ML17252B502

LER 77-039/03X-1 for Dresden, Unit 2 Re During Testing Required by LLRT Procedure Dts 1600-15 a Gasket Failure Was Found on Torus Drain Flange 313A Which Degraded the Primary Containment Boundary

ML17252B502
Person / Time
Site:	Dresden
Issue date:	11/23/1977
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
BBS LTR 1088-77 LER 77-039/03X-1
Download: ML17252B502 (4)

Text

• Flt[

~* .-

Commonw9h Edison Dresden Nuclear Power Station R.R. #1 REGUlATOnY DOC~(tT Morris, Illinois 60450 Telephone 815/942-2920 COPY November 23, 1977

• ,,.,:c': BBS LTR /11088-77 James G. Keppler, Regional Director Directorate of Regulatory Operations - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

. Reportable Occurrence "Update Report" 77-039/03X-l is hereby submitted to your office in accordance with Dresden Nuclear Power Station Techni-cal Specification 6.6.B.2.d;, abnormal degradation of systems other than those spetified in technical Specifi~ation B.l.e. designed to con-tain radioactive material resulting from the fission process.

eph so~

Station Superintendent Dresden.Nuclear Power Station BBS:dlz Enclosure cc: Director of Inspection & Enforcement Director of Management Information & Program Control File/NRC

-N6V 3o1971

J*JRC fORM 366 U.S. NUCLEAR REGULATORY COMMISSION (7-711 *; - **

• LICENSEE EVENT REPORT UPDA~PORT - PREVIOUS REPORT

\\

• DATE ~l4/77

• CONT.AOL BLOCK: ._I_-'----'---'-----_.__----:!10 (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 1 6

~

7 8 r 1 1 L 1 D 1 R 1 s 1 2 101 9 LICENSEE CODE 14 15

°1 °1 -1 ° 1 °1 °1 °1 ° 1 - 1 °1 ° icv1 4 1 1 1 1 1 1 1 1 101 LICENSE NUMBER 25 26 LICENSE TYPE JO 1

57 CAT 58 10 CON'T

[ill]  :~~~~~ L!J© I o I s I o I o I o I 2 I 3 I 1 101 o I 9 I 1 I s I 1 I 1 I© I 1 I 1 I 2 I 3 I 1 I 1 10 7 8 60 . 61 DOCKET NUMBER 68 69 EVENT DATE

• 74 75

• REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES@

[IIIJ I During testing required by LLRT Procedure DTS 1600-15 a gasket failure was found on torus drain flange 313A which degraded the primary containment boundary. Measured

~ leakage was 34.0 SCFH (T.S.4.7.A.2.g limit is 29.38 SCFH). There was no effect on

(]:ITI public health or safety since the redundant outer gasket was leaktight. There are

~ no previous events of a similar nature at this facility.

II0

[ill]

7 8 9 . 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE , CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE.

[ill]

7 8 9 Is I Al@ w@.w@

10 11 12 IP IE IN I El Tl RI@

13 18 LK.I w@

19 20 SEQUENTIAL OCCURRENCE REPORT REVISION

~

~

LE R/RO LVENT YEAR REPORT" NUMBER I 71 21 71 22 I I 23 I

24 REPORT NO.

01 31 91 26

. I /I 27 28 CODE I 0I 3 I 29 wTYPE 30 l=J' 31 NO.

LJJ 32 ACTION* FUTURE EFFECT SHUTDOWN ~ ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS ~ SUBMITTED FORM SUB. SUPPLIER MANUFACTURER.

W@w@ W@

33 34 35 W

36 101oro101 37 40 liJ@

41 ll!J(§)

42 L!U@

43

• 1 cl3 44 11 lo 47 I@

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS@

The leakage was caused by deterioration of the inner 0-ring seal. 0-ring replacementl and routine cleaning of the flange mating surface prior to reassembly, reduced leak-age through the penetration to 0.0-:: SCFH. An improved 0-ring material and periodic LLRT's will prevent recurrence.

7 8 9 80 FACILITY METHOD OF ~

STATUS  % POWER OTHER STATUS DISCOVERY DESCRIPTION ~

o::m DISCOVERY

~@ 10 I 01 Ol@)l......___ _ NA_ _~ l.!J~~l ____L_o_c_a_l_L_e_a_k_R_a_t_e_T_e_s_t_______

8 9 10 12 '13 44 45 "46 80 ACTIVITY CONTENT Q\

RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE@

~ L1..J@) W@I NA . NA 7 8 9 10 11 44 45 80 PERSONNEL EXPOSURES r:;;:-.

NUMBER (:;:;\TYPE DESCRIPTION

[TI2J 7 8 9 I 0 I 0 I OJ~L----------=N=A=---------------------'

11 12 13 80 PERSONNEL INJURIES (,;"'.;\

NUMBER DESCRIPTION6

[2TIJ I 0 I 0 I 0 l@'-------------=N=A,_____ _ _ _ _ _ _ _ _ _ _ _ _ ____.

7 8 9 11 12 80 LOSS OF OR DAMAGE TO FACILITY t4J\ I TYPE DESCRIPTION v::::J (2I2J ~@)._______________N~A~------------------'

8 9 10 so PUBLICITY Q\ NRC SEQ ISSUEDQ DESCRIPTION~ - U NL y "'

rilIJ L!U~~-------------N_A_ _ _ _ _...,...-_ ____. I I I I I I I I I I I I I~

8 9 10 68 69 80 c;;

0 NAMEOFPREPARER _ _ _ _ _ _R_._w~_e_1_*d_n_e_r_______ PHONE:----=2:.:=6:.:::5;___ _........_ _ __ a.

Cl

ATTACHMENT TO LICENSEE EVENT REPORT 77-039/03X-i.

COMMONWEALTH EDISON COMPANY (CWE)

DRESDEN UNIT 2 (ILDRS-2)

DOCKET # 050-237 During refueling tests required by LLRT Procedure*DTS 1600-15, a gasket failure was found on torus drain flange 313A which degraded the primary.

containment boundary. Measured leakage was,34.0. SCFH (T.S.4.7;A.2.g limit is 29.38 SCFH). This event had minimai sa,fety significance since the redundant outer gasket was demonstrated to beieaktight.

Awork request was written to investigate and repair the inner gasket.

failure in accordance with station procedures. However, the personnel involved in the torus cleaning effort, which was already in progref;s, removed* the flange without being aware of the need to retain the gaskets for examination.

The leakage was attributed to deteri6ratio~ of the inner O~:ting seal based on the inact.ive nature of the. component and previous LLRT results ..

The results of the four LLRT's performed on.flange 313A since November of 1974 were ,8, 3.3, 17.4, and 34.041 SCFH.

Engineering evaluation of the .material originally specified for this flange by Chicago Bridge and Iron indicated that S613-7 type material wou_ld offer superior performance to the orig:i,nal S416-6 type. Both 0- . -..;..,;;.

rings on flanges 313A and 313B *were re.placed with* t_he improved S613- 7

_:~!!'~P~~- b~ ~~~rpo:_gr~o~'Aft~~~ET~::_:~-=---:*

~~s*tea .:~E_Es>~g~he penetra.ti~-*--~rth~.r. ~or_rective as,tion .

is planned.. * * * * *

.9-rr o~c 8 PM 12

.. ,