ML18046A517
| ML18046A517 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/19/1981 |
| From: | Johnson B CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8103230636 | |
| Download: ML18046A517 (18) | |
Text
{{#Wiki_filter:.. consumers Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201 * (517) 788-0550 March 19, 1981 Director, Nuclear Reactor Regulation Att Mr Dennis M Crutchfield, Chief Operating Reactors Branch No 5 U S Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - FIRE PROTECTION MODIFICATIONS By letter dated November 24, 1980 the NRC transmitted a revised Section 50.1+8 and a new Appendix R to 10 CFR 50 regarding fire protection features of nuclear power plants. The new 10 CFR 50.48 defines specific actions to be taken by all licensees and invokes a number of specific design requirements as detailed in Appendix R for the Palisades Plant. 'I:he portions of Appendix R which thereby became applicable are Sections III.G, Fire Protection of Safe Shutdown Capabil-ity; III.J, Emergency Lighting; and III.O, Oil Collection System for Reactor Coolant Pump. of the November 24, 1980 letter also defines the PalisadesPlant areas for which the Section III.G requirements are to be addressed, and invokes the performance goals for Safe Shutdown Capability as delineated in Section III.L.. By March 19, 1981, 10 CFR 50.48 requires submission of our plans and schedules for achieving compliance with applicable sections of Appendix R, and submission of a design description for NRC approval of modifications necessary to satisfy Section III.G.3. This letter and the enclosed information are being submitted in response to that reqUirement. NRC Generic Letter 81-12 dated February 20, 1981 (received March 2, 1981), provides further guidance on the information desired by the staff to facilitate design reviews. Because of the late receipt of Generic Letter 81-12, and because the scope of the information requested goes considerably beyond that necessary to satisfy 10 CFR 50.48, all desired information could not be included in t.his submittal. This submittal, however, is in full compliance with 10 CFR 50.48. The additional information requested by Generic Letter 81-12 will be provided by the prescribed date of May 19, 1981. 8103230635
Mr ~ennis M Crutchfield Palisades Plant March 19, 1981 2 Brief descriptions and schedules for completion of those modifications required by Appendix R Sections III. G,- III..;r and III. 0 are enclosed as Attachment I'. It is our intent to complete these modifications as prescribed in 10 CFR 50.48. A design description of Alternate Shutdown Capability is provided for NRC review as Attachment II. This description specifically addresses the Palisades fire areas defined in NRC letter of November 24, 1980 as well as the performance goals of Appendix R Section III.L. As stated above, however, additional infor-mation will be provided as requested in Generic Letter 81-12. Brian D Johnson Senior Licensing Engineer CC JGKeppler, USNRC NRC Resident Inspector-Palisades Attachment (15 pages)
ATTACHMENT I Palisades Plant PLANS FOR ACHIEVING COMPLIANCE WITH 10 CFR 50.48 AND APPENDIX R Requirement
- 1.
Section III.G Fire Protection of Safe Shutdown
- 2.
Section III.J - Emergency Lighting
- 3.
Section III.O - Oil Collection System for Reactor Coolant Pump Description Alternate shutdown capability will be installed per III.G.3. Design will address III.L and NRC letter of Nov 24, 1980. Design description is provided as Attachment II. Plant shutdown will be required because of the need to de-energize important electrical circuits during installation. Emergency lights will be modified or replaced to provide 8 hour operation in those areas deemed necessary for operation of safe shutdown equipment. Plant shutdown will not be required for installation. Primary coolant pump oil collection systems previously installed will be modified as prescribed. It is believed that the only change required will be the re-placement of existing 20 gal collection tanks with larger tanks. Plant shutdown will be required for installation because radiation levels preclude access to the pumps during operation. Schedule Completion expected by end of refueling outage which starts 180 days or more after NRC approval of design. Completion expected prior to Nov 17, 1981. Completion*expected by end of refueling outage which starts after August 16, 1981.
