ML17095A852

Redacted Byron Nuclear Station, Amendment 27 to Fire Protection Plan, Chapter 2.4, Safe Shutdown Analysis. Section 2.4 Public Version Pages 1-19 and 1626-1643

ML17095A852
Person / Time
Site:	Byron, Braidwood
Issue date:	12/15/2016
From:	Exelon Generation Co
To:	Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation
Shared Package
ML16357A264	List: ML16357A507 ML16357A508 ML16357A509 ML16357A521 ML16357A523 ML16357A524 ML16357A526 ML16357A529 ML16357A530 ML16357A532 ML16357A533 ML16357A534 ML16357A535 ML16357A536 ML16357A537 ML16357A540 ML16357A545 ML16357A549 ML16357A579 ML16357A580 ML16357A583 ML16357A584 ML16357A591 ML16357A592 ML16357A593 ML17086A588 ML17086A589 ML17086A590 ML17086A591 ML17086A592 ML17086A593 ML17086A595 ML17086A596 ML17086A597 ML17086A598 ML17086A599 ML17086A600 ML17086A601 ML17094A865 ML17095A852 ML17095A866 RS-16-248, Braidwood Nuclear Station, Amendment 27 to Fire Protection Report, Chapter 3.0, Guidelines of BTP Cmeb 9.5-1 RS-16-248, Braidwood Nuclear Stations, Revision 16 to Updated Final Safety Analysis Report, Technical Requirements Manual RS-16-248, Braidwood Nuclear Stations, Revision 16 to Updated Final Safety Analysis Report, Technical Specifications Bases RS-16-248, Byron Nuclear Station, Amendment 27 to Fire Protection Report, Chapter 3.0, Guidelines of BTP Cmeb 9.5-1 RS-16-248, Byron Nuclear Stations, Revision 16 to Updated Final Safety Analysis Report, Technical Specifications Bases RS-16-248, Byron/Braidwood Nuclear Stations, Amendment 27 to Fire Protection Report, Chapter 4.0, Fire Protection Program RS-16-248, Byron/Braidwood Nuclear Stations, Revision 16 to Updated Final Safety Analysis Report, Appendix B - Construct Material Standards and Quality Control Procedures RS-16-248, Byron/Braidwood Nuclear Stations, Revision 16 to Updated Final Safety Analysis Report, Appendix C - Deleted RS-16-248, Byron/Braidwood Nuclear Stations, Revision 16 to Updated Final Safety Analysis Report, Appendix D - Computer Programs ... further results
References
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BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-1 2.4 SAFE SHUTDOWN ANALYSIS 2.4.1 Introduction 2.4.1.1 Purpose The purpose of this analysis is to demonstrate that for a fire in any single plant fire zone in the Byron plant, sufficient equipment will remain operational in other parts of the plant to achieve and maintain a safe shutdown condition in both units independent of that fire zone. For the purpose of this analysis, hot standby and cold shutdown are defined as follows:

a.

Hot standby - A plant condition in which the reactor is subcritical with a shutdown margin per the Technical Requirements Manual, and the primary coolant system average temperature is greater than or equal to 350!F.

b.

Cold shutdown - A plant condition in which the reactor is subcritical with a shutdown margin per the Technical Requirements Manual, and the primary coolant system average temperature is less than or equal to 200!F.

A safe shutdown condition is achieved by satisfying the following requirements:

a.

maintain a condition of negative reactivity, b.

monitor and control the primary system coolant inventory and pressure, c.

remove decay heat, d.

provide process monitoring capability, and e.

provide essential support functions.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-2 2.4.1.2 Analysis Criteria The criteria used as a guideline for this safe shutdown analysis are that for a fire in any fire zone in the plant, sufficient redundant and/or diverse equipment will remain available to ensure that the capability to achieve safe shutdown still exists independent of equipment or systems located within or affected by the fire in the affected fire area/zone. The requirements listed above in Subsection 2.4.1.1 shall be satisfied. A secondary goal of the analysis was to identify adjacent fire zones in the plant where the wall or barrier separating the two fire zones does not meet the separation requirements of Section C.5.b of BTP CMEB 9.5 -1. For those cases, one of the following was provided: 1) a BTP CMEB 9.5 -1 deviation was prepared for which justification for the existing separation is provided, 2) an evaluation was performed per the guidance of Generic Letter 86-10, which determined that the barrier is adequate to prevent the spread of fire such that redundant safe shutdown components are not adversely affected, or 3) the separation was upgraded to a justifiable level.

2.4.1.3 Evaluation Methodology The evaluation methodology, which was utilized to conduct this safe shutdown evaluation, can be summarized as follows:

a.

Systems, components, and instrumentation that could be used to satisfy the safe shutdown requirements listed in Subsection 2.4.1.1 were identified. Criteria and assumptions used to identify safe shutdown components are provided in following Subsection 2.4.1.4. The systems so identified are listed in Table 2.4-1 and the equipment and instrumentation so identified are listed in Table 2.4-2.

b.

Once safe shutdown equipment and instrumentation had been identified, power, control and instrumentation cables necessary for the operation of this equipment and instrumentation were then identified. For equipment, the cables identified include power cables back to the primary source of power (the 4160V and 480V safety-related buses, MCCs, and the 125Vdc distribution buses), and all control cables necessary for proper functioning of the control circuit. For instrumentation, cables identified include power feeds from the instrument power buses, and signal cables to primary display locations (usually the main control room, the remote shutdown control panels, and/or the fire hazard panel). Cables associated with tertiary functions are not included. The detailed criteria used for the cable selection process are provided in following Subsection 2.4.1.5.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-3 c.

Once the list of safe shutdown cables was generated, the routing of each cable through the plant fire zones was identified. This was accomplished in the following manner. For the Byron/Braidwood plants, the cable tray system has routing points identified at frequent intervals. Each of these routing points was assigned the number of the fire zone in which it was located. A computerized database containing important cable data is maintained for all cables in the plant. For cables routed in the tray system, the routing points through which the cable passes are listed in the data base. Using the routing point/fire zone correlation which was developed, the fire zones through which each safe shutdown cable passes were listed. For cables routed wholly or partially in conduit, or in free air, the cable routings were manually checked, and all fire zones through which they passed were added to the previously generated list of fire zones for each cable. The cable data base is kept current and is updated periodically, thus, the routing information is current and representative of the as-built condition of the plant.

d)

A logic model of the plant was developed to aid the analysts in performing the area analysis. The logic model is in the form of a fault tree. It incorporates each individual component from the safe shutdown equipment list, and associated cables, if any.

e)

An area analysis was performed for each fire zone in the plant that contains safe shutdown components or cables. The logic model of the plant was used to identify each instance where components or cables located within a given fire zone are redundant to each other. Each such occurrence is evaluated to determine other acceptable means to satisfy safe shutdown requirements. The means of satisfying the safe shutdown requirements for each such occurrence is documented by identification of an exception. The exceptions provide the detailed rationale why the presence of redundant components or cables is acceptable from a safe shutdown viewpoint. Typical exceptions consist of the following items: 1) identification of a manual action to compensate for the postulated fire damage (e.g., manually operate a valve with its handwheel); 2) justification for existing physical separation as documented in a BTP CMEB 9.5-1 deviation or technical evaluation per the guidance of NRC Generic Letter 86-10; or 3) fire proofing of potentially affected cables.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-4 2.4.1.4 Identification of Safe Shutdown Equipment The philosophy used in generating the Byron/Braidwood safe shutdown equipment lists was to identify as much safety-related equipment as possible which could be available during and after a fire and utilized to perform the safe shutdown functions identified in Subsection 2.4.1.1. The result is that the list includes redundant and in some cases diverse equipment for performing each function. It also follows that not all of this equipment needs to be available to achieve safe shutdown following a fire in any plant fire zone.

