05000237/LER-1976-066, Updated LER 76-066/01T-1:on 761113,during Maint Outage,Hpci Injection Valve M02-23018 Found in Closed Position W/Valve Stem Severed.Caused by Mechanical Overstress of Stem.Stem Replaced

Updated LER 76-066/01T-1:on 761113,during Maint Outage,Hpci Injection Valve M02-23018 Found in Closed Position W/Valve Stem Severed.Caused by Mechanical Overstress of Stem.Stem Replaced

ML20084A197
Person / Time
Site:	Dresden
Issue date:	05/13/1977
From:	Stephenson B, Wujciqa J COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084A199	List: 05000237/LER-1976-066, Updated LER 76-066/01T-1:on 761113,during Maint Outage,Hpci Injection Valve M02-23018 Found in Closed Position W/Valve Stem Severed.Caused by Mechanical Overstress of Stem.Stem Replaced ML20084A215 ML20084A261
References
77-424, LER-76-066-01T, LER-76-66-1T, NUDOCS 8304050125
Download: ML20084A197 (4)

LER-2076-066, Updated LER 76-066/01T-1:on 761113,during Maint Outage,Hpci Injection Valve M02-23018 Found in Closed Position W/Valve Stem Severed.Caused by Mechanical Overstress of Stem.Stem Replaced

Event date:
Report date:
2372076066R00 - NRC Website

text

-

CONTROL BLOCC

. . Previous Report Date: 11/23/76

' , \

1 (PLEA?E P lNT ALL REQUIRED INFORMATIC -

uCENsEE L1

'3- h )

NAug uCENst NLMBEE. uCENse' TYPE \ u/[/MEvE~t oiIilLlDlRlSl2l l0l0l-l0l0l0l0l0l-l0l0[

7 89 14 15

[204 l 1 l1 l 1 l1~l'l 0 ll l TYP 25 30 31 32 cATECCRY " TypE sYus$ ocCxET NuucE9 EVENT CATE nEPORT lTl Q hCONTl 7 8 57 l

58 l

59 l610l 5l0 l-l0 l2 l3 l7 l l1l1l1l3l7l6l l 0 l 5 l 1 l 3a[7 l 60 68 69 74 75 c.

EVENT DESCR;PTION

• HE I During a weekend maintenance outage, HPCI injection valve M02-2301-8 was found to be in -

7 89 Q l the closed position with its valve stem severed. The valve was last observed to '

7 89 g l function properly during the previous refueling outage. The valve is located in the b 7 89 gg l "X-Area", which is not routinely accessible during operation. From the beginning of "

7 89 Ql this fuel cycle until 10/12/76, the valve was cycled on a monthly basis with proper sYsTEu ' cAust couEmf (continued) C CCCE CCMacumi CCCE COMPCNENT CODE SUPPUER MANUNTurut VOLATON

@6 l 5 l F l @

7 89 il 11 lV lA lL lV l E lX l 12 17 W

43 44

[ Cl 6l 6l 5l 47 lN l 48 CAUSE DESCR;PTION l The original Licensee Event Report described the failure of the HPCI M0-2-2301-8 ,

7 89 g l valve stem and the immediate corrective ae_ tion associated with the event. This 65 7 89 Ml supplemental report documents the results of tests performed on the damaged valve '{

7 89 sacuTY 60 STATUS 4 POWER OTHEA STATUS utTuoO cr - (continued)

EH1 7 8 y

9 l0l0l0l l NA l OrscCVERY y OtSCOVERY CESCA.PTCN l DC Ground' Electrical inspection I 10 12 13 44 45 46 ec ACTMTV CCNTENT RELEASED AMOUNT OF ACTMTY E

7 8 Q

9 OF yRELEASENAl l l NA

- LOCATCN OF RELE SE l

10 11 44 45 PERSONNEL EXPOSUAES 60 NUMBER TYPE CESCAFTCN DE l Ol 0l 0l 7 89 11 Wl12 13 NA l

' SJ PERSONNEL INJURIES NUMBER CESCRWTCN h l 0l 0l 0l 7 89 l NA l

11 12 OFFSITE CONSEQUENCES

,Ql NA ~

• g 7 89 -

LOSS OR DAMAGE TO FACILITY Su TYPE cEscaPTCN hdl 7 89 10 NA

~

w PUBLICITY

.Ql7 89 NA e w.

