ML20084J513
| ML20084J513 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities, 05000000 |
| Issue date: | 08/09/1974 |
| From: | Brian Lee COMMONWEALTH EDISON CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8305130342 | |
| Download: ML20084J513 (1) | |
Text
{{#Wiki_filter:_ _____-_______-____ - __ - .e ,,h Common th Edison [i{ ) One First Nati, pQ ..c i4 / p,1-(b Plaza. Chicago, Ithnois.
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- To August 9, 1974
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a. Mr. Angelo Giambusso W m Deputy Director for Reactor Projects Directorate of Licensing Office of Regulation j U. S. Atomic Energy Commission f Wnhington, D. C. 20545
Subject:
Review of Dresden Units 2 'and 3, and Quad-Cities Units 1 and 2, Control Ciyit Deficiendies., AEC Dkts 50-237, 50-249,e50-254 and 50-265 J , Desr Mr. Giambusso: In a letter to you dated April 25,,1974 concerning this subject, the schedule for com91eting the associated corrective measures was indicated ~ l ca the 197' refueling outages. The corrective measures were completed on Quad-l Cities Ur : 1 during its recently completed refueling out; age, llowever,'because j delivery of the necessary materials was delayed, the corrective measures were not completed during the Dresden Unit 3' refueling outage. All materials have be:n delivered and the corrective measures for Unit 3 will be completed during the pe.v.t outage of at leact five (5) days. The refuelin;; outages for Drc::dcr. Unit 4 and Quad-Cities Unit 2 are to begin December 1st and January 1st, respectively, at which time the necessary~ modifications are to be made. It is not expected.that any further change in these schedules will ba necessary; however, you will be notified if changes do occur. Administrative Controls that were discussed in a letter to Mr. D. J. Skovholt dated March 7, 1973.will be maintained until the final corrective measures are comp 3 eted. Very truly yours, s C ) U ') ti7 1 h tC s.--} Byrdn Lee, Jr. Vice-President ,[ 1 i .,o 5g(200 e p* [ . e 'QV 8398 f
fue q,A @m UNITED STATES s /F ' l \\ v ./, g ATOMIC ENERGY COMMISSI 4 1. i *I W ALH WG TOh O C. MM e',y;n'" j;3 s i, Mcenber 22, 372 Docket.m s. 50-10, Su-237, 5G-?49, E 254 and WN f unille nwea i t ;. ial i si. Lor.pany NiTN: '.c Byror. Lee, Jr. Assistant to the President Post 011 ice hux 767 Ci.i c ago, Illinois 6u690 'Je.it lemen : Wo incidents have ocemrmd at a nuclear power plant that indicate a 42ficiency in the control circuit desie7. that viarrants a myiew of the con;ml circuits of all facilit123 to assure that these types of aeficiencies,dc not oxist or am cormoted if they do exist. Botn incic.2nts inm1ved the inadvertent disaalin; c; a component by racking cut 'the circuit bmaxer for a diffemnt cogonent. In o.e case, this caused the loss of cap.2ility to isolate secondary containmnt when taia capability was mquimd. In the second case, the racking out of a bmaker for one pump disr21ed r.ot only the pup being remved fmm servico but also its mdundant countemart. Both of there occurmnces meulted fmm the use of auxiliary coc. tacts on the :.ovacle portion of tne circuit bmakers in the control circuits of other corponents. Wnen the bmaker is racked out, the control circuit epicying these contacts is opened and my be mndered inoperable. A copy of the licensee's mports on these two occurmnces am enclosed for your informtion. 2.e licensee's cormative macams for coth of these cases included mdesign of the contml circuits so that rac'dng out the bmakers would not render the contml circuits of other equipmnt inoperable. AJ, e '+ M' Wae occurrences, we n_ ;uest tnat you perfor~. a myiew of the control circuits of all safety m13ted equipent at the pler. to assure that disablira of one compcnent does not, thrcuf. incorporation in ciner interlocking er segrnc'ng controls, mndar other co.,~..e...., 'rageraule. All modes of test, operation, and failum must be considemd. It appears that in the casas cited rtove, the racked out positicn of omnxers had r. t been included in the failum mde analysis of those cont:m ciremits. AMo,your nmcedur.,a;.aala L mviewed to enaum the, proviw th,
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O O 'ihe moults of your myiew am mquested within sixty days. "b.is infonration should be provided with cne sigr.ed original and thir:;y-nine additional copics.
