Text

e FI :AL REPORT FOR PRD :;0. 79/11 U I.]

j AS DEFIT,23 I:i 10 CF" 50.33 (c)

I.

Description of Deficiency Control device assemblies used on 4.16 'J/ switchpar, o.>

switchgear, 480 V load centers were found with.airl;nc ca.~.

An inspection of control device assemblies en mitch;;ca.

.a load centers was performed. This ir. spec tion f ound app ru:.c.a te.

180 control device assemblics with cracks.

II.

Safety Implication:

The supplier has conducted endurance, torque, force a::J.acr=al cycle tests to determine the cause and si3aitic; ace of tie irahier

!!o s tructural or control device malfunction resulteu Ju riu, th e.s c tes ts.

In addition, '.Jyle Labc ra tories a t !!u n ts. ; 'le, A lab a.

t' c conducted a seismic simulation test to further de nans trata a

integrity of these control devices. ::o loss or i.gatracc.: uf function was evident. The cracks did not show any signs af pro-pagation.

It 1:, concluded, from the above, that these crac.:, vill

.A ca ::..:

in a control device failure of malfunction.

TE2refora. it is not af considered to be a reportable deficiency uith(n the

..u....,

III.

Ccrrective Ac tion Taken:

Details of our corrective actions will be summarized in L e a r e '.

Management Corrective Action Report, GG.' S :!o. 31, and will 'ae available for your review at the Grand Gulf jobsite.

1866 323 ossy

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ML19257D535