ML19308C965
| ML19308C965 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/17/1980 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002130010 | |
| Download: ML19308C965 (9) | |
Text
c A/#c PDR UNITED STATES i
NUCLEAR REGULATORY COMMISSION y
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. j WASHINGTON, D. C. 20666
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JAN 171980 MEMORANDUM FOR:
R. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors FROM:
G. Lainas, Chief f
Plant Systems Branch Division of Operating Reactors
SUBJECT:
FIRE PROTECTION FOR ARXANSAS UNIT 1 -
CORRIDOR AND CABLE SPREADING ROOM P1 ant Name: Arkansas Nuclear One - Unit 1 Licensee: Arkansas Power and Light Company Docket No. : 50-313 Project Manager:
G. Vissing Status : Awaiting further details to ccmplete review of design criteria for certain modifications; no incomplete items.
The Arkansas 1 fire protection SER supplement of May 23, 1979, noted that the fire protection was still under review for the corridor and cable spreading room areas. At that time we had discussed with the licensee the additional actions required to make the fire protection designs acceptable. The enclosed paragraphs further document the basis for our position, and identify two alternatives for the cable spreading recm in lieu of satisfying our position on the water spray system.
The design of the protection proposed for the auxiliary building corridor at elevation 372 feet is found acceptable as described in the attached paragrapns.
The attached paragraphs should be included in a letter to the licensee.
We request a response within 20 days that indicates which alternative will be satisfied for the cable spreading room; however, if the licensee chooses not to satisfy this requirement, a meeting should be scheduled within the same 20 days with appropriate management individuals to resolve this item prior to initiating an order.
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G. Lainas, Chief Plant Systems Branch Division of Operating Reactors
Contact:
H. George, X27136 l
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ENCLOSURE ARKANSAS 1 FIRE PROTECTION
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By letters of January 18 and 31,1979, you provided certain details on the modifications (SER items 3.3 and 3.7) being made to protect safe shutdown cabling in the cable spreading room and the corridor at elevation 372 feet. Our fire protection SER supplement of May 23, 1979 noted that we were continuing to review these items.
By letters of March 19 and 20,1979, you provided a design description of the protection for the corridor which would include an automatic directed water spray system as well as Kao-wool insulation on all cables from the " red" safety division. We have concluded our review and find that this modification will provide the protection we intended in the ANO-1 fire protection safety evaluation report of August 22, 1978.
Our letter of March 5,1979, identified specific items that should be satiefied in order for us to find the protection for the cable spread-ing room acceptable. We have reviewed your response of March 19 and 20, 1979, which included your basis for not satisfying certain items of our position. We find your basis unacceptable in the following areas:
(1) Smoke detector in-situ tests have not been proposed or conducted and therefore an adequate basis has not been provided to demon-strate response time of the smoke detectors.
Prompt detector response is required to actuate the spray system in time to protect redundant cables in conduit that are in close proximity to each other, and to notify the brigade so that they can suppress a fire promptly in case the water spray fails to operate.
(2) AP&L's basis for not improving the suppression system actuation logic to any one line detector or smoke detector zone with any other line detector or smoke detector zone does not resolve our concerns over sensitivity and reliability of the actuation circuit. The additional flexibility in the actuation circuit that would be provided by satisfying our position would assure prompt actuation of the system due to fires in transient combustibles or if portion s of the detection systems are out of service.
Because of the above deficiencies, we find that the fire protection systen, as proposed for the cable spreading room does not provide the protection we intended in our SER and is, therefore, not acceptable.
To provide adequate protection for safe shutdown equipment due to i
postulated fires in the cable spreading room, one of the following should be provided in lieu of satisfying our position of March 5, 1979: (1) provide an alternate shutdown capability independent of cabling in the cable spreading room, or (2) provide one-hour fire-rated insulation to protect safe shutdown cables of one safety division.
If an alternate shutdown system is to be provided, it should satisfy the enclosed position.
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.t STAFFPOSITION
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1 SAFE SHUTDOWN CAPABILITY Staff Cor:cern During the staff's evaluation of fire protection programs at.
operating plants, one or more specific plant areas may be identified in which the staff does not have adequate assurance that a postulated fire will not damage both redundant divisions of shutdown systems.
This lack of assurance in safe shutdcwn capability has resulted frem one or both of the following situations:
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- Case A: The licensee has not adequately f dentified the I
systems and components required for safe shutdown and their location in specific fire areas.
Case 3: The licensee has not demonstrated that the fire protection for specific plant areas will prevent damage to both redundant divisions of safe shutdcwn com:0nents identified in these areas.
For Case A, the staff has required that an adequate safe shutdcwn analysis be performed. This evaluation includes -the identification of the system.s required for safe shutdcwn and the location of the system components in the plant. Where it is determined by this evaluatien that safe shutdown components of both redundant divisions are located in the same fire area, the licens.ee is required to de:renstrate that a postulated fire will not damage both divisions or provide alternate snutdown cacability as in Case S.
l For Case 3, the staff may have required that an alternate shutdown l
capability be provided with is incependent of the area of concern or the licensee may have pr0 posed such a capability in lieu of t
certain additional fire protection modifica icns in the area. The specific modifications associated with the area of concern along with other systems and equipment already independent of the area forn the alternate shutdcwn capability.
