ML19308B813
| ML19308B813 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/18/1979 |
| From: | Fairburn G BABCOCK & WILCOX CO. |
| To: | Geoffrey Miller METROPOLITAN EDISON CO. |
| References | |
| TASK-TF, TASK-TMR TMI-79-56, NUDOCS 8001170343 | |
| Download: ML19308B813 (2) | |
Text
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Babcock &Wilcox
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s P.O.,5:x 1250, Lyretu,g. Va. 245cs Te'ep.cre: (Sca) 384 5111
. April 18,1979 THI-79-56
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Mr. G. P. Miller -
Station Superintendent
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Metropolitan Edison Ocmpany A)O V l 19~~/1 P.O. Ecx 480 Middletown, PA 17057
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Subject:
Three Mile Island Nuclear Generating Station - Unit I
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HPI - Operating Instructions
Reference:
Letter, GT Fairburn to GP, Miller, TMI-79-47; dated 4/,4/79
Dear Mr. Miller:
The operating instructions, given in the above reference, for operator action to override the engineering safety. features.actuatien system and terminate HPI have been revised.
This revision (attached) allows the operator'an alternative to the 20 minute operability period, (E
under certain~ conditiens, to preclude the pressurizer frca scing solide,
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This information supplements that previcusly transmitted.
If you have any questions regarding this advisory, please advise.
Very truly yours,
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G. T. Fairburn Service Manager' GTF/hh
, Attachment cc: w/ attachment RM Klingaman JF Hilbish LL Lawyer JL Seclinger CR Montgomery LC Rogers SL Smith bcc: GM Olds JD Phinney
.T Record Ctr. NSS-5/T1.2
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Tr.e Baxock & Wacos cems.any I Estatteed 1857 l
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SUPPLEMENTAL OPERATING INSTRUCTIONS FOR HPI SYSTEli CPERATION 3
REV. 01 - 4/17/79 Although details of the causes and course of events of the incident at Patropolitan Edisen's,7MI-2 plant on March 28, 1979Lare still being developed, it appears that the incident was initiated by a less-of-main feedwater flew (LOFW) and that a distinguishing characteristic of this transient compared to other previous LOFW transients was the securing of the high pressure injection (HPI) system.
Consequently, all operating plants are advised to implement the folicwing immediately:
.lf the HPI system has actuated because of low pressure condition, it must remain in operaticn until one of the folicwing criteria is satis-fied:
1.
Both' LPI pumps are.in. operation and flcwing at a rate in excess
'of 1000 spm each and the situation has been stable for 20 minutes.
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2.
The HpI system has been in operation for 30 minutes and all het and cold leg temperatures are at.least 50 belowghesaturation g:es-temperature for the existing RCS cressure.
If 50 subccoling N, _
cannot be maintained, the HPI shall be reactivated.
ORI 3.
All hot and cold leg temperatures are at least 50 below the saturation temperature for the existing RCS pressure, at least one RC pump in each 1 cop is running, aTd the action is necessary topreventtgeindicatedpressurizerleclfromgoing.off-scale high.
If 50 s t coling cannot be maintained, the HP! shall be reactivated.
If the HPI system has L activated and if RC pumps are in operation, at least one RC pump per loop should be maintained.
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