )

changes for responding to the first indication of a fire,

4. A summary of all Operator actions taken in response to a fire in a narrative form, and

5. A description of the permanent resolution of the event and a schedule for completion.

4 A detailed Fire Hazard Analysis prepared for the two Byron fire zones 3.2A-1 .

and 2 is contained in Attachment A (Item 1 above). The attached analysis concludes that the circuit configuration, fire protection features, and the  ;

compensatory actions established for the fire zones provide reasonable  ;

assurance that safe shutdown will not be affected in the event of fire, l pending permanent resolution of the concern. Attachment B (items 2,3, & 4 above) contains a summary of the compensatory actions put in place and details of the Operator response should a fire detection sensor alarm in the Main Control Room for the two fire zones of concern. Attachment C (Item 5 above) describes the planned permanent resolution of the concern in fire zones 3.2A-1 and 2 and a schedule for implementing the resolution. '

Please address any questions to Marcia Lesniak, Nuclear Licensing Administrator, at (630) 663-6484.

Respectfully, K. L. Kofron Station Manager Byron Nuclear Power Station KLK/DR/pw Attachments cc: A. B. Beach, NRC Regional Administrator Region til G. F. Dick, Jr., Byron Project Manager - NRR S. D. Burgess, Senior Resident Inspector - Byron Office of Nuclear Safety - IDNS p:\sec\byrltr\96-5188. doc

Attachment C Planned Permanent Resolution for Concerns from Byron ENS Event Notification on November 7,1996 The planned permanent resolution for the concern described in the Byron ENS Event notification on November 7,1996, is the following.

UNIT 1:

Conduit C1 A5186 will be protected with a qualified 1-hour rated fire barrier in fire zone 3.2A-1. This conduit contains cable 1 AP178 which is fed from cubicle # 1 of ESF Bus 141 and powers the Division 11 Unit Substation (131Z) at the Essential Service Water Cooling Tower. When the fire rated protection is added to this cable, there will be no 4 Kv power circuits normally fed from ESF Bus 141 which are routed through zone 3.2A-1.

Therefore, there will not be a power circuit located in this zone during normal plant operations, that could generate a 4 Kv fault on ESF Bus 141.

With this permanent change, Byron Unit 1 SSA will be in compliance with the accepted safe shutdown analysis documented in Fire Protection Report Section 2.4.2. 7.

The qualified fire barrier will be installed on conduit C1 A5186 by no later than May 31,1997.

UNIT 2:

Conduit C2A7422 will be protected with a quali'ed 1-hour rated fire barrier in fire zone 3.2A-2. This conduit contains cable 2AP178 which is fed from cubicle # 5 of ESF Bus 241 and powers the Division 21 Unit Substation (2312) at the Essential Service Water Cooling Tower. When the fire rated protection is added to this cable, there will be no 4 Kv power circuits normally fed from ESF Bus 241 which are routed through zone 3.2A-2.

Therefore, there will be no power circuits located in this zone durieg normal plant operations that could generate a 4 Kv fault on ESF Bus 241. With this permanent change, the Byron Unit 2 SSA will be in compliance with the accepted safe shutdown analysis documented in Fire Protection Report Section 2.4.2. 6.

The qualified fire barrier will be installed on conduit C1 A5186 by no later l than May 31,1997.

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Attachment A Fire Hazard Analysis of Byron LER 454-95-005-S2 PURPOSE:

l The purpose of this analysis is to analyze the concerns outlined in LER 454-95-005-S2 to determine if reasonable assurance is provided to insure that redundant circuits will not be damaged in the event of a fire in the affected zones. The concerns involve redundant

circuits required for Appendix R safe shutdown (SSD) located within the same fire zone (s).

j 4

i BACKGROUND:

On November 7,1996, during the ongoing Byron Fire Protection Report Improvement i Review, it was confirmed that the existing Safe Shutdown Analysis (SSA) of the Fire l Protection Report (FPR) does not evaluate the potential for a single fire to result in the

loss of both 4 Kv ESF bases and both diesel generators in Byron fire zones 3.2A-l&2.