I. General ATTACHMENT II Palisades Plant DESCRIPTION OF CAPABILITY TO ATTAIN SAFE SHUTDOWN FOLLOWING A DAMAGING FIRE The information provided in this document is presented in two basic sections. The first addresses the way in which the Appendix R, Section III.L performance goals are or will be met with damaging fires in the areas defined in NRC letter of November 24, 1980. The fire areas which are explicitly addressed are the Control Room, Cable Spreading Room, Engineered Safeguards Panel Room with adjacent stairwell, and the corridor between the Charging Pump Room and Switch-gear Room 1-C. The second section provides a summary of all modifications to be performed in support of the performance goals. With respect to O*ff'-site and on-site sources of AC power, fires in the Control Room or Cable Spreading Rooms could affect both their availability and the methods required for control. In all discussions which follow, the following basic considerations apply: A. It is possible that fire damaged control and relay circuitry associated with circuit breakers that connect off-site power to the plant will cause the separation of off-site power from the plant busses and not the loss of the transmission system to supply off-site power. In addition, it appears to be the position of the NRC that a fire in either of these two areas of this plant will cause the loss of off-site power. In the analyses that follow, therefore, if any operation requires 2400V or 480V power, it will be supplied by one or the other of the diesel generators. B. A Fire in either of these two areas could damage circuitry for the control of the operation of the diesel generators and/or the circuitry to the 2400V switchgear positions. This could result in the inability to remotely operate the equipment or diesel generator circuit breakers. Each switchgear position and the diesel generators are normally operable locally or can be made operable. If necessary, the damaged circuitry could be disconnected, and then local action would be taken to clear the 2400V bus, start its diesel generator, connect into the bus and close the circuit breakers for the desired loads. C. A fire in either area could also damage control circuitry to circuit break-ers supplying power from the 2400V busses (Class lE and non-Class lE) to the 480V load centers (Class lE and non-Class lE). If this is the case, the damaged circuitry could be disconnected and the circuit breakers closed locally, as required. II. Attainment of Performance Goals The analysis is developed by describing how each performance goal is accom-plished postulating a destrictive fire in each of the specific fire areas.
Attachment II (cont.) A. & B. Reactivity Control and Reactor Coolant Make-up The minimum equipment required to borate the reactor coolant or to make up to the reactor coolant are: One Charging Pump One concentrated boric acid tank or the safety injection and re-fueling water (SIRW) tank. - Associated flow paths This equipment is maintained operable as follows:
- 1.
Control Room Fire
- a.
Damage - Loss of off-site power, charging pump motor starting control circuitry, control circuitry to valves in a flow path from the concentrated boric acid or SIRW tanks to the primary coolant system via a charging line.
- b.
Operation - Start the selected charging pump at its circuit breaker, if necessary, and open a flow path by positioning the necessary valves manually, if necessary. All valves in the flow path can be positioned manually, or fail open on loss of air.
- 2.
Cable Spreading Room Fire
- a.
Damage - Same as for a control room fire plus the loss of 125V d-c operating and control power to the 480V Class lE load centers and damage to the load centers.
- b.
Operation - Same as for a control room fire. If the normal 480V supply for the charging pumps is damaged, charging pumps P55B or P55C can be connected to non-Class lE 480V bus #13 via a permanently installed feeder from the bus (see Figure #1). 480V bus #13 is normally supplied from 2400V safeguards bus 1-C that can be powered by its associated diesel generator.
- 3.
Engineering Safeguards Panel Room Fire
- a.
Damage - Boric acid and SIRW tanks outlet valve operator control circuitry. Charging pump circuit breaker control circuitry does not exist in this room.
- b.
Operation - Normal control for charging pump. Selected boric acid or SIRW tank outlet valve would be opened manually.
- 4.
Corridor Between Switchgear 1-C Room and Charging Pumps Area Fire
- a.
Damage - Charging Pumps P55A and P55B motor feeders and control and power circuits to concentrated boric acid and SIRW tank outlet valves. 2
Attachment II (cont.) b *. Operating - Motor feeder to charging Pump P55C is not in this fire area and would be started in the normal fashion. The selected boric acid tank outlet valve can be opened manually. C. Reactor Decay Heat Removal 3 This performance goal will be analyzed in two parts. The first will discuss the attainment of this goal when maintaining hot shutdown and the second will discuss the attainment of this goal when initiating shutdown cooling and maintaining cold shutdown.
- 1.
