ML20092N535
| ML20092N535 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/22/1984 |
| From: | Gallagher J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| REF-PT21-84-352-000 142, PT21-84-352, PT21-84-352-000, QUAL-2-10-2, NUDOCS 8407030251 | |
| Download: ML20092N535 (3) | |
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50-3s.2 PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHI A, PA. 19101
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JUN 221984
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MANAGEN Ef.GONE ENf MG AND NESE ARCH Mr. Thomas E. Murley, Director Office of Inspection and Enforcement - Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 1 94 %
Subject:
Limerick Generating Station, Unit 1 Final Significant Deficiency Report No.142 Damaged Shaf ts on ITI Actuators
Reference:
Telecon:
J. P. Evans /PECO to Walt Baunack/NRC, Dated 05/25/84 File:
QUAL 2-10-2 (SDR No.142)
Dear Mr. Murley:
In compliance with 10CFR50.55e, enclosed is the final report on the subject deficiency.
Yo ur office was informed of this matter on May 25,1984 by the referenced telecon.
Sincerely, u.-
WSS /drd840618 Attachment Copy to: Director of Inspection and Enforcement United States Nuclear Regulatory Comission Washington, DC 20555 S. Chaudhary, Resident NRC Inspector (Limerick)
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8407030251 840622 P,DR ADOCK 05000352 PDR 1 l p p
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Significant Deficiency Report - SDR No.142 IXunaged Shafts on I'1T General Controls Actuators Limerick Generating Station NIC Constructi6n Permit No. 50-352 and 50-353 Description of Deficiency In April, 1984 ITr General Controls, Series NH90 electro-
, hydraulic actuators were returned to the vendor for routine actuator seal replacenent. Sixty-one of the actuators are used for actuating safety-related ilVAC dampers manufactured by American Warming and Ventilation Co.
Eight of the actuators are used for controlling the blade pitch on safety-related vancaxial fans manufactured by Joy Fan Co.
During the course of disassanbly and inspection it was found that six of the actuator shafts exhibited scoring due to previous operation. It was determined that this scoring was the result of excessive lateral movanent of the actuator shaft during operation, due to italequate design provisions to limit such movanent.
Corrective Action All defective actuator shafts were replaced during the seal replacanent program and returned to the jobsite. Manufacturer's representatives from American Warming and Ventilating Company, Joy Fan Company and ITr, General Controls visited the jobsite to inspect the actuator attachment to actuated device. As a result of this inspection it was determined that design modifications were required to provide improved actuator shaft support that would limit lateral shaft movenent and the resultant scoring of, shafts.
The design modifications were provided by Joy Fan Company and American Warming and Ventilation Company ind have been canpleted for all Unit 1 and Comon equipnent. Unit 2 components Imve
had non-conplianc,e reports issued against thm, docunenting that they require design modifications prior to use.
Safety Implications The design of the ITT General Controls actuator is such that the actuator shaft can tolerate only limited anounts of lateral novment.
. Excessive lateral movment can cause shaft scoring and excessive hydraulic seal wear, which could eventually result in loss of hydraulic fluid with the dampers and fan blades then going to their fail-closed position.
A caninon mode failure of this type could result in the inability of safety-related INE systes (SGTS, RERS, CREPAb, Control Room INIC, Control Enclosuro INAC, Dicsol Generator INFC, Spray Pond IIVtc) to perform their functions, although it is extr mely unlikely that these projected failures would occur abruptly and simultaneously without early and gradual warning.
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