ML20126D291
| ML20126D291 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 03/18/1980 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 8004240442 | |
| Download: ML20126D291 (12) | |
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,'o, UNITED STATES
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fi NUCLEAR REGULATORY COMMISSION
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,5 WASHINGTON, D. C. 20555 1, '~+,( j S.,,..
Docket No. 50-344 March 18,1980 i'r. Charles Goodwin, Jr.
Assistant Vice President Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204
Dear Mr. Goodwin:
Fire protection for the Trojan train B switchgear room was identified as an incomplete item in our SER of March 9,1978 (item 3.2.2).
The enclosed Staff requirement provides our evaluation of information submitted by you on this item, and our requirement for additional modifications to resolve this item, t
We request a response within 20 days of your receipt of this letter indicating which of the acceptable additional modifications identified ir. the enclosure you choose to adopt.
If none of these options are acceptable to you, we request that you arrange to meet with us in Bethesda within the same 20-day period to discuss the matter.
Please contact us if you have any questions concerning this requirement.
Sincerely, i ((t/H82 -
A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors
Enclosure:
Staff Requirement cc: w/ enclosure i
See next page 80042 40 Y I
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Mr. Charles Goodwin, Jr.
Dortland General Electric Company March 18,1980 cc: Mr. J. W. Durham, Esquire Robert M. Hunt, Chairman
'/ ice President and Corporate Counsel Board of County Comnissioners Portland General Electric Company Columbia County 121 S.W. Salmon Street St. Helens, Oregon 97501 Portland, Oregon 97204 l
Warren Hastings, Esquire Counsel for Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204 Mr. Jack W. Lentsch, Manager Generation Licensing and Analysis Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204 Columbia County Courthouse Law Library, Circuit Court Room j
St. Helens, Oregon 97501 Director, Oregon Department of Energy Labor and Industries Building, Room 111 Salem, Oregon 97310
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Richard M. Sandvik, Esquire Counsel for Oregon Energy Facility Siting Counsel and Oregon Department of Energy 500 Pacific Building S20 S.W. Yamhill Portland, Oregon 97204 Michael Malmros, Resident Inspector U. S. Nuclear Regulatory Connission Trojan Nuclear Plant P. O. Box 0 Rainier, Oregon 97048 Mr. Donald W. Godard, Supervisor Siting and Regulation Oregon Department of Energy Labor and Industries Building, Room 111 Salem, Oregon 97310
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STAFF REQUIREMENT -
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TROJAN TRAIN B SWITCHGEAR ROOM FIRE PROTECTION (Item 3.2.2 of F. P. SER)
Backcround The Train B switchgear room predominantly contains cabling, switchgear, and other electrical equipment associated with safety train B.
The room I
also contains a small amount of train A equipment, including the preferred instruraent a-c buses, battery chargers, inverters, and cabling routed to the train A battery. The train A cabling and equipment are generally 1
well separated from train B equipment and cabling.
However, due to the large amount of cabling in the room and the non-safety related cable trays that provided patnways for fire to be transmitted between safety divisions, the staff was concerned that a fire in one safety division could affect cabling in the redundant safety division.
As noted in our fire protection SER of March 9,1978, PGE had committed to provide fire-stops in non-safety cable trays in this area that provided a pathway for fire to be transmitted between safety divisions.
In addition, PGE had committet to provide an analysis based on cable tray tests to demonstrate the effectiveness of the room air coolers to remove heat from a fire and thus protect cables not involved in the fire from being damaged due to heat buildup.
The FGE letter of January 9,1979, indicated that adequate test data was available and that no tests would be performed. The staff then requested PGE :o submit the promised analysis based on available data or to satisfy one of three alternatives for the train B switchgear room:
(a) Provide an alternate shutdown capability independent of cabling and equipment in this room to achieve safe shutdown, or (b) Provide an automatic total flooding gas suppression system in this area, or (c) Install a 3-hr rated barrier to separate the train A cabling and equipment in the room from the train B cabling and equip-ment.
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Evaluation By letter of July 30, 1979, PGE submitted the results of an analysis of the capability of the air recirculation units in this area to protect cables and equipment in the safety division not involved in the fire. We have reviewed the assumptions used in this analysis and the conclusions made, and find the results unacceptable for the following reasons:
(1)
The analysis is not conservative because it is a thermal analysis that assumes unifor:n air mixing.
It does not consider localized higher temperatures, exposure fires from transient combustibles, and radiant energy effects. With these other cor.siderations the temperature could increase much more rapidly.