For each plant, the modifications needed and the comoinations of systems which provide the shutdown functions may be unicue for each critical area; however, the sh0tdown functions provided should maintain plant parameters within the bounds of the limiting l
safety censequeNes deemed acceptable for the design basis event.
Staff Position Safe shutdown capability shculd be demonstrated (Case A) or I
altemate shutdcwn ca: ability provided (Case B) in accordance with the guidelines previded belcw:
- 1. Cesi n Basis Event t
l The design basis event for considering the need for alternate j
snute:wn is a postulated fire in a specific fire area containing i
redundant safe shut:cwn cables / equipment in close proximity wnere it has been determined that fire protection means cannot assure that safe shut:cwn capability will be preserved. Two cases snculd be censidered: (1) offsite power is available; and (2) offsite pcwer is not available.
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- 2. Limiting Safety Consecuences and Required Shutdown Functions 2.1 No fission product boundary integrity shall be affected:
a.
No fuel clad damage; b.
No rupture of any primary coolant boundary; c.
No rupture of the containment boundary. -
2.2 The reactor coolant system process variables shall be within these predicted for a loss of normal ac power.
2.3 The alternate shutdown capability shall be able to achieve and maintain subcritical conditions in the reactor, maintain reactor coolant inventory, achieve and maintain hot standby
- conditions (hot shutdown
- for a BWR) for an extended perioc of time, achieve cold shutdown
- conditiens within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and maintain cold shutdown COnditiens tnereafter.
6 As defined in the Standard Tecnnical Specifications.
- 3. Per#creance Gcais 3.1 The reactivity centrol function shall be capable of achieving and maintaining cold shutdewn reactivity conditions.
3.2 The reacter c:olant makeup function shall be cacable of maintaining the reactor coolant level acove the top of the core for SWR's and in the pressuri:er for PWR's.
3.3 The reactor heat removal function shall be capable of achieving and maintaining decay heat removal.
3.4 The process monitoring functicn shall be capable of providing direct readings Hof tne process variaoles necessary to perform and control the above functions.
3.5 The su: porting function shall be capable of providing th"e process cooling, lubrication, etc. necessary to permit the operatien of the equipment used for safa shutdcwn by the systems identified in 3.1 - 3.4.
3.6 The ecuipment and systems used to achieve and maintain hot stancby conditiens (hot shutdown for a SWR) should be (1) free of fire damage; (2) capable of maintaining such conditions for an extended time period longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> l
if the equipment required to acnieve and maintain cold shutdcwn is not availaole due to fire damage; and (3)
I pcwered by an ensite emergency pcwer system.
3.7 The ecuipeent and systems used to acnieve and maintain cold shutdcwn conditions should be either free of fire damage er the fire damage to such systems should be limited such that recairs can be made and cold shutdcwn conditions achieved witnin 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Equipment and systems usec prior to 72 hcurs after the fire should be pcwered by an onsite emergency power system; those used after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> may be powered by l
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3 offsite power.
3.8 These systems need not be designed to (1) seismic category I criteria; (2) single failure cri.teria; or (3) cope with other plant accidents such as pipe breaks or stuck valves (Appendix A BTP 9.5-1), except those portions of these systems which interface with or impact existing safety systems.
- 4. pWR Equioment Generally Necessary.For Hot Standby (1) Reactivity Control Reactor trip capability (scram). Boration capability e.g.,
charging pump, makeup pump or high pressure injection pump taking suction from concentrated borated water supplies.
and letdown system if required.
(2) Reactor Coolant Makeuo Reactor coolant makeup capability, e.g., charging pumps or the high pressure injection pumps. Power operated relief valves may be required to reduce pressure to allow use of the high pressure injection pumps.
(3) Reactor Coolant System pressure Control l
Reactor pressure control capability, e.g., charging pumps or pressurizer heaters and use of the letdown systems l
if required.
l (4) Cecay Heat Removal Decay heat remcval capability, e.g., power operated relief valves (steam generator) or safety relief valves for heat removal with a water supply and emergency or auxiliary feedwater pumps for makeup to the steam generator. Service water or other pumps may be required to provide water for auxiliary feed pump suction if the condensate storage tank capacity is not adequate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
(5) process Monitoring Instrumentation Process monitoring capability e.g., pressurizer pressure and level, steam generator level.
(6) Succort.
The equipment required to support operation of the above described shutdown equipment e.g., component cooling water service water, etc. and onsite power sources (AC, CC) with their associated electrical distribution system.
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- 5. PWR Equipment Generally Necessary For Cold Shutdown *
(1) Reactor Coolant System Pressure Reduction to Residual Heat Removal System (RHR) Capacility Reactor coolant system pressure reduction by cooldown using steam generator power operated relief valves or atmospheric dump valves.