The safe shutdown equipment list that has been generated for the Byron plant is presented below.

a.

Systems which may be used by the operators to perform the safe shutdown functions of reactivity control, primary coolant system inventory and pressure control, decay heat removal, and provide essential support are listed in Table 2.4-1.

b.

Equipment and instruments which may be used to accomplish the safe shutdown functions for both hot standby and cold shutdown are listed in Table 2.4-2. The equipment on this list includes redundant, and in some cases, diverse means of accomplishing the safe shutdown functions.

The safe shutdown component selection process and criteria are described below.

Once the safe shutdown systems were identified, the P&IDs for those systems were reviewed to identify essential safe shutdown flowpaths and system boundaries.

Component selection was performed by reviewing the flowpaths to identify components which require operation/repositioning to accomplish the desired safe shutdown function.

In addition, components whose fire-induced spurious operation could impair safe shutdown are identified. This includes normally open valves/dampers in the required flowpath whose spurious closure could prevent the required flow, and normally closed valves/dampers forming a system boundary whose spurious opening could divert flow from the desired flowpath.

The following guidelines were used to determine which components to include on the safe shutdown equipment list:

a.

Components such as pumps and fans which require operation to accomplish the desired safe shutdown function are listed on the safe shutdown equipment list.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-5 b.

Valves or dampers in the identified safe shutdown flowpath whose spurious operation could adversely affect system operation are included on the safe shutdown equipment list. Manual valves or dampers requiring repositioning during the post-fire shutdown are also included. Manual valves/dampers/check valves which do not require manual actions during the post-fire shutdown are not required to be included.

c.

Electrically operated/controlled valves or dampers constituting system boundaries are evaluated for spurious operation. If the spurious operation of a single valve or damper could have a significant adverse impact on the capability to achieve a safe shutdown function by diverting flow from the desired safe shutdown flowpath, then the valve or damper is included on the safe shutdown equipment list. When performing this evaluation, it is necessary to consider only a single spurious operation. Normally closed manual valves and properly oriented check valves credited as system boundaries are not required to be included.

d.

Manual drain, vent, and instrument root valves are not included on the safe shutdown equipment list.

e.

Safety/Relief valves provided for equipment and piping protection are not included. However, safety/relief valves which provide an active safe shutdown function, such as main steam safety valves, or pressurizer power-operated relief valves, are included on the safe shutdown equipment list.

f.

Loops or bypasses within a system where spurious operation would not result in a loss of flow or inadequate flow to safe shutdown flowpaths are not included in the safe shutdown equipment list.

g.

For tanks, all outlet lines are evaluated for their functional requirements. For lines not required to be functional, a means of isolation is included when necessary to prevent unnecessary drawdown of the tank. Tank fill lines are also evaluated as necessary.

h.

Steam traps in the safe shutdown flowpath, designed to remove condensate and trap steam, are not included in the safe shutdown equipment list. Based on this design function, steam exiting via these flowpaths is considered to have a negligible impact on RCS cooldown.

i.

Solenoid pilot valves are not listed on the safe shutdown equipment list. The process valves with which the pilot valves are associated are identified on the safe shutdown equipment list. Cabling for the solenoid pilot valves is associated with the process valve component number.

j.

Passive mechanical components such as tanks, heat exchangers and pressure vessels are specifically included on the list for completeness.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-6 k.

Fire dampers in the flowpath whose operation could adversely affect system operation, whether actuated by fusible links or electro-thermal links, are included on the list. Fire dampers actuated by electro-thermal links are evaluated for spurious operation.

l.

Equipment that is not normally required for safe shutdown, but whose spurious operation could either prevent or have a significant adverse impact on the capability to achieve a safe shutdown function, is included on the safe shutdown equipment list.

Components for functions not involving mechanical/fluid flowpaths (e.g., process monitoring, essential power, support systems) were then identified. The following guidelines were used:

a.

For the process monitoring function, the guidance provided in IE Information Notice No. 84-09 was considered in the identification of the minimum set of instruments that are required to monitor plant process variables.

b.

Power supplies for safe shutdown components that require power to achieve their safe shutdown function are identified as safe shutdown components.

Identification of power supplies includes both motive and control power sources.

c.

Safe shutdown components typically are major components within a safe shutdown system, such as pumps, fans, valves, tanks, electrical busses, etc.

The subcomponents such as panels, cabinets, control boards, solenoids, relays, switches, transmitters, etc. are not included on the safe shutdown equipment list.

The circuits associated with these items are included via the cable selection criteria, and the cables are listed with the major safe shutdown components.

Therefore, these subcomponents are implicitly accounted for in the analysis via identification of the electrical schematic diagrams and their identified safe shutdown cables.

d.

Other diesel-backed support systems such as service water, component cooling water, HVAC, heat tracing, lubrication, and air systems are included in the safe shutdown equipment list if required for system support.

e.

For the 4160Vac ESF switchgear busses, special selection criteria apply. Power feeds to these busses, and loads fed from these busses are controlled by air circuit breakers (ACBs). The fire-induced spurious closure of an ACB in conjunction with a fault on the feed cable or bus bar associated with that ACB could disable the bus. Therefore, all 4160Vac ACBs which are not associated with a safe shutdown component are specifically listed on the safe shutdown equipment list.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-7 2.4.1.5 Cable Selection Criteria and Damage Assumptions The criteria used to select safe shutdown cables for components identified on the safe shutdown equipment list, and the assumed failure modes and related assumptions are described in the following subsections.

2.4.1.5.1 Cable Selection Criteria The method used to identify safe shutdown cables is described in the following paragraphs.

a.

Review the safe shutdown equipment list to determine all safe shutdown components which are required to be evaluated. All electrically powered or electrically controlled components are identified. Passive mechanical components such as pressure vessels, tanks, heat exchangers and manual valves are excluded from the list of components to be evaluated.

b.

For each component, review the applicable schematic diagram, single-line diagram, instrument loop schematic, wiring diagram, or vendor drawings, as required.

c.

For electrically powered components, the power cable from the primary power supply for the component (e.g. 4160Vac or 480Vac safety-related buses or MCCs, or 125Vdc distribution panel) is identified as a safe shutdown cable if the component is an active component.

d.

For electrically controlled components whose control circuits receive power from separate and specific power sources, the control power cables are identified as safe shutdown cables.

e.

For electrically controlled components, each conductor in the control circuit is reviewed to evaluate the effect on the circuit of the four postulated failure modes (open circuit, short circuit, short to ground, hot short) described in the following subsection. If the effect of one or more of the failure modes is to render the component unavailable, or cause a spurious operation of the component, then the cable which carries that conductor is identified as a safe shutdown cable.

f.

The following assumptions were made when evaluating safe shutdown component control circuit conductors for failures:

1)

Components are assumed to be in their normal operating position.

2)

All relay, position switch, and control switch contacts in the control circuit are assumed to be in the position that corresponds to the normal plant operating condition of that device unless specifically stated otherwise.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-8 3)

Test switches in the control circuits are assumed to be in their normal plant operating position.

4)

Automatic logic interlocks from other circuits are assumed to be in a permissive position unless the circuits for the interlock are included in the safe shutdown cable selection for the component of concern, or the interlock is otherwise shown to be unaffected by fire.

