ML19254D397
| ML19254D397 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 10/11/1979 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 7910250439 | |
| Download: ML19254D397 (9) | |
Text
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k UNiic0 STATES f' i NUCLEAR REGULATORY COMMISSION y %. 4 J/, j 4 %Tg WASHINGTON, D. C. 20555
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October 11, 1979 Docket No. 50-10 Mr. Cordell Reed Assistant Vice President Commonwealth Edison Company Post' Office Box 767 Chicago, Illinois 60690
Dear Mr. Reed:
We have reviewed your letter dated August 31, 1979, addressing three incomplete items (3.2.5, 3.2.6, and 3.2.7) of the Fire Protection Safety Evaluation Report dated August 9,1979 for the Dresden Station Unit No. 1.
Your letter states that since the safe shutdown capability is being evaluated in the Systematic Evaluation Program (SEP), your evaluation concerning modifications to the emergency condenser will
-be deferred until the completion of the SEP. The SEP, which is seneduled to be complete in 1982, will evaluate the adequacy of the safe shutdown capability. After the results of that evaluation, including any required modifications, are known,.the fire protection afforded that safe shutdown capability will be evaluated.
We find that the deferral of these safe shutdown capability issues are consistent with the Commission's policy and will allow integration of fire protection requirements with any other requirements which result from the review of other topics in the SEP. When you submit your safe shutdown analysis and any proposed modifi ations resulting therefrom, you should use the enclosed document for guidance in meeting our fire protection criteria.
Sincerely,
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'A W Denn? L. Ziemann, hief Operating Reactors ~13 ranch #2 bivision of Operating Reactors
Enclosure:
Staff Positions - Safe Shutdown Capability cc w/ enclosure:
See next page 1208 321 7910250 bf F
Mr. Cordell Reed October 11,10'/9 cc w/ enclosure:
Isham, Lincoln & Beale Counselors at Law One First National Plaza, 42nd Floor Chicago, li'inois 60603 Mr. B. B. Stephenson Plant Superintendent Dresden Nuclear Power Station Rural Route =l Morris, Illinois 60450 U. S. Nuclear Regulatory Commission ATTN:
Jimmy L. Barker P. O. Box 706 Morris, Illinois 60450 Susan N. Sekuler Assistant Attorney General Environmental Control Division 188 W. Randolph Street Suite 2315 Chicago, Illinois 60601 Merris Public Library 604 Liberty Street "erris, Illinois.60451 i208 322
STAFFPOSITION ENCLOSURE SAFE SHUTDOWN CAPABILITY Staff Concern During the staff's evaluotien 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 shutdown capability has resulted from cne or both of the folicwing situatiens:
- Case A: The licensee has not adequately identified the systems and components required for safe shutdown and their location in specific fire areas.
Case B: The licensee has not demonstrated that the fire protection for s:ecific plant areas will prevent damage to both redundant divisiens of safe shutdown ccm;:enents identified in these areas.
For Case A, the staff has required that an adequate safe shutdown analysis be performed. This evaluation includes the identification of the systems required for safe shutdown and the locatien of the system com;:enents 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 js required to demonstrate that a pestulated fire will not damage both divisions or provide alternate shutdcwn capability as in Case B.
For Case B, the staff may have required that an alternate shutdcwn capability be provided with is independent of the area of concern cr the licensee ray have proposed such a capability in lieu of certain additional fire protection modifications in the area. The specific modifications associated with the area of concern along with c ner systems and equipment already independent of the area form the alternate shutdown capability.
For each plant, the modifications needed and the cc=binations of systems which provide the shutdown functicns ray be unique for each critical area; however, the sh0tdown functions provided should maintain plant parameters within the bounds of the limiting safety consequences deemed acceptable for the design basis event.
Staff Position Safe shutdown capability shculd be demenstrated (Case A) or alternate shutd wn capability provided (Case 3) in acc rdance with the guidelines provided belcw:
- 1. Cesi::n Basis Event The design basis event for censidering the need for alternate shutd:wn is a postulated fire in a stecific fire area containing redundant safe shutdown cables /ecui;: ment in clcse pr:ximi y where it has been determined that fire protection reans cannot assure that safe shu:::wn ca;,2bility will be preserved.
Two cases should be c:nsi:ered:
(1) offsite pcwer is available; and (2) cffsite
- wer is not available.
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. 2. Limitine. Safety Consecuences and 40uired Shutdewn Functions 2.1 No fissien product boundary integrity shall be affected:
a.
No fuel clad damage; b.
No rupture of any primary coolant boundary; c.
No rupture of the containrent boundary.