(2)
The electrical equipment in this room is designed to operate in a maximum ambient temperature of 104'F.
The analysis indicates that 104'F would be reached in approximately 20 minutes and 180*F in 25 minutes with the air recirculation units operating in a fire. This means that the air recir-culation units cannot overcome the heat generated by the fire prior to loss of vital equipment without intervention by the brigade to suppress the fire.
(3)
The credit in this analysis taken for the room air coolers is not conservative. They centain particulate type filters that could become clogged with smoke particles in a fire, 1
thereby greatly reducing tneir heat removal capability.
These particulate filters are required to prevent dust buildup on the blower fan or heat exchanger fins during normal operation for heat leads in the room.
Staff Position Based on the above, we find the licensee's analysis unacceptable because there is not reasonable assurance that snutcown conditions can be achieved and maintained. We do not accept fire brigade actions as the only means of preserving safe shutdown capability wnere the separation between redundant systems is inadeouate.
Passive protection, such as barriers, l
l automatic suppression, and/or alterr. ate shutdown capability are required where a fire could damage redundant safe shutdown cabling.
. l To provide adequate protection for this area, we will require that one of the following be provided:
(1) An alternate shutdown capability independent of cabling and equip-ment in this room to achieve safe shutdown. This should be equivalent to the remote shutdown capability being provided for the control room and cable spreading room so that the staff's criteria for alternate shutdown (attached) are satisfied.
Or (2) An automatic total flooding gas suppression system. This system should: be actuated by smoke or rate-of-rise heat detectors located at the ceiling; have a mininum design concentration of 50% if CO2 and 20% if halon; have twq-shot capability; be able to maintain a soak time of 30 minutes considering leakage through doors and ventilation dampers; and conferm to NFPA 12 or 12A for deep-seated fire conditions, or (3) A 3-hour fire-rated barrier separating the train A cabling and equipment in the room from the train B cabling and equipment. This may be done by metal lath and plaster construction whose design has been tested to demonstrate a 3-hour fire-rating.
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STAFF POS8 TION SAFE SHUTDOWN CAPABlL8TY Staff Concern During the staff's evaluation of fire protection programs at i
operating plants, one or more specific plant areas may be identifiedT 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 shutdown capability has resulted from one or both of the following situations:
- Case A: The licensee has not adequately identified the systems and components required for safe shutdown and their location in specific fire areas.
t Case B: The licensee has not demonstrated that the fire protection for specific plant areas will prevent damage to both redundant divisions of safe shutdown components identified in these areas.
For Case A, the staff has required that'an adepuate safe shutdown analysis be performed.
This evaluation includes the identification of the systems required for safe shutdown and the location of the system components in the plant.
Where it is determined by this evaluation that safe shutdown components of both redundant divisions are located in the same fire area, the licensee is required to demonstrate that a postulated fire will not damage both divisions or provide alternate shutdown capability as in Case B.
1 For Case B, the staff may have required that an alternate shutdown capability be provided with is independent of the area of concern I
or the licensee may have proposed such a capability in lieu of I
certain additional fire protection modifications in the area. The specific modifications associated with the area of concern along with other systems and equipment already independer.t of the area form the alternate shutdown capability.
For each plant, the modifications needed and the combinations of systems which provide the shutdown functions may be unique for each critical area; however, the shutdown functions provided should maintain plant parameters within the beunds of the limiting safety consequences deemed acceptable for the design basis event.
Staff Position Safe shutdown capability should be demonstrated (Case A) or alternate shutdown capability orovided (Case 5) in accordance with the guidelines proviced below:
- 1. Desien Basis Event Tne design basis event for considering tne need for alternate l
shutdown is a postulated fire in a specific fire area containing redundant safe shuteewn cables /ecui: ment ir. close proximity where l
it has been eetermined that fire er: tecti r means cannot assure that safe shutcown cacability will :e preserved.
Two cases should be considered:
(1) offsite pc er is avaCaole; and (2) offsite power is not available.
- 2. Limitino Safety Consecuences and F.ec: ired Shutdown Functions 2.1 No fission product boundary intagrity shall be affected:
a.
No fuel clad damage; b.
No rupture of any primary c:clant bcundary; c.
No rupture of the contair:mer.t bcundary.
