ML19261F213

RO 76-40/3L:on 761106,abnormal Degradation of Decay Heat Removal Sys Seal Ring DH-V1,causing Leakage While Valve Open.Leak Sealing Compound Immediately Injected.Cause Not Yet Determined

ML19261F213
Person / Time
Site:	Three Mile Island
Issue date:	12/03/1976
From:	Arnold R METROPOLITAN EDISON CO.
To:
References
GQL-1649, NUDOCS 7910250634
Download: ML19261F213 (4)

Text

v.s. NUCLE A R REGULATORY ' ' .t itS ION OOCKET NUMBE R f L t ;nu 195  !

,;. m . 5, 2:e -

Ff LE NUVnE R l

. rhRC DISTRIPUTION roR PART 50 DOCKET MATERIAL INCIDENT REFORT i TO. FROM: DATE CF OCCUME NT

,, , , "etro,Olitan Idison Comman' :2/: '

• 1. • ' ' ^ * ,',,,",,7,,

ca 'in;, P0nna. DATE RECE'V E Q l

?. C. Arnold 12/!'/'A i

)(LETTER O NOTORIZ E D PRCP INPUT FORM NUMBER OF COPIES RECFit EO ,

I KO RIGIN A L %NCLASSIFIED Cne S i '.*11 !

~

CCGPY CESCRIPTICN ENCLOSU RE Licensee " vent Re,crt (',0 51-239/76 L'/3L) on 1/6/76 concernin; abno ,al 'etra'la tion ef the sea 1 Sin- in D:{-71 (Jaca: Ucat ACKh,OWLEDGED '

".c,0 val S sten).

<2.P> 0NOT REMoyg PLANT NAME:

Three :lile Islan?. Unit "o. 1 NOTE: IF PERSO:ErdL EXPOSURE IS INVOLVED SEND l'IRECTLY TO KREGER/J. COLLINS FOR ACTION /INFORMATION 12/ H/76 c ,I L i X BRANCH CHIEF: eid W/3 CYS FOR ACTICN X LIC. ASST.: In ra, ,

i VI CY_S , / / j,

• X ACRS /,fy CYS - .GL;G 'SENT 1 (_,#r . JP'. //A// B6)

~ '

i I f _

INTERNAL DISTRIBUTION i r-M I & E (2) i y MIPC i y SCHROEDER/IPPOLITO  !

X' 110USTON i M NOVAK/C:lECK '

CRIMES i CASE BUTLER i X HANAUER 6

~

~ TEDESC0/MACCARY i EISENHUT I V BAER I Q SFAO l VOLL ER/BUNCII '

' KREGER/J. COLLINS l

EXTERN AL DISTRIGUTiON _ CONTROL NUMBER g LPDR: a- -i eur ,'a. ' -

[g. [;

TIC: /

_NS t r .

/A%f 1481 165 i

NRC rORM 195 (2 7G) O 7910250 h3 V J

?,n%. ',-

"7MM n.,-

x-m METROPOLli AN EUISON COMPANY -  : . .

POST OFFICE BOX 542 READING. PENNSYLVANIA 19603 TELEPHONE 215 - 929 3601 Dece=ber 3,1976 GQL 16k9 Mr. J. P. O'Reilly, Director Office of Inspections & Enforcement, Regien 1 U. S. Nuclear Replatory Cc==ission

/,c- /d % -

631 Park Avenue * ' :~ ,

• King of Druscia, Pennsylvania 19hC6

Dear Sir:

Docket No. 50-289 Operating License No. DPR-50 In accordance with the Technical Specifications of our Three Mile Island Nuclear Statien Unit 1 (TMI-1), we are reporting the folleving reportable cecurrence.

(1) Repcrt Nu=ber: 76 h0/3L (2a) Required Repcrt Date: December 6,1976 (2b) Late of Occurrence: Neve=ber 6, 1976 (3) Facility: Three Mile Island Nuclear Statien - Unit I (h) Identification of Occurrence:

Title:

Abncr=al Degradation of the Seal Ring in DH-V1 Type: A reportable oce trence as defined by Technical Specification 6.9 2. R (h) in that there was abnormal degradation of a syste=, in this case the Decay Heat Re=cval System, other than those specified in Ite 6.9 2.A(3), designed to contain radicactive material resulting frc= the fission process.

(5) Conditions Prior to Occurrence: a Power: Cere: 0 nEGliign . . - ,'- J ' r-Elec.: 0 [

\

RC Flev: 75 x 106 lbs/hr 's/

jN DCCI""o uswt b-RC Pressure: 330 psig ,

7

/',J..[ //[- f/y:n t

n$b g ,

RC Temp.: 275cy , s

- -s 148\ \b6

Report Number 76 h0/3- Dece=ber 3, 1976 GQL 16hr PRZR Level: 307 inches FRZR Temp.: h230F (6) Description of Occurrence:

On November 6, 1976, at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, during reactor plant cocidown, while in the process of establishing decay heat receval flew, valve EH-71 was opened using the manual handvheel. Previcus to this, when the valve was closed, a leak rate past the seal ring gasket frem 0.2 to 0 5 gym had been detected.

After the valve was opened the leak rate increased to approxi=ately 30 to 60 gp=. Because the leakage increased only after the valve was crened the leak was censidered part of the Decay Heat Removal System and T.S. 3.1.6.1, limiting total reactor ecolant leakage to 10 gym, was not violated. However, the leak is reportable because of abner =al degradatien of the Decay Hest Removal System, under T.S. 6.9.2.B(h).

I==ediately DH-V1 was shut, thus reducfng the leakage to 0.2 to 0.5 ep=.

(7) Designation of Apparent Cause of Occurrence:

The cause of this cccurrence has not been determined. An evaluation of the cause of the failure vill be made upon diaassembly of the valve at sc=e future dat e.

(8) Analysis of Occurrence:

It has been determined that this cecurrence did not constitute a threat to the health and safety of the public or exceed 10 CFR 20 limits for offsite personnel in that the leakage which cccurred during nor=al reactor operation was within the limits for identified reactor coolant leakage.

(9) Corrective Action:

In addition to the i==ediate corrective action described above, an approved leak-sealing ec=peund (Furmanite) was injected at a reduced Reactor Ccolant System pressure of 300 psig and successfully sealed the leak. Decay Heat Removal flev was then initiated without incident.

Other long-ters action may include:

1) seal ri:'g replacement

2) valve repair or replacement

3) reinjection of Fur =anite if leakage restarts (10) Failure Data:

Walvorth 12" Pressure Seal dcuble wedge gate valve (5262 PS) motor operated.

Design Pressure 2500 psig Design Temp. 650 F .

Schedule 140

• Body Material - 316 Stainless Ste<1 -

Seal Ring Material - Co==ercial "A" Nickel -

9 8\ \.61

.Rersort : lumber 76 h0/3L ~1 -

December 3, 1976

• ~

GCI 16L9 Similar Occurrence: : lone Sincerely, R. C. Irnold Vice President RCA:DGM:tas

.