ML20085H082
| ML20085H082 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/30/1974 |
| From: | Eric Thomas TENNESSEE VALLEY AUTHORITY |
| To: | Case E US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20085H085 | List: |
| References | |
| NUDOCS 8308300151 | |
| Download: ML20085H082 (2) | |
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r r., (we r Mr. Edson G. Case
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Office of Regulation U.S. Atomic Energy Commission j
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Dear Mr. Case:
t TE!!ITESSEE VAT.TFf AUTHORITY - BR0h'I!S FERRY UUCLH.Ut PLMIT UNIT 1 -
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DOCI2T NO. 50-259 - FACILITY OPERI, TING LICEIS3 DPR ABHO W E OCCUREIICE REPORT BFAO-50-259/7448if The enclosed report is to provide details conce$ning RER put:ps B
,i andDifnichexperiencedfailureof1/2-inchcizeschedule40ctninlecc-steel pipe nipples supplying pump seal water and is submitted 3.1 accordance with Appendix la to Regulatory Guide 1.16, Revision 1, October 1973. This event occurred on Bronto Ferry Nuclear Plent unit 1 on September 20, 1974.
l Very truly yours, TEICESSEE VALLEY AUTHORITY C/)
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Director of Power Production Enclosure CC (Enclosura):
i Mr. Hornan C. Moseley, Director
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Region II Regulatory Operations Office, USitEC j
230 Peachtree Street, ITcl., Suite 618 1
Atlanta, Georgia 30303 83083001
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.O AETORMAL OCCURRSiCE REFORT Report No.: BFAO-50-259/74h8W Report Date:
September 30, 1974 Occurrence Date:
September 20, 1974 Facility: Browns Ferry Huelcar Plant unit 1 Identification of Occurrence On September 20,1974, unit 1 RER pumps B and D cxperienced failure of 1/2-inch size schedule 40 stainless-steel pipe nipples supp3ying pump seal water.
Conditions Prior to Occurrence The, unit was in the shutdown cooling mode with icactor coolant at approximately 125 F. with Rh3 pu=ps A and C out of service for scheduled maintenance.
Designation of Annarent Cause of Occurrence Investigation revealed that vibration experienced while operating at high flows in the shutdoun cooling mode apparent 3y caused the nipples to crack.
Analysis of Occurrence The reactor was in a shutdown cooling mode. There was no damage to any other plant systems, components, or structurcs. The leakage water was confined to the pump room and elevator pit from which it was directed to the radwaste facility.
The,re were no adverse effects on the health and safety of the public as a result of these failures.
Corrective Action Replacement nipples of schedule 40 carbon steel were nstalled, and the pu=ps were returned to service. This nipple raterial was used because of its imm.ediate availability and the desire to restore service promptly. These replacement nipples subsequent 37 failed, and schedule 80 carbon-steel nipples were installed. These heavier nipples performed satisfactorily.
During the period of repairs, the pumps were intermittently operated. Fine water spray or moisture vapor in the pu=p room caused a ground relay operation, and the D pump motor tripped. The pu=p motor wiring was meggered and hipotted _ cnd found satisfactory. The D pump was returned to service. Also, during this period the local pushbutton switch for the B pump experienced a short circuit due to moisture and tripped the B pu=p.
The switch box was dried out and the B pump returned to service.
- Investigation of the system vibration and detemination of corrective action, if required, cre currently being conducted by design engineers.
Failure Data There have been no previous failurcs of nipples in this application..
s 90 mm-_.__