ML20084M631

Unusual Events 72-1,2 & 3:on 720812,simultaneous Safety Injection Signal Occurred,Packing in Ctr Stuffing Box of Charging Pump 3A Failed & Diesel Generator a Could Not Produce Test Output of 2750 Kw,Respectively

ML20084M631
Person / Time
Site:	Turkey Point
Issue date:	09/08/1972
From:	Schmidt A FLORIDA POWER & LIGHT CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084M560	List: ML20084M589 ML20084M631 ML20084N516
References
72-1, 72-2, 72-3, RO-720908, NUDOCS 8306020262
Download: ML20084M631 (2)

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T LO R ' D A f e'.*. [ R P. L' 3 C C C '.' W. '

Turkey Point Plant September 8, 1972

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. 'h lir. John O' Leary, Director '

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Division of Leactor Licensing U. S. Atomic Energy Commission 3 c i. . _ . ' i G Washington, D. C. 20545 ,

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Re: TURKEY POINI PLANT UNITS 3 and 4 o )  !

DOCKET NOS. 50-250 & 50-251 N ' . C'-, $@ 4 UrdSUAL EVENTS 72-1, 72-2, 72-3 NV, ; . ' '. .G

Dear L!r. O' Leary:

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In accordance with Technical Specifications 6.6.2b, the following three Unusual Events are reported:

72-1. Sinultaneous safety injection on both units.

At 5:15 a.m., August 12, 1972, Preoperational Procedure f-4000.1, Integrated Test of Enginecred Safeguards System and Energency Pouer System was in progress on Unit 4. Unit 4 is not licensed for operation and the reactor coolant system was open. Unit 3 was in cold shutdown. The first part of the test was injection of safety injection and containment spray signal with offsite posar availa' ale . All safeguards related equipnent functioned properly.

The second part of the test was injection of safety injection water into the reacter coolant system and containment spray siSnal with loss of offsite power to both units with both dicscis avail-able. As loads were sequenced on the A diesel, severe voltage transients were noted and voltage decayed sufficiently to cause the 3A and 4A busses to restrip on undervoltage. . The voltage t,ransient was caused by safety injection loads for both units sequencing back onto the busses. The safety injection signal was present on No. 3 unit because 3A inverter was out of service and its vital bus was being fed fron the AC maintenance source (motor centrol center).

Normally the three safeguards channels are fed by inverter A, inverter L and an AC source from a motor centrol center. Con-sequently, with the A inverter oct of service, two safeguards channels were being fed from totcr control centers. Wnen all AC power was locc to both units for the loss of effsite power portion of the test, the two AC channels fed by noter centrol centers generated sir,nals for safety inj ection because of the f ail safe feature of the circuitry. This 2 out of 3 logic gave a s fety in-jection signal for Unit 3. '

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September 8, 1972 Page 2 The diesels are not designed to supply safety injection loads for both units simultaneously, but te supply safety injection loads for the accident unit only, and hot shutdown loads for the other unit.

Design changes will be required to prevent loss of offsite power from causing spurious 2 out of 3 logic signals. The safety injecticn initiating signals for Unit No. 4 havc been inhibited to prevent simultaneous safety injection actions on both units. The safeguards design is under review and this problem will be resolved and implemented prior to fuel loading on Unit 4.

72-2. Chargind Pump Packing Failure On August. 21, 1972, during normal operation of the 3A charging pump, the packing in the center stuffing box failed. The charging pump is a Union Pump Company type TX-150 positive displacement triple plunger pump. When the center plunger rod stuffing box assembly was dis-assembled and inspected, the plunger was found to be badly scored, the male packing adapter retainer ring was found broken into three pieces and the chevron packing rings deforned. The deepest scores on the plunger appeared to originate from deep blisters in the coating.

The outer two plunger rod stuffing box assemblies had been Icaking, but not excessively during the previous pump operation. The coating on these two plungers was found to be intact, but with some unbroken blisters on the surface opposite the stuffing box. The damaged parts were returned to the vendor for failure analysis. The cause of the failure is not known at this time. Corrective action will be determined after the vendors' report is reviewed.

s 72-3. Energency Diesel Generator _ Load Test Failure On August 21, 1972, during a routine weekly load test in accordance with Operating Procedure 4304.1, the A diesel generator could not produce the test output of 2750 KW. The diesel was run for 55 minutes but the highest loading obtained was 2350 KW. The diesel controls were checked and the governor was found dirty.and sluggish., The governor was cleaned and adjusted. The diesel generator was then tested and performed satisf actorily.

Sincerely yours,

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' A. D. Schmid t

'W f Director of Power Resources ADS /DWJ:vv cc: Director, Region II, Directorate of Regulatory Operation U. S. Atomic Energy Commission Suite 218 230 Peachtree Street, N. W.

Atlanta, Georgia

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