Reactor Decay Heat Removal - Hot Shutdown The systems available to be used to maintain bot shutdown are dependent upon the area of the fire. For. exampl~a fire in the Control Room or Cable Spreading Room cou1d cause loss of off-site power, which w:ould pre-clude i:;ne use of the main feedwater system. The following discussions are based on equipment expected to remain operable considering fire damage and loss of off-site power, if applicable. The systems and equipment which can be utilized for taking the plant to hot shutdown and maintaining hot shutdown are the auxiliary feed water system, the main feed water and condensate system, the condenser, and the turbine bypass valve, the atmospheric dump valves and code safety valves.
- a.
Control Room Fire ( 1). Damage - Loss of off-site p@wer (precludes use of the main f'eedwater system), damage to control circuitry for equipment of the auxiliary feedwater system~ the lE and non lE 2400V and 48ov power sources, the safety and nonsafety-related instruments and power sources, and the control panel 125V d-c power supply. This damage can be total, limited to the bench board or vertical panel, or localized in one of the control panels only. If the damage is small, various options in the use of equipment or systems are available. If damage is extensive, the following discussion presents the ultimate method of taking !-be. _:plant to hot shutdown. (2). Operation - An auxiliary shutdown control panel will be installed in the southwest electrical penetration room. From this panel, the turbine-driven auxiliary feedwater pump can be started and the auxiliary feedwater valves can be controlled. Assured opening of a steam source valve for the turbine-driven auxiliary feedwater pump is pro-vided by the installation of a second solenoid valve into the control of the valve CV0522B (see Figure #3). The power source for this solenoid valve is from the auxiliary
Attachment II leant.) shutdown control panel anQ the installation is such that energizing of either solenoid valve will open the steam valve. Control of the auxiliary feedwater valves CVOT36A and CVOT3TA is accomplished by enabling the auxiliary shutdown control panel devices for control and disabling 4 the main control panel devices via a transfer switch (see Figure #5). Operation of this transfer switch will be annunciated in the main control room. In the event the fire causes the loss of normal control air, the standby nitrogen bottle source will supply these three valves and the steam pressure regulating Valve PCV0521A for 12 ho-i.irs. The only electrical p:iwer required for control from the auxiliary shut-down control panel is 125V d-c. The source for this power and circuit routing to the panel lies away from these two fire areas. Steam for operation of the turbine-driven aux-iliary feedwater pump will be available from the steam gener-ators if there is decay heat to remove. The code safety valves release the decay heat and are neither located in these fire areas nor need power for their operation.
- b.
Cable Spreading Room Fire (1). Damage - Same as that of the control room except that all the lE 480V power sources, the lE and non lE instrument power sources, the 125V d-c power sources (except the 125V d-c power and control source to the diesel generators, the lE 2400V busses, the auxiliary shutdown control panel and non lE 480V bus #13) are subject to partial or total damage. (2). Operation - The auxiliary feedwater system will be used as described for the control room fire.
- c.
Engineered Safeguards Panel Room or Corridor Between 1-C Switchgear and Charging Pump Rooms Fire (1). Damage - Control circuitry to auxiliary feedwater valves, and the turbine bypass and atmospheric dump valves. (2). Operation - The auxiliary feedwater system will be used as discussed under the control room fire.
- 2.
Reactor Decay Heat Removal - Cold Shutdown The systems and equipment that are used to take the reactor system from the hot shutdown condition to a cold shutdown system are a low-pressure safety injection pump, a shutdown heat exchanger, the component cooling water system and the service water system. The performance goals are met for fires in each of the specified areas as follows:
Attachment II (cont.) 5
- a.
Control Room Fire (1). Damage - Sarne as control room fire in C.1.a above. (2). Operation - Manually position valves as required to line up the shutdown cooling flow path. Start selected low-pressure safety injection pump manually at its circuit breaker.
- b.
Cable Spreading Room Fi re (1). Damage - Same as discussion of cable spreading room fire in C. l. b above. (2). Operation - Same as operation discussion for control room fire.
- c.