2.2 The reactor coolant system process variables shall be within these predicted for a loss of nor=al ac pcwer.
2.3 The alternate shutdcwn capability shall be able to achieve and maintain subcritical conditions in the reactor, maintain reactor coolant inventory, achieve and maintain hot standby
- conditions (hot shutdcwn' for a BWE) for an extended period of time, achieve cold shutdewn' conditions 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 conditions thereafter.
- As defined in the Standard Technical Specific >tiens.
- 3., performance Goals 3.1 The reactivity centrol function shall be capable of achieving and maintaining cold shutdown reactivity conditions.
3.2 The reactor ecolant makeup function shall be capable of maintaining the reactor coplant level above the top of the core for SWR's and in the pressurizer for PWR's.
3.3 The reactor heat removal functicn shall be capable of achieving and maintaining decay heat removal.
3.4 The crocess monitoring function shall be capable of providing direct readings of the process variables necessarj to perforct and control the above functions.
3.5 The supporting function shall be capable of providing th'e process cooling, lubrication, etc. necessary to per:1it the operatien of the equiprent used for safe shutdown by the systems identified in 3.1 - 3.4.
3.6 The equipment and systems used to achieve and maintain hot standby conditiens (hot shutdcwn for a SWR) should be (1) free of fire damage; (2) ca able of maintaining such conditiens for an extended time period lenger than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> if the equip ent recuired to achieve and maintain cold shutdewn is not available due to fire damage; and (3) capable cf :eine powered by an ensite emergency power system.
3.7 The ecuicmen and systems used to achieve and maintain cold shutdcwn conditicns should be either free of fire damage or the fire damage to such syste s shculd :e limited such that recairs can be made and cold shutdown cunditiens achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
E;u', ment and systems used orior to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> af ter tne fire should ce capable of being powered by an onsite eme ge.cy ;cwer system; trose used af ter 72 hcurs may be powered by
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. cffsite pcwer.
3.3 These systems need not be designed to (1). seismic category I criteria; (2) single failure criteria; or (3) cope with other plant accidents such as pipe breaks er stuck valves
( A;;endix A BTP 9.5-1), except these portions of these systems which interface with or impact existing safe,ty systems.
- 4. PWR Ecuiement Generally Necessary For Hot Standby
-(1) Reactivity Control Reacter trip capability (scram). Scratien capabili ty e.g.,
charging pump, makeup pump or high pressure infecticn pump taking suction from concentrated borated water supplies.
and letdown system if required.
(2)
Reactor Coolant Makeue Reactor coolant makeup capabilit,, e.g., charging pumps or the high pressure injection pumps.
Fewer cperated relief valves may be required to reduce pressure to allcw use of the high pressure injection pumps.
(3) Reacter Ccolant System pressure Centrol_
Reactor pressure c:ntrol 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) or safety relief valves for heat removal with a water supply and energency or auxiliary feedwater pumps for makeup to the steam generator.
Service water or othe' pumps may be required to provide water for auxiliarf feed pump sv.tfa if the condensate storage tank capacity is not adequate 'er 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
(5) precess Monitorine Instrumentation pr: cess.:nitoring capability e.g., pressurt:er ;resa.e and level, steam generator level.
(5)
Screert.
The ecuipment recuired to su:;crt Operation Of the above
- escrited shutd:an ecui: ment e.g., c:m; nent cooling water se vi:i w:er, etc. and ensite pc-er scurces ( AC, CC) wi:n eir : ;cciated electrical cistribution system.
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- 5. FWR E:ui: ment Generally racessarv For Cold Shutdewn*
(1) Reactor Coolant System Pressure Reduction to Residual Heat Removai System ( RMR) Cacacility_
Reactor coolant system pressure reduction by coold:wn using steam generator power operated n! lief valves er ate: spheric dump valves.
(2)- Decay Heat Removal Decay heat rer. val capabikity e.g., residual heat receval system, compenent cooling water system at d service water system to removal heat and maintain cold shutd wn.
(3) Succort Support capability e.g., ensite 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 distributien system to supply the above equip ent.
Equipment necessary in addition to that already provided to maintain hot standby.
- 5. SWR Ecuicment 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 isolatien cooling system (RCIC) or the high pressure coolant injection system (HPCI).
(3) Reactor Pressure Centrol and Decav Heat Removal De'pressuri:ation system valves or safety relief valves for dump to the suppression pool.
The residual heat renoval system in steam condensing m:de, and service water system may also be used for heat removal to the ultimate heat sink.
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Sur:ression p:01 C:Oline Residual heat mm va' system (in su::ression ;oci c:oling mece) service water system :: maintain het snutd:wn.
