ML20054H612
| ML20054H612 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 06/15/1982 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Fiedler P JERSEY CENTRAL POWER & LIGHT CO. |
| References | |
| TASK-03-04.C, TASK-3-4.C, TASK-RR LSO5-82-06-047, LSO5-82-6-47, NUDOCS 8206240261 | |
| Download: ML20054H612 (23) | |
Text
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June 15,1982 Docket No. 50-219 LS05-82 047 Mr. P. B. Fiedler Vice President and Director Oyster Creek Nuclear Generating Station Post Office Box 388 Forked River, flew Jersey 00731
Dear Mr. Fiedler:
SUBJECT:
SEP TOPIC III-4.C. IllTERNALLY GENERATED MISSILES OYSTER CREEK Enclosed is our final evaluation of SEP Topic III-4.C.
It is based on a Safety Analysis Report which you supplied and other infonnation available on Docket No. 50-219.
The evaluation concludes that your facility meets the criteria for
)
protection against internally generated missiles.
The evaluation will be a basic input to the integrated safety assess-i ment of your facility.
It may be changed in the future if your facility design is changed or if NRC criteria change before completion of the integrated assessment.
fgoY Sincerely, gg (rd A OD' Dennis M. Crutchfield, Chief Operating Reactors Branch fio. 5 Division of Licensing
Enclosure:
As stated cc w/ enclosure:
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NRC FORM 318 @80) NRCM cm OFFIClAL RECORD COPY usom Isai-sweso
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Mr. P. B. Fiedler O
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G. F. Trowbridge, Esquire Resident Inspector Shaw, Pittman, Potts and Trowbridge c/o U. S. NRC 1800 M Street, N. W.
Post Office Box 445 Washington, D. C.
20036 Forked River, New Jersey 08731 g
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J. B. Liebennan, Esquire Commissioner Berlack, Israels & Lieberman New Jersey Department of Energy 1
26 Broadway 101 Commerce Street New York, New York 10004 Newark, New Jersey 07102-
- 1
, Ronald C. Haynes, Regional Administrator l~
Nuclear Regulatory Commission, Region I 631 Park Avenue j
King of Prussia, Pennsyl.vania 19406
^i J.. Knubel BWR Licensing Manager i
GPU Nuclear 100 Interplace Parkway Parsippany, New Jersey 07054 Deputy Attorney General'
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State of New Jersey i
Department of Law and Public Safety
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36 West State Street - CN 112 Trenton,' New Jersey 08625
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' Mayor Lacey Township 818 Lacey Road Forked, River, New Jersey __08731
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U. S. Environmental Protection Agency 4
Region II Office
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ATTN:
Regional Radiation Representative 26 Federal Plaza
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. New York, New York 10007 ll Licensing Supervisor i
Oyster Creek Nuclear Generating Station Post Office Box 388 Forked River, New Jersey 08731
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.C SAFETY EVALUATION REPORT SEP TOPIC:
III-4.C INTERNALLY GENERATED MISSILES l
OYSTER CREEX NUCLEAR GENERATING STATION, UNIT 1
-f I.
INTRODUCTION Missiles which are generated internally to the reactor facility (inside and outs'ide containment), may cause damage to structures, systems and components that are necessary for the safe shutdown of the reactor facility.
I or accident mitigation and to the structures, systems and components i
l whose failure could result in a significant release of radioactiv'ity.
l Thje potential squrces'of'such missiles"are valve bonnets, hardwari
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retaining bolts, relief valve parts, instrument wells, pressure containing i
equipment, high speed rotating machinery, and r6tating segments '(e.g.,
impellers and fan blades).