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/ / /'/* C* /. / ,.(f)g;.V,/ '/b# ' W Donald J/Skovholt Assistant Dimctor for Operating Reactors Dimctorate of Licensing Enclosurus: Licensee's n; ports on occurmnces cc w/ enclosure: Mr. Charles Whitmore President and Chairman Iowa-Illinois Gas and Electric Company 206 Eas t Second Avenue Davenport, Iowa 52801 John W. Rowe, Esquire Isham, Lincoln & Beale Counselors at Law One First National Plaza Chicago, Illinois 60670 1
/ O O .lersey Central Power & Ligllt Company w a n. son AVENV E A T PUNCH soWL RoAo e MoRAa5 Town N ; 07960 e 5 39 6' April 20, 1972 7e / /Q ja
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I.) Dr. Peter A. Morris, Director Division of Reactor Licensing !r United States Atomic Energy Commission { ~ > Washington, D. C. 20545 s '2 ~ /
Dear Dr. Morris:
s
Subject:
Oyster Creek Station Docket No. 50-219 Loss of Secondary Containment Integrity The purpose of this letter is to report to you a violation of a Limiting Condition for Operation in that Secondary Containment Integrity was not maintained as required by Specification 3.5.B.1. of our Technical Specifications. On April 11, 1972, during performance of a routine weekly surveillance test of isolation of the Reactor Building and initiation of the Standby Gas Treatment System due to simulated high radiation levels on the Reactor Building Operating Floor and in the Reactor Building Ventilation Exhaust ducts, the supply dampers for the Reactor Building Ventilation System failed to close as required. As a result of this failure, Secondary Containment was not in effect. Isolation of the Reactor Building Ventilation System supply damper is initiated by "b" contacts f rom the Re. : tor Building Ventilation Syst em supply fans, SF1-12, SF1-13, and SF1-14 wired in series.
- However, due to an electrical problem wi th supply f an 1-13. which resulted ta the ut+covery that the motor was shorted, its supply breaker was racked-out.
T'as, the logic control circuit for the dampers was ip en ed ", the normal sttuatton with the fans in operation. When the remaining tans were tripped during the surveillance test conducted at 2:00 a.m. on Acril ll, ;972, the logic control circuit was att11 open, tne damper - ontrol relays remained de-energized, and the dampers did not close. L-- g R p- ..':2
s e_j }Q 3W r p ,,QJy ) e t Dr. Peter A. Mc r c ia page 11 April 20, 1972 The logic circuit was restored by disconnec ting the motor leads f rom the breaker and racking-in the breake. At 9:20 a.m. on April ll,1972, an operability check of Reactor Building Isolation was conducted and proved to be satisfactory. A caution tag was placed at the fan control switches in the Control Room to notify operators that if a supply fan breaker le racked-ou; the Reactor Building supply dampec isolation control logic is def eated unless a jumper is installed in the breaker cabinet. A similar caution note is being stenciled locally on the supply fan breakers. As noted in the FDSAR, the primary objectiv a of the Secondary Containment System is to minimize ground level release of airborne radioactive' materials and to provide f or controlled elevated release of the building atmosphere under accident c o nd i t ions. The containment systems, Primary and Secondary, provide the principle mechanism f or mitigation of accident consequences. The of f-site accident consequences, however, are relatively insensitive to the Reactor Building in-lcakage rate as long as the Standby Gas Treatment System can maintain the building at a vacuum. In this particular instance, the supply and exhaust fans tripped, the exhaust dampers closed, and the Standby Gas Treatment System was initiated. With the above situation, the pg{ air supply to the building was not only via the various in-leakage 3 ff ;e.. } c paths but also, and no doubt primarily, via the Reactor Building supply dampers. ,.p--,- ...a.. <: W s. Any accident conditione postulated that require secondary ,g y. containment in determining environmental releases would, under these _fj;.; t conditions, have a second path permitting release of the Reactor (gg P ye,. h-Y Building air at approximately a 60-foot elevation. ? r 5' a b Ir. order to prevent a reoccurrence of this incident, a circuit design change will be it:.p l eme n t ed tnat will permit a Reactor Building supply fan breaker to be racked-out for maintenance without defeating the Reactor Building supply damper isolation logic. Until this design change can be implemented, a standing order will be issued instructing plant personnel in the appropriate practice to be followed to avoid defeating the Reactor Building supply damper isolation logie. Very trulv yours, f \\ ) e f 'hh ,{ / Ivan R. FinffockjJr. Manager, Nuclear Generating Stations IRF/pk Enclosures cc: Mr. J. P. O'Refily, Director Division of Compliance, Region 1
