ML19268B970

Abnormal Occurrence 74-14:on 740818,during Routine Insp, Three Hydraulic Shock Suppressors Found Empty of Hydraulic Fluid.Caused by Oil Reservoir Separating from Main Cylinder & Loose Lock Nut.Suppressors to Be Replaced & Reoriented

ML19268B970
Person / Time
Site:	Three Mile Island
Issue date:	08/19/1974
From:	Herbein J METROPOLITAN EDISON CO.
To:
References
NUDOCS 7910250756
Download: ML19268B970 (3)

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Ot.T OFFICE DOX 400 MIDDLETOWN,PENNGYLVANIA 17C37 T E LE P H ONE 717.GW4 c41 August 19,1974 Hr. J.P. C'nailly, Dir:ctor -

o ::: Of Regulatory D D [ [

631 Park f. venue King Of Pr;ssia, Pa. 19t05 Operatin') License OpR-50 Docket 50-EC9

Subject:

Abr.or: al Occurrence !!o. A0 74-14

Dear Mr. O'Reilly:

This tolcaram is to confim the telo:cn bet,1cen Lee Spes:crd (P.adn I-T4EC),

and J.G. U:rbein (iiil-Superintendent) at 150] ll:urs, August 10,1974.

The folic sina re :srt is subitted in e.ccordance with par:;r:ph 6.7.2.a.4 (p:;a 6-11) of the t: hnical Opsciiicctions.

During c routir.2 surnillcnce insp:ction, on 13 Arlust, three hydrauli: tho:k supprc :crs on scistic clots enc syst:.ms t~;ro found c:pty of hydrtulic fluid.

The att:ched t:ble delinettes the suppressor nir.cor, location, ralfunctlen.

and pl:nned corrective action.

All fciled suppr: sors eare pf cylinders with a 5," piston strc'c s hich vore manuftetured by Grinnel,

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Pressurizer ciec- 011 f!ccevoir n.pn . .cd Relece PR 49 froa nun cylind:r due Suppr:t.ror

- tre. .~ic relief vsly,: di cci...rr e to thtmal en:ncion line. Elev. 325' and cent.ct uith int .r-P.,D1dg. forence piping.

f:ain cylinder leck nut Reorient stopressor, PR 50 Pressurit:r cic:- '

treatic relief uns not tR,ht. Thitr , l T.d t.a.1c: : :ws.

paraitt:d cylinder Rep)::e riuid.

valve di:ch:rca line. Elev. ;'i5' rotation and sub:cquent R. Bldg. drcin of hydraulic fluid thru oil rosevoir vent.

Empty oil resevoir. No Repl:ce suppresser MS 207 Main stem lino Insp ct drj :uppr:ss: ..

"A" frca "A" evid:nce of leskcgo ste m gcrurater. to d.temina ccusa c Elev. 35S' R. Oldg oil loss.

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-1. Report 110. _ 74-10

. 2a. Date August 19, 1974 2b. Occurrence Date August 17, 1974

3. Facility Nine Mlle Point Unit

4. Identification of Occurrence Set point drift. in Barton differential pressure instrument 1505C (Emergency Cooling liigh Flow)

S. Conditions Prior to Occurrenco Unit at steady state 98t full load .

6. Descrintion of One"rrence During routine surveillanco testing Dcrton instrument 1 E05C pro-vided the desired trip action at a lower than required value.

7. Desir.nntion of Annarent Cause of the Occurrence Set point drif t.

8. - Analysis of Occurrence Each of two. differential aressure switches provides inputs to one instrument channel in caca trip system. Therefore, with one instrument trip occurring at a lower than required value, the isolation of the emerncncy condensers would still have occurred at the desired set point. Bar.cd upon the fact that the redundant components actuated at the required set point as well as the fact that the set point drift ucs in the conservativo direction it is concluded that at no time would a hazard be presented to the general public as a rcst +, of this set point drift.

9. Correctivo Action The instrument was recalibrated to required set point.

10. Failure Data

a. Trpc: Barton

b. No. : 2SD-703 c.- fauures: first this instrument.