2.2 The reactor coolant system process variables shall be within those predicted for a loss of' n:rr.a1 ac power.
2.3 The alternate shutdown capabili y shall be able to achieve and maintain suberitical cencitions in the reactor, maintain reactor coolant inven cry, acnieve and caintain het standby
- conditions (het shutdo n* for a BWR) for an extended period of time, achieve cold sh.tdown= conditions within 72 hcurs and maintain cold shut:ow conditions thereafter.
As defined in the Standard Tecnrical Sce:ifica)f ens.
- 3. Per'er-ance Goals 3.1 The reactivity control functi:n shall be capable;of achieving and maintaining cold shutd:wr reactivity conditions.
3.2 The reactor coolant r.akeue frenc-icn shall be casable of maintaining the rea:::r co lant level a:ove the top of the core for BWR's and in tne ;rass;rizer f:r PWR's.
3.3 The reactor heat renovel f.r. ti:n snail be capa:1e of achieving and maintaining :e:ay hen: re. oval.
3. t.
Tne process monitoring fca::i on snail be casable of providing direct readir.gs cf tre ;r: cess variables necessary to perfom and c:n:rc the ab:ve func:1ons.
3.5 Tne supporting function shti be ca:abit of providing th'e process cooling, lubricati:n, e:c. ne:essary : pe rmi t tne operation of the e:uip er.: : sed f:r safe shutdown by tne systems identified in 3.~ - 3.4.
3.6 The equipment and systens sed o a:hieve and r.aintain hot standby conditions (het sh:::ow. #cr a 5WR) shcald be (1) free of fire damage; (I' :::a:1e Of maintaining such conditions for an ex ended :"me peri:d longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> if the equipment re;uired :: a: ieve and maintain cold snutdown is not availadle :.:e : #i e car. age; anc (3) i powered by an ensite erergen:y ::we syster.
3.7 Ine equipment and systems.se: :: a:nisse an: aintain cold snu cown c:ncitiens sn:vi: :e e'.ns #ree :f re camage or
- ne fire camage :: su: sys s 1 s :.: :e lirited such ne repai-s can be a:e a : :::: s u ::w- ::n:itiens achieve:
witnin 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, hu :ren: En: sys:s.s use: :-i:r to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> d
a'ter tne fire sno.1: :e ::-ered :; a :nsi:e emergency power system; those use: a#:ar 72 r:u s ma;. se ;cwered by gcog 9 3 q'
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3.8 These systems need not be designed to (1) seismic category I criteria; (2) single failure criteria; or (3) cope with other plant accid'ents 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 Ecuipment 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) _Rg etor Coolant Makeue Re.sctor coolant makeup capability, e.g., charging pumps c-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 Centr:1
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Reactor pressure control capability, e.g., charging pumps or pressurizer heaters and use of the letdown systems if required.
(4)
Decay Heat Removal Decay heat removal capability, e.g., power operated relief valves (steam generator) er scfety relief valves for heat removal with a water supply and emergency or auxiliary feedwater pumps for makeu; to the steam generator.
Service water or other pum:s may be required to provice 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 Monitorin; Instrumentation Process monitoring capability e.g., pressuri:er pressure and level, steam generator level.
(6)
Succort.
The equipment reacired to su:: rt c:eratien o' the above described shutdowr e:ui:rar.: e.g., c:r:enent :: cling water service water, et:. and cr. site pc e-s:urces ' A:, DC) with their associated ele:trical distri:vti:n syster.
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- 5. P'4R Ecuiement Generally Necessa y For Cold Shutdown *
(1)
Reactor Coolant System Pressure Reduction to Re:idut.1 Heat Removal System (RrR) Caca:i.irf Reactor coolant system pressure reduction by cooldown using steam generator power operatec 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 :mair.tain cold shutdown.
(2)
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 /> a-d the associated electrical dis rbution system to su:;7y the above equip ent.
E:uiprent necessary in additier :o that already provided to maintain nct standty.
E. WR E:uiement Generally Necessar:. F:r Hot Shutdown (i)
Reactivity Control
-Reactor trip capability (scrat.
(2)
Reactor Coolant Makeue Reactor coolant inventory make;p capability e.g., reactor core isolatien cooling system (R;1C. or tne high pressure coolant injecticn system (HPCI).
(2)
Reacter Pressure Control and Cecay Heat Removal Deeressurization system valves or safety relief valves far dump to the suppression p:c~. The residual heat removal system in steam condensing oca, and service water system may alsc be used for heat rem:tal to the ultimate heat sink.
(')
Suo:ression Pool Cocline Resideal heat removal syste i n superessien : col cooling i
r.o:e) service water syste to aintair no: sha :cwn.
