ML19343C417
| ML19343C417 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 03/19/1981 |
| From: | Johnson B CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| GL-81-12, NUDOCS 8103240120 | |
| Download: ML19343C417 (8) | |
Text
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2 Power w%gyy Company ceneres offices: 212 West MicNgan Avenue, Jackson, MI 49201 e (517) 788-0550 March 19,1981 e
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9, Director, Nuclear Reactor Regulation d
9 Att Mr Dennis M Crutchfield, Chief C
Operating Reactors Branch No 5 h
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.. g Washington, DC 20555
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DOCKEI 50-155 - LICENSE DPR ~
BIG ROCK POINT PLANT - FIRE PRO'5ECTION MODIFICATIONS h
By letter dated Nove=ber 2,1980, the NRC transmitted a revised Section 50.h8 and a 0.ev Appendix R to 10 CFR 50 regarding fire protectica features of nuclear peser plants.
The nev 10 CFR 50.h8 defines specific actions to be taken by all licensees and invokes a nu=ber of specific design requirements as detailed in Appendix R.
For the Big Rock Point Plant, the portions of Appendix R vhich thereby becsce applicable are Sections III.G, Fire Protection of Safe Shutdown Capability; III.J, I=ergency Lighting; and III.0, 011 Collec-tien Syste= for Reactor Ccolant Pu=p. of the November 24, 1980 letter also defines the Big Rock Point areas for which the Secticn 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.h8 requires submission of our plans and schedules for achievin6 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 infor=atien are being sut=itted in response to that requirement.
I NEC Generic Letter 81-12 dated Februa y 20,1981 (received March 2,1981),
provides further guidance en the infomatien desired by the staff to facilitate design reviews.
decause of the late receipt of Generic Letter 81-12, and because the scope of the infor: ation requested gces considerably beyond that necessary to satisfy 10 CFR 50.h8, all necessary infomation eculd net be included in this sub=ittal.
This submittal, however, is in full ec=pliance with 10 CFR 50.h8. The additicnal infer ation requested by Generic letter 81-12 vill be provided by the prescribed date of May 19, 1981.
Brief descriptiens and schedules for ec=pletion of these =cdificatiens re-quired by Appendix R Secticns III.G, III.J and III.0 are enciesed as Attach-
=ent I.
It is cur intent to ec=plete modifications for III.J and III.0 as prescribed in 10 CFR 50.h8. With respect to alternate shatdevn capabi'.ity s108240 110 Q
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Mr Dannis M Crutchfield, Chief 2
Big Rock P] int Plant March 19,1981 for III.G, hcVever, the recently ec=pleted Probabilistic Risk Assessment for Big Rock Point has indicated that a nu=ber of changes to cur present design concepts may be in order. ~(The Prebabilistic Risk Assess =ent has been previously discussed with the.'IRC in various letters and rest recently in meetings on March 17 and 18,1981. ) In so=e cases, the FRA indicates that
= ore stringent requirements should be i= posed than specified in Appendix R, and in other cases that specific Appendix R requirements =ay be unnecessary in that they have no effect on the probability of core A-age.
A re-evaluation of modifications necessa:7 for alternate shutdown capability which factors in the FRA results is nov in progress. Although Attachment II provides the description of plant nodifications now envisioned for ec=pliance with Appendix R, and toward which our design efforts are being focused, it 1.s probable that these design changes to these concepts which are identified vill be submitted by May 19,1981, in conjunction with the info:=ation requested in Generic Letter 81-12.
Brian D Jchnson Senior Licensing Engineer CC JGKeppler, USITEC IIRC Resident Inspector Attach =ent 4
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ATTACEMETT I Big Rock Point Plant PLANS FOR ACHIEVING COMPLIMICE IJITH 10 CFR 50.h8 NTD APPETDIX R Requirement Description Schedule
- 1. -Section III.G -
Alternate shutdown capability vill Complection by end of Fire Protection of be provided which addresses both refueling outage starting Safe Shutdown Appendix R requirements and the at least 180 days after experience gained through the NRC approval of design, Probabilistic Risk Assessment (PRA).
if feasible.