Engineered Safeguards Panel Room or Collidor Between 1-C Switchgear and Charging Pump Rooms Fire ( 1). Damage - Control circuitry of certain control valves for shut-down cooling. (2). Operation - Valves that cannot be operated electrically can be positioned manually. The selected low-pressure safety injection pump to be used for shutdown cooling can be started in the manual fashion. D. Process Monitoring The minimum process variables required for monitoring the operations of hot shutdown, reactivity control, reactor system inventory control and cold shutdown are pressurizer level, primary system pressure, steam generator level, and auxiliary feedwater flow or main feedwater flow. Measurement of primary system boric acid concentration following addition of concentrated boric acid following shutdown is by grab sample and laboratory analysis. The displays for these process values are located on the main control panels and on the auxiliary shutdown control panel and their availability is assured on the particular control panel where the shutdown functions are being per-formed. The measurements of pressurizer level, reactor pressure and steam generator level are assured in the control room because of the redundant channel design except for control room or cable spreading room fires. In the event the fire damage prevents use of any portion of the auxiliary feedwater system from the main control room, the above mentioned process values are displayed on the auxiliary shutdown control panel by transfer of the primary sensor for each measurement from its normal* power supply and instruments to a power supply and display instruments on this panel. This transfer is by a selector switch and the transfer is annunciated in the main control room (see Figures 6 and 7). The one exception to the above is measurement of reactor pressure in which the primary sensor is new and supplies only this panel's indicator.
Attachment II (cont.) 6 E. Support Functions Required support functions depend on the specific shutdown operation being performed and of the specific system selected to provide that operation. Support functions for any shutdown operation include the service water sys-tem, the component cooling water system, the diesel generator fuel oil system and the control air system. The availability of control for hot shutdown operations is discussed in C.l above. The availability of control air would facilitate cold shutdown ope_ration but is not mandatory. Service water is required for operation of the component cooling system and diesel generators in the event of loss of off-site power. A fire in any of the specified fire areas will not preclude the ability to power and operate a service water pump. Component cooling is required to support cold shutdown (shutdown cooling) operations. A fire in any of the specified fire areas will not preclude the ability to power and operate a component cooling pump. Diesel generator operation depends on the availability of fuel oil. The day tanks hold sufficient fuel oil for 24 hours of full load operation. Operation beyond 24 hours can be supported by the diesel fuel oil trans fer system, if available, or by direct refill of the day tanks from external tank truck deliveries.
Attachment II(cont.) 7 III. Summary of Mqdifications A. Modifications for the Assurance of Accomplishing "Hot Shutdown"
- 1.
The following modifications assure the use of sufficient components of the auxiliary feedwater system and sufficient process information in the event a fire damages equipment and circuitry of the main feedwater system or the auxiliary feedwater system in the control room, calbe spreading room, redundant safety injection control Panel C33, and the corridor between switchgear Room 1-C and the charging pumps' rooms. The modifications are: Install in the southwest electrical penetration room an auxiliary shutdown control Panel Cl50. From this panel control of the auxiliary feedwater Valves CV0736A and CV0737A is enabled by transfer (see Figure 5) and of auxiliary feedwater turbine steam supply Valve CV0522B directly (see Figure 3). Indication of auxiliary feedwater flow to both steam generators, the water level of both steam generators and the pressurizer level is enabled by transfer (see Figure 6 and 7). In addition, primary system pressure (pressurizer pressure) is displayed by a new primary sensor (PTOllO) dedicated to this use. Transfer of the above mentioned systems is annunciated in the control room.
- 2.
The following modifications assure the use of sufficient components of the auxiliary feedwater system and process information from the control room in the event of a damaging fire in switchgear Room 1-C. The modifications are: Reroute the control circuitry of the auxiliary feedwater Valves CV0736A and CV0737A and auxiliary feedwater turbine steam supply Valve CV0522B and the circuitry of auxiliary feedwater flow instruments FT0736 and FT0737 to bypass switchgear Room 1-C.
- 3.