. This unanalyzed condition does not literally comply with 10CFR50, Appendix R separation requirements.

CONCERNS:

1. Fire Zone 3.2A-2 (Unit 2 Non-segregated Bus Duct Area. 439' Aux Building)

In fire zone 3.2A-2, Division 21 safe shutdown equipment is relied upon for safe shutdown since Division 22 cables are routed through this zone. In this zone, Bus 241  !

(Div 21) normal DC control power supply cable 2DC037 and reserve DC control power supply cable 2DC038 are routed in separate conduits. A design basis fire in this zone could damage these cables and interrupt all control power to Bus 241. FPR Section 2.4.2.6 discusses this loss in terms oflosing the ability to close needed breakers remotely. The SSA takes credit for operators to manually close the breakers as needed using BOA ELECT-5. The SSA does not address that loss of DC control power prevents Bus 241 breakers from opening to isolate cable faults.

Power cable 2APl78, from Bus 241 Cubicle 5 to the SX Tower Unit substation 2AP99E, is also routed in conduit through this zone. Therefore, a single fire could cause the loss of control power to Bus 241 and, subsequently, cause a 3 phase or phase-to-phase fault on the cable from Bus 241 Cubicle 5. If the sequence of cable failures should occur in a specific order such that the control / power cable fails before the service power cable fails, the fault current would not be interrupted and damage could occur to the ESF bus and D/G 2A because their respective breakers would not have control power. Safe shutdown cannot be assured if either D/G 2A or Bus 241 is unavailable.

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. j Attachment A (continued)

Fire Hazard Analysis of Byron LER 454-95-005-S2

2. Eire Zone 3.2A-1 (Unit 1 Non-Segregated Bus Duct Aga m 439' Aux Building)

In this zone, Division 11 is relied upon for safe shutdown. Bus 141 (Div i1) control I power cables IDC037 and IDC038 are located in this zone. Cable 1 APl78 to SX Tower Substation l AP99E is also located in the zone.

i Therefore, a single fire could cause the loss of control power to Bus 141 and, subsequently, cause a 3 phase or phase-to-phase fault on the cable from Bus 141

? Cubicle 5. If the sequence of cable failures should occur in a specific order such that the control / power cable fails before the service power cable fails, the fault current

would not be interrupted and damage could occur to the ESF bus and D/G 1 A because their respective breakers would not have control power. Safe shutdown cannot be

, assured if either D/G 1 A or Bus 141 is unavailable.

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COMPENSATORY ACTIONS TAKEN:

The following actions were established to compensate for these conditions on an interim basis, pending permanent resolution of these concerns:  ;

1. Site Engineering has initiated revisions to appropriate Annunciator Response procedures for Fire Detection panels IPM09J and 2PM09J that will specify all 4 Ky i ESF equipment potentially affected by a fire in the zone and what equipment should be i shutdown to prevent unexpected damage to the ESF buses. This action will ensure that operators isolate the potentially affected equipment prior to fire damaging the  ;

redundant circuits. '

2. To further minimize the probability and consequences of a fire in the affected zones:

a. Previously established hourly fire watches will be continued. The fire watches 4 have been in place since 1992 due to Thermo-Lag fire barrier deficiencies.

b. Transient combustibles and hot work will be prohibited unless a continuous fire watch is established.

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Attachment A(continued)

F!re Hazard Analysis of Byron LER 454-95-005-S2 METHODOLOGY:

To determine if the compensatory actions taken provide reasonable assurance to insure redundant safe shutdown circuits will not be damaged in the event of a fire, this Fire Hazard Analysis considered the following factors:

Horizontal spatial separation between the redundant circuits.

1 The qualification of the cables (e.g., IEEE-383 qualified). I The presence of an automatic fire suppression system over the intervening combustible and vulnerable SSD cables. l The presence of fire stops to inhibit fire propagation in intervening cable trays.

