ML17252A535
| ML17252A535 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/18/1974 |
| From: | Stephenson B Commonwealth Edison Co |
| To: | O'Leary J US Atomic Energy Commission (AEC) |
| References | |
| BBS Ltr. #440-74 | |
| Download: ML17252A535 (3) | |
Text
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Commonwealth Ed.._
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- One First National Plaza:~;go, Illinois Address Reply to: Post Office Box 767 Chicago, Illinois 60690 BBS Ltr.11440-74 Dresden Nuclear Power Station
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Morris, Illinois_
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June 18, _1974
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Mr. J. F. O'Leary, Direc Directorate of Licensing 5 0.. 2 4 9 JUN241974,~-
U. s. Atomic Energy Conmission Washington, D. C.
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SUBJECT:
LICENSE DPR-25, DRESDEN NUCLEAR POWER STATION, UNIT 13, REPOR - -
OF ABNORMAL OCCURRENCE PER SECTION 6.6.B.l.a OF THE TECHNICAL SPECIFICATIONS.
STEAM LINE SUPPLY TO "B" RECOMBINER BOOSTER JET LEAK.
References:
l) Notification of Region III of ABC Regulatory Operations Telephone: Mr. F. Maura, 1115 hours0.0129 days <br />0.31 hours <br />0.00184 weeks <br />4.242575e-4 months <br /> on June 11, 1974 Telegram: Mr. J. G. Keppler, 1317 hours0.0152 days <br />0.366 hours <br />0.00218 weeks <br />5.011185e-4 months <br /> on June 11, 1974
- 2) P&ID M-345, M-371 Sheet #2
Dear Mr. O'Leary:
This letter is_ to report a condition relating to the operation of the unit at about 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> on June 11, 1974. At this time, a small leak was detected in line #3-3037B which supplies steam to the "B" recom-biner booster jet.
. ~ rnrnGY This malfunction is contrary to section l.A. 5 of the Technical' Specifications, which defines an abnormal occurrence as an abnormal degradation of one of the several *boundaries which are designed to contain the radioactive materials resul~ing-from the fission process.
PROBLEM The problem was discovered when checking the "I" steam jet air ejector during unit startup. The line designated as 3-3037A-l\\"B, was noted to be leaking cin the "B" ejector room where this new line had been tied into the "B"*ejector steam feed line.
The booster jet which is supplied by this line, along with the off gas preheater, ar~ not in service at this time.
They are part of the new "Off-Gas" system.u 5718
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'.:.--:::') Ml-. J. F. O'Leary
- e June 18, 1974
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------------*The* -1eak-wa-s-f*ouna,:- in-$weld at-:Su-ilbowapproxim1itely~f2-:-£eet -- --
from the tie in. The ~ea];c -~s' subsequently determined _:to have been caused by slag inclusion in the weld...
When the" leak was discovered, it* was isolated by' closing two" root valves upstream of the leak. This immediate*action was p~ssible since the off gas system is not 1et in service. The leak was stopped by closing these valves (not shown on P&ID).
The* condition was.corrected when it was found on June 11, 1974 at 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />.
The line which was leaking will supply steam to the "A" system
-booster jet and off gas preheater when the off gas system, is pl~ce4 in service *.
- INVESTIGATION.*
when the weld was partially ground out to locate the actual source of. the leak, a small pinhole was found.
Approximately 1/3 of the weld was removed -to allow rewelding.
When first pass was made slag flowed from. area of pinhole indicating the source of the leak was slag inclusion.
The weld was hydrostatically tested earlier µi 1974 as ~art of the system installation testing and did not leak at this time.
The cause of the failure is thus determined to be a -defective
-weld.
CORRECTIVE ACTIONS The-weld was partially ground out and wasrewelded.
Pressurizing the line with its_ normal steam source verified sat~sfactory repair.
No referrals for supplementary investigations are necessary.
EVALUATIONS There were no airborne or contamination problems resutting from the failure.
The effect of the occurrence on safety of operation during.
the _p_!riod _o~ ~n~_orrec~!l_d condition was negligible. *.The area radiation monitors in the totally enclosed afr ejector room wou~d have detected the problem had it not been detected visually.
This occurrence did not jeopardize the safety of the plant or t}le public.
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- ) Mr. J. F. *O'Leary
-* e June 18, 1974
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The.nature of the failure is such that normal maintenance and operating inspections are adequate to prevent or minimize failures of this type on similar equipment.
This occurrence poses no reason for limiting the future* operation of Dresden Units 2 or 3~
Cumulative experience regarding ~iscellaneous contaminated steam line leaks of this nature is minimal.
This type of small leak ~s not
~eportable until recently.
Thus there is no conclusive recorded history available at this time *.
BBS:JD:do tephenson
- Superintendent
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