5)

Isolation switches in control circuits are analyzed in their expected positions. For control room operation, isolation switches are not operated and are assumed to be in the REMOTE position. For local operations, both REMOTE and LOCAL positions are considered, since the switches are initially in the REMOTE position, and will subsequently be placed in the LOCAL position. (The diesel generators are an example of a component that must be evaluated with the switches in both positions).

6)

Annunciator alarm, metering, and instrument circuits and cables whose failure does not impact safe shutdown functions are not included in the safe shutdown equipment-cable list.

7)

Associated circuits cables, as defined in Generic Letter 81-12, are identified unless manual actions are identified that mitigate the consequences of the postulated cable failure.

g.

For instrumentation required for safe shutdown, power cables from the Instrument Buses to the required instruments were identified as safe shutdown cables. Also instrument cables from the required instrument sensors to the required instrument indicators were also identified as safe shutdown cables.

h.

The final product of the safe shutdown cable selection process is an equipment -

cable list which lists required safe shutdown cables for each electrically powered and/or controlled safe shutdown component. The list includes appropriate annotations or notes to identify cables capable of causing spurious operation of the component, and for components with isolation switches, the list identifies cables which cause loss of local and/or control room control.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-9 2.4.1.5.2 Cable Damage Assumptions This subsection describes the basic assumptions made with regard to fire damage to electrical cables.

a.

The insulation and external jacket material of electrical cables is susceptible to fire damage. Damage may assume several forms including deformation, loss of structure, cracking, and ignition. The relationship between exposure of electrical cable insulation to fire conditions, the failure mode, and time to failure may vary with the configuration and cable type. To accommodate these uncertainties in a consistent and conservative manner, this analysis assumes that the functional integrity of electrical cables is lost when cables are exposed to a postulated fire in a fire area, except where protected by a fire rated barrier within the fire area (or radiant energy shield within containment). Electrical cable failures are limited by the following considerations:

1)

Fire damage occurs throughout the fire area or fire zone under consideration.

2)

Fire damage results in an unusable cable that cannot be considered functional with regard to ensuring proper circuit operation.

b.

Fire-induced damage to cables may cause the following types of failures:

1)

Open Circuit - An individual conductor that loses electrical continuity.

2)

Short Circuit - An individual conductor that comes into electrical contact with another electrical conductor and bypasses the normal electrical load (i.e., relay coil, solenoid valve, motor, etc.), thereby resulting in a very high current flow.

3)

Short to Ground - An individual conductor that comes into electrical contact with a grounded conducting device, such as a cable tray, conduit, or metal housing.

4)

Hot Short - An energized conductor that comes into electrical contact with another conductor and bypassing control contacts in a circuit, thereby spuriously energizing the affected electrical load.

c.

For components which do not form part of a high-low pressure interface between the RCS and a lower pressure system, credible circuit failures include multiple open circuits, short circuits, shorts to ground, and a single hot short on any one conductor within the control circuit. For these components, 3-phase ac power circuit cable-to-cable proper phase sequence faults and 2-wire ungrounded dc circuit cable-to-cable proper polarity faults are considered of sufficiently low likelihood that they are not assumed to be credible. This assumption is consistent with guidance provided in Generic Letter 86-10.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-10 d.

For components which do form part of a high-low pressure interface between the RCS and a lower pressure system, credible circuit failures include multiple open circuits, short circuits, shorts to ground, and multiple hot shorts within the control circuit. In addition, 3-phase ac power circuit cable-to-cable proper phase sequence faults and 2-wire ungrounded dc circuit cable-to-cable proper polarity faults are considered to be credible, and must be evaluated. The application of this assumption to high-low pressure interfaces is discussed in Section 2.4.3.

2.4.1.6 Associated Circuits and Other Electrical Issues Associated circuits and other electrical issues that are relevant to BTP CMEB 9.5-1 are discussed in the following sections.

2.4.1.6.1 Common Power Source Associated Circuits For the majority of ESF power supplies, this issue is addressed by providing coordinated circuit protection between the feed breakers for a supply and the load breakers fed by the supply. Calculations are available to demonstrate proper breaker coordination for these power supplies. The coordinated circuit protection ensures that the power supply will provide sufficient current to a faulted load to clear the load breaker prior to affecting the power supply feed breaker. Such coordination is demonstrated for the following ESF power supplies: 1) 4160Vac switchgear buses; 2) 480Vac unit substations; 3) 480Vac motor control centers; 4) 120Vac panels; and 5) 125Vdc distribution systems.

The interrupting device design is factory tested to verify overcurrent protection as designed in accordance with the applicable standards. The low and medium voltage switchgear (480V and above) circuit breaker protective relay will be periodically tested to demonstrate that the overall coordination scheme remains within the limits specified.

The molded case circuit breakers will be periodically manually exercised and inspected to ensure ease of operation. In addition, a sample of these breakers will be periodically tested to determine that breaker drift is within the allowed according to the design criteria, and all the tests will be performed in accordance with an accepted industry testing program. In the instances where fuses are being used as interrupting devices, administrative controls will ensure that correct replacement fuses will be used.

Therefore, a common source with the redundant shutdown equipment is always protected.

For the Byron station, one bifurcated feed is present between 480Vac switchgear bus 132X and motor control centers 132X3 and 132X5 (component id numbers 1AP12E, 1AP24E and 1AP32E, respectively). This is accounted for in the safe shutdown analysis by including the feed cables for both MCCs with the safe shutdown cable list for each MCC.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-11 Coordinated circuit protection cannot be demonstrated for each units four 120 Vac instrument power buses between the main feed breakers and the load breakers. The 120Vac instrument bus distribution panels are normally powered from the 120Vac vital instrument inverters, which current limit at 150% of rated output current. This is accounted for in the safe shutdown analysis by including all of the cables fed from each 120Vac instrument bus distribution panel as safe shutdown cables. Therefore, an instrument bus is only considered to be available for safe shutdown use if none of the buss cables are routed in the fire zone being analyzed.

2.4.1.6.2 Common Enclosure Associated Circuits This issue is not a concern at Byron for the following reasons. The raceway system is divided by unit, by division (train), by safety class, and by cable type (power, control, or instrument). Each raceway is assigned a segregation code, and only cables with the same segregation code are routed together. Therefore, cables from unit 1 are not routed together with cables from unit 2. Cables from one division (e.g. Division 11) are not routed together with cables from the redundant division (e.g. Division 12). Non-safety related cables are not routed together with safety related cables. Finally, power, control and instrument cables are not intermixed within any given raceway; each is routed in separate raceways with cables of the same type. In addition, cables used for Byron meet the flame test of IEEE 383-1974, which demonstrates that the cable does not propagate fire outside of the area of flame impingement. Thus, in the absence of external influences, a cable fire in one fire zone will not propagate through the raceway system to a different fire zone.

When non-safety related cables share a common enclosure (e.g., control panel, motor control center, terminal box) with safety related cables, an analysis has been performed and documented to demonstrate that a failure of the non-safety related cable will not degrade any safety related circuits in the enclosure.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-12 2.4.1.6.3 Multiple High Impedance Faults (MHIF)

High impedance faults are defined in Generic Letter 86-10 as postulated faults which result in fault currents just below the breaker/fuse fault current setting or rating.

Therefore, high impedance faults by definition do not result in clearing of the fault by the load breaker (or fuse). The referenced Generic Letter requested nuclear plant licensees to consider multiple (simultaneous) high impedance faults on safe shutdown power supplies. The concern is that the summation of fault current from such faults on both safe shutdown and non-safe shutdown loads could trip the main feed breaker for the affected safe shutdown power supply prior to clearing the individual load faults.

