ML20199G439

Final Part 21 Rept Re Hydraulic Fluid Leakage in Itt General Controls Hydramotor Actuators.Initially Reported on 860418. Caused by Lack of Adequate Testing & Preventive Maint. Condition Not Reportable Under Part 21

ML20199G439
Person / Time
Site:	Davis Besse
Issue date:	06/16/1986
From:	Williams J TOLEDO EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
REF-PT21-86, REF-PT21-86-225-000 1-640, PT21-86-225, PT21-86-225-000, NUDOCS 8606250228
Download: ML20199G439 (3)

Text

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Serial No. 1-640 June 16, 1986 Mr. James G. Keppler, Regional Administrator United States Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137

Dear Mr. Keppler:

Our letter of April 30, 1986 (Serial 1-632) confirmed telephone notifica-tion to your Mr. Nick Jackiw by our Mr. Rod Cook on April 18, 1986 of a potential 10 CFR Part 21 concerning ITT General Controls Hydramotor actuators. These devices are utilized at Davis-Besse Nuclear Power Station Unit No. I as ventilation system damper actuators that modulate to control temperature in areas where safety-related equipment is located.

The notification was triggered by a discovery of hydraulic fluid leakage in two of thirteen actuators that had been tested. This loss of fluid rendered the Hydramotor actuators inoperable. A specific commitment was made in Serial 1-632 and LER 86-019 (dated May 16, 1986) to: 1) investigate and evaluate the cause of hydraulic fluid leakage and the extent of deficiencies in the two Hydramotor actuators, and 2) define appropriate corrective action. The leakage was found during a Hydramotor actuator testing program. This program was part of an overall effort to upgrade the testing and maintenance of ventilation systems that support safety- I related equipment.

l As corrective action, Davis-Besse is in the process of rebuilding or replacing each of 22 such Hydramotor actuators in safety-related ventilation systems. To date, 16 Hydramotor actuators have been replaced or rebuilt.

Also, the maintenance history of the Hydramotor actuators and the cause of l hydraulic fluid leakage was investigated. Our investigations and evaluation 8606250228 860616 PDR ADOCK 05000346 S PDR fJUN2 01986' ko THE TOLEDO ED: SON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652

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Docket No. 50-346 License No. NPF-3 Serial No. 1-640 June 16, 1986 Page 2 have confirmed that hydraulic oil leakage from the two failed Hydramotor

actuators was caused by a lack of adequate testing and preventive mainten-ance. This lack of testing and maintenance resulted in the Hydramotor actuators being operated for periods in excess of the recommended useful life of the elastomeric oil seals. The investigation also indicates that a major contributing factor to the maintenance deficiencies was a lack of technical support in the development of adequate maintenance requirements and procedures for the Hydramotor actuators.

Disassembly and inspection of the Hydramotor actuators also indicated a few manufacturing details that appeared to be out-of-tolerance. Specifically, visual examination of the housings from units which were fabricated in the early 1970's, revealed apparent out-of-tolerance conditions on machined bolting lugs and on 0-ring retention grooves. A meeting was held at the Davis-Besse site with the Quality Control Manager of ITT General Controls, Mr. Ira Silverman to discuss these conditions. Mr. Silverman stated the observed imperfections would not have precluded proper functioning of the Hydramotor actuators. He further indicated that current quality control I practices would not accept these imperfections. Based on our examination and inspection and discussions with ITT General Controls we conclude that a Part 21 condition (defect that could result in a substantial safety hazard) does not exist in these Hydramotor actuators.

To prevent recurrence of the maintenance deficiencies described above, a Preventive Maintenance Procedure will be issued by the end of July 1986 providing for periodic functional testing of each Hydramotor actuator to  !

ensure the unit functions and leakage is not occurring. Functional testing ,

will be performed for the Hydramotor actuators listed in Serial 1-632.

This functional testing is being incorporated as part of the Davis-Besse i Course of Action to establish equipment performance trending that will allow our engineering staff to identify and react to equipment degradation before failure occurs. A Preventive Maintenance program will n!oo be initiated to provide periodic maintenance / testing of spare Hydramotor actuator units in storage.

Based on vendor recommendations, each Hydramotor actuator installed in the plant and in storage will be overhauled and then bench tested on a regular recurring basis to ensure operability. When the units are reinstalled or when a spare unit is installed, a functional test will be performed to ensure operability. To accomplish this maintenance and testing program, a special on-site facility has been established and testing / maintenance personnel have been sent to the vendor's facilities for trcining. A formal training program is also being developed to train additional Davis-Besse personnel on the overhaul of Hydramotor actuators.

k Docket No. 50-346 License No. hTF-3 Serial No. 1-640 June 16, 1986 Page 3 We believe that the above investigations and corrective actions fulfill our commitments related to this matter and will minimize the potential for in-service failures of the Hydramotor actuators in the future.

l Very truly yours,

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JE:plf cc: DB-1 NRC Resident Inspector

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