The following modifications assure an air supply for twelve hours for the operation of the auxiliary feedwater Valves CV0736A and CV0737A, steam supply valve to the auxiliary feedwater Turbine CV0522B and the auxiliary feedwater pressure regulating Valve PCV0521A in the event a fire in the control room, cable spreading room, switchgear Room 1-C in the turbine room damages the power source, motor feeder or control circuitry of the instrument air compressors. The modifications are: Install in the auxiliary feedwater pump room a 2400 psig nitrogen cylinder manifold and pressure reducing station for five cylinders. This control air source will be connected to auxiliary feedwater
Attachment II (cont.) turbine ste8Jll source Valve CV0522B and ste8Jll pressure regulating Valve PCV0521A. Install in the component cooling room a second 2400 psig nitrogen cylinder manifold and pressure reducing station for three cylinders. This control air source will be connected to the auxiliary feedwater control Valves CV0(36A and CV0(3(A. Figure 4 illustrates typical interface of the normal air source and the 12-hour standby air source to the valves. B. Modifications for the Assurance of Initiating Shutdown Cooling and Maintaining a Cold Shutdown Condition The following modifications assure the availability of service water and component cooling water to the component colling water system and shutdown cooling heat exchangers in the event fire d8Jllages motor feeder circuits or power sources in the switchgear Room 1-C or the corridor between this room and the charging pumps' rooms. The modifications are: Reroute the service water pump motor feeder from switchgear Bud 1-D to bypass switchgear Room 1-C. Reroute the component cooling water pump motor feeder to bypass the corridor between switchgear Room 1-C and the charging pumps' rooms. C. Modifications for the Assurance of Reactivity Control and Reactor Coolant Make-up Following Shutdown The following modifications assure the use of a charging pump to in-crease the boric acid concentration of the reactor coolant system prior to the cold shutdown operation and for making up to the reactor coolant system in the event fire d8Jllages the carging pumps' 480V power sources in the cable spreading room. The modifications are: Install a circuit from non-Class IE 480V Bus #13 to the vicinity of charging Pumps P55B and P55C. This standby charging pump motor feeder will be connected to the charging pumps in the fashion of Figure 1. D. Modifications for the Assurance of 125V D-C Operating and Control Power The following modifications assure the availability of 125V d-c power for the operation of diesel generators 1-1 and 1-2, Class lE 2400V Busses 1-C and 1-D, non-safeguards Busses 13 and 14 and the auxiliary shutdown control Panel Cl50 in the event a fire d8Jllages 125V d-c distribution equipment in the cable spreading room. The modifications are: 8
Attachment II (cont.) 9
- 1.
Relocate the fuses between each battery and its bus from the cable spreading room to their respective battery rooms.
- 2.
In each battery room, install a nonautomatic circuit breaker with a shunt trip in the circuit between the relocated battery fuse and its bus.
- 3.
Install a distribution panel in switchgear Room 1-C and diesel Generator 1-1 room and connect them to their respective batteries with a fuse. The fuses will be located in the battery rooms. Each new distribution panel will contain a push button for energizing the shunt trip of the above mentioned circuit breaker.
- 4.
From each of the new distribution panels, install new circuits for operating and control power to each diesel generator and 2400V bus. This routing of these new circuits will avoid the cable spreading room and the diesel generator and switchgear rooms of the other channel. In addition, the new distribution panel serving 2400V switchgear Bus 1-C will also supply the new auxiliary shutdown control Panel Cl50 and non-safeguards 480V Busses 13 and 14. The above is illustrated by Figure 2. This figure is also part of the October 13, 1980 letter, DPHoffman to NRC, D M Crutchfield. E. Modifications for the Assurance of 2400V Operating Power
- 1.
The following modifications assure the availability of power from the Class lE 2400V Busses 1-C and 1-D and the operability of diesel Generators 1-1 and 1-2 in the event a fire damages control circuitry of the equipment in the control room or the cable spreading room. The modifications are: a) Relocate the power source to the diesel generator crankcase blowers from the present sources (MCC #1 and #2 in the cable spreading room) to the 2400V terminals of the diesel generator. b) Identify the termination of control room or cable spreading room routed circuitry of the diesel generators and 2400V Bus 1-C and 1-D positions. In the event of fire damage, the sliding links of the terminal blocks can be opened to isolate the damaged circuitry.
- 2.
The following modifications assure the operability of diesel Generators 1-2 in the event a fire damages equipment and electrical circuits in switchgear Room 1-C. The modifications are: Relocate control and instrument circuits from diesel Generator 1-2 to the control room to bypass switchgear Room 1-C.
Attachment II (cont.)
- 3.
The following modifications assure the operability of diesel Generator 1-2 in the event a fire damages equipment and electrical circuitry in diesel generator Room 1-1. The modifications are: Reroute the generator power cables and control and instrument circuits from diesle Generator 1-2 to 2400V Bus 1-D to bypass diesel Generator 1-1 Room. 10
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