For Byron Station, MHIF are not considered to be credible for medium voltage buses (4.16 kV and 6.9kV) because at this voltage level, postulated arcing faults will clear by one of two mechanisms. The fault current will rapidly propagate into a bolted fault, which will be cleared by the individual feed breaker, or the energy of the postulated fault will be sufficient to vaporize the target and break the fault circuit path. Also, at this voltage level, phase-to-phase and three-phase arcing faults approach the magnitude of a three-phase bolted fault. Even if this fault were to remain an arcing fault, it would be cleared by the protective devices. Minimum arcing ground faults are not a concern at the medium voltage level because the individual load breakers are provided with ground fault protection. Coordination of the ground fault protection between the bus main supply breaker and the individual load breakers ensures that a ground fault on an individual load will trip the load breaker first.

MHIF are considered to be credible at the 480 Vac level. An analysis has been performed to demonstrate that the 480 Vac switchgear buses and MCCs required for safe shutdown are adequately protected against MHIF. For phase-to-phase and three-phase MHIF, the analysis assumed that the normally energized cables that are not routed in the fire zone under consideration will draw their rated full load current. A High Impedance Fault (HIF), where the load current is assumed to be just below the trip setpoint of an individual load breaker, is assumed to be present on all normally energized cables that are routed in the zone under consideration. To address the design basis of one spurious operation, the worst case (i.e., largest breaker trip rating) normally de-energized load on the bus is assumed to be always faulted due to the fire.

The analysis verified that the individual load breakers would trip before the main supply breaker for phase-to-phase and three-phase MHIF.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-13 High impedance arcing ground faults were also evaluated for the safe shutdown 480 Vac switchgear buses. Each 480 Vac switchgear breaker provides phase overcurrent protection. Additionally, ground fault protection is provided for each 480 Vac switchgear bus by a ground overcurrent relay that monitors current on the 4160 - 480/277 volt transformer secondary grounded neutral. If a ground fault is sensed, the ground overcurrent relay will trip the 4160 volt supply breaker to the transformer that feeds the 480 Vac switchgear bus. However, an arbitrary fault current, just below the feed breaker trip setting, is not credible. Research has shown that the minimum arcing ground fault current is 38 percent of the bolted three-phase ground fault value. If the ground fault current is less than 38 percent, the ground fault will self extinguish. If the ground fault current is greater than 38 percent, the energy of the fault will cause the fault current to go to a condition close to a three-phase bolted fault current value. The analysis has verified that for each high impedance arcing ground fault, the individual load breaker will clear 38 percent of the three-phase bolted fault current value prior to the ground overcurrent relay tripping the switchgear bus supply breaker. Therefore, the safe shutdown 480 Vac switchgear buses and MCCs are adequately protected against both ungrounded MHIF and grounded arcing MHIF.

For the 120 Vac distribution buses, high impedance arcing faults are not considered to be credible. Based upon research, the peak line-to-neutral voltage is not high enough to cause arcing current to flow. However, a coordination analysis has been performed to verify that the circuit breakers for the 120 Vac distribution buses provide adequate protection against multiple faults with minimum fault current values. For worst case loads with the longest cable runs and therefore the lowest fault currents, the analysis calculated the minimum fault current that could be present at a load taking into account the impedance of the cable between the bus and the load. The analysis verified that the load protective device (i.e., a fuse or circuit breaker) would trip before the upstream protective device. The analysis also verified that the upstream protective devices have adequate margin to accommodate multiple faults. Therefore, the 120 Vac voltage level distribution buses are adequately protected against multiple faults with minimum current values.

A MHIF analysis has not been performed for the 120 Vac instrument power buses. As stated previously in Section 2.4.1.6.1, an instrument bus is only considered to be available for safe shutdown use if none of the buss cables are routed in the fire zone being analyzed.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-14 For the 125 Vdc distribution buses, high impedance arcing faults are not considered to be a concern, because the fault will either develop into a full bolted fault or will self extinguish. Given the very small maximum separation requirements between conductors for an arc to occur at the 125 Vdc level, there is enough energy in a 125 Vdc fault to melt the two conductors together which will result in a bolted fault that will trip the protective device or to burn the wire open. However, a coordination analysis has been performed to verify that the circuit breakers for the 125 Vdc distribution buses provide adequate protection against multiple faults with minimum fault current values.

For worst case loads with the longest cable runs and therefore the lowest fault currents, the analysis calculated the minimum fault current that could be present at a load taking into account the impedance of the cable between the bus and the load. The analysis verified that the load protective device would trip before the upstream protective device.

The analysis also verified that the upstream protective devices have adequate margin to accommodate multiple faults. Therefore, the 125 Vdc voltage level distribution buses are adequately protected against multiple faults with minimum current values.

2.4.1.6.4 Spurious Operations The licensing basis of the Byron plant is to assume one spurious operation per fire, as documented in the Byron and Braidwood SERs. Each electrically controlled component on the safe shutdown equipment list was considered to be susceptible to postulated spurious operations.

As discussed in criteria (b) and (l) from the component selection criteria presented in Subsection 2.4.1.4, the spurious operation of valves and dampers in safe shutdown flowpaths was considered during the component selection process. The effects of postulated spurious operation of these components, and the required actions to mitigate them, if any, are addressed in the safe shutdown analyses for individual fire zones in Section 2.4.2. Post-fire operating procedures have also been prepared which include manual actions to address postulated spurious operations for selected electrically driven safe shutdown components (fans and pumps powered from the 4160Vac ESF switchgear buses). For other electrically powered components (480Vac and lower rated supplies), the spurious start of an inactive component has no adverse consequences (e.g., spurious start of a small pump or fan). For these components, any damage to the components control circuit is assumed to render the component unavailable for safe shutdown. No specific discussion of spurious operation is provided.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-15 2.4.1.6.5 Cable Fireproofing Material 1.

The 3M Interam Type E-54 fire wrap is an acceptable one-hour and three-hour fire barrier based on existing qualification reports and test data (ASTM E-119 Fire Test, Hose Stream tests, etc.). Furthermore, the 3M Type E-54 fire wrap possesses endothermic properties and shall not be treated as a combustible. Per the Technical Evaluation of 3M Interam one and three-hour Fire Protective Wraps Applied to Electrical Circuits (June 1999), the E-50 series of 3M Interam base material has passed the ASTM E-136 testing requirements for noncombustible materials, It has also passed the ASTM E-84 testing requirements for surface flame spread (with a flame spread rating of 0.7). The ASTM E-136 testing was conducted at Omega Point Laboratories in January of 1995, project 14540-99235 (CTP-2004), and the ASTM E-84 testing was conducted at Underwriters Laboratories, report file R10125, project 82NK21937.

It is recognized that deviations from the tested fire wrap configuration will occur. Generic Letter 86-10 also recognizes this fact and allows for technically justified deviations. Any deviations that occur during the installation will be evaluated based on the criteria discussed in Generic Letter 86-10 (e.g., continuity of the fire barrier, adequacy of the barrier thickness, etc.) prior to acceptance of the installation.

2.4.1.7 Assumptions The following assumptions were made in performing the safe shutdown analysis:

1.

Initial Plant Operating Conditions

a. Both units of the station are operating at 100% power.

b. Normal system and component alignments are assumed.

2.

All safe shutdown components and systems are assumed to be available prior to the onset of the fire. In other words, no allowance is made for systems or components being out of service for maintenance or testing.

3.

