Part 21 Report - 1996-340

ACCESSION #: 9603210271 Illinois Power Company Clinton Power Station P. O. Box 678 Clinton, IL 61727 Tel 217-935-5623 Fax 217-935-4632 Wilfred Connell ILLINOIS Vice President POWER U-602564 4F.140 WC-091-96 March 13, 1996 Docket No. 50-461 10CFR21.21 Document Control Desk Nuclear Regulatory Commission Washington, D.C. 20555 Subject: 10CFR21 Interim Report 21-96-001: Ideal Generators Installed with Emergency Diesel Generators Have Generator Rotor Mass Greater Than Originally Calculated Dear Sir: On January 15, 1996, Illinois Power (IP) identified a condition involving the Divisions 1 and 2 Emergency Diesel Generators (EDGs) as potentially reportable under the provisions of 10CFR21. Specifically, Condition Report (CR) 1-96-01-029 was initiated to identify that Ideal Electric, the manufacturer of the generator portion of the EDGs, had discovered that the mass of the generator rotors had been incorrectly calculated. The revised calculation shows a larger rotor mass and rotational inertia. IP has completed an evaluation of the impact of this condition on the seismic qualification of the diesel generator units and has concluded that the increase in mass has no adverse impact on the units. However, IP has not completed an evaluation of the impact on the frequency and torsional analysis of the units. IP purchased the EDG units from Stewart & Stevenson. The generators are Ideal model numbers SA6-50 and SA6-44, and Ideal drawings B-MED-221 and B-MED-217. The evaluation for reportability under the provisions of 10CFR21 is currently scheduled to be completed by July 12, 1996. Following completion of the evaluation, IP will report the results to the NRC in a final report. Additional information regarding this issue may be obtained by contacting M. M. Gandhi, Engineering Projects, at (217) 935- 8881, extension 4082. Sincerely yours, Wilfred Connell Vice President RSF/csm U-602564 Page 2 cc: NRC Clinton Licensing Project Manager NRC Resident Office, V-690 Regional Administrator, Region III, USNRC Illinois Department of Nuclear Safety INPO Records Center Ideal Electric Steward & Stevenson *** END OF DOCUMENT ***

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