ML17252A245

Dresden Unit 3, Letter Submitting Reportable Occurrence Number 050-249/1976-25 in Accordance with Technical Specifications, Section 6.6.B

ML17252A245
Person / Time
Site:	Dresden
Issue date:	11/04/1976
From:	Stephenson B B Commonwealth Edison Co
To:	Keepler J G NRC/RGN-III
References
BBS Ltr. #76-776
Download: ML17252A245 (3)

See also: IR 05000249/2019076

Text

,/ ' e o:if*e-gu-,*f""'a_to_ry_;;, -4, 1976 Mr. James G. Keppler, Regional Director . Directorate of Regulatory Operations -Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 I i Enclosed please find Reportable Occurrence report number 50-249/1976-25. This report is being submitted to your office in accordance with the Dresden Nuclear Power Station Technical Specifications, Section 6.6.B. * ... , BBS :jo Enclosure h. B. Stephenson . tation Superintendent * Dresden Power Station cc: Director of Inspection & Enforcement Director.of Management Information & Program Control File/NRC

---*-. --4 . * ** . * * * * LICENSEE EVENT REP OR. ., /.. CONTROL BLOCK: l ! I I I I I . 1 6 [PLEASE PRlf'.IT ALL li'JF0:1MATION) LICENSEE NAME @El l1 ILIDIRISl31 7 8 9 14 LICENSE NUMSER 15 . 25 . LICENSE TYPE l4ltlll!lfl 26 . 30 REPORT * REPORT TYPE. SOURCE DOCKET NUMBER EVENT DATE EVENT TYPE IOl31 31 32 . REPORT DATE . *---* CATEGORY @E]coNI I I I LbJ LhJ ll IOIOl7171GI 1111 IOl.Lfl7 l01 7 8 57 58 59 60 61 68 "i69 . 74 75 BO EVENT DESCRIPTION @lli' I L?uR1NG--REFUEL/NG: QUTAG-£ kQCAb *LEAK-RAT£ T*STIAlG-j FEE.DWAT£R CHEckl 7 8 g* * . . BO [§§ I VALvz::s 3-lJ.0-5<6B AND -(;.lB r=:xH1B1TED L£flkAC£ RirrES or: Lf37 AND I 7 * 8 9 *eo llit::t SCF/4 R£SP*CTJVELY {JECH SP£C LfM/T: scw),,11DD1T10NALLY,.TH£1 7 8 9 80 ffi* ILEAKAG£ RAif.<; cxH1f3tTE:D Gy TH£S£ Two VALVES CAUS£D TH£ TOTfi/..._ LEAKAGE:. I 7 8 9. . ' . 80 (o'lsl RATE Fo ALL TES.TA8Lt= A ND 1sDJ...flT1aN * V/11-To 7 8 9 PRIME (SEE ATTACHE]) SN£ ET BO SYSTEM * CAUSE COMPONENT COMPONENT CODE CODE . COMPONENT CODE SUPPLIER MANUFACTURER VlOlATION @0,lCIHI IVIAIL-IVIEIXI '-L6J* 7. 9 10 11 12 . . . 17 43. 44 . 47 w 48 . ..... I CAUSE DESCRIPTION * . @raj\ ltHE LEAl<AG* Tl-t'R,OUG-H EACH CH£c..1< VALVE"* flPPf/R£NTLY CAUS*D I. -7---8' 9 * * * * * BO . @§\Jay. '1?1R.T.1N THE SE.AT/NG-BREA I WHICH RESULTED. IN .£X:(.£s;s1v*****l>1sc-I* 7 8 9 . . . 80 *, :.* . .:*'.,v,:*4,,jqj -GLEARANC£$*\* PRcSSURFi1NW REJillVG;t3£h\;*. I . " ?.: ... B g FACILITY METHOD OF ;,(_5Ef.*, ATt7fi_L.tJ§iJ SH._f.E:.T)' BO STATUS % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION EEi [HJ. lololol I AIA I NA I 7 8' 9 . 10 12 13 44 45 46 80; FORM OF . ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE [@ . * .. I NA NA . L 7 B . 9 . 10 11 44 45 80 PERSONNEL EXPOSURES .. NUMBER TYPE DESCRIPTION .l!EJ IOI o 10 I A/A 7 8 g: 12 13 BO PERS.dNN.EL . INJURIES . . . NUMBER DESCRIPTION *EE 1010 I 01 ____ 7 8 9 11 12 BO OfFSITE CONSEQUENCES .[ili) * :Alf/ 7 B 9 80. LOSS OR DAMAGE TO FACILITY TYPE DESCRIPTION IZJ NA 7 B 9 . . * 10L..---=-:..:....:.-----------.,----------------,,...----,_--;:8;;::0 PUBLICITY liliJ .. 1 NA* 7 .8 9 8*J ADOiTIOf\JAL FACTORS 7 8 9 Nfc"' 80 filfil 7 8 9 80 ED WAR]) ,l. S*Cl<ING*&_ PHONE: E°XT. J_t,S

. \ * EVENT DESCRIPTION (Continued) the Tech Spec limit. A few days later, these check valves were pressurized with water to 500 PSIG in an attempt to more closely approximate accident ditions. retesting of valves and -62B yielded leakage rates of 15.9 and 29.7 SCFH respectively. Since the leakage through valve 3-220-58B was reduced to a value below Tech Spec limits, no further action was necessary. Valve 220-62B .was disassembled and inspected. Redundant valves were available and operable during unit operation. This is a repetitive occurrence*. (50..

..249/1976-25) CAUSE DESCRIPTION (Continued) these clear.ances and resulted in much lower leakage rates. Disassembly of valve -62B revealed abnormality was dirt in the valve* seat. assembly and seai ring.were replaced as reassem"ly, valve 220-62B was retested, obtained. no defective components; the only The valve was cleaned, and the d.isc a precautionary measure *. Following and a leak rate of. 1.03 SCFH was Because of the high incidence of initial LLRT failures on the* feedwater check vaJ_ves, the station has reevaluated the present method. of testing these.** vaives **A new method has* been developed which more closely represents the * , '* a will be submitted delineating .the station's Bo1h valves are *18-inch tilting disc check valves manufa'ctured by the Cra.ne Company ..