C-O j @?) .w.s .lersey Central P wer & Light Company ~ t., i M ADISON AVENUE AT PUNCH UOWL RO AD e MoRRISTOWN. N.J. 07960 e 839 6118 October 6, 1972 N 9 Q yf Mr. A. Cfambusso Deputy Director for Reactor Projects Ill.U.I f j, h Directorate of Licensing b United States Atomic Energy Commission OCT101972> I -f k'ashington, D. C. 20545 ( ns. y g gwm c Re
Dear Mr. Giambusso:
"gulatory
Subject:
Oyster Creek Station Docket No. 50-219 Inoperable Standby Liquid Control System 'the purpose of this letter is to report to you an incident that occurred at Oyster Creek on September 26, 1972 in which it was discovered that the two pumps in the standby liquid control system were inoperable at the same time. At 10:45 a.m. on September 25, 1972, the "A" standby liquid control pump was removed from service for replacement of the pump packing. The pump was taken out of service using Technical Specification 3.2.C.3 as the basis. It states, "If one standby liquid control system pumping circuit becomes in-operabic during the run mode and specification 3.2.A is met, i the reactor may remain in operation for a period not to exceed seven dayn, provided the pump in the other circuit is demon-strated daily to be operable". Specification 3.2.A is met, therefore, the "A" pump breaker was racked out and the pump necured in accordanco with plant safety procedures. The work was not corpleted by the end of the day shif t, and the "A" 1 pump was left in an inoperable condition. At 4:20 a.m. on September 26, 1972, the "B" liquid control system pump was to be run to comply with Technical Specification 3.2.C.3. b' hen the operator depressed the start button, the -pump did not start. An interlock in the starting circuitry prevents two acandby 1Iquid contiol pumps from being run simultaneously. This interlock ulso prevents 'the "B" pump f rom starting when i the'"A" pump breaker.1s in the rccked out position. The interlock is corpoced of a normally closed contact in'the ntarting; circuit of each pump. This contact is operated from a relay in the opposite pump circuit. If the "A" . standby liquid control pump is started either from the 5508 control room with the key lock switch or locally from the DO h. 4, W N N '1 - vy j
,e )- Pago Il {/ October 6, 197? puoh button station, a relay is picked up which opens the normally closed contact in the "B" standby liquid control pump starting circuit which provents this pump f rom operating with the "A" pun:p running. The reverse is true if the "B" pump in started. Ihc problem developed when the breaker for the "A" pump was racked out. It dionbled the pump and at the same time it physienlly removed the contact in the totarting circuitry f or the "B" pump which aimulated un open contact. This prevented the "B" pump from ntarting. As soon as the Shift Foreman was aware of the inoperability i of both pumps, he started a normal shutdown of the plant. In the meantime, he received permission to clear the maintenance safety tagn and rack the "A" pump breaker to its normal position. lie then ran a succeosful operability check on the "B" pump. The load reduction was stopped and the plant returned to full load. In order to prevent a recurrence of this event, operating procedures have been changed so that operability tests of redundant enginected safeguards system components will be made immediately following any action that requires one of the systems to be inoperable for maintenance purposes. ' We are encloafng forty copies of this letter. Very truly yours, ( $(f11 h. .k i R i 9 ( Ivan R. Finfr ek, Vice Presiden IRT/pk Enclosures 3 cc: Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region 1 h _ _. _ _......}}