Independent failures (i.e., failures that are not a direct consequence of fire damage) of systems, equipment, instrumentation, controls, or power supplies, do not occur before, during, or following the fire.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-16 4.

The postulated fire shall not be considered to occur simultaneously with other accidents, events, or phenomena such as a design-basis accident except a Loss of Offsite Power (LOOP). Furthermore, for any given fire zone, a LOOP need only be postulated if the offsite power circuits are affected by a fire in that fire zone. When it can be demonstrated that a fire in a specific zone will not affect the offsite power circuits, and alternative shutdown capability is not credited, then a LOOP need not be postulated to occur. In the event of a LOOP and the failure of the emergency diesel generator to auto start due to fire damage, station emergency procedures initiate actions to restore at least one ESF 4 KV bus using the unit to unit 4 KV cross-tie or local start of the emergency diesel generator. The SSA credits either local start of the emergency diesel generator or use of the 4 KV cross-tie in the fire zones where LOOP can occur. Depending upon what equipment is affected by the fire, station emergency procedures may require the stopping of the Reactor Coolant Pumps (RCPs), isolation of RCP seal cooling, and proceeding to cold shutdown using natural circulation in the reactor coolant system.

5.

Assumptions regarding fire damage to mechanical components are described in Subsection 2.1.1(h) of the Fire Hazards Analysis.

6.

Assumptions regarding fire damage to electrical cables are described in previous Subsection 2.4.1.5.2 Cable Damage Assumptions.

7.

For a control room fire, evacuation of the control room is assumed.

However, credit is taken for reactor trip and verification of control rod insertion prior to evacuation. Control rod insertion is sufficient to ensure subcriticality to maintain hot standby. For this event, the operators would utilize plant procedures 1(2)BOA PRI-5 Control Room Inaccessibility - Unit 1(2) and fire response guideline procedures to control the plant.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-17 8.

For fires outside the control room, the operators are assumed to remain in the control room and to utilize the instruments and controls provided there to the greatest extent, in accordance with existing station procedures.

Operators would utilize fire response guideline procedures in conjunction with Emergency, Abnormal, Normal and General Operating procedures to place the plant in a safe condition during fires affecting safe shutdown equipment. The fire response guideline procedure provides operators with guidance describing the potential affects of a fire on a specific fire zone basis and actions to mitigate the potential affects. When proper operation of equipment cannot be performed or confirmed from the control room, alternate procedures are utilized. For example, 1(2)BOA PRI-5 Control Room Inaccessibility - Unit 1(2), or 1(2)BOA ELEC-5 Local Emergency Control of Safe Shutdown Equipment - Unit 1(2) could be used (this list is not meant to be complete - other procedures are available and could be used). These procedures are symptom-oriented rather than event-oriented. That is, there are no special procedures for fire in fire zone X, rather the procedures cover the loss of equipment X for whatever reason. Where the safe shutdown analysis shows that control cables from both redundant trains of equipment are located in the same fire zone, credit is taken for shutdown via local operation of equipment as specified in various plant procedures (including but not limited to the procedures referenced above). However, reference to a particular procedure for a particular fire zone, is not a commitment to automatically use that procedure in the event of a fire in that zone. For a fire less severe than the design basis fire, normal control room controls will continue to be used as long as they remain undamaged.

9 If a fire causes electrical shorting or overload, it is assumed that automatic circuit protection will function properly. If manual action is required to reclose a breaker that is not in the fire zone, credit is taken for such action where the breaker is accessible.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-18 2.4.1.8 Repairs For many of the fire zones, credit is taken for making repairs to equipment in order to perform one or more of the safe shutdown functions. In all cases, such credit is taken only to accomplish a function required for cold shutdown. The ability to achieve and maintain hot standby independent of each fire zone, without taking credit for repairs, is demonstrated in Subsection 2.4.2.

Specific repairs credited for individual fire zones are discussed in Subsection 2.4.2 and summarized in Table 2.4-3. Most repairs identified consist of installing temporary cable to replace cables that are assumed to be damaged by a fire. For each repair credited in Subsection 2.4.2, a station procedure has been written and is available to cover the repair. The procedure is general for each type of repair. For example, a repair procedure covers the temporary repair of cables and is applicable for all zones where such repairs are referenced. For each repair credited in Subsection 2.4.2, the quantity and specific type of materials required by the analysis and the procedure are reserved onsite.

The nature and scope of these repairs are such that they can be implemented and cold shutdown can be achieved in the affected unit(s) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This meets the requirements of BTP CMEB 9.5-1. The repairs would be performed by the plants normal maintenance staff, who possess adequate training to complete these tasks.

Neither additional nor specially trained personnel would be required. Furthermore, the repairs are simple enough that no special efforts to demonstrate the capability to implement them within a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> time period (and subsequently achieve cold shutdown) are deemed to be necessary.

For Measurement Uncertainty Recapture (MUR) Power Uprate (EC 378382(B-1)

EC 378383(B-2) EC 378380(BR-1) EC 378381(BR-2)), an analysis was performed based on bounding repair activities performed concurrently with bounding plant operating conditions and concluded that the unit can reach cold shutdown in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

(Reference EXBY001-RPT-001 Rev 0 dated March 14, 2011 BYRON & BRAIDWOOD FIRE PROTECTION COLD SHUTDOWN EVALUATION IN SUPPORT OF MUR PU REPORT).

2.4.1.9 Staffing Requirements for Safe Shutdown Staffing requirements for safe shutdown are met by the minimum plant operating staff as set forth in the current plant procedure that governs staffing. A control room fire is generally assumed to be the most restrictive fire with regards to staffing, since evacuation of the main control room (MCR) is required for both units. Fire damage assumptions for a postulated control room fire are addressed in the introductory paragraphs to subsection 2.4.2.3. Based upon the assumptions, 3 licensed operators, 4 non-licensed operators for safe shutdown, 4 non-licensed operators for the fire brigade, and one fire brigade chief will be available to shut down the fire affected unit and the opposite unit. Current minimum staffing levels are adequate to support shutdown of both units as specified above, and also man the fire brigade.

BYRON - FPR AMENDMENT 27 DECEMBER 2016 2.4-19 2.4.2 Fire Area/Zone Safe Shutdown Analysis The following safe shutdown analysis is performed on a fire zone basis. For Byron and Braidwood, the fire zones on which this analysis are based are considered to be equivalent to fire areas.

The fire zone boundaries and designations originated during the preparation of the original fire hazards analysis Fire Area Analysis in approximately 1977, prior to the issuance of 10CFR50 Appendix R and BTP CMEB 9.5-1. However, these same zone boundaries and designations were utilized during preparation of the original Byron unit 1 safe shutdown analysis (circa 1982), and the subsequent safe shutdown analyses for the other three units. They are retained during the current re-analysis.

All fire zone boundaries in the safety related auxiliary building, where most safe shutdown equipment is located, consist of walls, floors and ceilings of substantial construction. Many fire zone boundaries carry a three hour fire rating, and therefore qualify as fire area boundaries. Many other fire zone boundaries are designated as radiation barriers, flood barriers or ventilation barriers. The fire hazards analysis Fire Area Analysis has demonstrated that a fire in any fire zone of the plant will not propagate to adjacent fire zones. Therefore, for the purpose of the safe shutdown analysis, the existing fire zones are considered to be equivalent to fire areas.

The present analysis applies to both unit 1 and unit 2. A safe shutdown component/cable listing and evaluation are provided for the majority of the fire zones included in the fire hazards analysis (Section 2.3). Essentially all safety related and many non-safety related areas are included. Those fire zones which are not addressed primarily consist of outbuildings and administrative offices, which have no safe shutdown impact.