The likely fire propagation direction of burning intervening combustibles in relation to the vulnerable shutdown cables.

The availability of compensating active and passive fire protection systems.

l Judgments with respect to likely fire propagation, mitigation, and consequences were <

made by qualified fire protection engineers.

ASSUMPTIONS:  !

1. Transient materials and cables in conduit are not considered intervening combustibles.

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Attachment A(continued)

Fire Hazard Analysis of Byron LER 454-95-OO5-S2 ANALYSIS:

1. Fire Protection Features Common to Both Fire Zones The combustible materials present in each room are cable insulation and ductwork gasket material. The fire loading in each room is less than 20,000 Btu /ft2, which equates to a fire severity ofless than 15 minutes. Considering the quantity (37 lbs) and configuration (e.g., between metal flanges) of the gasket material versus the cable insulation (15, 000 to 19,000 lbs, distributed in open cable trays, etc...), the contribution of the gasket material to the combustible loading is negligible and does ,

not represent a credible fire source. Therefore, the only credible fire scenario is one that involves the cable insulation.

The walls, floor and ceiling of these rooms are 3-hour rated. Water hose stations and portable extinguishers are provided in each room. CO2 hose stations are located just outside the rooms. The primary fire protection systems protecting the rooms are automatic total flooding CO2 systems. Smoke and heat detectors are located at the ceiling. The smoke and heat detectors are located adjacent to each other throughout the rooms. A signal from one detector in each of the two trains actuates the CO2 system (eg., one smoke and one heat detector signal is required to actuate the system).

During the incipient stage of a fire, or for small fires that do not release significant quantities of heat, the smoke detectors also provide early warning notification to the control room.

2. Fire Zone 3.2A-2

a. Horizontal Separation Cable 2APl78 is routed in a 4 inch metal conduit (C2A7422). The conduit is approximately 20 feet in length. Cable 2DC037 (normal supply)is routed in a 1.5 inch diameter conduit (C2A51D8). The conduit is approximately 50 feet in length. At a location near column / row M-26, the conduits extend vertically from the floor (e.g., parallel to each other) and are horizontally separated by 5 feet. The conduits remain vertical until approximately eye level, at which point they are routed horizontally in opposite directions until they exit the room.

Cable 2DC038 (reserve supply) is routed in a 4 inch conduit (C2A6175) locat-ed approximately 20 feet away from 2APl78.

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4 Attachment A(continued)

Fire Hazard Analysis of Byron LER 454-95-005-S2

b. Cable Qualification 4

All power and control cables in the zone are IEEE-383 qualified. As such, they, will not propagate fire along the cable route after the piloted igition source is remcVed.

c. Automatic Suppression The entire zone is protected by an automatic total flooding CO2 system actuat-ed by smoke and heat detectors. A signal from one detector in each of the two trains actuates the CO2 system (e.g., one smoke and one heat detector signal is required to actuate the system). The smoke and heat detectors are located in pairs. There are two pair of detectors located horizontally within 10 feet of i

location where the redundant circuits are closest (e.g., where conduits are separated by 5 feet).

All of the cables routed in open trays (e.g., exposed cables) are located above the HVAC ducts and grills. Therefore, air movement will not impact the ability of the

. smoke detectors from detecting a cable fire in its incipient stage. In addition, the i ceiling of the room is divided into " pockets" by large structural steel beams that are approximately 4 feet high. Such a configuration could potentially delay the early warning detection capability if smoke were to collect in an area where there were no detectors. However, this configuration will not adversely impact the detection system ,

because a pair of detectors is provided in each " pocket." l l

d. Fire Stops Fire stops are not prosided in any cable trays in this zone. However, the large 4

structural steel beams that support the ceiling will inhibit the spread of a hot gas layer (as opposed to a smooth ceiling where there is not significant interference to collect heat.).

