ML20084D756
| ML20084D756 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/18/1970 |
| From: | Hoyt H COMMONWEALTH EDISON CO. |
| To: | Morris P US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084D760 | List: |
| References | |
| 04979, 4979, NUDOCS 8304120319 | |
| Download: ML20084D756 (2) | |
Text
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L Com monwealth Edison ComI>anv ONE F1RST NATOONAL PLAZA
- CHICAGO. ILLINOIS POST OPPICE 80X 747
- C H I C A G O, ILLINO45 40490 Dresden Nuclear Power Sta tica R. it. :j l Morris, Illino is 60450 Decembe: 18, 1970 Dr. Det :c Por r ia, :)irectot h iv i ; ion o f
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Dear Dr. ':
orris:
Th ic le t t e r i:: to reper* a con litior. relating to t he opera t ie:: of the station ia anich centrol red i:-ive L.13 (J -6) ' *a s leclared ino;1erable as reynired by section 3.3./..
ci t L e T 2chnical S;'ecif ica tions.
P robler ami Initial ;ctica 0:. :e ;. -. r ', 2 r 10,. + 7:
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/: 15 a... control rc.! dris. J '.faib? L a r:ov '
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criv2'c pro len oa ::o,, b-20 reveale ' that tho
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-ere ta::pilated and the not al d-ice
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c' : r:: - o n wr z, an,i-it a.ptcJ durine reactor o:c m '.i-u a.
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up w c nc.
o operate prcperl:
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co::.c- - ' ioa.-
.ettiim ir t o tc t. notches in the
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- a.
of tts :troke was somewhat slower than normal.
This is indicative of increased friction in tr.e drive r.echanism. The drive was stroked several additional times arm was sermi tes ted twice.
The scrna tir.es for 907. inse *, ion were 3.00 and.'.96 sco.'
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'rvice at
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' ' De el,er D, 1970 is 1-
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- . e - tr wp of dri,
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- i nr w nitcred periodical 5.
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..od i ie
'o re.ao' c t E t; arive fro: the r'i 't cr ior inipet. ion at 'ho ext er y,
li io
_ :h.n 10, l'DO, b:!ve J-6 was removed fro. the renctor. It was disas-v :.< in ;pe ;t eJ c: ecc.
r 16, l') 70.
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oms 8304120319 701218 COPY SENT REGION M
PDR ADOCK 05000237
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,e-Dr. I ite r A. ?!orria, Director ! m c o n.b-r 11:, 1970
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The cause of the erratic operation and apparent increased T-fotion ua; found
/tobeateflonsplit ring spacer was used in drive reassembly procedure which
/ inadvertently left in the drive during the previous drive ou rhaul.
This type
/ of spacer is 'ao longer used in Unit 2 control rod drives.
The reassembly of overhauled drives will be r.iore closely monitored La the tuture to prevent this type of occurrance.
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