(5) 3r::ess V.:nitorin; Or::ess m:nitorin; :a:a:"':y e.;., rea::or vessei level an: o essure and sa:: essi:
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(6) Sueoort Support capability e.g., onsite power source (AC & DC) and their associated distribution systems to provide for the shutdown equipment.
- 7. BWR Ecuioment Generally Necessary Fcr Cold Shutdown
- At this point the equipeent necessary for het shutdown has reduced the primary system pressure and temperature to where the RHR system may be placed in service in R4R cooling mode.
(1)
Decay Heat Removal Residual heat removal system in the RHR cooling mode, service water system.
(2) Suocort Onsite sources ( AC & DC) or effsite af er 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 shutcown equipment.
Equipment provided in addition o that for achieving hot shutdown.
- 8. Information Recuired For Staff Eeview (a)
Description of the systems or portions thereof used to provide the shutdown capability and modifications required to achieve the alternate snutd:wn capa:ility if recuired.
(b)
System design by drawings which show normal and alternate shutdown control and power cir:uits, ic:ation of components, and that wiring which is in the area and the wiring which is out of the area that required the alte-nate system.
(c) Verification that changes to safety systems will not degrade safety systems.
(e.g.,new isclation switches and control switches shoulc rest design criteria and standards in FSAR for electri:11 ecuip er.: in the system that the switch is to be irstalled; cabinets that the switches are to be mounted in snculd also meet the same criteria (FSAR) as other safety re'. ate: cabinets and panels; to avoid inadvertert isolatien frc the control room, the isolation switches snoul: be keylocked, or alarmed in the control reor if in :ne 'lecti" :r " isolated" position; periodic checks should be race :: veri #y switch is in the procer position for nor nal ::e sti:n; and a single transfer switch or etner nea devi:e sn:.1: n
- s a scurce for a single f ailure to :ause 10ss :# recun: ant safety systems).
(d) Verification that wiring, ' :*i. tin; ::-e-sources for tne control circuit an: e:vi:re-
- e it': #:r the alterna e shutdown metned, is in:e:e :e
- f e:.i:rea.: wiring in the area to be avoided.
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(e)
Verification that alternate sh;tdown power sources, including all breakers, have isolati:n oevices en control circuits that are routed through the area to be avoided, even if the breaker is to be operated can ally.
(f)
Verification that licensee pro:edure(s) have been developed which describe the tasks to be perfomed to effect the shutdown 1
method.
A summary of these pr:cedures should be reviewed by the staff.
(9)
Verification that spart fuses are available for control circuits where these fuses,c.ay 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 sh:uld be located convenient to the existing fuses. The statdown procedure should inform the operator te check tnese fuses.
(h)
Verifica' tion that the man;ower,recuired to perform the j
shutdown functions using ne p ocecures of (f) as well l
as to provide fire brigade ner:ers to fight the fire is available as required by the fire trigace technical specifications.
(i)
Verification that adecuate a::eptanie ests are oerformed.
These snould verify that: equipment c:erates from the local control station wher. :.ne transfer or isolation switch
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is placed in the " local" ;osition and that the equipment cannot be operated from the centrol rc:m; and that equip-ment operates from the cor.t: o'. room but cannot be operated at the local control statier. een the transfer er isolation switch is in the " rem:te" pcsition.
(j)
Technical Specificatiens f the surveillance recuirements and limiting conditions f:r o:eration fer that equipment not already covered by existir; Te:h. Specs.
Fer example, if new isolation and cont-o'. switenes are added to a service water system, the existin; Tecn. Spec. surveillance require-ments en the service wate system should add a statement similar to the following:
"Every third pum; test sh:u'.d also verify tha: the pump starts frem the alternate sru:down station after moving all service water syste 'sciatier. switches to the local control position."
(k)
Verifica:icn tha: the sys:e.s availa: e are ace:vate to perform the necessary snu.down 'u eti:9s. One fur.ctions recuired shculd be :asec :r. Orevi:.s a alyses, i' ::ssible (e.g.,
in :ne FSAq), su:P as a 1:s s :f n:-.a' a.:. power or shutdown on a Gr up I isciatien '5J. Tne e:.ictent recuired for ne alte-.a:e :acabW y s":.*: :t :9e sa e c-ec;; valent to
- na relie: on dn :ne a::.e a t'ysis.
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(1)
Verification that repair procedures for cold shutdown systems are developed and material for repairs is maintained on site.
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