ML19329B095

Interim Deficiency Rept Re Red Lead Primer on Emergency Diesel Generator Jacket Cooling Water Heat Exchangers.Tube Bundles in Exchangers Replaced

ML19329B095
Person / Time
Site:	Davis Besse
Issue date:	10/26/1976
From:	Roe L TOLEDO EDISON CO.
To:
Shared Package
ML19329B081	List: IR 05000346/1976019 ML19329B079 ML19329B083 ML19329B089 ML19329B094 ML19329B095 ML19329B096 ML19329B097 ML19329B101
References
136, NUDOCS 8001300681
Download: ML19329B095 (2)

Text

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TOLEDO G Gwsom

' October 26, 1976 LOWEU. E. ROE

%ce Persident Se,ria). No. 136 Facikties Development MiD3 253 E242 Docket No. 50-346 Mr. James G. Keppler Regional Director, Region III Directorate of Regulatory Operations U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

This letter is submitted in accordance with 10CER50.55(e) as a tion of the Interim Report dated October a-24, 1975 regarding the d fi ic en-

[~'s exchangers for Davis-Besse Nuclear Power Station Unitcy con e

1.

_ Description of the Deficiency The. subject heat exchangers were received on site April 25 Bruce GM in a condition suitable for long-term storage; i.e., the nozzles

, 1974 from were adequately covered to prevent the entry of foreign matter.

heat exchangers were placed outdoors on dunnage after receipt inspection The j

and covered with canvas to provide adequate weather protection.

i receipt inspection had revealed red lead primer on the inuide of the The nozzles which was not acceptable.

Procedures were then developed to remove the red lead primer, and a few montha after roccipt of the units, the channel heads were removed to facilitate the removal of the red lead primer from the inside of the channel heads.

that the tube shoct and tubes of each unit were in poor condition fouling of the tubes and channel heads due to dirt, Inspectio I

cud other foreign matter.

scale, broken glass

'Gf tube to tube sheet connections were not inInspection of the su tandards as required by the specification.

accordance with TR*A the tube material extend 1/16" to 1/8" beyond the tube sheet toThe TEMA at revent errosion of the tube sheet due to turbulence.

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cf tube ends were found to be installed flush with or below the face A small number

, cf the tube sheet and a large number did no i

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k The cause of the corrosion has been postulated to be improper handling during tests conducted at. the vendor's facility.and subsequent inadequ preparation for shipment.

After the manufactuer's test, the carbon draining and taping covers over the nozzles. steel heat exchan The applicant believes that a high degree of tube blockage occurred

.during the vendor's tests due to some unidentified substance present in the cooling water used at the vendor's facility.

Make-up to the loop was from a city unter supply. water f cooling tower loop or the city water was not recorded. Water quality of the Corrective Action Taken c

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The heat exchangers were shipped to the manufacturer for repair.

repairs progressed, it became evident that the extent of corrosion in As the tubes precluded their repair for permanent installation s

been no permanent damage to the shell, baffles, There had tube sheet, etc., of the heat exchangers; therefore, the corrective action taken was to replace the tube bundles in both heat exchangers and correct the improper tube t tube sheet connections.

It was felt desirable to have at least one diesel o

generator in operable condition for testing and operator training during the repair interim, so one heat exchanger was cleaned, judged adequate

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for temporary use, and shipped back to the job site for the stated use The second heat exchanger remained at the manufacturer's facility and was later shipped to the job site fully repaired, including a new tube bundle, along with the new tube bundle for the other heat exchanger which was subsequently installed in the field.

Both replacement heat 1cally tested.exchangers were fabricated to original specifications and hydrostat-All repairs have been completed.

Safety Implications The condition of the heat exchangers was detected prior to installation and start-up testing.

The tubes were fouled / corroded to such an extent that it is extremely doubtful that the diesels could have passed start-up testing,without detection of the damaged condition.

The full repair of the heat exchangc~rs prior to operation of the facility and acceptable in place assures that the health and safety of the public dized.

Yours

,6-cd'rytruly$W h PC/29-3&4 CC.

Dr. Ernest Volgenau, Director Office of Inspection and Enforcement U.S. Nuc1 car Regulatory Commission Washington, D.C.

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