Scope of Review 6'
The scope of review is as outlined in the Standard Review Plan (SRP) l Section 3.5.1.1, " Internally Generated Missiles (Outside Containment),"
2 i
and SRP Section 3.5.1.2, " Internally Generated Missiles (Inside ~ Containment)." '
3 The review includes internally generated missiles associated with component 1
overspeed failures, missiles that could originate from high energy fluid i
i system failures, and missiles due to gravitational effects.. Gravitational i
i missiles are considered for the components inside containment only. The review specifically excludes SRP Section 3.6.1, " Plant Design for Protection Against Postulated Piping Failures in Fluid Systems Outside Containment,"
3.5.2, " Determination of Break Locations and Dynamic Effects Associated 4
I with the Postulated Rupture of Piping," as well as those SRP sections j
draling with natural phenomena (including missiles generated by natural f
phenomena), missiles generated outside the facility, and turbine missiles.
I j
II.
REVIEW CRITERIA The acceptability of the design for protection for facility structures, systems, and components from internally generated missiles is based on meeting the follcwing criteria:
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1.
General Design Criterion 4, " Environmental and Missiles Design Bases"
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with respect to protecting structures, systems and components against 9
the effects of internally generated missiles to maintain their essential safety functions.
2.
Regulatory Guide 1.13, ',' Spent Fuel Storage Facility Design Bas'is" as related to the spent fuel pool systems and structures being capable of withstanding the effects of internally generated missiles, and preventing missiles from impacting stored fuel assemblies.
l, l
3.
Regulatory Guide 1.27. " Ultimate Heat Sink for Nuclear Power D1 ants" I
as related to the ultimate heat sink being capable of withstanding
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the effects of internally generated missiles.
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l III.
RELATED SAFETY TOPICS AND INTERFACES j
Review Areas Outside the Scope of this Topic i
'As stated previously, this review specifically excludes the following:
j 1.
SRP Section 3.6.1, " Plant Design for Protection Against Postulated 1
Piping Failure in Fluid Systems Outside Containment" - This matter will i
be covered under Safety Topic III.5.B " Piping Break Outside Containment."
2.
SRP Section 3.6.2, " Determination of Break Locations and Dynamic Effects Associated with the Postulated Rupture of Piping" - This mat'ter will be covered under Safety Topic III-5.A, " Effects of Pipe Break on Structures, Ij Systems and Components Inside Containment"
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3.
Natural Phenomena "This matter will be covered under Safety Topics III-6, " Seismic Design Considerations" and III-4.A. " Tornado Missiles."
1 4.
Turbine Missiles - This matter will be covered under Safety Topic i
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III-4.B " Turbine Missiles."
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Interfaces with Other SEP Safety Topics Satisfactory resolution of the following safety topics wil1 depend, at l
least in part, on the satisfactory resolution of this topic':
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l 1.
Topic VI,I-3, " Systems Required for Safe Shutdown"
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2.
Topic VII-4, " Effects of Failure in Non-Safety Related Systems on Selected Engineered Safety Features" 3.
Topic IX-1 " Fuel Storage" i
4.
Topic IX-3 " Station Service and Cooling Water System" 5.
Topic II-3.C " Safety-Related Water -Supply (Ultimate Heat Sink)"
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IV.
REVIEW GUIDELINES 1
.l Systems and components needed to perform safety functions were identified 1
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as those listed in SRP Section 3.2.2, " Systems Quality Group Classification."
1.
Systems needed to perform safety functions (safe plant shutdown or 4
l accident mitigations) are:
j a.
Reactor Coolant Pressure Boundary l
b.
Reactor Coolant Recirculation System i
l c.
Shutdown Cooling System (RHR)'
d.
Cleanup Demineralizer System 4
i l
L 4-t i
i e.
Control Rod Drive Hydraulic System f.
Core Spray System g.
Main Steam System j
h.
Feedwater System
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j i.
Emergency Conrienser System i
j Reactor Building Closed Cooling Water System k.
Service Water System
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1.
Liquid Poison System i
m.
Containment Spray System 4
Reactor Head Cooling, System n.
o.
Control Room Ventilation System p.
Diesel Fuel Oil System 2.
