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IN79023 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 September 25, 1979 MEMORANDUM FOR: B. H. Grier, Director, Region I J. P. O' Reilly, Director Region II J. G. Keppler, Director, Region III K. V. Seyfrit, Director, Region IV R. H. Engelken, Director, Region V FROM: Norman C. Moseley, Director, Division of Reactor Operations Inspection, IE SUBJECT: Information Notice No. 79-23, EMERGENCY DIESEL GENERATOR LUBE OIL COOLERS The enclosed information notice should be dispatched September 26, 1979 to all power reactor facilities holding operating licenses and construction permits. Norman C. Moseley, Director Division of Reactor Operations Inspection Office of Inspection and Enforcement Enclosures: 1. Information Notice No. 79-23 2. Draft Transmittal Letter CONTACT: H. A. Wilber, TP 49-28180 . (Draft letter to all power reactor facilities with operating licenses and construction permits.) Information Notice No. 79-23 Gentlemen: The enclosed Information Notice provides information with regard to failures of lube oil coolers for emergency diesel generators. Sincerely, Signature (Regional Director) Enclosures: 1. Information Notice 79-23 2. List of IE Information Notices Issued in the Last Six Months . Accession No: 7908220121 SSINS: 6870 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 September 26, 1979 Information Notice No. 79-23 EMERGENCY DIESEL GENERATOR LUBE OIL COOLERS Within a two week time span (August 27 to September 11, 1979), the tube sheets failed in the Arkansas Nuclear One (ANO) Unit 1 lube oil coolers for both of the Unit 1 Emergency Diesel Generators. The introduction of water into the diesel lube oil system resulted in trips of both diesels during surveillance testing. The diesels were not considered capable of sustained operation. Investigation by the licensee has indicated cracks around the outer periphery of the tube sheets. The exact failure mode has not been assessed; however, the licensee has replaced the Emergency Diesel lube oil coolers for both diesels with a cooler of different design. The original lube oil coolers had tube sheets which were one-eighth (1/8) inch in thickness and the tubes were soldered in place. Epoxy was also used as a sealer on the tube (water side) of the lube oil cooler. The new coolers have one-half (1/2) inch tube sheets and the tubes are rolled. The ANO, Unit 1 Emergency Diesel Generators were purchased in 1970 and were manufactured by the Electromotive Division of General Motors Corporation. The lube oil coolers (Model Number D-191700) were manufactured by Young Radiator Corporation. This information is provided as an early notification of a possible significant matter. It is expected that recipients will review the information for possible applicability to their facilities. No specific action or response is requested at this time. If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions. If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
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