ML20062D038

Final Deficiency Rept Re Defective Bearings Mfg by Control Components,Inc in Manual Steam Dump to Atmosphere Valve Actuators.Initially Reported on 820628.Bearings & Races Replaced in Both Units 2 & 3

ML20062D038
Person / Time
Site:	San Onofre
Issue date:	07/23/1982
From:	Papay L SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8208050434
Download: ML20062D038 (3)

Text

. _ . - .

Docket Do. 50-362 50.55(e) Raporg

. .. 7..l;;

I Southem Califomia Edison Company h5 R O. BOX 800  !. i [

2244 WALNUT GROVE AVENUE

,p ROSEMEAD, CALIFORNIA 91770 vsce passtDres7 213*S72 1474 July 23, 1982 Mr. R . H. Eng e lke n, Regional Administrator U. S . Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368

Dear Mr. Engelk en:

, Subj ec t: Docket No. 50-36 2 San Onofre Nuclear Generating Station, Unit 3 In a letter to your office dated June 28, 198 2, we identified a condition which we consider reportable in accordance with 10CFR50.5 5(e) . The condition involves defective bearings in the manual actuators of the Steam Dump to Atmosphere l

Valves which could prevent required manual operation in the event of an emergency c aused by fire.

Enclosed in accordance with 10CFR50.5 5(e) ar e ,

twenty-f ive ( 2 5) copies of a Final Report entitled, " FINAL REPORT ON ATMOSPHERIC DUMP VALVES DEFECTIVE BEARINGS AND BEARING RACES ASSOCIATED WITH MANUAL HANDWHEEL".

If you have any questions regarding this report, we would be pleased to discuss this matter with you at your convenienc e.

, Very truly yours,

.f'7 i

4

Enclosures cc: R. C . DeYoung (NRC, Director I&E)

A.E. Chaffee (NRC, San Onofre Units 2 and 3) 4 8208050434 820723 PDR ADOCK 05000362 ro S PDR Col

A .

Pags 1 of 2

. SAN ONOFRE NUCLEAR GENERATING STATION UNIT 3 FINAL REPORT ON ATMOSPHERIC DUMP VALVES DEFECTIVE BEARINGS AND BEARING RACES ASSOCI ATED WITH MANUAL HANDWHEEL INTRODUCTION Tnis report is submitted pursuant to 100FR5 0. 5 5(e) (3) . It d escribes a condition identified by the equipment supplier, Cont rol Components, Inc. of Irvine, California. This report includes a description of the deficiency, analysis of the saf ety implications and a summary of the corrective action t aken. By letter dated June 28, 1982, Edison confirmed notification to the NRC of this potentially reportable condition f or SONGS Unit 3.

BACXGROUND At the t ime of disassembly of the atmospheric dump valves (3HV-8419 and 3HV-8421) to install a second spring due to insufficient spring load, it was found that the bearings and bearing races associated with th e manual han dsheel wer e d amaged.

DISCUSSION Th e f olloaing d iscussion is responsive to 100FR5 0. 55(e) (3) .

Description of Deficiency During installation of a second spring within the actuator of the subjec t valves , the bearings and bearing races associated with the manual h andsheel were found to be d amaged. This h andaheel is used to open the subject valves in the event of los s of air supply to the v alve actuator, as manual override.

Analysis of Safety Implications Tne Steam Dump to Atmosphere Valves are normally closed. They are installed to provide for controlled removal of reactor decay heat daring reactor cooldoan when the condenser is not in service, when th e plant is being started up or shut down, when a turbine trip occurs on loss of condenser vacuum, or when a turbine trip occurs 3;e to loss of electrical power to the turbine auxiliaries. Thes e v alves are provided with a manual handaheel to enable an operator to open the valve in the event of los s of air supply to the actuator.

F a ..

FINAL REPORT ON ATMOSPHERIC DUMP VALVES. . . Page 2 of 2 Cr ed i t i s t a'k e n fo r u s e o f th e manu a l h an d h e e l i n th e Fir e Haz ar d s An aly sis Section 0.2. a. , Sa fety Sh utdown An alysis, Re actor Coolant System Temperature Oontrol, secondary Side Pressure Control which states, "The atmospheric damp valves used for long-term control are adequately separated so that access to the valves for manual actuation c an be assured during a fire."

23e identified f ailure of capability to operate the subject valves in the manual override mode due to defective bearings and bearing races does not meet the requirement for manual actuation.

CORRECTIVE ACTION The bearings and r aces have been replaced (in both Units 2 and 3) making it possible for thes e valves to be opened manually by one person against the s pring load without any equipment aid. As a long-term reliability measure, the bearings and races will be replaced with parts c apable of carrying higher loads.

l l

l 1

10910

- - _