Systems whose failure may result in release of unacceptable amounts.of j
radioactivity.
a.
Spent Fuel Pool Cooling System 4
i b.
Sampling System i
c.
Radioactive Waste Systems i
j (i) Off-Gas System I
(ii) Liquid Radwaste System (iii) Solid Radwaste System (iv) Standby Gas Treatment System j
3.
Electrical systems which are necessary for safe shutdown operations.
1 j
These electrical systems are:
a.
4160V - System b.
Emergency Diesel Generators c.
460 Volt System
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. ~ij d.
Motor Control Center e.
Cable Spreading Room f.
Station Batteries 4.
Additionally, there are instrumentation and electrical items which 1
1 are necessary to support safe shutdown operations. These items qj include the reactor pressure and level indicators, isolation con-denser shell side level indicators, and the power cables to the ADS valves.
V.
REVIEW AND EVALUATION 1
For our review and evaluation we utilized an analysis provided by the I
licensee in its submittal received on May 7,1982. The licensee presented an evaluation of the potential effects of internally generated missiles on safety equipment. A plant trip on May 18, 1982 was taken by ASB staff ij members to view the arrangement of safety reldted equipment and resolve ques-tions concerning internal missilei.' During 'our visit to the plant there were j
certain areas which we were unable to enter.
For those areas we depended
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upon the licensee's statements or-our review of drawings. The licensee I
L1 stated that all safety equipment inside the primary containment (drywell) 11 are protected from gravitational missiles Ly seismically supported overhead h
equipment.
l:
The system and components required for safe shutdown of the plant and their a
i l
protection from internal missiles are discussed below.
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1.
Systems Needed to Perfom Safety Functions l
a.
Reactor Coolant Pressure Boundarv 3
lij The reactor coolant pressure boundary. up to the outboard main
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steam isolation valves and containment isolation valves, is 1..
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b l
i located in the reactor building. The portion of the reactor coolant l'
system inside the drywell is conpletely enclosed by a five foot thickness of reinforced concrete.
The reactor building walls enclosing the remainder of the reactor coolant system up to the outboard containment isolation valves are reinforced concrete 18 inches thick.
The reactor vessel is a cylindrical vessel with a gasketed removable upper head. The vessel upper head is held in position by studs.
It is extremely unlikely that any of these studs will become a-missilebecauseofthereactorheadventandmainsteampressure relief valves.
Therefore, these studs are not considered to be exposed to sufficient pressure to create an accelerating force
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enough to cause them to become missiles, i
l j
Our discussion of internal missile protection for main steam pressure j
relief valves, core spray, and recirculation piping are provided in
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separate subsections of this report.
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Instrumentation generally requires some pene'tration into the i]
reactor coolant system. These penetrations are usually small and take the form of welded wells.
We have considered the failures of these wells and conclude that their failure would be improbable.
However, should their welds fail and the wells become missiles,
l their orientation is such as not to be a danger to other safety related systems.
i 1
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l 7-The possibility that potential missiles may also result from destruc-i tive overspeeding of one of the coolant pumps i.n the event of a pipe break in the pump discharge was also reviewed.
Potentially damaging impeller missile eje~ction from the broken pipe is minimized by a massive steel pump casing. We believe that the probability of missiles from overspeed of both the motor and impeller of a coolant pump that could result in damage to safety-related equip-
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ment is acceptably low to allow continued operation of this plant.
i The reactor coolant pressure boubdary i:: protected from gravitational missiles by seismica}ly supported overhead equipment in the drywell.
In summary, in considering the reactor coolant pressure boundary because of its equipment design features, component arrangement nj (i.e., separation), and various alternative methods to accomplish y
j core cocling, it is our judgement that this systems function will lj not be detrimentally affected considering internally generate'd missile sources from the sources as identified above.
- However, i
q should a missile create a break in the reactor coolant pressure boundary, the emergency core cooling system will keep the core i
cooled after vessel depressurization.
