ML20085E938

AO BFAO-50-259/75-10W:on 751001,diesel Generator Power Supply Unavailable Automatically to RHRSW Pump Running Continuously to Supply Water.Caused by Commencement of Mod Second Phase Prior to Completion of First Phase

ML20085E938
Person / Time
Site:	Browns Ferry
Issue date:	10/10/1975
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Rusche B Office of Nuclear Reactor Regulation
References
NUDOCS 8308170142
Download: ML20085E938 (3)

Text

-

~

C

y. q O

TENNESSEE VALLEY AUTHORITY o -

E CHATTANOOGA. TENNESSEE 374ot s..e 9 ,~

October 10, 1975 -

,,y 0 ((yg

.I <$) $

1 ,, / /7 Mr. Benard C. Rusche Director of Nuclear Reactor Regulation

'\ -

\ ',

% (f

, , $s N '

U.S. Nuclear Regulatory Commission i- . ct

'\ 0 N*

Washington, DC 20555 .

. De.ar Mr. Rusche: . .

TENNESSEE VALLEY AUTHORITY - BRORNS FERRY NUCLFAR PIANT UNIT 1 -

DOCKET NO. 50-259 - FACILITY OPERATING LICENSE DPR ABNORMAL OCCURRENCEREPORTBFAO-50-259/7510W The enclosed report is to provide details concerning the RHRSW pump which did not have a diesel generator power supply available automatically and is submitted in accordance with Appendix A to Regulatory Guide 1.16, Revision 1, October 1973 This event occurred on Browns Ferry Nuclear Plant units 1 and 2.

Very truly yours, TENNESSEE VALLEY AUTHORITY i,<

/I -

(Q\

0 FE..r. Thomas Director of Power Production Enclosure CC(Enclosure):

Mr. Norman C. Moseley, Director U.S. Nuclear Regulatory Commission Regional Office 230 Peachtree Street, NW., Suite 818 Atlanta, Georgia 30303 .

8308170142 751010 PDR ADOCK 05000259 PDR g -

1101!'O An Equal Opportunity Employer

/

COPY SENT REGION] w -

ABNORMALOCCURRENCEREPORTO G Beport Number ,: BFAO-50-259/7510W , ,

Beport Date  : October 10, 1975 Occurrence Date: October 1, 1975 Facility  : Browns Ferry Nuclear Plant units 1 and 2 4

Identification of Occurrence The RHRSW pump running continuously to supply water to the north emergency equipment cooling water header (EECW) did not have a diesel generator power supply available automatically as required by the technical specifications.

Conditions Prior to Occurrence The fuel for units 1 and 2 was removed from the reactor vessels and stored in the spent fuel pools. Plant maintenance, modifications, and fire restoration work were in progress.

Description of Occurrence On September 28, 1975, the FHFSW pu=p supplying water to the north EECW header was removed from service and an alternate RHRSW pump was placed in operation to provide this service. It was not recognized until October 1, 1975, that the alternate pu=p in service did not have a diesel power supply available automatically.

Designation of Apparent Cause of Occurrence Plant modifications had been authorized which involved changing the control and power supplies to the RHRSW pumps. The work instructions specified that the work to be performed in one phase of the activity had to be i completed and tested before proceeding to the next work phase. On Sunday, September 28, 1975, work instructions were violated when the second work phase was commenced before testing had been completed on the preceding work phase.

l I

~

O -=-

o This resulted in a pump being in service without the necessary diesel l generator power supply available automatically. The occurrence was caused by personnel performing plant modification work not observing the restrictions contained in the work instructions.

Analysis of Occurrence There was no damage to the plant equipment and there were no plant personnel injuries or consequences to the public health and safety as a result of this occurrence. The south EECW header was in service and capable of being supplied by a diesel generator. The north EECW header re=ained in service, and in the event of loss of normal power it could have been returned to service by manual operation.

Corrective Action Immediately upon discovery of the occurrence, action was initiated to place a pur.:p in service which would comply with the technical specifications.

Personnel authorized to initiate work activities have been required to attend retraining classes stressing the importance of observing all precautions and requirements contained within work instructions using the events leading to and resulting in this abnormal occurrence es an example. This retraining ,

which began immediately will be completed before October 16, 1975 Failure Data There were no equipment failures associated with this occurrence.

I l

i C