ML20084U950

AO 50-265/74-29:on 741223,cracks at Welds in 4 Inch Reactor Recirculation Discharge Valve Bypass Lines Indicated.Cause Undetermined.Piping on a & B Loops to Be Completely Replaced

ML20084U950
Person / Time
Site:	Dresden, Quad Cities, 05000000
Issue date:	01/02/1975
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Oleary J Office of Nuclear Reactor Regulation
Shared Package
ML20084U927	List: ML20084U925 ML20084U950 ML20084U956
References
AO-50-265-74-29, IEB-74-102, NJK-75-3, NUDOCS 8306290663
Download: ML20084U950 (3)

Text

!

g ~3, C mmr~':icalth Edisen p\

/ C p.N Ouad-C[ ' enerating Gtation 3

(

'Oh

%) 4 Mr Post Officwbx 216 W %/

Corcova. !!!mois 61242 Te:ephone 309/C54-2241 /[/M '

k<%

eD ].1 s l  % 4 ~

i

- 'yQJ -

O NJ K-75-3 y JANm,.m, 6 1975 > f j!

- -E:ru l'intn t'a hefa January 2, 1975 g'/ ~I j ..

Mr. John F. O' Leary, Director Directorate of Licensing Regulation U. S. Atomic Energy Commission Washington, D. C. 20545

REFERENCE:

quad-Cities Nuclear Power Station Docket No. 50-265, DPR-30 Appendix A, Sections 1.0.A.5, 6.6.B.I.a

Dear Mr. O' Leary:

Enclosed please find Abnormal Occurrence Report No. 50-265/74-29 for quad-Cities Nuclear Power Station. This occurrence was previously reported to Region ill, Directorate of Regulatory Operations by telephone on December 23, 1974, and to you and Region li t , Directorate of Regulatory Operations by telecopy on December 23, 1974.

This report is subraltted to you in accordar ce witii the requir ements of Tech-nical Specif.ication 6.6.B. I .a.

Very truly yours, COMMONWEALTH EDIS0N COMPANY' QUAD-CITIES NUCLEAR POWER STATION

./

[  !

ffkQ-N. J. Kallvianakis Station Superintendent NJrJCWS/vmm

. cc: Assistant Director for Construction and Operations, Directorate of Regulatory Operations Region 111, Directorate of Regulatory Operations J. S. Abel 8306290663 750210 PDRADOCK05000g a as l

.?. -

REPORT hUMBER: AO-50-265/74-29 REPORT DATE: January 2, 1975 OCCURRENCE DATE: December 23, 1974 FACILITY: Quad Cities Nuclear Power Station Cordova, Illinois 61242 IDENTIFICATION OF OCCURRENCE: Indications of cracks at welds in the 4 inch Reactor Recirculation Discharge valve bypass lines CONDITIONS PRIOR TO OCCURRENCE: Unit 2 in cold shutdown DESCRIPTION OF OCCURRENCE:

In accordance with the provisions of AEC R.O. Bulletin 10A, ultrasonic j testing of accessible welds in the bypass piping lines around the recirculation pump discharge valves was performed.

On December 23,1974 at 1:00 AM, this testing revealed Indications of cracks at the following locations:

Loop Weld Position Length of Crack A 2AB-Fi I:00 o' clock to 2:00 o' clock 2 1/2 inches 3:30 o' clock to 4:00 o' clock 1 inch 4:30 o' clock to 5:30 o' clock 2 inches A 2AC-F10 2:00 o' clock to 4:00 o' clock 2 3/4 inches 4:30 o' clock to 5:00 o' clock 1 inch 5:30 o' clock to 6:00 o' clock I inch B 2BB-F1 1:00 o' clock to 2:00 o' clock 1/8 inch These results were confirmed by additional ultrasonic testing on the morning of December 23, 1974.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE EQUIPMENT FAILURE The cause of the above referenced indicated failures has not yet been deter-mined. An investigation is in progress and a report of results will be made to the Director of Licensing in January, 1975 ANALYSIS OF OCCURRENCE Prompt compliance with the provisions of AEC R.O. Bulletin 10A led to early detection of Indications of cracks. The health and safety'of the public and plant personnel was not jeopardized at any time since no catastrophic weld

., failures occurred.

CORRECTIVE ACTION The original Unit 2 recirculation pump discharge valve bypass piping on "A" and "B" loops will be completely replaced during the current Unit 2 refuel

. outage. .

g y n v%--t- y. , m.

x -

0 0 l FAILURE DATA l On September 16, 1974, quad Cities Unit 2 experienced a crack at weld 2BB-F 10 on the "B" loop. Corrective action at that time was to replace. the weld and a short section of pipe.

T In light of the present Indications of cracks at quad Cities Unit 2, and previous similar problems at Quad Cities Unit 2, Dresden, and HIIIstone, all Unit 2 recirculation pump discharge valve bypass piping is being replaced.

+

e se s.

v .

n -r.a-., - , . _ _ _ . ->-se