ML19261D532

RO 50-366/79-45,Revision 1,on 790607:during Reactor Power Ascension,Power Level Fell Below 1,000 Counts,Causing HPCI to Initiate.Caused by Leaking HPCI Pump Mechanical Seal. Vessel Level Maintained by Restoring Condensate Sys

ML19261D532
Person / Time
Site:	Hatch
Issue date:	06/07/1979
From:	Manry M GEORGIA POWER CO.
To:
References
NUDOCS 7906190436
Download: ML19261D532 (3)

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ATLA 4TA, GEORGIA 30303 J EHCE SLD)ECT: H4TCH UNIT 2. DDCKET HD. 50-356 HDTIFICATION OF REPORTAB {f.

NO. 50-35f/1979-45, Rgy. 1 L NOTIFILD: Ross F. Rogers

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DATE: 6/7/79 DATE: 6/4/79 q TIME: 3:30 PM i f

CESCRIPTION OF REPORTACLE OCCURRENCE  !.

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Initial Condition:

During reactor power ascension, at 2387 mega watts thermal, a reactor The reactor scram power i, occurred at 1850 CDT due to a condensate system trip. 7, level fell below 1300 counts per second. 9 L

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Nature of Occurrence:  :

Dae to the low level in the reactor at 1855 COT. the HPCI System was required (

to initiate and pump water to the vessel. ' Although the HPCI received an  ;

initiation signal. it did not start because the turbine stop valve f ailed to 5 open. .

Irredia te Correcti.ve,f,c tion _:

5 The HPCI was secured and the rtquirements of Technical Specifications 3.5.1  ;

co nplied with. The vessel level was maintained by restoring the condensate system to operability.

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Cause:

One of the HPCI pump mechanical seal cooling injection water If nes wasThis leak drained to r leaking the at the bracket threaded drain cavity.connection at the This pump casing.The bracket drain cavity drain I installed for reasons presently unknown. valve was closed thus allowing .

the Icak to fill the bracket drain cavity to a point above the shaf t. The '

adjacent bearing housing does not have a liquid tight seal by design (not r requi red ) . This allowd water to enter the bearing housing from theHad flooded the bracket drain cavity. This water then drained to the oil system.

bracket drain line valve not beenThe closed bracket the leakdrainwould not was line valve havenot affected listed the operat ion of the HPCI in any way.

in the system velve lineup procedure nor was it shown on the system P&lD.

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S,upp.lemental Correc tive Action:

4. The reactor was brought to the hot shutdown condition.

b. The leaking seal injection line was repaired by replacing a section of i-the leaking line.

c. The oli system was drained, flushed and refilled twice. E:'

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d. An investigation of the oil system was made to deterTnine if there were [

any other ways for water to enter the system. The oil cooler in the system was identified as being a possibility but pressure test proved the [,

coaler to be good. flo other possible water sources were identified. ..

e. The turbine bearings were inspected for possible danuge. The inspection I,

revealed a "1D.e new" condition. T X-

f. The volves in the bracket drein lines will be locked open prior to startup 5.

and a study initiated to deterrnine if the valves could be remsved from the F

lines. In the interim this valve has been added to the systen valve lineup r

procedure. .

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g. A study has been initiated to select a nethod whereby water in the oil 4-systems of RCIC and llPCI turbines may be readily identified. {-

h. Until the above study is completed the oil systers on the HPC! turbine r will be sarnpled on a weekly basis. -

1. A study has been initiated to detemine if the seal injection lines L need additional support to help prevent future leaks.

i Status of Redundan.t.or Backup Syste_ms.;, f The RCIC failed to operate but the Automtic Depressurization Systes, ,

Core Spray System and 1.ow Pressure Coolant Injection System were operable.

Inpset To_,0.th,er Uni t:  :

a. A lack of a water detection in the turbine oil system may be a problem ( -

with other stcam-driven pumps.

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b. An investigation was made on Unit 2 RCIC system and Unit 1 HPCI and RCIC Systems to determine if the same valves exist in the cavity drain lines. h The results are as follows: (u

1. ' Unit 2 RCIC - tio drain line. The cavity drain hold is open snd . 1 will drip to the pump skid. 5 Unit I flPCI - Drain line to floor drain with no valve installed.

Unit 1 RCIC - flo drain line. The cavity drain hole is open and t will drip to the pamp skid, t.

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RO Telegram Cont'd  ;. .

June 7, 1979 L

E JuJtification For C,0n_t.inued Operation: i The llPCI system oil was analyzed for water. flo detectable msisture was g

present. The stop and control valves were cycled to insure proper operation. ,

An operability test will be perfomed as soon as reactor Conditions pernit. t I

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