ML20084D993
| ML20084D993 | |
| Person / Time | |
|---|---|
| Site: | Dresden, 05000000 |
| Issue date: | 03/13/1973 |
| From: | Worden W COMMONWEALTH EDISON CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084D897 | List: |
| References | |
| 178-73, NUDOCS 8304130142 | |
| Download: ML20084D993 (4) | |
Text
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50-237 Commonwealth 3dison Company v
72 W Es? ADAMS STREET
- C H I C A G O.
ILLINOls m.,.,r, POST OFFICE SON 76F
- C ae l C A 0 0 ILLINOIS 60690 Dresden Nuclear Power Station R. R. #1 gsQt!etpf Morris, Illinois 60450 g
Wd Ltr. #178-73 h.. 4.g.
March 13, 1973 k
._ v a,. 7 Deputy Director for Reactor Projects
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Q((. l.2hf Mr. A. Giambusso N) l -
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U. S. Atocic Energy Comission 4*);2][f%,,
- Directorate of Licensing
'dashington, D.C.
20545 W
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SUBJECT:
_QCD:SE PPR-M. DRFSD N NUCLEAR PUGR STATION t* NIT #2, SECTION 6.6.C.1 of THE TECHNICAL SPECIFICATIONS.
Dear Mr. Gia:
busso:
This is to report a condition relating to the operation of the unit
.n which, on February 19, 1973, throo contrbl red drives (CRD) gave indication of an apparent uncoupled condition when they were withdrawn during a startup Tf travel check performed.During the startup, CRD B-6 was withdrawn to position 48 and an ever The CRD overtravel alarm annunciated and a less of 7
of an apparent uncoupling condition. position indicatien and red back lightine wa ae the first attempt and tested for couplina.The drive was successfully recoupled on 1
The results were satisfactory; no uncoupline resulted.
samo condition existed with CRD K-8Further along in the control rod withdrawal scouence, the The rod was recoupled and tested satis-factorily.
At this tico, CRD's B-6 an ' K-8 were scra==ed and a recoupling check perforced.
No abnormalitics were found.
As the startup continued, the overtravel alarm was received on the third CRD, L-ll.
This drivo also recoupled and tested satisfactorily.
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It should be noted that all CRD's withdrawn to position 48 were instrumentation response. checked for coupline, and CRD's at partial positions were c drawn to position 48.
This is normal proceduro whenever a CRD is with-actually uncoupled, although all indications were there.No conclusion w that, following the recoupling opemtion, drives were courled and no safety It was cencluded
$ mue existed.
The startup was continued without any further incidents.
8304130142 740306 PDR ADOCK 05000237 S
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A raview of the problem with General Electric resulted in essentially the as=o conclusions that were reached by the station.
It was suggested that the three CRD's be tested a nu=ber of times to confirm that the drives were coupled.
On February 20,1973, CRD's B-6, K-8, and L-11 were inse. ted from position 48 to positien 44 and then given a centinuous withdraw signal I
to position 48 to verify coupling.
This was performed twenty-five times f;:#
en each drive withcut indication of uncoupling.
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.i-check ence per day en each of the three drives fer a pericd of one week and enco per week thereafter until the next outage.
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e During the outage, beginning en March 25,1973, CRD.'s B-6, K-8, and L-11 will be removed and
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inspected in an effort to determine the cause of the ano=aly.
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all CRD's will be timed and checked for, overtravel indications.Additienally,
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... :" i It is phnned to sub$1t a report by approximately April describing the firdings mado during disassembly and inspection of these30, 1973, kbi drives.
Investigation on Unit #3 will proceed as indicated by the results tA, of tho inspection.
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Sincerely, b
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O,. N W. P. Worden Superintendent
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W74:TPS:jv
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50-237 Commonwealth Edison Company 72 Wts? ADAMS STREET
- C H I C A G O.
ILLINOIS au,., r, POST 07PICE BOX 7 4 7
- C M I C A O O. IL&lNOIS 40690 Dresden Nuclear Power Statien R. R. #1
- MtIf6 Morris, Illinois 60450 g.
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b,,b. D, WPri Ltr. t/178-73 Y
March 13, 1973 g
Pr. A. Giambusso q. <.,g
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v-Deputy Director for Reactor Projects
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Directorate of Licensin;;
U. S. Atotic Energy Cc mircion Q/
Washington, D.C.
20545 h,, #
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SUBJECT:
LTCErSE ppR-M. DRFSDF?! ?!UCLEAR POTR STATIC?! U'!TT 42,
[$0N A.6.C.1 of THE TFCR?!ICAL SPECIFICATIG?!S.
Dear Mr. Giambusso:
This is to rotort a condition relating to the operatien of the unit in which, on February 19, 1973, thrcu control red drives (CRD) gavo indicatien of an apparent uncoupled conditien when they were withdrawn during a startup.
During the startup, CRD B-6 was withdrawn to position LG and an ever-travel check performed.
The CRD overtravel alara annunciated and a loss of psitien indicaticn and rcd back lichtinr was observed, givinc an indicaticn of an apparent unceupling cenditien.
the first atteert and tested for coupline.The drive was successfully reecupled en The results were satisfactory; no uncouplinz resultcd.
Further alcng in the control red withdrawal sequence, the same condition existed with CRD K-8.
The rod was recou factorily. At this ti=c, CRD's B-6 cnd K-8 vere scran: pled and tested satis-check performed. No abnormalitics wero found.
cd and a recoupling As the startup centinued, the overtravel alarm was received on the third CRD, L-ll.
This drivo also recoupled and tested satisfactorily.
It thouhi be noted that all CRD's withdrawn to positica 48 were checked for ecupline, and CRD's at partial positions were checked for nuclear instrumentatien response.
drawn to position 48.
This is normal procc.tarc whencyc: a CRD is with-No conclusien was reached as to whether or not the drives h.d netually uncoupled, althouch all indications were there.
It was concluded that, following the recouplin.7 ope atien, drives were courled and no safety issue existed.
The startup was centinued without any further incidents.
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O A review of the probles with Conoral Electric resulted in essentially the same cenclusiens that were reached by the statien.
It i
was suggested that the three CRD's be tested a number of times to confir=
that the drives were coupled.
On February 20,1973, CRD's B-6, K-8, and I,-ll were inserted I
from position 48 to positien 44 and then given a centinuous withdraw signal to positien 48 to verify coupling. This was perfor=ed twenty-five times en each drive withcut indication of uncoupline.
A surveillance procram was initiated to perform the uncoupling j
check cnce por day en each of the threo drives for a period of cne week and ence per week thereafter until the next outage. During the cutare, beginning en March 25,1973, CRD's B-6, K-8, and L-ll vill be recoved and inspected in an effort to determino the cause of the ancmaly. Additienally, all CRD's will be timed and checked for overtravel indicatiens.
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It is planned to submit a report by approximately April 30, 1973, describinn the findings made during disassembly and inspecticn of these drives.
Investiration on Unit #3 will proceed as indicated by the results of the inspection.
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Sincerely, O,. Mw W. P. Worden Superintendent h74:TPS :jv cc: h74 Ltr. Filo