For the individual fire zone evaluations, the discussion follows a structured format.

First, common systems are addressed. Common safe shutdown systems include the control room ventilation (VC) system and the auxiliary building ventilation (VA) system supply and exhaust fans. Other systems, such as component cooling and essential service water, have the capability to be shared, but are normally operated in a unit isolated mode. These systems are discussed separately for each unit. Following the discussion of common systems, the discussion of the safe shutdown impact on unit 1 is provided, followed by the unit 2 discussion.

For each unit, the discussion first addresses essential AC and DC support systems.

These are addressed first since the availability (or unavailability) of these systems can significantly impact the choice of individual components or trains of remaining safe shutdown systems which are to be credited for safe shutdown. Next, the following safe shutdown functions are discussed in order: RCS inventory control (including reactivity control), hot standby decay heat removal, essential support, and cold shutdown decay heat removal. For fire zones where essentially all of the components/cables are associated with only one unit, and the other unit is unaffected or minimally affected, the discussion for the unaffected/minimally affected unit is condensed into a single paragraph.

BYRON-FPR AMENDMENT 27 DECEMBER 2016 Finally, for fire zones whose boundaries deviate from BTP CMEB 9.5-1, either a deviation or Generic Letter 86-10 evaluation is discussed at the end of the subsection.

2.4-20

BYRON - FPR AMENDMENT 20 DECEMBER 2002 (Sheet 1 of 6)

TABLE 2.4-5 REMOTE SHUTDOWN PANEL (RSP) INSTRUMENTATION A.

PANEL 1PL04J INSTRUMENT NO. DESCRIPTION 1FI-AF011B*

Auxiliary Feedwater Pump 1A Flow to Steam Generator 1A 1FI-AF013B*

Auxiliary Feedwater Pump 1A Flow to Steam Generator 1B 1FI-AF015B*

Auxiliary Feedwater Pump 1A Flow to Steam Generator 1C 1FI-AF017B*

Auxiliary Feedwater Pump 1A Flow to Steam Generator 1D 1LI-501 Steam Generator 1A Level 1LI-502 Steam Generator 1B Level 1LI-503 Steam Generator 1C Level 1LI-504 Steam Generator 1D Level Essential Service Water Pump 1A Discharge Temperature Essential Service Water Return Header OA Temperature 1PI-0514B Steam Generator 1A Steam Pressure 1PI-0544B Steam Generator 1D Steam Pressure

BYRON - FPR AMENDMENT 20 DECEMBER 2002 (Sheet 2 of 6)

TABLE 2.4-5 (Contd)

B.

PANEL 1PL05J INSTRUMENT NO. DESCRIPTION 1FI-AF012B*

Auxiliary Feedwater Pump 1B Flow to Steam Generator 1A 1FI-AF014B*

Auxiliary Feedwater Pump 1B Flow to Steam Generator 1B 1FI-AF016B*

Auxiliary Feedwater Pump 1B Flow to Steam Generator 1C 1FI-AF018B*

Auxiliary Feedwater Pump 1B Flow to Steam Generator 1D 1TI-RC005A Reactor Coolant Loop 1A Hot Leg Temperature 1TI-RC006A Reactor Coolant Loop 1B Hot Leg Temperature 1TI-RC007A Reactor Coolant Loop 1C Hot Leg Temperature 1TI-RC008A Reactor Coolant Loop 1D Hot Leg Temperature 1TI-RC005B Reactor Coolant Loop 1A Cold Leg Temperature 1TI-RC006B Reactor Coolant Loop 1B Cold Leg Temperature 1TI-RC007B Reactor Coolant Loop 1C Cold Leg Temperature 1TI-RC008B Reactor Coolant Loop 1D Cold Leg Temperature

BYRON - FPR AMENDMENT 20 DECEMBER 2002 (Sheet 3 of 6)

TABLE 2.4-5 (Contd)

B.

PANEL 1PL05J (Contd)

INSTRUMENT NO. DESCRIPTION Essential Service Water Pump 1B Discharge Temperature Essential Service Water Return Header OB Temperature 1PI-0524B Steam Generator 1B Steam Pressure 1PI-0534B Steam Generator 1C Steam Pressure 1FT-0110*

Emergency Boron Injection Flow C.

PANEL 1PL06J INSTRUMENT NO.

DESCRIPTION 1LI-0459B Pressurizer Level 1LI-0460B Pressurizer Level 1PI-0455B Pressurizer Pressure Volume Control Tank Level Charging Header Pressure 1FI-0121B*

Charging Header Flow 1NI-NR001*

Source Range Neutron (NE-31) Indicator 1NI-NR002*

Source Range Neutron (NE-32) Indicator

BYRON - FPR AMENDMENT 20 DECEMBER 2002 (Sheet 4 of 6)

TABLE 2.4-5 (Contd)

D.

PANEL 2PL04J INSTRUMENT NO. DESCRIPTION 2FI-AF011B*

Auxiliary Feedwater Pump 2A Flow to Steam Generator 2A 2FI-AF013B*

Auxiliary Feedwater Pump 2A Flow to Steam Generator 2B 2FI-AF015B*

Auxiliary Feedwater Pump 2A Flow to Steam Generator 2C 2FI-AF017B*

Auxiliary Feedwater Pump 2A Flow to Steam Generator 2D 2LI-501 Steam Generator 2A Level 2LI-502 Steam Generator 2B Level 2LI-503 Steam Generator 2C Level 2LI-504 Steam Generator 2D Level Essential Service Water Pump 2A Discharge Temperature Essential Service Water Return Header OA Temperature 2PI-0514B Steam Generator 2A Steam Pressure 2PI-0544B Steam Generator 2D Steam Pressure

BYRON - FPR AMENDMENT 20 DECEMBER 2002 (Sheet 5 of 6)

TABLE 2.4-5 (Contd)

E.

PANEL 2PL05J INSTRUMENT NO. DESCRIPTION 2FI-AF012B*

Auxiliary Feedwater Pump 2B Flow to Steam Generator 2A 2FI-AF014B*

Auxiliary Feedwater Pump 2B Flow to Steam Generator 2B 2FI-AF016B*

Auxiliary Feedwater Pump 2B Flow to Steam Generator 2C 2FI-AF018B*

Auxiliary Feedwater Pump 2B Flow to Steam Generator 2D 2TI-RC005A Reactor Coolant Loop 2A Hot Leg Temperature 2TI-RC006A Reactor Coolant Loop 2B Hot Leg Temperature 2TI-RC007A Reactor Coolant Loop 2C Hot Leg Temperature 2TI-RC008A Reactor Coolant Loop 2D Hot Leg Temperature 2TI-RC005B Reactor Coolant Loop 2A Cold Leg Temperature 2TI-RC006B Reactor Coolant Loop 2B Cold Leg Temperature 2TI-RC007B Reactor Coolant Loop 2C Cold Leg Temperature 2TI-RC008B Reactor Coolant Loop 2D Cold Leg Temperature

BYRON - FPR AMENDMENT 20 DECEMBER 2002 (Sheet 6 of 6)

TABLE 2.4-5 (Contd)

E.

PANEL 2PL05J (Contd)

INSTRUMENT NO. DESCRIPTION Essential Service Water Pump 2B Discharge Temperature Essential Service Water Return Header OB Temperature 2PI-0524B Steam Generator 2B Steam Pressure 2PI-0534B Steam Generator 2C Steam Pressure 2FT-0110*

Emergency Boron Injection Flow F.

PANEL 2PL06J INSTRUMENT NO.