ADOITIONAL FACTORS ,

~

Q@ l NA '

7 89 l

8304050125 770513 es PDR ADOCK 05000237 -

Ml S PDR -

g 7 89 ts NAME: John Wujciga Ext, 265

, , , gg, ,

m-

a' ' _

l l EVENT DESCRIPTION (continued) i control room position indication. On 10/12/76, valve 2301-8 was taken out of service in the open position (according to position Indication) In order to isolate a 250V DC ground which was present only when the valve was closed. The HPCI pump discharge line was then isolated by closing valve 2301-9 This is not a repetitive occurrence.

(50-237/1976-66) l l CAUSE DESCRIPTION (continued) stem by Commonwealth Edison's Operational Analysis Department and the final corrective action taken to repair the valve.

Examination of the Dresden Unit 2 HPCI valve stem (M0' 2-2301-8) indicates that the failure was not material-related but was a one time mechanical overstress of the stem. Utilizing macro-photographic and electron microscope fractographic techniques, coupled with a chemical analysis of the valve stem, it was determined that approximately sixty (60) percent of the.facture surface separated by the quasi-cleavage mode, and forty (40) percent failed in shear. The shear portion of the fracture is thought to have occurred during bending of the valve stem when the torque switch momentarily remained energized, after the valve seated. Because of moisture accumulation in the valve operator, with 40% of the cross section fractured and the valve stem severely bent, final through-fracture occurred during the next attempted backseat cycle.

During a planned 5 day Unit 2 outage beginning on March 16, 1977, the HPCI M02-2301-8 valve was disassembled and the failed valve stem was replaced. While the valve was disassembled, a visual code examination of the valve body and internals, including the seating faces, was satisfactorily canpleted. The examined components were found free of any detectable erosion, corrosion, or mechanical adamage. In addition, during the same outage period tr.e junction boxes and conduits in the "X-Area: were sealed to prevent a possible recurrence. '

l l

e I

l 7

+- .

t

. SUPPLEMENT TO DVR -

l ,

l DVR tio. .

.: STA utilT. YEAR NO.

• D- 12 - 2 - 76 - 102 PART l l TITLE OF EVEtiT OCCU?. RED 11/13/76 0930 Failure of 2-2301-8 Valve stem DATE TIME ,

REASON FOR SUPPLEME 4TAL REPORT To report results of ter.ts or. valve stem and to document final corrective action to repair the va'Ive.

PART 2 l J

ACCEPTANCE BY STAT 10tl REVIEV @j ,f wp ,)

~!

/ '.>-1 DATE 6h ot [ l') /

p,y , , . .

.$[Q !77, SUPPLEttENTAL REPORT APPROVED ,

AllD AUTHORIZED FOR DISTRIBUT10tl f /,,~d fgj ff ).

. NTATIOWSUPERitiTE!GEtiT / 'DATE O

O l

O e

r O

C

~ ~'

Comman$lth Edison (

\d

.. Dresden Nuclear Power St: tion ,

I .- R.R. #1 Morris, i;tinois 60450 Telephone 815/942-2920 BBS Ltr. No.77-424 May 9, 1977 Mr. James G. Keppler, Regional Director Directorate of Regulatory Operations - Region lli JEgmg U. 3. Nuclear Regulatory Commiss!on 799 Roosevelt Road Glen Ellyn, Illinois 6013/

Enclosed please find an update report to Repo,rtable Occurrence report number 50-237/1976-66. This report is being submitted to your office in accordance with the Dresden Nuclear Power Station Technical Specifications, Section 6.6.B.

/A r

l

- f M

. . Stephenson Station Superintendent Dresden Nuclear Power Station BBS:sm Enclosure cc: Director of Inspection & Enforcement Director of Management i nformation & Program Control File /NRC -

s i

I

-ou