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Attachment A(continued)

Fire Hazard Analysis of Byron LER 454-95-005-S2 i e. Likely Fire Propagation There are no intervening combustibles at the floor level, however, there are four cable trays that pass through the area between the conduits (where they are within 5 feet of each other). The trays are 18 inches wide and moderately filled with cable. Since the trays are perpendicular to the line that forms the 1

. spatial separation of the conduits, and they are located above the conduits, they do not provide a contiguous path of combustibles between the redundant circuits.

Since IEEE-383 cables will not sustain combustion absent a piloted ignition 4

source, a fire involving these trays is not credible unless a significant transient exposure is introduced into the area. However, if an unmitigated fire were to occur in these trays, it would spread horizontally along the trays and away from the conduits.

f. Fire Protection System Availability In accordance with the Byron Administrative Technical Requirements, the fire protection systems provided to protect the room (e.g., CO2 system, detection, hose stations, etc...) are required to be operable whenever the equipment in this zone is required to be operable. Compensatory measures such as backup hose lines, hourly fire watch for detection, and continuous fire watch for the CO2 system, are required to be established when these systems are impaired.

Therefore, the availability of the fire protection systems, or an equivalent compensatory measure, is assured during power operation.

3. Fire Zone 3.2 A-1

a. Horizontal Separation Cable 1 APl78 is routed in a 4 inch diameter conduit (CI A5186). The conduit is approximately 10 feet in length and is located in the center of the room.

Cables IDC037 and IDC038 are routed in 4 inch diameter conduits (CI A6175 and CI A6176). Each conduit is approximately 10 feet in length and are located in the northeast corner of the room. As a result, the redundant circuits are horizontally separated by a minimum distance of 30 feet.

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Attachment A(continued)

Fire Hazard Analysis of Byron LER 454-95-005-S2

b. Cable Qualification All power and control cables in the zone are IEEE-383 qualified. As such, they, will not propagate fire a'.ng the cable route after the piloted ignition source is removed.

c. Automatic Suppression l l

The entire zone is protected by an automatic total flooding CO2 system actuat-ed by smoke and heat detectors. A signal from one detector in each of the two trains actuates the CO2 system (e.g., one smoke and one heat detector signal is required to actuate the system). The smoke and heat detectors are located in pairs. There is on pair of detectors located directly above the DC cables in the nonheast corner. There are three pairs of detectors within 10 feet of the AP cable.

All of the cables routed in open trays (e.g., exposed cables) are located above the HVAC ducts and grills. Therefore, air movement will not impact the ability of the smoke detectors from detecting a cable fire in its incipient stage. In addition, the ceiling of the room is divided into " pockets" by large structural steel beams that are approximately 4 feet high. Such a configuration could potentially delay the early warning detection capability if smoke were to collect in an area where there were no detectors. However, this configuration will not adversely impact the detection system because a pair of detectors is provided in each " pocket."

d. Fire Stops Fire stops are not provided in any cable trays in this zone. However, the large structural steel beams that support the ceiling will inhibit the spread of a hot gas layer (as opposed to a smooth ceiling where there is significant interference to collect heat.).

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j Attachment A(continued)

Fire Hazard Analvsis of Byron LER 454-95-005-S2 l e.- Likely Fire Propagation

] There are no intervening combustibles at the floor level and there are a number-of cable trays that are perpendicular to the line formed by the spatial separation of the conduits. There are only two cable trays that nm from the DC cables in i

the northeast corner towards the AP cable in the center of the room (e.g., the i cable trays pass within 6 feet horizontally of the AP cable). The trays are 24 inches wide and moderately filled with cable. The length of the cable tray run is approximately 50 feet between redundant conduits. l I I Since IEEE-383 cables will not sustain combustion absent a piloted ignition I

source, a fire involving these trays is not credible unless a significant transient

exposure is introduced into the area. However, if an unmitigated fire were to occur in these trays, it could spread towards the redundant conduits.

f. Fire Protection System Availability 1 l.

i In accordance with the Byron Administrative Technical Requirements, the fire

. protection systems provided to protect the room (e.g., CO2 system, detection, hose stations, etc...) are required to be operable whenever the equipment in 4 this zone is required to be operable. Compensatory measures such as backup i

hose lines, hourly fire watch for detection, and continuous fire watch for the j CO2 system, are required to be established when these systems are impaired.

