ML19319C123

Interim Deficiency Rept Re GE 480 Volt Breaker Per 740904 Telcon to Aec.Ge to Submit Explanation of Differences in Power Sensor Test Set Instruction Book (GER-7301),analysis of Power Sensor Failures & GE QA Changes

ML19319C123
Person / Time
Site:	Davis Besse
Issue date:	10/03/1974
From:	Roe L TOLEDO EDISON CO.
To:
References
NUDOCS 8001310483
Download: ML19319C123 (2)

Text

f v ppa: .

. t w w g ,.q e

e a TOLEDO E iISON Docket No. 50-346 LOWELL E. RCE oc. % .,e.e.

..ee i e c.m.-.,i October 3,1974 i4,sia a-sa42 Dr. Donald F. Knuth, Directorate of Regulatory Operations Office of Regulations U.S. Atomic Energy Commission Washington, D. C. 20245

Dear Dr. Knuth:

3 This letter is submitted as an Interim Report regarding the Davis-Besse Nuclear Power Station Unit No.1 General Electric 480 voit breaker problems related by telecon to Str. D. W. liayes, Directorate of Regulatory Operations, Region III on September 4, 1974.

A joint meeting was held at the General Electric factory between General Electric, Bechtel Company, our Architect-Engineer, and Toledo Edison Engineering and Quality Assurance representatives to clarify certain conditions affecting the operational status of the General Electric type AK-3A-50S and type AK-3A-25 switchgear installed at the Davis-Besse Nuclear Power Station Unit No.1.

The items which General Electric agreed to provide to effect complete uncerstanding are:

1 An explanation of the differences in the Power Sensor Test Set Instruction Book (GEK-7301) from Revision D to Revision E; specifically the widening of the tnp bands given in Table 1.

2. An analysis of failure causes in the Power Sensors returned to G.E.

3. Changes in G.E. Quality Control practices, which have resulted in satisfactory replacement parts for; (a) Binding magnetic trip devices (b) Out of timing tolerance power sensor logie units.

\

THE TCLEDO ECISCN COMPANY EO! SON PLAZA 300 MACISCN AVENUE TCLECO. CHIO 43652.s c ,, ..

' fc , J_v w .J 8001310 '

2 E

e The foregoing items are currently being acted upon by General Electric. Upon the submittal to Toledo Edison of the G.E. findings, a definitive report of the deficiency, analysis of the safety implications, and the corrective action being taken will be submitted to your office in accord with 10 CFR Part 50.55.

Yours very truly, 7

O-J

/

wr dd/10 cc:

J. G. Keppler, Regional Director Directorate of Regulatory Operations Region III