DESCRIPTION 2LI-0459B Pressurizer Level 2LI-0460B Pressurizer Level 2PI-0455B Pressurizer Pressure Volume Control Tank Level Charging Header Pressure 2FI-0121B*

Charging Header Flow 2NI-NR001*

Source Range Neutron (NE-31) Indicator 2NI-NR002*

Source Range Neutron (NE-32) Indicator

• Not identified as a safe shutdown instrument.

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 1 of 12)

TABLE 2.4-6 REMOTE SHUTDOWN PANEL CONTROLS A. PANEL 1PL04J EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 1AF005A AFW Regulating Valve 1HK-AF031B Position controller 1AF005B AFW Regulating Valve 1HK-AF033B Position controller 1AF005C AFW Regulating Valve 1HK-AF035B Position controller 1AF005D AFW Regulating Valve 1HK-AF037B Position controller 1AF013A AFW Steam Generator 1HS-AF071 Open-close switch Isolation Valve 1AF013B AFW Steam Generator 1HS-AF073 Open-close switch Isolation Valve 1AF013C AFW Steam Generator 1HS-AF075 Open-close switch Isolation Valve 1AF013D AFW Steam Generator 1HS-AF077 Open-close switch Isolation Valve 1AF01PA AFW Pump 1A 1HS-AF003 On-off switch 1CV01PA Centrifugal Charging 1HS-CV001 On-off switch Pump 1A 1CV01PA-A CCP 1A Lube Oil Pump 1HS-CV013 On-off switch 0CC01P Component Cooling 0HS-CC001 On-off switch Pump O 1CC01PA Component Cooling 1HS-CC001 On-off switch Pump 1A 1MS001A,D Main Steam Isolation 1HS-MS143 Open-close switch Valves 1A, 1D

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 2 of 12)

TABLE 2.4-6 (Contd)

A. PANEL 1PL04J (Contd)

EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 1MS018A Main Steam Atmospheric Relief Valve 1A 1PK-MS041B Setpoint controller 1MS018D Main Steam Atmospheric Relief Valve 1D 1PK-MS044B Setpoint controller 1RC01PA Reactor Coolant Pump 1A 1HS-RC001 On-off switch 1RC01PD Reactor Coolant Pump 1D 1HS-RC004 On-off switch 1SX01PA ESW Pump 1A 1HS-SX003 On-off switch 0SX02PA ESW Makeup Pump 0A 0HS-SX009 On-off switch 0SX03CA ESW Cooling Tower Fan 0A low speed 0HS-SX001 On-off switch 0SX03CB ESW Cooling Tower Fan 0B low speed 0HS-SX002 On-off switch 0VC01CA MCR Supply Fan 0A 0HS-VC111 On-off switch 0VC02CA MCR Return Fan 0A 0HS-VC008 On-off switch 0VC18Y,19Y, 20Y MCR Outside Air Dampers 0HS-VC118 Open-close switch 0VC21Y,22Y, 43Y MCR Charcoal Filter Iso.

Dampers 0HS-VC120 Open-close switch 1VP01CA Reactor Cont. Fan Cooler high speed 1HS-VP011 On-off switch 1VP01CC Reactor Cont. Fan Cooler high speed 1HS-VP013 On-off switch

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 3 of 12)

TABLE 2.4-6 (Contd)

B. PANEL 1PL05J EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 1AF005E AFW Regulating Valve 1HK-AF032B Position controller 1AF005F AFW Regulating Valve 1HK-AF034B Position controller 1AF005G AFW Regulating Valve 1HK-AF036B Position controller 1AF005H AFW Regulating Valve 1HK-AF038B Position controller 1AF013E AFW Steam Generator 1HS-AF072 Open-close switch Iso. Valve 1AF013F AFW Steam Generator 1HS-AF074 Open-close switch Iso. Valve 1AF013G AFW Steam Generator 1HS-AF076 Open-close switch Iso. Valve 1AF013H AFW Steam Generator 1HS-AF078 Open-close switch Iso. Valve 1AF01PB AFW Pump 1B 1HS-AF004 On-off switch 1CV01PB Centrifugal Charging 1HS-CV002 On-off switch Pump 1B 1CV01PB-A CCP 1B Lube Oil Pump 1HS-CV014 On-off switch 1CV8104 Emergency Boration 1HS-CV005 Open-close switch Valve 0CC01P Component Cooling 0HS-CC002 On-off switch Pump 0 1CC01PB Component Cooling 1HS-CC002 On-off switch Pump 1B 1MS001B,C Main Steam Isolation 1HS-MS144 Open-close switch Valves 1B, 1C

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 4 of 12)

TABLE 2.4-6 (Contd)

B. PANEL 1PL05J (Contd)

EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 1MS018B Main Steam Atmospheric 1PK-MS042B Setpoint controllers Relief Valve 1B 1MS018C Main Steam Atmospheric 1PK-MS043B Setpoint controller Relief Valve 1C 1RC01PB Reactor Coolant 1HS-RC002 On-off switch Pump 1B 1RC01PC Reactor Coolant 1HS-RC003 On-off switch Pump 1C 1SXO1PB ESW Pump 1B 1HS-SX004 On-off switch 0SX02PB ESW Makeup Pump 0B 0HS-SX010 On-off switch 0SX03CE ESF Cooling Tower 0HS-SX005 On-off switch Fan 0E low speed 0SX03CF ESF Cooling Tower 0HS-SX006 On-off switch Fan 0F low speed 1VP01CB Reactor Containment 1HS-VPO12 On-off switch Fan Cooler - high speed 1VP01CD Reactor Containment 1HS-VP014 On-off switch Fan Cooler - high speed

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 5 of 12)

TABLE 2.4-6 (Contd)

C. PANEL 1PL06J EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION Plant Evacuation Alarm 1HS-CQ001 On switch Plant-wide Fire Alarm 1HS-CQ002 On switch Plant Evac. & Fire Alarm Reset 1HS-CQ003 Reset switch 1AB03P Boric Acid Transfer 1HS-AB001 On-off switch Pump 1A 1CV8145 Pressurizer Auxiliary 1HS-CV039 Open-close switch Spray Valve 1CV8149A Letdown Orifice 1HS-CV007 Open-close switch Isolation Valve 1CV8149B Letdown Orifice 1HS-CF009 Open-close switch Isolation Valve 1CF8149C Letdown Orifice 1HS-CV011 Open-close switch Isolation Valve 1CV02P Position Displacement 1HS-CV017 On-off switch Charging Pump 1CV-LCV459 Letdown Isolation Valve 1HS-CV019 Open-close switch 1CV-LCV460 Letdown Isolation Valve 1HS-CV021 Open-close switch 1CV02P P. D. Charging Pump 1SHC-459B Pump speed controller 1CV-FCV121 Charging flow 1FHC-121 Flow controller control valve

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 6 of 12)

TABLE 2.4-6 (Contd)

C. PANEL 1PL06J (Contd)

EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION Steam Generator 1LSH-FW047 SG high level alarm 1A Level Steam Generator 1LSH-FW048 SG high level alarm 1B Level Steam Generator 1LSH-FW049 SG high level alarm 1C Level Steam Generator 1LSH-FW050 SG high level alarm 1D Level 0PW02A Primary Water Pump 0A 0HS-PW011 On-off switch Press. Heaters Backup 1HS-RY001 On-off switch Group A Breaker Press. Heaters Backup 1HS-RY002 On-off switch Group B Breaker Press. Heaters Backup 1HS-RY005 On-off switch Group A Contactor Press. Heaters Backup 1HS-RY006 On-off switch Group B Contactor 1VP03CA CRDM Exhaust Fan 1A 1HS-VP112 On-off switch 1VP03CB CRDM Exhaust Fan 1B 1HS-VP114 On-off switch 1VP03CC CRDM Exhaust Fan 1C 1HS-VP116 On-off switch 1VP03CD CRDM Exhaust Fan 1D 1HS-VP118 On-off switch