Therefore, the availability of the fire protection systems, or an equivalent compensatory measure, is assured during power operation.

l 1 CONCLUSIONS:

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!' l. Fire Zone 3.2A-2

. The only credible fire in this zone is a fire involving cable insulation. Transient

!' combustible material and hot work have been prohibited pending permanent

! resolution of the concern. Since the only combustible material in the room is the l IEEE-383 qualified cable insulation, a slow developing fire is expected to occur, j Such a fire would be detected in its incipient stage by the smoke detectors and an

alarm signal would be transmitted to the control room. At this point, the alarm would be investigated by an operator / fire brigade member. If the responder finds j that the fire is in the incipient stage, it would be extinguished manually with i portable equipment or by manually actuating the CO2 system. A cable fire in the

} incipient stage would not threaten the redundant circuits because there is not a j contiguous path of combustible material between the conduits.

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i Attachment A(continued)

Fire Hazard Analysis of Byron LER 454-95-005-S2

If the fire has developed beyond the incipient stage, the intensity of the fire would automatically actuate the CO2 system (e.g., heat detector alarm) prior to exposing <

the redundant conduits. Since the intervening cable trays are located above the conduits, the CO2 system would also be actuated prior to damaging the redundant 1

circuits even if a significant fire occurred within the trays where they pass between the conduits. In either case (e.g., incipient stage or more fully developed fire), the provision of the IEEE-383 qualified cables, the fact that the cables of concern are

, routed in conduit, the lack of continuity of combustibles, and the automatic

suppression and detection systems ensure that there is sufficient time for the i

control room to isolate the circuits prior to damage occurring.

Therefore, the circuit configuration, fire protection features, and the compensatory actions established for the zone provide reasonable assurance that SSD will not be  ;

affected in the event of a fire pending permanent resolution of the concern.

2. Fire Zone 3.2A-1 1

The only credible fire in the area is one involving cable insulation. Transient combustible material and hot work have been prohibited pending permanent resolution of the concern. Since the only combustible material in the room is the IEEE-383 qualified cable insulation, a slow developing fire is expected to occur.

. Such a fire would be detected in its incipient stage by the smoke detectors and an i

alarm signal would be transmitted to the control room. At this point, the alarm

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would be investigated an operator / fire brigade member. If the responder finds that the fire is in the incipient stage, it would be extinguished manually with  !

, portable equipment or by manually actuating the CO2 system. A cable fire in the l incipient stage would not threaten the redundant circuits because the conduits are separated horizontally by over 30 feet. If the fire has developed beyond the incipient stage, the intensity of the fire would automatically actuate the CO2 system (e.g., heat detector alarm) prior to exposing the redundant conduits. Since the redundant circuits are horizontally separated by over 30 feet, and all cables in the room are IEEE-383 qualified, a significant fire that went unmitigated for an i extended period of time would not damage the redundant circuits prior to extin- I guishment by the fire brigade and / or the CO2 system.

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e' . i d

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Fire R=-ti Advsis of Byron Irn 454-95-005-S2 4

Therefore, the circuit configuration and fire protection features provided in this I zone provide reasonable anurance that SSD will not be affected in the evet of a fire, and provide a level of protection equivalent to Section III.G.2 of Appendix R.

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REFERENCES:

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1. Byron Fire Hazards Analysis (FHA).

2. Operability Assessmet 96-049, 1

3. Byron Appedix R Deviation A.23.

4. Generic Letter 86-10.

5.

Electrical Drawin8s 6E-1(2)-3361.

