ML20084A027

Significant Deficiency Rept SDR-5 Re Weld Failure on High Pressure Svc Water Valve.Initially Reported on 730601.Eight Failed Valves Identified.All Valves Returned to Vendor for Rework to Eliminate Shims

ML20084A027
Person / Time
Site:	Peach Bottom
Issue date:	10/01/1973
From:	Boyer V PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Knuth D US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20083R894	List: ML20084A027 ML20084A090
References
10CFR50.55(E), 10CFR50.55E, SDR-5, NUDOCS 8304050073
Download: ML20084A027 (2)

Text

.c .

o f . . .

o:

ATTACHHEUT A

/ ,

PHILADELPHIA ELECTRIC COMPANY

-f 2301 MARKET STREET i

i PHILADELPHIA. PA.19101 l V. $. BOYER 4 VICE PRESIDENT s

October 1, 1973 Dr. D. F. Knuth, Director Directorate of Regulatory Operations United States Atomic Energy Cozrnission Washington, D.C. 20545

Subject:

Significant Defici6ncy Report -

High Pressure Service Water Valve Weld Failure Peach Botton Atomic Power Station - Units 2 & 3 AEC Construction Permit Hos. CPPR-37 and CPPR-38 File: OUAL 2-10-2 SDR No. 5

Dear Dr. Knuth:

5 In compliance with 10CFR50.55, paragraph (e) attached is the Signi'icant f Deficiency Report concerning the weld failure on the High

,i Pressure Service Water valve in Unit.No. 2. This iten was reported to 9

AEC DRO I by telecon on June 1, 1973 We trust that this satisfactorily resolves this iten. If further information is required, please do not hesitate.to contact us.

We appreciate your extending the time for our response to October 1, 1973 as agreed by telecon on September 14, 1973 between our Mr. G. R. Hutt and Mr. R. Heischmann, USAEC DRO I.

Sincerely, q -;

i h' ,. I i: t t J u .,

er Copy to: J. P.~O'Reilly, US EC a

8304050073 740103 PDR I&E 3 .,, f f.3

, BULLETIN 74-01 PDR

~

1 '-4

\ T g

V --

iv SIGNIFICANT DFFICIE:CY REPORT - SDR UO. 5 HIGU PREESURE SERVICE VATER VALVE UELD FAILURE PEACl! BOTTCM ATMIC POWER STATION - UNITS 2 & 3 AEC COMSTRUCTION PERMIT UOS. CFPR-37 AUD CPPR-38

- 1 Description of Deficiency During a routine walk-thru of Unit No. 2 plant by the licensees operating personnel, a 12 inch - 300 pound motor operated globe valve

. in the High Pressure Service Water line on the discharge side.of one Residual Heat Removal heat exchanger was discovered to have experienced a weld failure. The failure occurred between the valve yoke and the motor operator mounting plato. The reason for the failure has been identified as insufficient fillet veld throat dimension caused by the installation of unauthorised shims between the yoko legs and the mounting plate, which reduced the effective size of the veld.

. j-l Correctivo Action

(

The failed valve is one of a series of eight valves (four in Unit 2 and four in Unit 3). These eight valves were visylly' inspected and a second valve was found to have cracks in the yoke to motor operator mounting plate wold.1 All eight valves were returned to the vendor for rework. The rework involved climination of the shims in the failed valve and the revelding of the counting plates to the yoke legs with full pene-tration welds on all eight valves. . i l

e An investigation of similar valves (supplied by the same vendor) elsewhere in the plant, was undertaken. A total of 108 valves were iden-tified struction by the vendortotothat similar haveofyoke the to motor failed operator valve. mountingincluding Fifty-eight (plate con-the above mentioned eight) of these valves are nuclear valves classified as Group II as defined b 7Figure A.2.1 of Appendix A of the Peach Bottom Atomic Power Station FSAR. The remaining valves are GroupIII non-nuclear balance of plant valves.

The Vendor s weld stress analysis calculations were reviewed and 8 -

a table of acceptable weld sizes prepared.

m' 1

This valve _was originally reported in the interim report to'have shims. The valve was only visually inspected at that time and '

tho' cracks were interpreted to indicate the procence of shims.

t. .

. - . - --- = ,- +

.(

t