(2) Decay Heat Removal Decay heat removal capability e.g., residual heat removal system, component cooling water system arid service water system to removal heat and maintain cold shutdown.
(3) Suecort Suoport capability e.g., onsite power sources (AC & DC) or offsite after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and the associated electrical distribution system to supply the above equioment.
Etuioment necessary in addition to that alreadv ;rovided to maintain hot stancby.
- 6. SWR Ecuioment Generally Necessary For Hot Shutdown (1) Reactivity Control Reactor trip capability (scram).
(2) Reactor Coolant Makeue Reactor coolant inventory makeup capability e.g., reactor core i
isolation cooling system (RCIC) or the high pressure coolant l
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i injection syst'em (HPCI),
(3) Reactor Pressure Control and Cecay Heat Removal l
Depressuri:ation system valves or safety relief valves for l
dump to the suppression pool. The resicual heat removal system in steam condensing mode, anc service water system may also be used for heat removal to the ultimate heat sink.
(4) Sucoressien Pool Cooling l
Residual heat removal system (in suppression cool cooling moce) service water system to maintain hot shutdown.
(5) Process Menitorinc Process :enitoring capacility e.g., reactor vessel level and pressure and suppression pool temperature.
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-s-(6) Support Support capability e.g., onsite power source (AC & DC) and their associated distribution systems to provide for the shutdown equipment.
- 7. BWR Ecuipment Generally Necessary For Cold Shutdown
- At this point the equipment necessary for hot shutdown has reduced the primary system pressure and temperature to where the RHR system may be placed in service in RHR cooling mode.
(1) Decay Heat Removal Residual heat removal system in the RHR cooling mode, service l
water system.
(2) Succort' Onsite sources (AC & DC) or offsite after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and their associated distribution systems to provide for shutdown equipment.
Equipment provided in addition to that for achieving hot shutdown.
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- 8. Information Recuired For Staff Review (a) Description of the systems or portions thereof used to i
provide the shutdcwn capability and modifications required to achieve the alternate shutdown capability if recuired.
(b) System design by drawings which shew normal and alternate shutdown control and power circuits, location of components, and that wiring which is in the area and the wiring which is out of the area that requi. red the alternate. system.
(c) Verification that c.ianges to safety systems will not degrade safety systems.
(e.g., new isolation switches and control switches should meet design criteria and standards in FSAR for electrical equipment in the system that the switch is to be installed; cabinets that the switches are to be mounted in should also meet the same i
criteria (FSAR) as other safety related cabinets and panels; to avoid inadvertent isolation from the control room, the isolation switches should be keylocked, or alarmed in the control room if in the " local" or " isolated" position; periodic checks should be made to' verify switch is in the procer position for normal operation; and a single transfer switch or other new device should not be a source for a single failure to cause loss of redundant safety systers).
(d) Verification that wiring, including cower sources for the control circuit and equipment operation for the alternate shutdown metnod, is independent of equipment wiring in the area to be avoided.
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.P (e) Verification that alternate shutdown power sources, inclu'ing d
all breakers, have isolation devices on control circuits that are routed through the area to be avoided, even if the breaker is to be operated manually.
(f) Verification that licensee procedure (s) have been developed which describe the tasks to be performed to effect the shutdown method. A sumary of these procedures should be reviewed by the staff.
(g) Verification that spare fuses are available for control circuits where these fuses,may be required in supplying power to control circuits used for the shutdown method and may be blown by the effects of a cable spreading room fire. The spare fuses should be located convenient to the existing fuses. The shutdown procedure should inform the operator to check these fuses.
(h) Verification that the manpewer required to perform the shutdown functions using the procedures of (f) as well as to provide fire b'rigade members to fight the fire is availacle as required by the fire brigade technical soeci fi cations.
j (i) Verification that adequate acceptance tests are performed.
D.ese should verify that: equipment operates from the local centrol station wnen the transfer or isolation switch i
is placed in the " local" position and that the equipment cannot be operated from the control roem; and that equip-ment operates from the control room but cannot be operated at the local centrol station when the transfer or isolation switch is in the "ren.ote" position.
(j) Tecnnical Specifications of the surveillance requirements and. limiting. conditions for coeration for that equipment not already covered by existing Tech. Specs.
For example, if new isolation and control switches are added to a service water system, the exist'.ng Tech. Spec. surveillance require-ments on the service water system should add a statement similar to the following:
"Every third pump test should also verify that the pumo starts from the alternate shutdown station after moving I
all service water system isolation switches to the local control position."
(k) Verification that the systems availacle are adequate to perform the necessary shutdewn ftnctions. The functions required should be based on previous analyses, if pessible (e.g.,
in the FSAR), such as a loss of normal a.c. power or shutdcwn on a Group I isolation (BWR). The equipment required for the alternate capability should be the same or ecuivalent to tnat relied on in the above analysis.
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s 7-(1) Verification that repair procedures for cold shutdown systems are developed and material for repairs is maintained on site.
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