ML19326B694

AO 50-313/74-11:on 741107,reactor Bldg Spray Pump P35B Suction Line Leaked.Cause Unknown.Spool Piece Will Be Removed for Replacement & Metallurgical Testing

ML19326B694
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/15/1974
From:	Cacanaugh W, Phillips J, Reuter D ARKANSAS POWER & LIGHT CO.
To:
Shared Package
ML19326B653	List: ML19326B651 ML19326B658 ML19326B662 ML19326B664 ML19326B670 ML19326B676 ML19326B683 ML19326B687 ML19326B691 ML19326B694
References
NUDOCS 8004170533
Download: ML19326B694 (3)

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1. Abnormal Occurrence Report No. 50-313/74-11 .

2. Report Date:

11/15/74 3. Occurrence Dato: 11/7/74

4. Facility:

Arkansas Nuclear One-Unit 1 Rus,sellville, Arkansas l i

, 5. Identification of Occurrence:

i Reactor Building Spray Pump P35B, Suction Line Leak

6. Conditions Prior to Occurrence:

, Steady-State Power Reactor Power 0 MWth

! Hot Standby Net. Output 0 MWe l

,, Cold Shutdown X Percent of Full Power 0  %

Refueling Shutdown -

i Routino Startup '

Operation I

Routine Shutdown

\ Operation ,

i Load Changes During Routine Power Operation

• Other (Specify)

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-, 7. Description of Occurrence: -

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• At 1450 hours0.0168 days <br />0.403 hours <br />0.0024 weeks <br />5.51725e-4 months <br /> on 11/7/74, during-a routine operator inspection, a leak was discovered in Reactor Building Spray Pump P35B suction line between valves BW5B and BW6B. Following repair and completion of a satisfactory hydrostatic test on 11/12/74, an additional leak was discovered at -

0630 hours0.00729 days <br />0.175 hours <br />0.00104 weeks <br />2.39715e-4 months <br /> on 11/13/74, near a new weld that was made during the repair ~

of the Icak discovered on 11/7/74. An additional inspection was made of the spray line and a small leak was found in the spray pumps suction crossover line between valves BW7A and Bh7B. A crack was found in the parent metal near a field weld in each case. ,

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July 5, 1974 NSP-10, Rev. O

Page 1 o.f 3

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Abnormal Occurrence Report No. 50-313/74-11 Sheet 2

8. Designation of Apparent Cause of Occurrence:

, Design Procedure i 1 .

Manufacture Unusual Service Condition Including Installation / Environmental

, Construction

• Component Failure Operator

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Other (Specify) X Not yet determined. ,

Note: It is our position that the crossover line leak is not an l abnormal occurrence s.tnce that section of pipe is isolated under normal modes required for spray system operation.

9. Analysis of Occurrence:

At the time of the occurrence, the reactor was in cold shutdown condi-(d) x tions on 11/7/74. On 11/13/7.4, the reactor was in hot shutdown condi-i tions. There was no hazard to the health and safety of the public or plant personnel due to the prompt identification and the fact that only one spray pump was required to be operable prior to criticality, per Technical. Specifications 3.3. ,

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10. Corrective Action:

A spool piece will be removed from each section of pipe where the leak  ;

occurred with the area of failure undisturbed for metallurgical exam-ination. A new spool piece will be installed, using qualified welders and procedures. The results of the metallurgical examination will be used to determine if additional corrective measures are necessary. .

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V July S, 1974 NSP-It, Rev. O Page 2 of 3

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'O Abnormal Occurrence Report No. 50-313/74-11 ' Sheet 3

11. Failure Data:

These are the second and third leaks in the vicinity of a weld In this type of pipe (Schedule 10), but it is not known at .this time if any of the three are caused by the same mode of failure. The first t

leak was reported in Abnormal Occurrence Report No. 50-313/74-2.

The results of 'the metallurgical examination will be forwarded upon <

availability.

12. Reviews and Approvals:

Reviewed and Approved by: Plant Safety Committee Yes (X) No ( )

i Plant Superintendent Yes (X) No ( )

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Reference:

JWA-662 Date: 11/14/74 Reviewed by:

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/ Licensing upervisor '

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Approved by:,'_

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Date:/[/5'-7[ '

[ S et eview ommit*ee s

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Approved by: L' J I~

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J ager of Nuc W Servic Approvedby:f .d/ p syd/ '/ Date: / b V S ~~ l V

/ D'irector of Power Productiion Approved by:

/ .,'d. ,a Date: //- O' M -

Senior Vice President I

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. July S, 1974 NSP-10, Rev. O Page 3 of 3