1 a
b.
Reactor Coolant Recirculation System 1:
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The reactor coolant recirculation system is located within the drywell area and contains several potential missile sources. These sources include five recirculation pumps, pump suction isolation valves, pump discharge isolation valves and bypass valves.
It is e
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assumed that a missile generated from the recirculation loops will damage the loop and any one of the target systems listed below..
Further, it is assumed that the recirculation system could be damaged by a missile originating from the main steam pressure relief valves (see " Main Steam System" subsection).
The possible targets for missiles generated by the, recirculation
[i system are:
t (1) Control Rod Insert and Withdrawal Lines' (ii)
Isolation Condenser Return I
(iii) Feedwater Line (iv) Shutdown Cooling (v) Main Steam Line f
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If the insert or withdrawal lines are damaged by a missile, the l
control rods will scram because of differential cooling water pressure.
The plant could then be safely shutdown using engineered H
safe shutdown methods, e.g., ADS, CRD, and/or ECCS.
9-For any of the other targets listed above, the reactor will scram
. i.
in a nonnal manner and be safely shutdown by the vessel depressuriz-ing through the postulated pipe typtures (or by using ADS) followed
.j by use of the ECCS.
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il The reactor coolant reci>culation system is protected from gravi-l tational missiles since all ovarhead components are seismically supported.
Lj
.g-1 Based on our evaluation we conclude that the reactor coolant recirculation system will not generate missiles that will preclude j
the plant from being safely shutdown or be susceptible to missiles 4
I from other sources, i
l c.
Shutdown Cooling System The shutdown cooling system removes fission products decay heat j
during reactor shutdown and provides means of cooling the reactor i
j from 350*F to 125'F during refueling or maintenance.
The major components are three heat exchangers, three pumps and i
isolation valves.
The three shutdown heat exchangers are of the horizontal U-Tube design. The portion of the heat exchangers that are considered as potential missiles are the studs for the heat exchanger heads ll and the relief valves. Neither are considered likely to be 1:
generating missiles due to code. built-in safety margins in the design. -
Both trains of the system are not subject to missiles from other
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sources because of their location in protected vaults. However, each train could be subject to missile damage from another train.
However, loss of this system does not result in inability to safely shutdown the plant since this system is a backup system, and normal f
shutdown via main feedwater is available, i
ci l
i s_
v.
, d.
Cleanup Demineralizer System The Cleanup Demineralizer System (CDS) is not required for safe shutdown.
However, it could be a potential source of missiles to nearby safe shutdown systems equipment.
Possible targets include:
(1) main steam (ii) feedwater 1
(iii) recirculation risers (iv) core spray 'A' piping Should one of the,co;re spray trains be damaged by a missile, the second train would be available (due to its separation or orien-tation from the first train).
Further the other engineered safety features would be available. Main steam, feedwater, and' recirculation systems are discussed in separate sections within this SER.
i e.
Control Rod Drive Hydraulic System l
The control rod drive (CRD) hydraulic system supplies and controls 3
- 1 j!
the pressure and flow combinations required for operation of the l
l control rod drives. The hydraulic system consists of two major f
subsystems:
the supply subsystem and the hydraulic control units.
4 This system is considered high energy (1750 psig). The control rod drives are located inside the drywell, with the balance of the system located in the reactor building (elevation 23'6" and 33'5").
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The accumulators are considered the most likely generators, of missiles
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- - ~.. _. -... -
i in this system.
However, there is a rupture disc which prevents any major missiles generated by the accumulator,s by insurin'g that design pressure is not exceeded. Additionallyi the accumulator is designed for 2000 psi ofreating pressure, 3000 psi proof and
.i 8000 psi burst which insures added safety.
The pump 'is a ten stage diffuser pump 85 gpm, 250 HP,1800 RPM and designed for 1750 psig.