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6. Plant Walkdowns Conducted on November 9,1996. 1 Prepared by: . -

Daniel 3. Roberta Fire Protection Engineer M&SE Reviewed by:- [

Stanley Chingo Fire Protection Engineer M&SE A- 10 '

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, Attachment B l i Summary of Compensatory Actions for i

Byron ENS Event Notification on November 7,1996 The following Compensatory Actions shall be in place for Byron Fire Zones -  !

!, 3.2A-1 and 2 (Unit 1 and Unit 2 Non-Segregated Bus Duct Area, Elev. 439 feet, Aux Building) i l Hourly Fire Watch:

Hourly fire watches shall be continued until permanent corrective i actions are taken in both fire zones 3.2A-1 and 2.

Control of transient combustibles: I i

Transient combustibles shall not be brought into fire zones 3.2A-1 and 2 unless a continuous fire watch is present in the zone. j i

Control of hot work:

1

. Hot work (welding, grinding, etc., ) shall not be permitted in fire zones 3.2A-1 and 2 unless a continuous fire watch is present in the zone.

Operator action upon receipt of fire detection alarm:

l Upon receipt of an alarm on the Main Control Room Fire Detection Panels of a fire in zones 3.2A-1 or 2, the Operator will immediately initiate the actions described on the attached Operator response summary and logic flow chart.

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Attachment B (continued) 4 Fire in LCSR Zone 3.2A-2 Operating Department Response Narrative

l [ Narrative for Unit 2 fire zone 3.2A-2, equally representative of Unit 1 fire zone]

i A fire alarm will annunciate on 2PM09J, alarm 2D-49, or 2D-50, (or both.) The Center Desk NSO will acknowledge the alarm (s), and pull BAR 2PM09J-E9, or E-10.

The BAR(s) instructs the Operator to immediately activate the Fire Brigade per the l Station Administrative Procedure BAP 1100-12, implementation Procedure for Fire,

, (Center Desk.) This procedure notifies the Fire Brigade by Plant Page, Plant Radio,

and the Plant Wide Fire Alarm to musw. et the fire cage, don fire fighting equipment, and proceed to the scene of the fire, l i

'l

Then the Center Desk Operator will check if there is a Suppression Alarm 2S-43 on- l 2PM09J.  !

• . If there is D91 a suppression alarm, the Center Desk Operator will dispatch 2 Operators to the LCSR Zone 3.2A-2 to investigate. (2 SCBA's are staged locally for personnel protection during this investigation.) l I

If there is D91 a fire, the Fire Brigade will be secured. I If there la a fire, then: )

The Operators at the scene will evacuate personnel from the Zone, and initiate CO2 to the Zone per BOP FP ~22, Local Operation of CO2 and Halon.

The Fire Brigade will start fire fighting activities.

The Center Desk Operator will transition to SPP 96-074, Operator Response to a Fire in LCSR Zone 3.2A 2, if there la a suppression alarm, then: ,

The Fire Brigade will start fire fighting activities. l The Center Desk Operator will transition to SPP 96-074, Operator Response to a Fire in LCSR Zone 3.2A-2.

SPP 96-074, Operator Response to a Fire in LCSR Zone 3.2A-2. Directs the Center i Desk Operator to immediately activate the Fire Brigado per the Station Administrative Procedure BAP 1100-12, implementation Procedure for Fire, (Center Desk.) if not already accomplished. Then the Center Desk Operator will align the Unit 2 SX tower, stop the fans powered from Bus 231Z, and de-energize Bus 231Z.

He will then verify open the normally open ESF Bus Ties for Bus 241. If all DC control power is lost to ESF Bus 241, the Center Desk Operator will instruct Electrical Operators, as necessary, to control breakers locally per BOA Elect-5, Local Emergency Control of Safe Shutdown Equipment. The procedure then, at the Shift Engineer's discretion, will start redundant equipment on Division 21 to minimize the impact on the plant of a loss of Division 22 due to the fire.