(5)
Process M:nitorine Pr: cess m: nit: ring ca:a:ility e.;., react:r vessel level and pressure and su::ressi:n :::1 tem:erature.
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. (6) Sue: ort Support capability e.g., ensite pcwer scur:e (AC & DC) and their associated distributien systems to provide for the shutd:wn equipment.
- 7. 5WR Ecui: ment Generally Necessary For Cold Shutdown' At this point the equipt. ant necessary fer hot shutdewn has reduced the primary system pressure and temperature to where the RhR system may be placed in service in FMR cooling mode.
(1) Cecav Feat Removal Residual heat removal system in the F3R c: cling mcde, service water system.
(2) Sue:crt Onsite scurces (AC & CC) or offsite af ter 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 additica to that for achieving het shutd:wn.
- 5. Infer ation Recuired Fer Staff Review (a) Descriptien of the systems' or portions thereof used to provide the shutdcwn capability and modifications retuired
, to achieve the alternate shutdcwn capability if required.
(b) System design by drauings which show normal and alternate shutdown centrol and power circuits, location of ccmpenents, and
. that wiring which is in the area and the wiring which is cut of the area that recuired the alternate system.
(c)
Demonstrate that changes to safety systems will not degrade safety systems.
(e.g., new isolation switches and centrol switches should meet design criteria and standards in F5AR for electrical ecuipment in the system that the switch is to be installed; cabinets that the switches are to be mounted in snculd also meet the same criteria (FSAR) as other safety mlated cabinets and
- anels; :: aveic inadvertent isolatien fr:= the cent-ol r::=, the isolation switches should be keylocked, er alarmd in :ne c:ntrei roem if in the "le:al" cr "isclated" ::siticn;
- ericcic cnecks snculo be made to verify swi.ch is in the
- recer pcsition for no - al coeration; and a single transfer switen or 0:ner new device should not be a s ur:e f:r a single failure :s cause 1:ss of redundant safe:/ syste:.s).
':) Demonstrate that wiring, inciuding wer scurces for the c:n:r:1 circui: and e:ui; men: :: era:icn f:r -he ai:ernate shu;d:nn methed, is ince:encent Of etui men. wiring in
- he area :: be aVcided.
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.S-(e)
Demenstrate that alternate shutd:wn ;cwer scurces, including all breakers, have isolatten devices en centr:1 circuits thit.are routed through the area to be avcided, even if the breaker is to be cperated manually.
(f)
Demonstrate that licensee procedure (s) have been developed which describe the tasks to be perfemed to effect the shutdown rethod. A su:n.ary of these procedures shculd be reviewed by the staff.
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(g)
Demonstrate that spare fuses are available fer centrol circuits where these fuses,may be required in supplying pcwer to centrol circuits used for the shutdewn rethod and may be bicwn by the effects of a cable spreading reem fire. The spare fuses should be located convenient to the existing fuses. The shutd:wn precec;re shculd inferm the operator to check these fuses.
(h)
Demonstrate that the manpcwer required to perform the shutdewn functions using the pro:edures of (f) as well as to provide fire brigade members to fight the fire is available as required by the fire brigade technical s p eci fi cations.
(i) Demonstrate that adequate acceptance tests are perfor ed.
These should verify that: equipment operates from the local control station when the transfer or isolation switch is placed in the " local" nesition and that the equipment cannet be operated from the centrol recm; and that etuip-rent operates frem the centrol reem but cannet be operated at the local centrol station when the transfer or isolation switch is in the " remote" position.
(j) Technical Specifications of the surveillance requirements and limiting conditions for cperation for that equipment not a'iready c:vered by existing Tech. Specs. Fcr examle, if new isolati:n and centrol switches are added to a service water system, the existing Tech. Spec. surveillance require-ments en the service water system should add a statement similar to the following:
"Every third pump test should also verify that the pump starts frem the alternate shutdcwn station after moving all service water system isolatien switches to the local
- ntr:1 positi:n."
N :emenstrate that the systems available are ade:uate to ;erform
- ne necessary sNtb:wn functi:ns.
The functions recuired sh:uld be based on revicus analyses, if possible (e.g.,
S ne FSAR), sucn as a 1:ss of nor al a.c. :cwer er shutdown
- a Gr:u: I isolation (5WR). The e ui; ment re:uired for the thernate ca: ability should be tne same Or e:vivalent to
- nat relied :n in :ne abcve analysis.
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. (1)
Demonstrate that repair precedures for cold shuthwn systems art developed and material for repairs is :.aintained en site.
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