Due to its rigid construction and code design margin (ASME Section VIII) it is not' considered likely to generate missiles.
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.l Failure of one of the CRD accumulators could result in a missile striking one of the core spray trains; however, the other core spray train would be available because of system spacing.
If the CRD system were damaged by a missile the damage in most cases would f
result in no more than a limited number of rods losing their ability to be inserted. Assuming the total system is lost the standby liquid poison system serves as a' backup reactor shutdown method, j
and is capable of making and holding the reactor core subcritical.
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f.
Core Soray System The core spray system (CSS) is the low pressure standby core cooling I-system and provides an alternate supply of reactor coolant makeup water in the event of a loss of normal supply via the feedwater system.
The CSS system has redundant loops, each with a 100%
o capacity.
Each loop is located in separate areas inside the reactor '
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building which provides optimum separation, such that loss of both lobps from a comon missile is highly unlikely.
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Further, the system is low pressure (250 psig) and therefore not likely to generate missiles.
The pumps are built to ASME III Class C requirements and are not considered as having missile generating potential in the unlikely event of pump overspeed due to the code design margins. Additionally, should one pump fail, separation assures that the redundant train can provide the necessary cooling.
j Other> potential core spray missile generators include the isolation s
l valves.
The only credible target would be the reactor coolant I
reciiculation system piping which has been previously discussed.
I g.
Main Steam System The main steam system is contained in the drywell, steam tunnel, and turbine building. The main steam system consists primarily I
of the system piping and valves. There are 21 safety valves inside i
the drywell sixteen of which discharge directly into the drywell.
The remaini.ng five safety valves are electromatic relief valves l
controlled automatically by pressure switches or manually from.
c-the control room. These valves discharge to the suppression pool.
There are air-cylinder-operated isolation valves for each of the main steam headers, one inside and one outside the drywell.
Within the drywell, missiles could be generated from either the pressure relief valves or isolation valves. A missile from these sources could disable either the feedwater, cleanup demineralizer system, main steam, core spray, or recirculation piping.
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. Loss of the main steam and feedwater systems can be handled by depressurizing the vessel thru the pipe rupture _ and then us'ing ECCS and the ADS, if necessary.
I Loss of the main steam and a core spray loop or recirculation piping could be mitigated by vessel depressurization via the pipe rupture
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(or ADS) snd then using the surviving loop of core. spray.
Loss of cleanup demineralizer system will not prevent safe shutdown
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i of the plant.
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J.
Based on our evaluatkon, we conclude that the main steam system.
will not generate missiles that will preclude the plant frru being safely s!.utdown or be susceptible to missiles from other sources.
f h.
Feedwater System The feedwater system consists of three parallel trains each
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train containing a feedwater heater,.a one-third capacity feedwater l
pump and the reactor feedwater lines with vessel penetrations, 11
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check valves, and isolation valves.
That portion of the feedwater system including the 'eedwater pumps located in the turbine building upstream of the isolati'on valves is not required for safe shutdown of the plant, and therefore, failure of this portion will not be addressed.
l Considering the essential portion inside containment (the drywell),
t:
.i the only potential missile sources from the feedwater piping would 1
be from a check valve and an isolation valve.
Because of valve 1]
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1 J *\\j orientation, the primary target would be the biological shield wall.
However, potential targets could include main steam piping and isolation valves, recirculation pump and suction piping, and i
i the cleanup demineralizer system.
All possible internal missile i
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affects generated by the feedwater system or impacting the system from other sources have been previously discussed un' der " Cleanup Demineralizer System", Recirculation System", and " Main Steam System."
l Therefore, in the event of a feedwater system missile generated inside containment, the reactor can be safely shutdown.
1 That portion of the system outside of containment, upstream of the outboard isolation valve is not required for safe shutdown.
Further it is physically separated from the ECCS and isolation condenser f
system. Therefore,' a missile from this portion of the system would not affect these safety systems and other methods of safely shutting the reactor down are available.
l f
1.