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 7 of 12)

TABLE 2.4-6 (Contd)

D. PANEL 2PL04J EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 2AF005A AFW Regulating Valve 2HK-AF031B Position controller 2AF005B AFW Regulating Valve 2HK-AF033B Position controller 2AF005C AFW Regulating Valve 2HK-AF035B Position controller 2AF005D AFW Regulating Valve 2HK-AF037B Position controller 2AF013A AFW Steam Generator 2HS-AF071 Open-close switch Isolation Valve 2AF013B AFW Steam Generator 2HS-AF073 Open-close switch Isolation Valve 2AF013C AFW Steam Generator 2HS-AF075 Open-close switch Isolation Valve 2AF013D AFW Steam Generator 2HS-AF077 Open-close switch Isolation Valve 2AF01PA AFW Pump 2A 2HS-AF003 On-off switch 2CV01PA Centrifugal Charging 2HS-CV001 On-off switch Pump 2A 2CV01PA-A CCP 2A Lube Oil Pump 2HS-CV013 On-off switch 0CC01P Component Cooling 0HS-CC001 On-off switch Pump O 2CC01PA Component Cooling 2HS-CC001 On-off switch Pump 2A 2MS001A,D Main Steam Isolation 2HS-MS143 Open-close switch Valves 2A, 2D

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 8 of 12)

TABLE 2.4-6 (Contd)

D. PANEL 2PL04J (Contd)

EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 2MS018A Main Steam Atmospheric Relief Valve 2A 2PK-MS041B Setpoint controller 2MS018D Main Steam Atmospheric Relief Valve 2D 2PK-MS044B Setpoint controller 2RC01PA Reactor Coolant Pump 2A 2HS-RC001 On-off switch 2RC01PD Reactor Coolant Pump 2D 2HS-RC004 On-off switch 2SX01PA ESW Pump 2A 2HS-SX003 On-off switch 0SX03CC ESW Cooling Tower Fan 0C low speed 0HS-SX003 On-off switch 0SX03CD ESW Cooling Tower Fan 0D low speed 0HS-SX004 On-off switch 2VP01CA Reactor Cont. Fan Cooler high speed 2HS-VP011 On-off switch 2VP01CC Reactor Cont. Fan Cooler high speed 2HS-VP013 On-off switch

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 9 of 12)

TABLE 2.4-6 (Contd)

E. PANEL 2PL05J EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 2AF005E AFW Regulating Valve 2HK-AF032B Position controller 2AF005F AFW Regulating Valve 2HK-AF034B Position controller 2AF005G AFW Regulating Valve 2HK-AF036B Position controller 2AF005H AFW Regulating Valve 2HK-AF038B Position controller 2AF013E AFW Steam Generator 2HS-AF072 Open-close switch Iso. Valve 2AF013F AFW Steam Generator 2HS-AF074 Open-close switch Iso. Valve 2AF013G AFW Steam Generator 2HS-AF076 Open-close switch Iso. Valve 2AF013H AFW Steam Generator 2HS-AF078 Open-close switch Iso. Valve 2AF01PB AFW Pump 2B 2HS-AF004 On-off switch 2CV01PB Centrifugal Charging 2HS-CV002 On-off switch Pump 2B 2CV01PB-A CCP 2B Lube Oil Pump 2HS-CV014 On-off switch 2CV8104 Emergency Boration 2HS-CV005 Open-close switch Valve 0CC01P Component Cooling 0HS-CC004 On-off switch Pump 0 2CC01PB Component Cooling 2HS-CC002 On-off switch Pump 2B 2MS001B,C Main Steam Isolation 2HS-MS144 Open-close switch Valves 2B, 2C

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 10 of 12)

TABLE 2.4-6 (Contd)

E. PANEL 2PL05J (Contd)

EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION 2MS018B Main Steam Atmospheric 2PK-MS042B Setpoint controllers Relief Valve 2B 2MS018C Main Steam Atmospheric 2PK-MS043B Setpoint controller Relief Valve 2C 2RC01PB Reactor Coolant 2HS-RC002 On-off switch Pump 2B 2RC01PC Reactor Coolant 2HS-RC003 On-off switch Pump 2C 2SXO1PB ESW Pump 2B 2HS-SX004 On-off switch 0SX03CG ESF Cooling Tower 0HS-SX007 On-off switch Fan 0G low speed 0SX03CH ESF Cooling Tower 0HS-SX008 On-off switch Fan 0H low speed 2VP01CB Reactor Containment 2HS-VPO12 On-off switch Fan Cooler - high speed 2VP01CD Reactor Containment 2HS-VP014 On-off switch Fan Cooler - high speed

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 11 of 12)

TABLE 2.4-6 (Contd)

F. PANEL 2PL06J EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION Plant Evacuation Alarm 2HS-CQ001 On switch Plant-wide Fire Alarm 2HS-CQ002 On switch Plant Evac. & Fire Alarm Reset 2HS-CQ003 Reset switch 2AB03P Boric Acid Transfer 2HS-AB001 On-off switch Pump 2A 2CV8145 Pressurizer Auxiliary 2HS-CV039 Open-close switch Spray Valve 2CV8149A Letdown Orifice 2HS-CV007 Open-close switch Isolation Valve 2CV8149B Letdown Orifice 2HS-CF009 Open-close switch Isolation Valve 2CF8149C Letdown Orifice 2HS-CV011 Open-close switch Isolation Valve 2CV02P Position Displacement 2HS-CV017 On-off switch Charging Pump 2CV-LCV459 Letdown Isolation Valve 2HS-CV019 Open-close switch 2CV-LCV460 Letdown Isolation Valve 2HS-CV021 Open-close switch 2CV02P P. D. Charging Pump 2SHC-459B Pump speed controller 2CV-FCV121 Charging flow 2FHC-121 Flow controller control valve

BYRON -FPR AMENDMENT 20 DECEMBER 2002 (Sheet 12 of 12)

TABLE 2.4-6 (Contd)

F. PANEL 2PL06J (Contd)

EQUIPMENT NUMBER DESCRIPTION CONTROL NUMBER CONTROL FUNCTION Steam Generator 2LSH-FW047 SG high level alarm 2A Level Steam Generator 2LSH-FW048 SG high level alarm 2B Level Steam Generator 2LSH-FW049 SG high level alarm 2C Level Steam Generator 2LSH-FW050 SG high level alarm 2D Level 0PW02B Primary Water Pump 0B 0HS-PW013 On-off switch Press. Heaters Backup 2HS-RY001 On-off switch Group A Breaker Press. Heaters Backup 2HS-RY002 On-off switch Group B Breaker Press. Heaters Backup 2HS-RY005 On-off switch Group A Contactor Press. Heaters Backup 2HS-RY006 On-off switch Group B Contactor 2VP03CA CRDM Exhaust Fan 2A 2HS-VP112 On-off switch 2VP03CB CRDM Exhaust Fan 2B 2HS-VP114 On-off switch 2VP03CC CRDM Exhaust Fan 2C 2HS-VP116 On-off switch 2VP03CD CRDM Exhaust Fan 2D 2HS-VP118 On-off switch