Reevaluation Modl.fications which provide the of designs in light of PRA greatest enhancement of overall could result in signifi-plant safety vill be installed.
cant changes, however, Plant shutdown vill be required which could render this for installation because work schedule impractical, would require de-energizing circuits necessary for reactor safety.
2.
Section III.J -
Modify or replace lights in Completion by Emergench Lighting appropriate areas as necessary November 17, 1981.
to provide eight-hour capabi-lity prescribed by 10 CFR 50.h8.
Plant shutdown vill not be required for installation.
3 Section III.0 -
Install oil collection systems Completion by end of 011 Collection as prescribed by 10 CFR 50.h8.
first refueling outage System for Reactor Plant shutdown vill be required starting after Coolant Pump because of radiation levels August 16, 1981.
present during plant operation.
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s ATTACHMENT II Big Rock Point Plant DESCRIPTION OF CAPABILITY TO ATTAIN SAFE SHUTDOWN FOLLOWING A DAMAGING FIRE I.
General The infor=ation provided in this document is presented in two basic sections.
The first, addresses the way in which the Appendix R,Section III.L perfor-mance goals are or vill be met with damaging fires in the areas defined in the NRC letter of November 2k,1980.
The second section provides a sm-an of all modifications to be performed in support of the perfomance goals.
II.
Attainment of Performance Goals A.
Reactivity Control The Big Rock Point Plant is a boiling water reactor and requires no further reactivity control following a reactor scram.
lg B.
Reactor Coolant Make-uo Make-up to the primary system is not required during short tem cooldown provided the system is isolated and a heat sink is provided.
The inventory nomally available in the system is sufficient to keep the core covered even after system cooldown. Make-up will be pro-vided for long tem shutdown to :mntain inventory losses due to nomal leakage. See C.2.
C.
Reactor Heat Re= oval This perfomance goal consists of two plant operating modes. The first, Hot Shutdown, is the operating mode of decay heat removal i= mediately following plant shutdown and while pressure above 300 psig exists in the primary coolant system. The second, Cold Shutdown, is the operating
=cde of decay heat removal when the primary coolant system pressure is between 300 psig and atmospheric pressure. These two decay heat re= oval operating modes are covered individually belev.
1.
The hot shutdown mode of operation can be implemented with either the main feedvater system including the turbine bypass valve and the condenser,_or with the emergency condenser. The =ain feed-vater system is the nor=al means of hot shutdown. This means of shutdown requires off-site power and its components, which are located throughout the turbine building and the service building.
A fire almost anywhere in these areas will affect the ability to use the =ain feedvater system.
The emergency condenser is located withi-contain=ent and is dependent on no syste=s _or equipment outside containment after it. is placed in service except for make-up to the shell. The
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l Attach =ent II (cont.)
2 modifications which vill be =ade to assure the use of the emergency condenser in the event of a fire in the turbine or service building areas of the plant are described in Part III.
2.
Reactor Decay Heat Removal-Cold Shutdevn An emergency power feeder cable vill be installed through contmimwnt to circuit breakers inside containment.
In the event of fire damage to the electrical penetration or cable spreading and electrical equipment areas, cable connections can be made between these circuit breakers and a CRD pt p for reactor coolant make-up, and/c-a reactor cooling water pt=p.
and a shutdown cooling pump for Tc.hing the plant to a cold shutdown and/or a fuelpit pump for fuel pool cooling. A suit-able source of 3-phase, h80V power would then be connected outside of containment.
The emergency power feeder cable vill penetrate containment via new electrical penetration assemblies installed in the equip =ent lock. The equipment No
' lock is remote from the turbine room and the principal elec-trical penetration area and would not be affected by fires in these areas.
D.
Process Monitoring Drum level and reactor pressure vill be displayed in the auxilian shutdown control area.
Emergency condenser shell side lov vater level vill be annunciated simultaneously in the control room and at the auxiliary shutdown'centrol area. Power for this instrumen-tation will be supplied fro = a battery located in the auxiliary shutdown control a:va. This area is protected from a fire in the electrical penetration, cable spreading, electrical equi;=ent, auxiliary boiler and turbine generator areas by separation.
E.