Emergency Condenser System e.
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The emergency condenser system is a standby, high pressure system for removal of. fission product decay heat after reactor isolation scram when the main turbine condenser is not available as a heat sink.
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- q
.. i The emergency condenser system consists of two loops, each with one condenser shell containing two tube bundles. The condensers are q
not considered a potential missile source due to their low design l
pressure (15 psig).
.)
The isolation condensers and piping are located in the reactor building.
This piping is physically separated from the main steam system, feedwater system, and ECCS piping and components. Therefore, j
a missile generated from these sy, stems has no effect on emergency condensers. Thus, the emergency' co/idensers are protected from missiles --
and several alternate safe shutdown methods are available.
j-p Other Systems That'Are Passive Relative to Safe Shutdown The following systems were listed by the licensee as being needed I
to perform safety functions:
(j) Reactor buildi.ng closed cooling water system
(.k) Service wat'er system *
(11 Liquid poison system (m) Containment spray system (p) Reactor head cooling system (o) Control room ventilation system (p) Diesel fuel oil system The licensee stated that these systems are either well protected by l:
barriers or they are not required to accomplish safe shutdown.
- Further, i:!t the above systems are either low energy or nomally not operating, and 4
2 l
1 a therefore, not capable of generating missiles.
For the purpose of completeness we have listed these systems which were identified by the licensee as systems needed to perform safety functions. We
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have reviewed the above systems and conclude that these systems
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either; do not pose a missile hazard to safe shutdown systems,
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are well isolated by plant structures, or are not needed for safe shutdown.
.i l
2.
Systems Whose Failure May Result in Release of Unacceptable Amounts of Radioactivity 1
a.
Spent Fuel Pool Cooling System The spent fuel pool cooling system removes residual heat from the spint fuel stored in the pool and consists o.f two pump / heat exchanger trains. Addf cionally, there is an augmented spent fuel pool cool-j ing system with one pump and a heat exchanger.
The spent fuel pool cooling system is a low energey system, therefore it is not postulated to generate missiles. The pumps o
- I and heat exchangers are protected from missiles from other sources
~
l due to th'eir compartmentalization. 'Should the equipment become inoperable due'to missile damage, there is sufficient time to effect repairs or arrange for alternate cooling such as fire hoses.
l Thus, failure of this system will not result in adverse radiological consequences.
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l b.
Sampling System A line break in the sampling system piping has been evaluated under SEP Topic XV-16.
The results of the analysis indicate that the dose consequences are a small fraction of 10 CFR Part 100 guide-lines.
Any break in the sampling system outside of tiie drywell t
can be controlled by valves in the drywell. A break inside the i
drywell will be contained and allow for repairs without significant release.
)
i c.
Radioactive Waste System (i) Off Gas System This system processes and disperses radioactive waste gases j
from the main condenser steam jet air ejectors, the turbine l
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gland seal exhauster and mechanical vacuum pump and discharges them via a stack to the atmosphere.
]
This system is a low pressure system and has no equipment ll that could generate missiles.
The licensee stated that the i
offgas system has already been analyzed for failure and shown to result.in doses that are a small fraction of 10.CFR Part 100 guidelines.
Breaks in the offgas system can be isolated by isolation valves inside the reactor building.
We conclude
[
that a failure in the offgas system due to a missile strike l
l will not result in significant radiological consequences.
l (ii) Liouid Radwaste System o
?
The liquid radioactive waste system is used to collect all I
potentially radioactive water leakage and drainage through 1
4
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0 out the plant.
The liquid radwaste system is low energy and thus not capable of generating a missile.
It is enclosed by the radwaste building and is separated from other missile sources.
However, should this system be impaired by a missile,
, then any leakage will be contained by the radwaste building-sufficiently to allow for cleanup and repair.
We conclude that failure of this system will not result in significant 3
radiological consequences.