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, , Attachment B x

ACTIVATE THE

IS THERE A FIRE FIRE BRIGADE PER ALARM IN LCSR A-2 (2D-49 N- Yu-+

/50) ON 2PMOGJ IMP M NTATION PROCEDURE FOR FIRE

% a i I

YM s

IS THERE SUPPRESSION \

ya - ALARM 1N LCSR A-2 D No  :

(2S-43) ON

! 2PM09J THERE AR I

N/ SCBA'S STAGED AT\

l o u u THE LCSR ZONE /

ENTRANCE l

PLACE OSXO3CCCD DISPATCH 2 ACTIVATE THE HIGH AND LOW OPERATORS WITH FIRE BRICADE PER SPEED FANS TO Yu SCBA'S TO i

BAP 110012, IMPLEMENTATION PTL, OPEN OA TOWER RISERS, l

!l INVESTIGATE PROCEDURE FOR CLOSE THE OA I FIRE TOWER BYPASS 1 VALVE.

j u j

I fN 's

/1S THERE A FIRE IN(N SECURE FIREN THE LCSR AREA A-2/ BRIGADE )

OPEN ACB 2415Z yn

'/

BUS 241 FEED TO XFMR 231Z j

OPEN ACB 2414, BUS EVACUATE FIRE 241 RESERVE FEED ! WATCH IN LCSR, OPEN ACB 2411

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, 1NITIATE CO2 TO NON ESF BUS TIE' LCSR AREA A-2 PER BOP FP-22 OPEN ACB 1414 RESERVE FEED y AT SE'S DIRECTION, CONTROL START REDUNDANT BREAKERS LOCALLYi EQUIPMENT ON PER 2 BOA ELECT-5, BUS 241 TO LOCAL EMERGENCY : MINIMlZE PLANT l

CONTROL OF SAFE IMPACT OF j SHUTDOWN POSSIBLE TRIP OF l

EQUIPMENT, BUS 242 l

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Attachment C Planned Permanent Resolution for Concerns from i Byron ENS Event Nc.tification on November 7,1996

. The planned permanent resolution for the concern described in the Byron l ENS Event notification on November 7,1996, is the following. j l

UNIT 1: ),

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Conduit C1 A5186 will be protected with a qualified 1-hour rated fire barrier l

in fire zone 3.2A-1. This conduit contains cable 1 AP178 which is fed from i cubicle # 1 of ESF Bus 141 and powers the Division 11 Unit Substation

{ - (131Z) at the Essential Service Water Cooling Tower. When the fire rated protection is added to this cable, there will be no 4 Kv power circuits normally fed from ESF Bus 141 which are routed through zone 3.2A-1.

Therefore, there will not be a power circuit located in this zone during normal plant operations, that could generate a 4 Kv fault on ESF Bus 141.

With this permanent change, Byron Unit 1 SSA will be in compliance with -

l the accepted safe shutdown analysis documented in Fire Protection Report l_

1 Section 2.4.2. 7.

l The qualified fire barrier will be installed on conduit C1 A5186 by no later ,

than May 31,1997.

j UNIT 2:

j Conduit C2A7422 will be protected with a qualified 1-hour rated fire barrier in fire zone 3.2A-2. This conduit contains cable 2AP178 which is fed from

cubicle # 5 of ESF Bus 241 and powers the Division 21 Unit Substation

! (231Z) at the Essential Service Water Cooling Tower. When the fire rated j protection is added to this cable, there will be no 4 Kv power circuits )

! normally fed from ESF Bus 241 which are routed through zone 3.2A-2. l j Therefore, there will be no power circuits located in this zone during normal <

plant operations that could generate a 4 Kv fault on ESF Bus 241. With this  ;

, permanent change, the Byron Unit 2 SSA will be in compliance with the l accepted safe shutdown analysis documented in Fire Protection Report i Section 2.4.2. 6. ,

The qualified fire barrier will be installed on conduit C1 A5186 by no later than May 31,1997.

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