Suptorting Functions i
Deineralized water or fire water is required for make-up to the i
emergency condenser shell when the emergency condenser is in operation.
l A fire in centain areas of the turbine or service building could affect the ability to utilize the de=ineralized water syste= as a source of make-up. The ; ire water system vill be operable in the l
event of a fire in these areas and make-up to the energency condenser vill be enabled from outside containment.
Service water supports the reactor cooling water system which is required when performing the shutdown cooling operation. A fire in the service building could affect the operability of this syte=;
however, the reactor cooling water heat exchangers which are inside containment can be supplied frem a fire water source inside contain=ent.
i III.
Su= mary of Modifications
/.onfications vill be made to assure the ability to take the plant to safe hutievn via the e=ergency cendenser in the event of a fire in the centrol econ, the cable spreading and electrical equipment roc = or any other area t-
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l Attach:nent II (cont. )
3 containing equipment, circuitry or pcver sources supporting the condensate, feedvater and condenser systems.
The modifications consist of installing a new power supply for operation of the emergency condenser outlet valves (M07052 and M07062), the =ain steam isolation valve M07050), fire water nake-up to the emergency condenser (Valve VEC-1*), and reactor pressure, drum level and emergency condenser water level instrument syste=s. Centrol of the main steam isolation valve is included so that it can be closed to prevent the loss of reactor coolant inventory and thus preclude or delay the need to provide 1:nmediate power to equipment for supplying make-up to the primary ecolant system. The power supply ar.d supporting equipment for these services vill be located in or
.within the immediate vicinity of the core spray equipment rocm. The power supply will be a 125V d-c battery, supported by a battery charger and supplying a distribution panel serving motor starters for' the valve motor operators, the instrument systems and the operation of the controlling area which vill be known as the auxiliar/ shutdown control station.
A-c power from a non-Class 1E power source vill be supplied to the area for batter /
charging, light, heat and ventilation cf the batterf room.
The modified valve operator control scheme of all valves vill feature a transfer switch which disconnects the valve operator, its power supply and its control system from the operator control switches and position indication lights at the main control panel, and enable the operator control switches at the new auxiliary shuwdown control station. This design isolates main control room destined circuitry and equipment which, in the event of a fire or other damage, could affect the satisfactorf operation of the valves from the auxiliary shutdown control station or could place a depletien load or fa tit on the battery. Operation of the transfer switches to enable auxili-ary shutdevn control station control of the valves will be annunicated in the main control rocm.
Figure 1 attached displays this concept.
Lov level in the emergency condenser tank vill be simultaneously alar ed in the main-centrol room and at the auxiliary shutdown control station.
The auxiliary shutdown control station drm level and pressure instruments
' vill be supplied by new transmitters within contain=ent.
Access for power to equipment located within contain=ent will be via the equipment lock by a new electrical penetration.
.The use of the core spray equipment rocm to house the new equipment of the auxiliar/ shutdown centrol station and the equiptent lock for supporting electrical-circuits into containment provides a locatien that is cc=pletely isolated and separated-from the turbine and service buildings, the 1ccation of the power supply and equipment for operation of the nain feedvater system.
- VEC-1 is a manual valve; it will be replaced with a type capable of re:::ote operation.
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s Attach =ent II (cont.)
h A source of 480V into containment via electrical penetration equip =ent located in the equipment lock will be provided through the following modifi-cation. The power feeder vill ter=inate at the outside of the electrical penetration located in the equipment lock outside of contain=ent and at circuit breakers inside of containment.
In the event of damage to nor=al power sources or electrical penetrations, power can be supplied as necessarf to a control rod drive pump for reactor coolant =ake-up, to a reactor cooling water pump and a shutdown puu:p for shutdown cooling or to a fuel pit pu=p for spent fuel pool cooling. In the event of the need to use this feeder, a power source would be connected to it at the exterior electrical penetration, and the motor of the pump or pumps of the system to be operated would be connected to one of the circuit breakers using te=porary cables.
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125 V,, D-C CIG ROCK POINT PLANT PROPOSED SCHEMATIC WIRING DIAGRAM i i EMERGENCY CONDENSER INLET VALVE
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FOR FIRE PROTECTION MODIFICATION
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