'l (111 ).
Solid Radwaste System 1
The solid radwaste system receives, processes, stores and l
'l i
disposes of sludge, resins, waste concentrate and other solid radwaste from the plant.
All system components are low energy and therefore, are not postulated missiles sources. Additionally, the remote location of the system provides protection from other missile sources.
Therefore the solid radwaste system is not considered likely-
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to generate or be affected by internally generated missiles.
(iv). Standby Gas Treatment System,
The standby gas treatment system is one of the plant engineered i
safety features.
It operates only during an emergency condition.
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!1 l
Consequently, the standby gas treatment system is contaminated only in accident conditions and therefore, should the system be hit by a missile, it will not release radioactive doses to the enYironment.
I j i Since the standby gas treatment system is not normally operating, and is not required for safe shutdown, then should it be impaired by an internally generated missile, safe shutdown l
of the plant is not affected.
We have not addressed potential failure of the system due to internal missile impact during or I
following accident conditions as this is not part of the review criteria.
In conclusion, should these systems be damaged by an internally i
generated missile, no threat to public health and safety would I
result.
o 3.
Electrical Systems Which are Necessary for Shutdown Operation
'l a.
4160V-System i
J There are four 4160V switchgear bus sections, two are powered from normal or startup sources (1C and 1D). The latter are normally
~
fed from the 1A and 1B buses with emergency power being supplied from the emergency diesel generators.
b j
They are located inside the turbine building in a seismic / fireproof L
enclosure.
No source of internally generated missiles is postulated L
from this system.
No other systems of missile potential are inside this structure.
Therefore, we conclude that adequate protection is ll l,
provided.
1 l;
a f'
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b.
Emerceacy Diesel Generators j
The emergency diesel generator (s) provide the source of onsite power.
1 l
They are housed in a separate building with separation between the two units which consists of a reinforced concrete wall, with the 3
f oil tank in a separate enclosure.
~
- 1 Due to this separation and compartmentalization, and non-existence
.i 1
i of other missile generating sources in the diesel generator building, the emergency diesel generators are not considered subject.
to internal missile damage. Additionally, failure of one diesel generator does not jbopardize the functioning of the other. We conclude that no additional protection is required.
c.,
460 Volt System There are six unit substations each consisting of a 4160/460 volt L
transformer with metal clad deadfront. Two of the six unit sub-l stations feed vital loads in the reactor building.and are separated from the other by a wall. They are not potential missile sources, I
and no other equipment in their vicinity is considered to generate missiles.
Therefore we cofielude that adequate missile protection is provided.
l d.
Motor Control Center l
The vital motor control centers (MCC) feed vital / critical plant valves and protective systems.
These MCCs are located in the same. room with the 4160/460 volt unit substations and are not potential missile i
sources.
Therefore weTonclude that adequate missile protection is l-l provided.
l! -l u
. e.
Cable Soreadino Room The cable spreading room is located directly under the control room.
There are no missile generating components in the cable spreading room. Therefore,se conclude that adequate missile protection is provided.
f.
Station Batteries There are two 125 volt batteries which supply DC power for operation.
of vital control circuits. The batteries and their DC switchgear arelocatedinareasenclosedby[r{i,nforced'oncrete' walls.
c The redundant DC power supply cables to 4KV and 480 volt switchgear, and motor control ce'nters, are physically separated by reinforced concrete walls in the reactor building.' Further, the above mentioned walls provide protection against internally generated missile damage to both divisions of the station batteries.
Based on our evaluation, we conclude that the station batteries are adequately protected and/or separated to preclude damage by an internally generated missiles.
4.
Reactor Pressure / Level and Isolation Condenser Shell Side Level Indications and Power Cables to ADS Valves The instrumentation and electrical items essential to safe shutdown are:
a.
Reactor pressure and level indicators b.
Emergency condenser shell side level indicators c.
Power cables to the ADS valves
.